Dreams, Hopes, Realities

NASA's Goddard Space Flight Center:
The First Forty Years

by Lane E. Wallace

The NASA History Series

SP-4312
NASA History Office
Office of Policy and Plans
Washington, DC
1999

Updated: May 29, 2006.
Steven J. Dick, NASA Chief Historian
Steve Garber, NASA History Web Curator
For further information E-mail histinfo@hq.nasa.gov
HTML work: Chris Gamble.

This title was converted to ebook on 30 July 2009 by Nathaniel Hoffelder. If you are in need of ebook conversion assistance, email nate.hoffelder@gmail.com.

- Contents -

Foreword .

Preface.

Chapter 1: Goddard's First Forty: The Quest to Learn.

Chapter 2: A Place for Science.

Chapter 3: The Tools.

Chapter 4: Exploring the Heavens.

Chapter 5: Exploring the Earth.

Chapter 6: The Endless Frontier.

References.

Bibliographical Essay.

Appendix A: Glossary of Acronyms.

Appendix B: Goddard Launches.

Appendix C : Directors of the Goddard Space Flight Center 1959-1998.

Acknowledgements.

Index.

The NASA History Series.

About the Author.

Foreword

An image of our "Big Blue Marble" taken from the GOES 8 weather satellite.

[vii] Throughout history, the great achievements of civilizations and cultures have been recorded in lists of dates and events. But to look only at the machinery, discoveries, or milestones is to miss the value of these achievements. Each goal achieved or discovery made, represents a supreme effort on the part of individual people who came and worked together for a purpose greater than themselves. Driven by an innate curiosity of the spirit, we have built civilizations and discovered new worlds, always reaching out beyond what we knew or thought was possible. These efforts may have used ships or machinery, but the achievement was that of the humans who made those machines possible - remarkable people willing to endure discomfort, frustration, fatigue and the risk of failure in the hopes of finding out something new.

This is the case with the history of the Goddard Space Flight Center. This publication traces the legacy of successes, risks, disappointments and internationally recognized triumphs of the Center's first 40 years. I t is a story of technological achievement and scientific discovery; of reaching back to the dawn of time and opening up a new set of eyes on our own planet Earth. In the end, it is not a story about machinery or discoveries, but a story about ourselves. If we were able to step off our planet, and if we continue to discover new mysteries and better technology, it is because the people who work at Goddard always had a passion for exploration and the dedication to make it possible.

The text that follows is a testimony to the challenges people at the Goddard Space Flight Center have faced and overcome over almost half a century. Today, we stand on the threshold of a new and equally challenging era. It will once again test our ingenuity, skills, and flexibility as we find new ways of working with our colleagues in industry, government and academia. Doing more with less is every bit as ambitious as designing the first science instrument to study the heavens. But if we are to continue exploring our world and our universe, it is every bit as important.

Robert Goddard once said, "The dream of yesterday is the hope of today and the reality of tomorrow." This is our heritage. Our challenge is to keep our spirit of dedication, [viii] vision and innovative thinking alive, so we can turn today's dreams into a new century of possibility and progress.

Our journeys into space are the greatest ongoing adventure the human race has ever undertaken, and everyone here has played an important role in that endeavor. I encourage you to read this work with a sense of pride in our history and a cheerful anticipation of our future. This book is about everyone who has worked at the Goddard Space Flight Center

A.V. Diaz
Center Director
May 1999

The Goddard Space Flight Center was the first NASA center dedicated to the exploration of space. Since its inception in 1959, the Center has been involved in the design, building, and operation of over 200 Earth-orbiting satellites.

Preface

[ix] The Goddard Space Flight Center is a truly remarkable place. From its humble beginnings in borrowed offices, Goddard has developed into an impressive, sprawling campus that supports the work of over 11,000 people. In only forty years, the Center has successfully launched over 200 scientific satellites that have investigated everything from the Earth's ozone layer to gamma ray bursts from distant reaches of the universe. Its work has also covered every aspect of space science experiments, from developing theory to building the spacecraft, instruments and launch vehicles, to operating and tracking the satellite in space, and finally collecting, analyzing, and disseminating the data to the international scientific community.

At the same time, Goddard has played an important role in developing communications, weather and Earth resources satellites. Its Wallops Island facility has been central to the sounding rocket, balloon and aircraft research NASA has conducted over the years. Goddard's tracking and data networks have involved up to 24 countries, and it has successfully managed numerous international projects in Earth and Space Science.

An illustrated book of this length could not possibly do justice to the history of this remarkable place. The history of Goddard is far too complex and far too rich to be covered adequately in a book even twice this length. All this book attempts to do is convey the basic story and character that has made Goddard the special place it is today, in terms the general public can understand. The hope is that readers will come away from this book with some sense of how Goddard evolved, what its strengths and challenges were, what it has accomplished, why that is important, and where it is headed from here.

Every person who worked at Goddard deserves to have their name mentioned in this book, because every single person played a critical role in making the Center's accomplishments possible. By the same token, every project should have its full story told, because each project was its own adventure, and no two were alike. Unfortunately, there simply isn't space. The projects and events included here have to serve as examples, therefore, of the unique talent, dedication, and spirit of innovation that was present in every project, directorate, and era of Goddard, and have made the Center what it is today.

Chapter 1:
Goddard's First Forty: The Quest to Learn

The ISEE-C undergoing evaluation in a dynamic test chamber at Goddard.

[1] On the night of October 4, 1957, a large rocket lifted off from its pad at a remote, secret installation in the Kazakhstan region of the U.S.S.R. In its nose cone was a 22-inch diameter sphere weighing 175 pounds.[1] A few minutes later, the rocket disappeared from sight. But the reverberations from that launch were felt more than half a world away. Almost two hundred years after the Battle of Lexington and Concord, another shot had been heard around the world. And it, too, would change the course of history.

The Russians' launch put Sputnik I, the world's first successful satellite, into orbit. In a single stroke, it also launched the space age and a race between two superpowers that would lead to the creation of a civilian U.S. space agency, a landing on the Moon, and....

[2]

Aerial View of the test and evaluation facilities at the Goddard Space Flight Center (NASA photo G93-010-030)

....an unprecedented level of support for an entirely new field of science - one that would explore what lay beyond the atmosphere and give us a new perspective on Earth itself.

The sudden boom of the space age, however, brought with it an acute need for new infrastructure to organize and manage projects that would involve thousands of people and millions of dollars. The National Advisory Committee for Aeronautics (NACA) had several aeronautical research centers around the country, but the size and scope of their projects were much smaller than the large-scale "big science" efforts a space program would require. As plans for the new National Aeronautics and Space Administration (NASA)[2] progressed throughout 1958, decision-makers realized there was a need for new research centers devoted expressly to space projects.

[3] This realization led to the creation of the Goddard Space Flight Center - NASA's first research center created specifically to support the space program. Over the past forty years, the Center has grown from a small collection of scientists and engineers trying to solve the basic problems of space flight into a remarkably diverse organization supporting and pursuing an ever-widening range of scientific research that rockets and satellites have made possible.

In many ways, the history of Goddard reflects the history of the space program itself. The center was formed at the same time as the new space agency, and its evolution has paralleled that of NASA. If Goddard has always been a complex Center, incorporating many diverse disciplines and groups, it's because the exploration of space itself was a complex challenge that required many different people and resources. A single scientist might conduct a wide range of experiments in a lab, but getting a satellite into space required support from government, industry and universities, scientists, technicians and engineers, and a tremendous amount of money. Balancing these different, and sometimes conflicting, resources has remained one of the major challenges not only for Goddard, but also for many people in the space program.

At the same time, what has allowed Goddard to succeed; to overcome the many obstacles that stood in its way, especially in the early days of space flight, was the same unbridled enthusiasm that took us to the Moon in less than a decade. Engineers and scientists did not go to work for Goddard or NASA for the money. They went to work there because they were fired up with excitement over the prospect of exploring a frontier no human had entered before. The challenge of space was bigger, tougher, and more awe-inspiring than any endeavor humankind had ever undertaken, and to work at NASA was to work on the cutting edge of the action.

When Goddard was founded, the field of space science - the term used to describe scientific research made possible or significantly aided by rockets and spacecraft[3] - was so new that a researcher could read all the space science literature that existed in a matter of two or three months. The newness of the field also meant that it had very few aging experts. Most of the emerging space scientists were young men and women who were not already invested in some other research field, infusing....

Technicians prepare multimission modular component for the Space Shuttle cargo bay.

[4] ....Goddard with a kind of youthful energy that resisted authority but excelled in innovation. The scientists and engineers who came to Goddard were young, energetic, fired up with a passion about space and willing to overcome whatever obstacles they had to in order to explore it.

This passion was important, because space was not a place for the fainthearted. A scientist might devote three, five, or ten years to an experiment only to have the launch vehicle carrying it drop into the ocean. To stay with such an uncertain and sometimes discouraging field, one had to have an enormous amount of enthusiasm and dedication for the work. This enthusiasm became one of the defining characteristics of Goddard, especially in the early days. Employees not only worked together but played together, staying after work for volleyball games, recreation, and Center-sponsored drama club productions. The employees worked and played hard, making the Center not only their place of work, but almost their place of residence. Long hours and seven-day weeks were taken in stride - something that allowed great progress to occur, but probably caused the sacrifice of more than a few marriages in the first decade of the space program.

Mission Planning at the Goddard Space Flight Center.

Goddard's place as the first space center also has given it a unique legacy in terms of the sheer scope of the work that it does. Goddard was formed when the space program was in its infancy and, as with many entrepreneurial organizations, the Center had to wear many hats. The number of projects involved in the early space effort was still small enough to be managed by one center, and even NASA managers did not quite realize yet how huge the space program would become. At the time Goddard was formed, there was also no other space center to share its responsibilities. The Jet Propulsion Lab (JPL) in Pasadena, California had been incorporated into NASA at the same time Goddard was founded, but JPL was given the task of managing planetary missions, not Earth-orbiting satellites.

As a result, Goddard initially was given responsibility not only for theoretical physics research to support space science, but also for all aspects of satellite development and operation, from project planning and development of instruments to fabrication and testing of the satellite itself, launch vehicle development, tracking and data analysis. The Center initially even had responsibility for the manned space flight program.[4]. While the astronaut program never actually took up residence at Goddard, the Center has retained some level of responsibility for the vast majority of NASA's unpiloted, Earth-orbiting satellites.

Over the years, Goddard also incorporated the management of several other facilities and projects, including the world-[5] wide manned space flight tracking and communications network during the Mercury, Gemini and Apollo eras. Today, the Center's responsibilities still include a separate Institute for Space Studies in New York, a satellite tracking and data facility at the White Sands Missile Range in New Mexico, and the Wallops Flight Facility in Virginia, which has always served as one of the primary locations for the launching of sounding rockets.

The scientific component of Goddard also gave it a different organizational personality than most of the NASA Centers. Most of NASA's aeronautics and space centers have focused on applied engineering tasks or research of one kind or another. Aeronautics has always been an engineer's field, and the human space flight program was fundamentally an engineering challenge until the Space Shuttle began to carry more scientific payloads into orbit. Goddard, on the other hand, focused primarily on space science efforts. The development of technology and the engineering accomplishments involved in getting satellites into orbit - while important contributions and a significant percentage of Goddard's work over the years - were not the sole goal of the Center. Most of Goddard's spacecraft were a means to an end; the tools that allowed scientists to get instruments up into space.

A Delta rocket stands ready to launch an ITOS weather satellite. Development of both the launch vehicle and satellite was managed by Goddard. (NASA photo 71-HC-1182).

This mix of engineering and science has always been one of the unique characteristics and strengths of the Goddard Space Flight Center. But it also presented a challenge for managers who had to incorporate scientists into an organization accustomed to working with engineers. The academically oriented scientists who came to work at Goddard tended to have a very different working style than their engineering counterparts. The scientists were used to working independently, with more flexible deadlines and schedules. Engineers, on the other hand, were more accustomed to team efforts and a more structured work schedule and environment with milestones, deliverables and fixed budgets. Goddard's managers had to find a way to accommodate both physicists who did their best [6] work at two in the morning as well as the more structured needs of a space research program that had firm launch dates, test points, schedules and budgets to meet.

The scientific focus and culture at Goddard also complicated its relations with both NASA Headquarters and the outside community. The individual research or "field" centers, even within the NACA, were known for their independence and resistance to central authority. In some senses, this tension between NASA's field centers and Headquarters was no different than that experienced by any organization with a similar structure. Headquarters personnel, by definition, have different agendas and burdens than staff working out in the field, whether they are managing a corporation, a government agency or a diverse university system. These different perspectives and job responsibilities often cause friction between Headquarters and field personnel.

This monstruous machine is Goddard's Launch Phase Simulator. It was designed to simulate the vibration, G-forces, and changing pressures a spacecraft would have to endure during its launch into orbit. It was this kind of thorough testing that gave Goddard satellites their remarkable sucess record. (NASA photo 6906313).

But while this tension may be inherent in any organization, it was probably heightened in Goddard's case by the less structured, academic approach of the Center's scientists. "As professional scientists, these persons were by training and experience accustomed to deciding for themselves what ought to be done," explained one of NASA's early managers. "They questioned everything, including orders from above." Or, as another early Goddard employee put it, "what you had was a bunch of people who weren't quite sure you had to have a Headquarters. They were pretty sure they didn't need to talk to it."[5]

The scientists wanted to be left alone to do their research. But space science was an expensive endeavor, and taxpayers were footing the bill. So managers at NASA Headquarters were under constant pressure to provide information to Congress on the status and progress of different programs. As a result, there was a continual conflict between Headquarters' desire for first-hand, up-to-date information and researchers' desire to be left alone.

While this conflict existed in some form at every NASA Center, the fact that Goddard was located a mere 13.4 miles away from NASA Headquarters (a specific distance almost every Goddard employee can quote by heart) intensified the friction. In fact, Goddard's first director, Dr. Harry J. Goett, was replaced in 1965 as a result of this conflict of wills between the Center and Headquarters.[6]

The science capability within Goddard complicated its relations with the scientific community outside of NASA, as well. The NACA field centers (which evolved into the NASA aeronautical research centers)....

[7]

Goddard personnel oversee construction of a pallet for the Space Shuttle cargo bay. These pallets are used to hold satellites and other scientific research equipment. (NASA photo G-79--074542).

....focused on applied engineering research, and their primary customer was the commercial aviation industry. NACA/NASA researchers would publish the results of their work in technical reports that industry engineers would use as reference guides when designing new aircraft or engines. The relationship was fairly smooth, because NASA researchers were providing a service that industry appreciated. By the same token, NASA's human space flight program was essentially its own customer.

Scientific satellites faced a different situation. The primary customer in space science was not a commercial industry, but an international scientific community, and the product was not a practical piece of technology but a more esoteric piece of knowledge to fit into a evolving picture of the universe. The situation was complicated by the fact that scientific and astronomical research, as opposed to human space exploration, was not exclusively NASA's domain. As a result, Goddard has always had to maintain a delicate balance between supporting research conducted by its own scientists and supporting the needs and desires of the external scientific community.

Adding to the complexity of Goddard's projects was the international character of the space program. The National Space Act of 1958 that established NASA specifically mandated that the new agency "cooperate with other nations and international.....

[8]

Explorer XIV, launched in October 1962, was designed to investigate solar wind and radiation phenomena.

....groups in the peaceful application of space."[7]. While these partnerships have been extremely fruitful over the years and are more prevalent than ever in today's global environment, international projects were more complex to manage.

Goddard also had to rely on international cooperation to build and manage its series of ground tracking and communication networks, which involved up to 24 different countries. The history of these ground station networks is colorful and includes some unique situations, such as problems with labor unrest in Australia and political unrest in South America. At one point the Guaymas tracking station in Mexico even had to be surrounded by troops to protect it from "unruly mobs."[8]

Goddard's diverse responsibilities and communities certainly created some unique management challenges, but its diversity created some important strengths and capabilities within the Center, as well. Goddard was one of the only places in the world where the entire cycle of a space science experiment could be conducted. The Center had sufficient in-house resources to develop the theory behind an experiment, carry out the experimental design and engineering necessary to determine if it was feasible, fabricate and test the instruments and spacecraft, provide a launch vehicle, launch and track the satellite, and collect and analyze the data sent back from space. This data would then feed additional theoretical studies, sparking yet another cycle of experimentation. This unique ability to take an experiment "from womb to tomb" has been one of the hallmarks of the Goddard Space Flight Center ever since it began.

Because Goddard had responsibility for building instruments and spacecraft as well as conducting scientific research, the Center also developed a remarkable in-house ability to imagine and build new kinds of instruments, satellites, and technology. Goddard's Explorer series of satellites, which conducted experiments in almost every facet of space science and became one of the most successful series of spacecraft in NASA's history, were a product and a primary example of this in-house, innovative spirit.

Goddard's engineers were also constantly looking at ways to improve basic spacecraft design. Very soon after the first satellites reached orbit, Goddard engineers began work on standardized, modular spacecraft that would be more cost-effective and easy to upgrade The first of these, the Orbiting Geophysical Observatory (OGO), was launched in 1964 Goddard expanded this concept in the early 1970s with its Multi-mission Modular Spacecraft (MMS), which was designed to be repaired in space by Shuttle astronauts. The concept was tested in 1984 when the Solar Max satellite was successfully repaired on station.

Because of Goddard's previous success in modular, servicable spacecraft,the Hubble Space Telescope was also designed to be serviced on station - a design characteristic that took on critical importance when a flaw was discovered in the telescope's primary mirror. The [9] award-winning effort that repaired the Hubble telescope was the culmination of 30 years of innovative, pragmatic engineering efforts at Goddard. And as we approach the millenium, Goddard's engineers are continuing this innovative and pragmatic tradition as they develop new spacecraft technology and a new class of smaller and yet more capable Explorer satellites.

At the same time, Goddard's roots as an "all-purpose" space center created a broad base of scientific capability that allowed the Center to expand its research efforts as technology improved. Space science efforts moved from simple particle and field research into visible, ultraviolet and high-energy astronomy, taking on more and more complex and difficult problems in all of these areas as technology and knowledge advanced. Weather and atmospheric satellite research expanded into an entire new field of Earth Science and remote sensing research. And Goddard's early work in communications satellites gave the Center the expertise to manage the development and operation of the space-based Tracking and Data Relay Satellite System (TDRSS) that now provides communication and tracking services for almost all Earth orbiting satellites, including the Space Shuttle.

These diverse technical and scientific strengths have allowed Goddard to make tremendously significant contributions to knowledge and space technology. In addition, while its range of projects and responsibilities has meant that it was never the single or top priority of any one manager at NASA Headquarters, Goddard's diversity has made it less vulnerable to cutbacks or cancellation of any given role, mission or program.

One of the most challenging missions undertaken by Goddard was the 1993 first servicing mission of the Hubble Space Telescope, which had a flaw in its primary mirror. (NASA Photo 94-HC-26).

Many things have changed at Goddard over the past 40 years. The Center has grown from humble beginnings in borrowed offices and a Naval Research Laboratory warehouse to a sprawling campus with a workforce of 11,800 people and more than 30 buildings. The basic challenge of getting into space at all has long since given way to the ongoing challenge of going further and doing it more cheaply, quickly, and efficiently.

From a day when receiving a faint tone from a satellite passing overhead was....

[10]

An image from the Hubble Space Telescope captures the stellar fireworks of two galaxies colliding. (NASA Photo PRC97-34A).

....a major accomplishment, we now find ourselves looking at breathtaking images of the Sun and distant galaxies, in wavelengths and detail our atmosphere had always hidden from view. In the early days, Goddard's experiments were simply trying to find out what existed in the space near Earth. Today, they are reaching back to the dawn of time to answer some of the biggest questions about the formation of our universe.

At the same time, Goddard's efforts in the field of space applications, which included not only weather and communication satellites, but also Earth resource imaging satellites, have helped create several thriving industries and a growing field of Earth science research . If phrases like "El Nino" and "ozone layer depletion" are now household terms, it is in large part because of research conducted at or with the Goddard Space Flight Center.

Without question, Goddard has had to change, adapt and reinvent itself and its mission to meet the changing times and priorities of the country. But the changes have been more evolutionary than revolutionary. As the NASA research center primarily responsible for Earth-orbiting satellites, the Goddard Space Flight Center's [11] mission has remained one of exploring the heavens and the Earth in order to improve our lives and our understanding of the universe in which we live. The satellites have become more capable and complex, the players have changed, and the goalposts have moved outward. But the mission, and the challenges inherent in that mission, have remained essentially the same.

Ever since it opened its doors, Goddard's biggest challenge has been to balance its complex array of activities, groups, external communities, and concerns while reaching beyond the limits of Earth. What has allowed it to succeed at that challenge is an enthusiastic spirit and entrepreneurial personality that has characterized the Center since its beginning. It was started by young scientists, engineers and technicians inspired by the possibilities of space and willing to overcome whatever obstacles stood in the way of exploring it. Goddard is a place where people have a passion to find out more about how our world and universe work; to reach outside the boundaries of our planet to gain a better perspective on Earth and a clearer view of the galaxies and the cosmos beyond.

The story of the Goddard Space Flight Center is the story of an amazing expedition into a strange new land. From our first stumbling steps, we have journeyed far. We have learned an amazing amount about our planet and our universe - and discovered how much vaster and more complex the picture is; how much we still have to learn. The journey has not been an easy one, but no exploration ever is. "One cannot discover new lands," the French author Andre Gide once wrote, "without consenting to lose sight of the shore for a very long time."[9]

Because of people like those at Goddard, who were willing to persevere through the rigorous demands, problems and frustrations of space exploration, we have discovered many new lands. But the journey continues, because the ocean of space still stretches before us. For every question we have answered - every new land we have discovered - there are a thousand left to understand. This is still the mission, the passion, and the driving life force behind the Goddard Space Flight Center. Forty years after its founding, its researchers are still probing the mysteries of a territory that has proven to be the most complex and challenging frontier we have ever endeavored to explore.

A graphic image of ocean wind currents compiled from satellite data.

Chapter 2:
A Place for Science

[12]

A new and much larger clean room facility was built at Goddard to accomodate servicing components for the Hubble Space Telescope (NASA Photo 93C-5065).

[13] Although the Goddard Space Flight Center received its official designation on the first of May 1959, Goddard's roots actually date back far beyond that. In a sense, they date back almost as far as civilization itself - for people have been gazing into the night sky and wondered about its secrets for thousands of years. In the fourth century B.C., Aristotle created a model of the universe that astronomers relied on for more than a millennium. His assumption that the universe revolved around the Earth proved to be incorrect, but his effort was no different than that of modern scientists trying to solve the riddles of black holes or dark matter.[1]

The roots of Goddard's work in rocket development and atmospheric research date back several centuries, as well. The first...

[14]

Robert H. Goddard with a vacuum tube apparatus that he built in 1916 to research rocket efficiency. (NASA Photo 74-H-1052)

...reported use of rocket technology was in the year 1232, when the Chin Tarters developed a "fire arrow" to fend off a Mongol assault on the city of Kai-feng-fu. In 1749, Scotsman Alexander Wilson was sending thermometers aloft on kites to measure upper-air temperatures. One hundred and fifty years later, meteorologists were beginning to accurately map the properties of the atmosphere using kites and balloons.[2]

Robert J. Goddard, for whom the Goddard Space Flight Center is named, received his first patents for a multi-stage rocket and liquid rocket propellents in 1914, and his famous paper on "A Method of Reaching Extreme Altitudes" was published in 1919. But it would not be until the close of World War II that all these long-standing interests and efforts would come together to create the foundation for modern space science and, eventually, the Goddard Space.Flight Center.[3]

The Goddard Space Flight Center was named in honor of Dr. Robert H. Goddard a pioneer in developing multi-stage rockets and liquid rocket propellants.

A certain amount of rocket research was being conducted in the United States even during the war. But the Germans had made far greater advancements in rocket technology. Before the end of the war, German scientists had developed a large, operational [15] ballistic rocket weapon known as the "V-2.". When the war came to a close, the U.S. military brought a number of these rockets back to the United States to learn more about their handling and operation.

A V-2 rocket just after launch at the White Sands Proving Ground in New Mexico.

The Army planned to fire the V-2s at the White Sands Proving Ground in New Mexico. The Army's interest was in furthering the design of ballistic missiles. But the military recognized the research opportunity the rocket firings presented and offered to let interested groups instrument the rockets for high-altitude scientific research.[4]

The V-2 program helped spark the development of other rockets, and research with "sounding rockets," as these small upper atmosphere rockets were called, expanded greatly over the next few years. The results from these rocket firings also began to gain the attention of the international scientific community.

In 1951, the International Council of Scientific Unions had suggested organizing a third "International Polar Year" in 1957. The first two such events had been held in 1882 and 1932 and focused on accurately locating meridians (longitudinal lines) of the Earth. A third event was proposed after an interval of only 25 years because so many rapid advances had been made in technology and instrumentation since the beginning of WWII. Scientists in the 1950s could look at many more aspects of the Earth and the atmosphere than their predecessors could even a decade earlier. In 1952, the proposed event was approved by the Council and renamed the International Geophysical Year (IGY) to reflect this expanded focus on studying the whole Earth and it immediate surroundings.[5]

The U.S. scientists quickly agreed to incorporate rocket soundings as part of their contribution to the IGY. But a loftier goal soon emerged.

In October 1954, the International Council's IGY committee issued a formal challenge to participating countries to attempt to launch a satellite as part of the IGY. In July 1955, President Dwight D. Eisenhower picked up the gauntlet. The United States, he announced, would launch "small, unmanned Earth-circling satellites as part of the U.S. participation in the IGY."[6] In September 1956, the Soviet Union announced that it, too, would launch a satellite the following year. The race was on.

[16] Sputnik, Vanguard, and the Birth of NASA

V-2 rockets, like this one, carried some of the first scientific payloads into the upper atmosphere.

The U.S. satellite project was to be a joint effort of the National Academy of Sciences (NAS), the National Science Foundation (NSF) and the Department of Defense (DOD). The NAS was in charge of selecting the experiments for the satellite, the NSF would provide funding, and the Defense Department would provide the launch vehicle.

Sparked by the V-2 launch program, the Naval Research Lab (NRL) already had begun work on a rocket called the Viking, and the NRL proposed to mate the Viking with a smaller "Aerobee." The Aerobee was a rocket that had evolved from a rocket JPL had first tested in 1945 and was used extensively for sounding rocket research. The Viking would be the first stage, the Aerobee would be the second stage, and another small rocket would serve as the third stage. The proposal was approved and dubbed "Project Vanguard."[7]

Yet despite these efforts, the Americans would not be the first into space. On 4 October 1957, the Russians launched Sputnik I - and changed the world forever.

The launch of Sputnik was disappointing to U.S. scientists, who had hoped to reach space first. But following good scientific etiquette, they swallowed their pride and gave credit to the Soviets for their impressive accomplishment. The rest of the U.S., however, had a very different reaction. Coming as it did at the height of the Cold War, the launch of Sputnik sent an astounding wave of shock and fear across the country. The Russians appeared to have proven themselves technologically more advanced. Aside from a loss of prestige and possible economic considerations from falling behind the Russians in technological ability, the launch raised questions of national security, as well. If the Soviets could conquer space, what new threats could they pose?

The situation was not helped by a second successful Sputnik launch a month later or the embarrassing, catastrophic failure of a Vanguard rocket two seconds after launch in early December. Space suddenly became a national priority. Congress began ramping up to deal with the "crisis." President Eisenhower created a post of Science Adviser to the President and asked his Science Advisory Committee to develop a national policy on space. That policy would lead to the National Aeronautics and Space Act of 1958 that created the National Aeronautics and Space Administration.[8]

In the months following the launch of Sputnik, numerous proposals were put forth about how the development of space capability should be organized. But in the end, President Eisenhower decided that the best way to pursue a civilian space program with speed and efficiency was to put its leadership under a strengthened and redesignated National Advisory Committee for Aeronautics (NACA). Proposed legislation for the creation of this new agency was sent to Congress on 2 April 1958 and signed into law on 29 July 1958.[9]

The Space Act outlined a tremendously ambitious list of objectives for the new agency.

[ 17] The U.S. space program was to be of benefit to the security and general welfare of the United States and to all mankind. Peaceful objectives were to be pursued, human scientific knowledge in aeronautical and space-related matters be expanded, international cooperation in space be promoted, public and private efforts in space coordinated, U.S. leadership in space preserved, and the long-range efforts of a space program studied. [10]

While the administrative and political debate over a new space agency was being conducted, work continued on the the IGY satellite project. The Vanguard rocket project had been approved not because the Viking and Aerobee were the only rocket programs underway, but because the military did not want to divert any of its its intercontinental ballistic missile (ICBM) efforts to the civilian IGY project. But the launch of Sputnik and the subsequent Vanguard failure changed that situation. Getting a satellite into orbit was now a top national priority.

In November 1957, the Army Ballistics Missile Agency was given permission to attempt the launch of a satellite using a proven Jupiter C missile from the Redstone Arsenal in Huntsville, Alabama. The United States finally achieved successful space flight on 31 January 1958 when a Jupiter rocket successfully launched a small cylinder named Explorer I into orbit[11]. In retrospect, it's interesting to speculate how history might have been different had the Army's Jupiter missile been chosen as the satellite launch vehicle from the outset, rather than the Vanguard. The United States might well have beaten the Soviets into space. But without the public fear and outcry at losing our technological edge, there might well not have been the public support for the creation of NASA and its extensive space program.[12]

Meanwhile, the Vanguard program still continued, although it was struggling. A third rocket broke apart in flight just five days after the successful Explorer I launch. Finally, on 17 March 1958, a Vanguard rocket successfully launched Vanguard I - a six-inch sphere weighing only four pounds - into orbit.

Explorer 1, America's first satellite lifts off the launch pad at Cape Canaveral, Florida on 31 December 1958 on a Jupiter rocket. (NASA Photo KSC-68P-17).

The Explorer I and Vanguard I satellites proved we could reach space. The next task was to create an organization that could manage our effort to explore it - an effort that would become one of the most enormous and expensive endeavors of the 20th century.[13]

[18] Origins of the Goddard Space Flight Center

As planning began for the new space agency in the summer of 1958, it quickly became clear that a research center devoted to the space effort would have to be added to the existing NACA aeronautical research centers. The space program was going to involve big contracts and complicated projects, and the founding fathers of NASA wanted to make sure there was enough in-house expertise to manage the projects and contracts effectively.

Even before the Space Act was signed into law, Hugh Dryden, who became the Deputy Administrator of NASA, began looking for a location for the new space center. Dryden approached a friend of his in the Department of Agriculture about obtaining a tract of government land near the Beltsville Agricultural Research Center in...

Construction in progress on Building 2 at GSFC.

....Maryland. Dr. John W. Townsend, who became the first head of the space science division at Goddard and, later, one of the Center's directors, was involved in the negotiations for the property. The process, as he recalls, was rather short.

He (the department of Agriculture representative) said, "Are you all good guys?" I said "Yes." He said, "Will you keep down the development?" I said, "Yes." He spreads out a map and says, "How much do you want?" And that was that. We had our place.[14]

On 1 August 1958, Maryland's Senator J. Glenn Beall announced that the new "Outer Space Agency" would establish its laboratory and plant in Greenbelt, Maryland. But while the new research center was, in fact, built in Greenbelt, Senator Beall's press release shows how naive even decision-makers were about how huge the space effort would become. Beall confidently asserted that the research center would employ 650 people, and that "all research work in connection with outer space programs will be conducted at the Greenbelt installation."[15]

The initial cadre of personnel for the new space center - and NASA itself, for that matter - was assembled through a blanket transfer authority granted to NASA to insure the agency had the resources it needed to do its job. One of the first steps was the transfer of the entire Project Vanguard mission and staff from the NRL to the new space agency, a move that was actually included in the executive order that officially opened the doors of NASA on 1 October 1958.[16]

The 157 people in the Vanguard project became one of the first groups incorporated into what was then being called the [19] "Beltsville Space Center." In December 1958, 47 additional scientists from the NRL's sounding rocket branch also transferred to NASA, including branch head John Townsend. Fifteen additional scientists, including Dr. Robert Jastrow, also transferred to the new space center from the NRL's theoretical division.

The Space Task Group at the Langley Research Center, responsible for the manned space flight effort that would become Project Mercury, was initially put under administrative control of the Beltsville center, as well, although the group's 250 employees remained at Langley. A propulsion-oriented space task group from the Lewis Research Center was also put under the control of the new space center. The space center's initial cadre was completed in April 1959 with the transfer of a group working on the TIROS meteorological satellite for the Army Signal Corps Research and Development Laboratory in Ft. Monmouth, New Jersey.[17]

The Beltsville Space Center was officially designated as a NASA research center on 15 January 1959, after the initial personnel transfers had been completed. On 1 May 1959, the Beltsville facility was renamed the Goddard Space Flight Center, in honor of Dr. Robert J. Goddard. [18]

Getting Started

Although Goddard existed administratively by May of 1959, it still did not exist in any physical sense. Construction finally began on the first building at the Beltsville Space...

Early aerial photo of GSFC showing a few complete buildings.

.....Center in April 1959,[19] but it would be some time before the facilities there were ready to be occupied. In the meantime, the Center's employees were scattered around the country. The Lewis and Langley task groups were still at those research centers. The NRL scientists were working out of temporary quarters in two abandoned warehouses next to the Naval Lab facilities. Additional administrative personnel were housed in space at the Naval Receiving Station and at NASA's temporary headquarters in the old Cosmos Club Building, also known as the Dolly Madison House on H Street in Washington, D.C. Robert Jastrow's theoretical division was housed above the Mazor Furniture Store in Silver Spring, Maryland.[20]

The different groups may have been one organization on paper but, in reality, operations were fairly segmented. The Center did not even have an official director and would not have one until September 1959. Until then, working relationships and facilities were both somewhat improvised.

[20] Not surprisingly, the working conditions in those early days were also less than ideal. Offices were cramped cubicles and desks were sometimes made of packing crates. Laboratory facilities were equally rough. One of the early engineers remembers using chunks of dry ice in makeshift "cold boxes" to cool circuitry panels and components. The boxes were effective, but researchers had to make sure they didn't breathe too deeply or keep their heads in the boxes too long, because the process also formed toxic carbonic acid fumes.

But there was a kind of raw enthusiasm for the work - a pioneering challenge with few rules and seemingly limitless potential - that more than made up for the rudimentary facilities. It helped that many of the scientists also came from a background in sounding rockets. Sounding rocket research, especially in the early days, was a field that demanded a lot of flexibility and ingenuity. Because their work had begun long before the post-Sputnik flood of funding, these scientists were accustomed to very basic, low-budget operations. Comfort may not have been at a premium in Goddard's early days, but scientists who had braved the frigid North Atlantic to fire rockoons (rockets carried to high altitude by helium balloons before being fired) had certainly seen a lot worse.[21]

As 1959 progressed, Goddard continued to grow. By June, the new research center had 391 employees in the Washington area and, by the end of 1959, its personnel numbered 579.[22] As the personnel grew, so did the physical facilities at the Greenbelt, Maryland, site. By September 1959, the first building was ready to be occupied.

Workers install the main entrance sign to the Goddard Space Flight Center before its March 1961 dedication ceremony.

The plan for Goddard's physical facilities was to create a campus-like atmosphere that would accommodate the many different jobs the Center was to perform. The buildings were numbered in order of construction, and there was a general plan to put laboratories and computer facilities on one side, utility buildings in the center of the campus, and offices on the other side. Most of the buildings were one, two, or three-story structures that blended inconspicuously into the landscape. The one exception was Building 8, which was built to house the manned space flight program personnel. Robert Gilruth, who was in charge of the program, supposedly wanted a tall structure, so the building was designed with six stories. The original plan to incorporate the manned space flight program at Goddard also resulted in the construction of a special bay tall enough to house Mercury capsules as part of the test and evaluation facility in Building 5. By 1961, however, this aspect of NASA's program had been moved to the new space center in Houston, Texas. So Building 8 was used to house administration offices, instead.[23]

Even as formal facilities developed, it still took something of a pioneer's spirit to work at Goddard during the early days. The Center was built in a swampy, wooded area, and wood planks often had to be stretched across large sections of mud between parking areas and offices. And on more than one occasion, displaced local snakes found their way into employees' cars, leading to distinctive screams coming from the parking lot at the end of the day.[24]

[21] Improvisation and flexibility were critical skills to have in the scientific and engineering work that was done, as well. Space was a new endeavor, and there were few guidelines as to how to proceed - either in terms of what should be done or how that goal should be accomplished. At the very beginning, there was no established procedure to decide which experiments should be pursued, and there was a shortage of space scientists who were interested or ready to work with satellites. As a result, the first scientists recruited or transferred to Goddard had a lot of freedom to make their own decisions about what ought to be done. In 1959, NASA Headquarters announced that it would select the satellite experiments, but a shortage of qualified scientists at that level resulted in Goddard scientists initially taking part in the evaluation process. Experiments from outside scientists were incorporated into virtually all the satellite projects, but there were soon more scientists and proposals than there were flight opportunities. The outside scientific community began to complain that Goddard scientists had an unfair advantage.

It took a while to sort out, but by 1961 NASA had developed a procedure that is still the foundation of how experiments are selected today. Headquarters issues Announcements of flight Opportunities (AOs), and scientists from around the country can submit proposals for experiments for the upcoming project. The proposals are evaluated by sub-committees organized by NASA Headquarters. The committees are made up of scientists from both NASA and the outside scientific community, but members do not evaluate proposals that might compete with their own work.

Goddard's Orbiting Solar Observatory (OSO) satellites provided scientists with their first extended look at the Sun in the high-temperature ultraviolet, X-ray and Gamma-ray portions of the electronic magnetic spectrum. The first OSO satellite, pictured here, was launched in March 1962. (NASA Photo G-63-3521).

These groups also conduct long-range mission planning, along with the National Academy of Sciences' Space Science Board.[25] The final selection of experiments for satellite missions is made by a steering committee of NASA scientists. Because of a possible conflict of interest, the selection board took care to ensure a fairness in selecting space science research.[26]

Yet in the early days of Goddard, uncertainty about how to choose which experiments to pursue was only part of the challenge. The work itself required a flexible, pragmatic approach. Nobody had built satellites before, so there was no established support industry. Scientists drew upon their sounding rocket experience and learned as they went. Often, they learned lessons the hard way. Early summaries of satellite launches and results are peppered with notes such as "two experiment booms failed to deploy properly, however...," "Satellite's tracking beacon [22] failed...," and, all too often, "liftoff appeared normal, but orbit was not achieved."[27] Launch vehicles were clearly the weakest link in the early days, causing much frustration for space scientists. In 1959, only four of NASA's ten scientific satellite launches succeeded.[28]

In this environment of experimentation with regard to equipment as well as cosmic phenomena, Goddard scientists and engineers were constantly inventing new instruments, systems, and components, and they often had to fly something to see if it would really work. This talent for innovation became one of the strengths of Goddard, leading to the development of everything from an artificial sun to help test satellites to modular and servicable spacecraft, to solid state recorder technology and microchip technology for space applications.

A researcher retrieves instruments from the remains of one of the early V-2 rockets after its flight. The rockets created large craters where they crash landed.

This entrepreneurial environment also spawned a distinct style and culture that would come to characterize Goddard's operations throughout its developmental years. It was a very pragmatic approach that stressed direct, solution-focused communication with the line personnel doing the work and avoided formal paperwork unless absolutely necessary.

One early radio astronomy satellite, for example, required a complex system to keep it pointed in the right direction and an antenna array that was taller than the Empire State Building. After heated debate as to how the satellite should be built, the project manager approved one engineer's design and asked him to document it for him. On the launch day, when asked for the still-missing documentation, the engineer ripped off a corner of a piece of notebook paper, scribbled his recommendation, and handed it to the project manager. As one of the early scientists said, the Center's philosophy was "Don't talk about it, don't write about it - do it!"[29]

Dedicating the new space center

This innovative and pragmatic approach to operations permeated the entire staff of the young space center, a trait that proved very useful in everything from spacecraft design to Goddard's formal dedication ceremonies. Construction of the facilities at Goddard progressed through 1959 and 1960. By the spring of 1961, NASA decided the work was far enough along to organize formal dedication ceremonies. But while there were several buildings that were finished and occupied, the Center was still lacking a few elements necessary for a dedication.

A week before the ceremonies, the Secret Service came out to survey the site, because it was thought President Kennedy might attend. They told Goddard's director of administration, Mike Vaccaro, that he had to have a fence surrounding the Center. It rained for a solid week before the dedication, but Vaccaro managed to find a contractor who worked a crew 24 hours a day in the rain and mud to cut down trees and put in a chain link fence.

After all that, the President did not attend the ceremonies. But...

[23]

Dedication ceremonies take place at Goddard Space Flight Center on 16 March 1961.

Esther Goddard talks with the bust of her husband, sculpted by Joseph Anthony Atchison.

....someone then decided that a dedication couldn't take place without a flagpole to mark the Center's entrance. Vaccaro had three days to find a flagpole - a seemingly impossible deadline to meet while still complying with government procurement regulations. One of his staff said there was a school being closed down that had a flagpole outside it, so Vaccaro spoke to the school board and then created a specification that described that flagpole so precisely that the school was the only bid that fit the bill. He then sent some of his staff over to dig up the flagpole and move it over to the Center's entrance gate - where it still stands today.

There was also the problem of a bust statue. The dedication ceremony was supposed to include the unveiling of a bronze bust of Robert J. Goddard. But the sculptor commissioned to create the bust got behind schedule, and all he had done by the dedication date was a clay model. Vaccaro sent one of his employees to bring the clay sculpture to the Center for the ceremonies, anyway. To make things worse, the taxi bringing the bust back to the Center stopped short at one point, causing the bust to fall to the floor of the cab. The bust survived pretty much intact, but its nose broke off. Undaunted, Vaccaro and his employees pieced the nose back together and simply spray painted the clay bronze, finishing with so little time to spare that the paint was still wet when the bust was finally unveiled.[30] But the ceremonies went beautifully, the Goddard Space Flight Center was given its formal send-off, and the Center could settle back down to the work of getting satellites into orbit.

The Early Years

In the view of those who were present at the time, the 1960s were a kind of golden [24] age for Goddard. There was an entrepreneurial enthusiasm among its employees, and NASA was too new and still too small to have much in the way of bureaucracy, paperwork, or red tape. The scientists were being given the opportunity to be the first into a new territory. Sounding rockets and satellites weren't just making little refinements of already known phenomena and theories - they were exploring the space around Earth for the first time. Practically everything the scientists did was something that had never been done before, and they were discovering significant and new surprises and phenomena on almost every flight.

Because of the impetus behind the Mercury, Gemini and Apollo space programs, space scientists also suddenly found themselves with a level of funding they had never had available before. Although there were many frustrations associated with learning how to operate in space and develop reliable technology that could survive its rigors, support for that effort was almost limitless. The Apollo program was "the rising tide that lifted all boats," as one Goddard manager put it. There was also a sense of mission, importance and purpose that has been difficult to duplicate since. We were going to space and we were going to be first to the Moon, and our national security, prestige, and pride was seen as dependent on how well we did the job.[31]

Gemini VI spacecraft as photographed by Gemini VII crew, 15 December 1965, 160 miles above the Earth.

The Goddard Institute for Space Studies

In this kind of environment, both the space program and Goddard grew quickly. Even before Goddard completed its formal dedication ceremonies, plans were laid for the establishment of a separate Goddard Institute for Space Studies in New York City. Two of the big concerns in the early days of the space program were attracting top scientists to work with the new agency and insuring there would be space-skilled researchers coming out of the universities. Early in NASA's development, the agency set aside money for both research and facilities grants to universities to help create strong space science departments.[32] But one of Goddard's early managers thought the link should be personal as well as financial.

Dr. Robert Jastrow had transferred to Goddard to head up the theoretical division in the fall of 1958. He argued that if Goddard wanted to attract the top theoretical physicists from academia to work with the space program, it had to have a location more convenient to leading universities. By late 1960, he had convinced managers at Goddard and Headquarters to allow him to set up a separate Goddard institute in New York. The Goddard Institute for Space Studies (GISS) provided a gathering point for theoretical physicists and space scientists in the area. But the institute offered them another carrot, as well - some of the most powerful computers in existence at the time. The computers were a tremendous asset in crunching the impossibly big numbers involved in problems of theoretical physics and orbital projections.

[25] Over the years, the Goddard Institute organized conferences and symposia and offered research fellowships to graduate students in the area. It also kept its place at the forefront of computer technology. In 1975, the first fourth generation computer to be put into use anywhere in the United States was installed at the Goddard Institute in New York.[33]

International Projects

Goddard's international ties and projects were expanding quickly, as well. In part the growth was natural, because Goddard and the space program itself grew out of an international scientific effort - the International Geophysical Year. Scientists also tended to see their community as global rather than national, which made international projects much easier to organize. Furthermore, the need for a world-wide network of ground stations to track the IGY satellites forced the early space scientists and engineers to develop working relationships with international partners even before NASA existed. These efforts were enhanced both by the Space Act that created NASA, which specified international cooperation as a priority for the new agency, and by the simple fact that there was significant interest among other countries in doing space research.

Early NASA managers quickly set down a very simple policy about international projects that still guides the international efforts NASA undertakes. There were only two main rules. The first was that there would be no exchange of funds between...

Researcher checks out Explorer XVIII, the first Interplanetary Monitoring Platform spacecraft, prior to launch. The satellite measured cosmic radiation, magnetic fields and solar wind beyond the Earth's magnetic field. (NASA photo G-64-269).

....NASA and international partners. Each side would contribute part of the project. The second was that the results would be made available to the whole international community. The result was a number of highly successful international satellites created by joint teams who worked together extremely well - sometimes so well that it seemed that they all came from a single country.[34]

Explorer X studied particles and fields in interplanetary space and near Earth's reaches. It was on 25 March 1961.

In April 1962, NASA launched Ariel I - a joint effort between Goddard and the United Kingdom and the first international [26] satellite. Researchers in the U.K. developed the instruments for the satellite, and Goddard managed development of the satellite and the overall project. Ariel was followed five months later by Alouette I, a cooperative venture between NASA and Canada. Although Alouette was the second international satellite, it was the first satellite in NASA's international space research program that was developed entirely by another country.[35]

The Explorer XVII was designed to measure the density, composition, pressure and temperature of Earth's atmosphere after NASA launched the spacecraft in 1963. It was launched on April 3, 1963. (NASA photo G-63-4001)

These early satellites were followed by others. Over the years, Goddard's international ties grew stronger through additional cooperative scientific satellite projects and the development of ground station networks. Today, international cooperation is a critical component of both NASA's scientific satellite and human space flight programs.

The Work

The work Goddard conducted throughout the 1960s was focused on basics: conquering the technical challenges of even getting into space, figuring out how to get satellites to work reliably once they got there, and starting to take basic measurements of what existed beyond the Earth's atmosphere.

[27] The first few satellites focused on taking in situ measurements of forces and particles that existed in the immediate vicinity of Earth, but the research quickly expanded to astronomy, weather satellites, and communication satellites. Indeed, one of the initial groups that was transferred to form Goddard was a group from the Army Signal Corps that was already working on development of a weather satellite called the Television Infrared Observation Satellite (TIROS). The first TIROS satellite was launched in April 1960.

Four months later, the first communications satellite was launched into a successful orbit. The original charter for NASA limited its research to passive communications satellites, leaving active communications technology to the Department of Defense. So the first communications satellite was an inflatable mylar sphere called "Echo," which simply bounced communications signals back to the ground. The limitation against active communications satellite research was soon lifted, however, and civilian prototypes of communications satellites with active transmitters were in orbit by early 1963.[36]

As the 1960s progressed, the size of satellites grew along with the funding for the space program. The early satellites were simple vehicles with one or two main experiments. Although small satellites continued to be built and launched, the mid-1960s saw the evolution of a new Observatory-class of satellites, as well - spacecraft weighing as much as one thousand pounds, with multiple instruments and experiments. In...

The Television Infrared Observation Satellite (TIROS) spacecraft were the first meteorological satellites. The first one was launche in April 1960. (NASA Photo G-65-5216)

....part, the bigger satellites reflected advances in launch vehicles that allowed bigger payloads to get into orbit. But they also paralleled the rapidly expanding sights, funding, and goals of the space program.

The research conducted with satellites also expanded during the 1960s. Astronomy satellites were a little more complex to design, because they had to have the ability to remain pointed at one spot for a length of time. Astronomers also were not as motivated as their space physics colleagues to undertake the challenge of space-based research, because many astronomy experiments could be conducted from ground observatories. Nonetheless, space offered the opportunity to look at objects in regions of the electromagnetic spectrum obscured by the Earth's atmosphere. The ability to launch larger satellites brought that opportunity within reach as it opened the door to space-based astronomy telescopes.

[28] Goddard launched its first Orbiting Astronomical Observatory (OAO) in 1966. That satellite failed, but another OAO launched two years later was very successful. These OAO satellites laid the groundwork for Goddard's many astronomical satellites that followed, including the Hubble Space Telescope. Goddard scientists also were involved in instrumenting some of the planetary probes that were already being developed in the 1960s, such as the Pioneer probes into interplanetary space and the Ranger probes to the Moon.

The other main effort underway at Goddard in the 1960s involved the development of tracking and communication facilities and capabilities for both the scientific satellites and the manned space flight program. Goddard became the hub of the massive, international tracking and communications wheel that involved aircraft, supertankers converted into mobile communications units, and a wide diversity of ground stations. This system provided NASA with a kind of "Internet" that stretched not only around the world, but into space, as well. Every communication to or from any spacecraft came through this network. A duplicate mission control center was also built at Goddard in case the computers at the main control room at the Johnson Space Center in Houston, Texas failed for any reason.

Goddard was the hub of an international tracking and communications network, which followed and communicated with scientific missions and manned spacecraft.

Whether it was in tracking, data, satellite engineering, or space science research, the 1960s were a heady time to work for NASA. The nation was behind the effort, funding was flowing from Congress faster than scientists and engineers could spend it, and there was an intoxicating feeling of exploration. Almost everything Goddard was doing had never been done before. Space was the new frontier, and the people at Goddard knew they were pioneers in the endeavor of the century.

External relations

This is not to say that there were no difficulties, frustrations, problems, or disappointments in the 1960s. Tensions between the Center and NASA Headquarters increased as NASA projects got bigger. Goddard's first director, Harry Goett, came to Goddard from the former NACA Ames Research Center. He was a fierce defender of his people and believed vehemently in the independence of field centers. Unfortunately, Goddard was not only almost in Headquarters' back yard, it was also under a much more intense spotlight because of its focus on space.

[29]

This was a parabolic antenna at the Rosman, North Carolina tracking station built in 1963. At one time, Goddard's tracking and data networks involved up to 24 countries.

The issues between Goddard and NASA Headquarters were not unique to Goddard, or even to NASA. Tension exists almost inherently between the Headquarters and field installations of any institution or corporation. While both components are necessary to solve the myriad of big-picture and hands-on problems the organization faces, their different tasks and perspectives often put Headquarters and field personnel in conflict with each other. In order to run interference for field offices and conduct long-range planning, funding, or legislative battles, Headquarters personnel need information and a certain....

[30]

An artist's concept of an Interplanetary Monitoring Platform. The IMP acronym for the satellites was chosen by its project's scientist Dr. Frank McDonald, "in honor of his children."

....amount of control over what happens elsewhere in the organization. Yet to field personnel who are shielded from these large-scale threats and pressures, this oversight and control is often seen as unwelcome interference.

In the case of NASA, Headquarters had constant pressure from Congress to know what was going on, and it had a justifiable concern about managing budgets and projects that were truly astronomical. To allow senior management to keep tabs...

Researchers prepare Explorer XX, the Topside Sounder IE-A, for launch. The satellite was put into orbit on 25 August 1964.

....on different projects and to maintain a constant information flow from the Centers to Headquarters, NASA designated program managers at Headquarters who would oversee the agency's various long-term, continuing endeavors, such as astronomy. Those program managers would oversee the shorter-term individual projects, such as a single astronomy satellite, that were being managed by Goddard or the other NASA field centers.[37]

These program managers were something of a sore spot for Goett and the Goddard managers, who felt they knew well enough how to manage their work and, like typical field office managers, sometimes saw this oversight as unwelcome interference. Managers at other NASA Centers shared this opinion, but the tension was probably higher at Goddard because it was so close to Headquarters. Program managers wanted to sit in on meetings, and Goett wanted his project managers and scientists left alone. Tensions over authority and management escalated between Goett and Headquarters until Goett was finally replaced in 1965.[38]

The increasing attention paid to the space program had other consequences, as well. If it created more support and funding for the work, it also put projects in the eye of a public that didn't necessarily understand that failure was an integral part of the scientific process. The public reaction to early launch failures, especially the embarrassing Vanguard explosion in December 1957, made it very clear to the NASA engineers and scientists that failure, in any guise, was unacceptable. [31] This situation intensified after the Apollo I fire in 1967 that cost the lives of three astronauts. With each failure, oversight and review processes got more detailed and complex, and the pressure to succeed intensified.

As a result, Goddard's engineers quickly developed a policy of intricate oversight of contractors and detailed testing of components and satellites. Private industry has become more adept at building satellites, and NASA is now reviewing this policy with the view that it may increase costs unnecessarily and duplicate manpower and effort. In the future, satellites may be built more independently by private companies under performance-based contracts with NASA. But in the early days, close working relationships with contractors and detailed oversight of satellite building were two of the critical elements that led to Goddard's success.

In its first decade, the Goddard Space Flight Center was responsible for launching more than 100 different spacecraft carrying a wide variety of weather, communications, space physics and astronomy experiments.

The Post-Apollo Era

The ending of the Apollo program brought a new era to NASA, and to Goddard, as well. The drive to the Moon had unified NASA and garnered tremendous support for space efforts from Congress and the country in general. But once that goal was achieved, NASA's role, mission and funding became a little less clear. In some ways, Goddard's focus on scientific [32] missions and a diversity of projects helped protect it from some of the cutbacks that accompanied the end of the Apollo program in 1972. But there were still two Reductions in Force (RIFs)[39] at Goddard after the final Apollo 17 mission that hurt the high morale and enthusiasm that had characterized the Center throughout its first decade. Yet despite the cutbacks, the work at Goddard was still expanding into new areas.

Spacecraft Technology

Even as the Apollo program wound down, NASA was developing a new launch vehicle that what would become known as the Space Shuttle. The primary advantage of the Shuttle was seen as its reusable nature.

NASA astronauts work to repair the Solar Maximum Mission spacecraft in the cargo bay of the Space Shuttle. The repair marked the first time a satellite was retrieved and serviced in space (NASA Photo S13-37-1711).

[33] But an engineer at Goddard named Frank Ceppolina saw another distinct opportunity with the Shuttle. With its large cargo bay and regular missions into low Earth orbit, he believed the Shuttle could be used as a floating workshop to retrieve and service satellites in orbit. Goddard had already pioneered the concept of modular spacecraft design with its Orbiting Geophysical Observatory (OGO) satellites in the 1960s. But in 1974, Ceppolina took that concept one step further by proposing a Multi-mission Modular Spacecraft (MMS) with easily replaceable, standardized modules that would support a wide variety of different instruments. The modular approach would not only reduce manufacturing costs, it would also make it possible to repair the satellite on station, because repairing it would be a fairly straightforward matter of removing and replacing various modules.

The first modular satellite was called the "Solar Max" spacecraft. It was designed to look at solar phenomena during a peak solar activity time and was launched in 1980. About a year after launch it developed problems and, in 1984, it became the first satellite to be repaired in space by Shuttle astronauts. The servicing allowed the satellite to gather additional valuable scientific data. But perhaps the biggest benefit of the Solar Max repair mission was the experience it gave NASA in servicing satellites. That experience would prove invaluable a few years later when flaws discovered in the Hubble Space Telescope forced NASA to undertake a massive and difficult repair effort to save the expensive and high-visibility Hubble mission.[40]

The International Ultraviolet Explorer, shown here during assembly at Goddard, became one of the longest-lasting and most productive satellites in the Center's history. When it was finally shut down, it had been returning useful data for nearly 19 years. (NASA Photo 77-HC-484).

The High Energy Astronomical Observatories (HEAO) made tremendous strides in the extraordinary world of X-ray and gamma-ray astronomy. Three HEAO spacecraft were built and launched successfully throughout the 1970s. (NASA photo 74-H-524).

Space Science

Goddard made significant strides in space science in the years following Apollo, developing projects that would begin to explore new wavelengths and farther distances in the galaxy and the universe. The International Ultraviolet Explorer (IUE) launched in 1978, has proven to be one of the most successful and productive satellites ever put into orbit. It continued operating for almost 19 years - 14 years beyond its expected life span - and generated more data and scientific papers than any other satellite to date.

Goddard's astronomy work also expanded into the high-energy astronomy field in the 1970s. The first Small [34] Astronomy Satellite, which mapped X-ray sources across the sky, was launched in 1970. A gamma-ray satellite followed in 1972. Goddard also had instruments on the High Energy Astronomical Observatory (HEAO) satellites, which were managed by the Marshall Space Flight Center.[41]

The Small Astronomy Satellite-A (SAS), launched on 7 May 1975, studied X-ray sources within and beyond the Milky Way galaxy. (NASA photo G-71-2213)

The HEAO satellites also marked the start of a competition between Marshall and Goddard that would intensify with the development of the Hubble Space Telescope. When the HEAO satellites were being planned in the late 1960s and early 1970s, Goddard had a lot of different projects underway. Senior managers at the Marshall Space Flight Center, however, were eagerly looking for new work projects to keep the center busy and alive. Marshall's main project had been the development of the Saturn rocket for the Apollo program and, with the close of the Apollo era, questions began to come up about whether Marshall was even needed anymore.

When the HEAO project came up, the response of Goddard's senior management was that the Center was too busy to take on the project unless the Center was allowed to hire more civil servants to do the work. Marshall, on the other hand, enthusiastically promised to make the project a high priority and assured Headquarters that it already had the staff on board to manage it.

In truth, Marshall had a little bit of experience with building structures for astronomy, having developed the Apollo Telescope Mount for Skylab, and the Center had shown an interest in doing high-energy research. When it got the HEAO project, however, Marshall still had an extremely limited space science capability. From a strictly scientific standpoint, Goddard would have been the logical center to run the project. But the combination of the available work force at Marshall and the enthusiasm and support that Center showed for the project led NASA Headquarters to choose Marshall over Goddard to manage the HEAO satellites.

The loss of HEAO to Marshall was a bitter pill for some of Goddard's scientists to swallow. Goddard had all but owned the scientific satellite effort at NASA for more than a decade and felt a great deal of pride and investment in the expertise it had developed in the field. It was an [35] adjustment to have to start sharing that pie. What made the HEAO loss particularly bitter in retrospect, however, was that it gave Marshall experience in telescope development - experience that factored heavily in Headquarters' decision to award the development of the Hubble Space Telescope to Marshall, as well.

There were other reasons for giving the Hubble telescope to Marshall - including concern among some in the external scientific community that Goddard scientists still had too much of an inside edge on satellite research projects. Goddard was going to manage development of Hubble's scientific instruments and operation of the telescope once it was in orbit. If Goddard managed the development of the telescope as well, its scientists would know more about all aspects of this extremely powerful new tool than any of the external scientists. By giving the telescope project to Marshall to develop, that perceived edge was softened a bit.

Indeed, Hubble was perceived to be such a tremendously powerful tool for research that the outside community did not even want to rely on NASA Headquarters to decide which astronomers should be given time on the telescope. At the insistence of the general astronomical community, an independent Space Telescope Science Institute was set up to evaluate and select proposals from astronomers wanting to conduct research with the Hubble. The important point, however, was that the telescope project was approved. It would become the largest astronomical telescope ever put into space - a lens into mysteries and wonders of the universe no one on Earth had ever been able to see before.[42]

This colorful image taken by the Hubble Space Telescope shows one of the most complex planetary nebulae ever seen. Planetary Nebulae are actually not planets at all, but gas clouds formed by dying "red giant" stars. This particular one, called the "Cat's Eye" Nebula, is about 1,000 years old and was formed by a star that was once about the size of our own Sun. (NASA Photo PRC95-01a).

Earth Science

The field of space-based Earth science, which in a sense had begun with the first TIROS launch in 1960, also continued to evolve in the post-Apollo era. The first of a second generation of weather satellites was launched in 1970 and, in 1972, the first Earth Resources Technology Satellite (ERTS) was put into orbit. By looking at the the reflected radiation of the Earth's land masses with high resolution in different wavelengths, the ERTS instruments could provide information about the composition, use and health of the land and vegetation in different areas. The ERTS satellite became the basis of the Landsat satellites that still provide remote images of Earth today.

Other satellites developed in the 1970s began to look more closely at the Earth's atmosphere and oceans, as well. The Nimbus-7 satellite, for example, carried new instruments that, among other things, could measure the levels of ozone in the...

[36]

Artist's concept of a Landsat satellite. Using remote sensing technology, the Landsat spacecraft furnish data on a variety of Earth resources and environmental conditions. (NASA photo G-75-070259).

....atmosphere and phytoplankton in the ocean. As instruments and satellites that could explore the Earth's resources and processes evolved, however, Earth scientists found themselves caught in the middle of an often politically charged tug-of-war between science and application.

Launching satellites to look at phenomena or gather astronomical or physics data in space typically has been viewed as a strictly scientific endeavor whose value lies in the more esoteric goal of expanding knowledge. Satellites that have looked back on Earth, however, have always been more closely linked with practical applications of their data - a fact that has both advantages and disadvantages for the scientists involved.

When Goddard began, all of the scientific satellites were organized under the "Space Sciences and Applications" directorate. Although the Center was working on developing weather and communications satellites, the technology and high resolution instruments needed for more specific resource management tasks did not yet exist. In addition, it was the height of the space race and science and space exploration for its own sake had a [37] broad base of support in Congress and in society at large.

In the post-Apollo era, however, NASA found itself needing to justify its expenditures, which led to a greater emphasis on proving the practical benefits of space. At NASA headquarters a separate "applications" office was created to focus on satellite projects that had, or could have, commercial applications. In an effort to focus efforts on more "applications" research (communications, meteorology, oceanography and remote imaging of land masses) as well as scientific studies, Goddard's senior management decided to split out "applications" functions into a new directorate at the Center, as well.

In many ways, the distinction between science and application is a fine one. Often, the data collected is the same - the difference lies only in how it is analyzed or used. A satellite that maps snow cover over time, for example, can be used to better understand whether snow cover is changing as a result of global climate system changes. But that same information is also extremely useful in predicting snow melt runoff, which is closely linked with water resource management. A satellite that looks at the upper atmosphere will collect data that can help scientists understand the dynamics of chemical processes in that region. That same information, however, can also be used to determine how much damage pollutants are causing or whether we are, in fact, depleting our ozone layer.

For this reason, Earth scientists can be more affected by shifting national priorities than their space science counterparts.[43] The problem is the inseparable policy implications of information pertaining to our own planet. If we discover that the atmosphere of Mars is changing, nobody feels any great need to do anything about it. If we discover that pollutants in the air are destroying our own atmosphere, however, it creates a great deal of pressure to do something to remedy the situation.

Scientists can argue that information is neutral - that it can show less damage than environmentalists claim as well as more severe dangers than we anticipated. But the fact remains that, either way, the data from Earth science research can have political implications that impact the support those efforts receive. The applicability of data on the ozone layer, atmospheric pollution and environmental damage may have prompted additional funding support at times when environmental issues were a priority. But the political and social implications of this data also may have made Earth science programs more...

A Landsat image of Baltimore/Washington area.

[38] ...susceptible to attack and funding cuts when less sympathetic forces were in power.[44]

Yet despite whatever policy issues complicate Earth science research, advances in technology throughout the 1970s certainly made it possible to learn more about the Earth and get a better perspective on the interactions between ocean, land mass and atmospheric processes than we ever had before.

The Space Shuttle Era

As NASA moved into the 1980s, the focus that drove many of the agency's other efforts was the introduction of the Space Shuttle. In addition to the sheer dollars and manpower it took to develop the new spacecraft, the Shuttle created...

An artist's concept of the Tracking & Data Relay Satellite System spacecraft. Three satellites in this space-based system could do the same work as the worldwide tracking and data ground stations Goddard used until the late 1980s.

....new support issues and had a significant impact on how scientific satellites were designed and built.

In the Apollo era, the spacecraft travelled away from the Earth, so a ground network of tracking stations could keep the astronauts in sight and in touch with mission controllers at almost all times. The Shuttle, however, was designed to stay in near-Earth orbit. This meant that the craft would be in range of any given ground station for only a short period of time. This was the case with most scientific satellites, but real-time communication was not as critical when there were no human lives at stake. Satellites simply used tape recorders to record their data and transmitted it down in batches when they passed over various ground stations. Shuttle astronauts, on the other hand, needed to be in continual communication with mission control.

Goddard had gained a lot of experience in communication satellites in the early days of the Center and had done some research with geosynchronous communication satellite technology in the 1970s that offered a possible solution to the problem. A network of three geosynchronous satellites, parked in high orbits 22,300 miles above the Earth, could keep any lower Earth-orbiting satellite - including the Space Shuttle - in sight at all times. In addition to its benefits to the Shuttle program, the system could save NASA money over time by eliminating the need for the worldwide network of ground stations that tracked scientific satellites. The biggest problem with such a system was its development costs.

[39] NASA budgets were tight in the late 1970s and did not have room for a big budget item like the proposed Tracking and Data Relay Satellite System (TDRSS). So the agency worked out an arrangement to lease time on the satellites from a contractor who agreed to build the spacecraft at its own cost. Unfortunately, the agreement offered NASA little control or leverage with the contractor, and the project ran into massive cost and schedule overruns. It was a learning experience for NASA, and not one managers recall fondly.

Finally, Goddard renegotiated the contract and took control of the TDRSS project. The first TDRSS satellite was finally launched from the Space Shuttle in April 1983. The second TDRSS was lost with the Shuttle "Challenger" in 1986, but the system finally became operational in 1989.

The TDRSS project also required the building of a new ground station to communicate with the satellites and process their data. The location best suited for maximum coverage of the satellites was at the White Sands Missile Range in New Mexico. So in 1978, Goddard began building the TDRSS White Sands Ground Terminal (WSGT). The first station became operational in 1983, and a complete back-up facility, called the Second TDRSS Ground Terminal (STGT), became operational in 1994. The second station was built because the White Sands complex is the sole ground link for the TDRSS, and the possibility of a losing contact with the Shuttle was unacceptable. The second site insures that there will always be a....

An aerial view of the White Sands Ground Terminal Tracking Station on the White Sands Missile Range in New Mexico. All the TDRSS data pass through this station before being networked throughout NASA. (NASA Photo 0691-1542).

....working communications and data link for the TDRSS satellites.[45]

The edict that TDRSS would also become the system for all scientific satellite tracking and data transmission did not please everyone, because it meant every satellite had to be designed with the somewhat cumbersome TDRSS antennas. But the Shuttle's impact on space science missions went far beyond tracking systems or antenna design.

Part of the justification of the Shuttle was that it could replace the expendable launch vehicles (rockets) used by NASA and the military to get satellites into orbit. As a result, the stockpile of smaller launch rockets was not replenished, and satellites had to be designed to fit in the Shuttle bay instead.

There were some distinct advantages to using the Space Shuttle as a satellite launch vehicle. Limitations on size and weight - critical factors with the smaller [40] launch vehicles - became much less stringent, opening the door for much bigger satellites. Goddard's Compton Gamma Ray Observatory, for example, weighed more than 17 tons. The Space Shuttle also opened up the possibility of having astronauts service satellites in space.[46]

On the other hand, using the Shuttle as the sole launch vehicle complicated the design of satellites, because they now had to undergo significantly more stringent safety checks to make sure their systems posed no threat to the astronauts who would travel into space with the cargo. But the biggest disadvantage of relying exclusively on the Shuttle hit home with savage impact in January 1986 when the Shuttle "Challenger" exploded right after lift-off. The Shuttle fleet was grounded for almost three years and, because the Shuttle was supposed to eliminate the need for them, there were few remaining expendable launch rockets. Even if there had been a large number of rockets available, few of the satellites that had been designed for the spacious...

A Black Brandt XII sounding rocket being launched Wallops Island. Wallops launches approximately 35 sounding rockets to conduct scientific research each year. (NASA Photo WI-88-589-4)

....cargo bay of the Shuttle would fit the smaller weight and size limitations of other launch vehicles. Most satellites simply had to wait for the Shuttle fleet to start flying again.

Wallops Island

The 1980s brought some administrative changes to Goddard, as well. NASA's Wallops Island, Virginia flight facility had been created as an "Auxiliary Flight Research Station" associated with the NACA's Langley Aeronautical Laboratory in 1945.[47] Its remote location on the Atlantic coast of Virginia made it a perfect site for testing aircraft models and launching small rockets. As the space program evolved, Wallops became one of the mainstays of NASA's sounding rocket program and operated numerous aircraft for scientific research purposes, as well. It also launched some of the National Science Foundation's smaller research balloons and provided tracking and other launch support services for NASA and the Department of Defense.

Yet although its work expanded over the years, Wallops' small size, lower-budget projects, and remote location allowed it to retain the pragmatic, informal, entrepreneurial style that had characterized Goddard and much of NASA itself in the early days of the space program. People who worked at Wallops typically came from the local area, and there was a sense of family, loyalty, and fierce independence that characterized the facility. As one of NASA smaller research stations, however, Wallops was in a less protected political position than some of its larger and higher profile counterparts.

[41]

Launch row at the Wallops Island Flight Facility on the eastern shore of Virginia. Wallops became a part of the Goddard Space Flight Center in 1982.

In the early 1980s, a proposal emerged to close the Wallops Station as a way of reducing NASA's operating costs. In an effort to save the facility, NASA managers decided instead to incorporate Wallops into the Goddard Space Flight Center. Goddard was a logical choice because Wallops was already closely linked with Goddard on many of its projects. The aircraft at Wallops were sometimes used to help develop instruments that later went on Goddard satellites. Goddard also had a sounding rocket division that relied on Wallops for launch, range, tracking and data support. As time went on, Wallops had begun to develop some of the smaller, simpler sounding rocket payloads, as well. By the late 1970s, NASA headquarters was even considering transferring Goddard's entire sounding rocket program to Wallops.

In 1982, Wallops Island Station became the Wallops Island Flight Facility, managed under the "Suborbital Projects and Operations" directorate at Goddard.[48] At the same time, the remaining sounding rocket projects at Goddard-Greenbelt were transferred down to Wallops. The personnel at Goddard who had been working on sounding rockets had to refocus their talents. So they turned their entrepreneurial efforts to the next generation of small-budget, hands-on projects - special payloads for the Space Shuttle.[49] As the 1980s progressed, Goddard began putting together a variety of small payloads to take up spare room in the Shuttle cargo bay. They ranged from $10,000 "Get Away Special" (GAS) experiments that even schoolchildren could develop to multi-million dollar Spartan satellites that the Shuttle astronauts release overboard at the start of a mission and pick up again before returning to Earth.

[42] The Post-Challenger Era: A New Dawn

All of NASA was rocked on the morning of 28 January 1986 when the Shuttle "Challenger" exploded 73 seconds after launch. While many insiders at NASA were dismayed at what appeared to have been a preventable tragedy, they were not, as a whole, surprised that the Shuttle had had an accident. These were people who had witnessed numerous rockets with cherished experiments explode or fail during the launch process.

The Extreme Ultraviolet Explorer satellite, was launched on June 7, 1992 on top of a Delta launch rocket. The Delta rocket program managed by Goddard remains one of the most successful launch vehicle programs in NASA history. (NASA photo PL92C-110006).

They had lived through the the Orbiting Solar Observatory accident, the Apollo 1 fire, and the Apollo 13 crisis. They knew how volatile rocket technology was and how much of a research effort the Shuttle was, regardless of how much it was touted as a routine transportation system for space. These were veteran explorers who knew that for all the excitement and wonder space offered, it was a dangerous and unforgiving realm. Even twenty-five years after first reaching orbit, we were still beginners, getting into space by virtue of brute force. There was nothing routine about it.

It was an understanding of just how risky the Shuttle technology was that drove a number of people within NASA to argue against eliminating the other, expendable launch vehicles. The Air Force was also concerned about relying on the Shuttle for all its launch needs. The Shuttle accident, however, settled the case. A new policy supporting a "mixed fleet" of launch vehicles was created, and expendable launch vehicles went back into production.[50]

Unfortunately, a dearth of launch vehicles was not the only impact the Challenger accident had on NASA or Goddard. The tragedy shattered NASA's public image, leading to intense public scrutiny of its operations and a general loss of confidence in its ability to conduct missions safely and successfully. Some within NASA wondered if the agency would even survive. To make things worse, the Challenger accident was followed four months later with the loss of a Delta rocket carrying a new weather satellite into orbit, and the loss a year later by an Atlas-Centaur rocket carrying a Department of Defense [43] satellite. While these were not NASA projects, the agency received the criticism and the consequential public image of a Federal entity that could not execute its tasks.

Launches all but came to a halt for almost two years, and even the scientific satellite projects found themselves burdened with more safety checks and oversight processes. The Shuttle resumed launches in 1989, but NASA took another hit in 1990 when it launched the much-touted Hubble Space Telescope, only to discover that the telescope had a serious flaw in its main mirror. As the last decade of the century began, NASA needed some big successes to regain the nation's confidence in the agency's competence and value. Goddard would help provide those victories.

Spacecraft Technology

One of Goddard's biggest strengths was always its expertise in spacecraft construction. Most of the incredibly successful Explorer class of satellites, for example, were built in-house at Goddard.But the size and complexity of space science projects at Goddard - and even the Center's Explorer satellites - had grown dramatically over the years. From the early Explorer spacecraft, which could be designed, built and launched in one to three years, development and launch cycles had grown until they stretched 10 years or more. Aside from the cost of these large projects, they entailed much more risk for the scientists involved. If a satellite took 15 years from inception to launch, its scientists had to devote a major portion of their careers to the...

The Submillimeter Wave Astronomy Satellite, launched December 1, 1998, detects water vapor throughout the Milky Way.

Hitchhiker payloads, developped at Goddard, offer researchers a low-cost opportunity to put small experiment in the Space Shuttle cargo bay.

....project. If it failed, the cost to their careers would be enormous.

In part, the growth in size and complexity of satellites was one born of necessity. To get sharp images of distant stars, the Hubble Space Telescope had to be big enough to collect large amounts of light. In the more cost-conscious era following Apollo, where new satellite starts began to dwindle every year, the pressure also increased to put as many things as possible on every new satellite that was approved.

But in 1989, Tom Huber, Goddard's director of engineering, began advocating for Goddard to begin building a new line of smaller satellites. In a sense, these "Small Explorers," or SMEX satellites, would be a return to Goddard's roots in innovative, small and quickly produced spacecraft. But because technology had progressed, they could incorporate options such as fiber optic technology, standard interfaces, solid state recorders, more advanced computers that fit more power and memory into less [44] space, and miniature gyros and star trackers. Some of these innovations, such as the solid state recorders and advanced microchip technology for space applications, had even been developed in-house at Goddard. As a result, these small satellites could be even more capable than some of the larger projects Goddard had built in the past. The goal of the SMEX satellites was to cost less than $30 million and take less than three years to develop. The program has proved highly successful, launching five satellites since 1992, and is continuing to develop advanced technology to enable the design of even more capable, inexpensive spacecraft.[51]

Space Science

In late 1989, Goddard launched the Cosmic Background Explorer (COBE) satellite aboard a Delta launch rocket. Originally scheduled for launch aboard the Space Shuttle, the COBE satellite, which was built in-house at Goddard, had been totally redesigned in less than 36 months after the Challenger accident to fit the nose cone of a Delta rocket. Using...

A sky map taknby the Differential Microwave Radiometer instrument on Goddard's Cosmic Background Explorer satellite. The map shows indications of anisotropy, or temperature fluctuations, in the background radiation of the universe. These irregulatities reveal the original structures of the universe.

....complex instruments, COBE went in search of evidence to test the "Big Bang" theory of how the universe began - and found it. Famed cosmologist Stephen Hawking called the NASA-University COBE team's discovery "the discovery of the century, if not of all time."[52] The COBE satellite had perhaps solved one of the most fascinating mysteries in existence - the origins of the universe in which we live. It had taken 15 years to develop, but the COBE satellite offered the public proof that NASA could take on a difficult mission, complete it successfully, and produce something of value in the process.

Goddard reached out into another difficult region of the universe when it launched the Compton Gamma Ray Observatory in 1990. The Compton was the second of NASA's planned "Four Great Observatories" that would explore the universe in various regions of the electromagnetic spectrum. The Hubble Space Telescope was to cover the visible and ultraviolet regions, the Compton was to explore the gamma ray region, and two additional observatories were to investigate phenomena in X-ray and infrared wavelengths. At over 17 tons, the Compton was the largest satellite ever launched into orbit, and its task was to explore some of the highest energy and perplexing phenomena in the cosmos.

Three years later, Goddard found itself taking on an even more difficult challenge when the Center undertook the first Hubble servicing mission - better known as the Hubble repair mission. The odds of successfully developing and implementing a fix for the [45] telescope, which had a flaw not in one instrument but in its central mirror, were estimated at no better than 50%. But because of Goddard's earlier successful pioneering efforts with servicable satellites, the Hubble had been designed to be serviced in space. This capability, and Goddard's previous experience repairing the Solar Max satellite, provided the critical components that made the Hubble repair possible. Fired with the same enthusiasm and sense of crisis that had fueled the Apollo program, the Goddard team assigned to manage the project, working with a hand-picked Shuttle crew from Houston's Johnson Space Center, succeeded beyond expectation. The success of such a difficult mission earned the team a Collier Trophy - the nation's highest award for the greatest aeronautical achievement in any given year.[53]

Earth Science

Even as Goddard launched the Compton Observatory and the Hubble Space Telescope to explore new regions of the universe, NASA announced the start of a massive new initiative to explore the planet we call home. Dubbed "Mission to Planet Earth" when it was introduced in 1990, the effort was expected to spend thirty billion dollars over at least 15 years in order to take a long-term, systems-oriented look at the health of the planet.. In some ways, the program was a natural outgrowth of increasing environmental concerns over the years and the improved ability of satellites to analyze the atmosphere and oceans of our planet. But it received a big boost...

An image of the ozone "hole" over Antarctica. Areas shown in and Blue/purple indicates areas of low ozone, while the red areas inidcate higher levels.

...when a hole in the ozone layer was discovered in 1985. That discovery, as one researcher put it, "dramatized that the planet was at risk, and the potential relevance of NASA satellite technology to understanding that risk." In the wake of the Challenger disaster, Mission to Planet Earth was also seen as one of the top "leadership initiatives" that could help NASA recover from the tragedy and regain the support of the American public.[54]

Although numerous NASA centers would participate in the MTPE effort, the program office was located at Goddard. It was a natural choice, because Goddard was the main Earth Science center in the agency anyway. Earth Science was broken out of the Space and Earth Sciences directorate and its research began to take on a new sense of relevance in the public eye.

As with earlier Earth science efforts, however, the political and social implications of this data also have made the program more susceptible to shifting national priorities than its space science counterparts. In the past eight years, the program has been scaled back repeatedly. Its budget is now down to seven billion dollars and the [46] name of the program has been changed to Earth Science Enterprise.[55]

There are numerous reasons for the cutback of the program. But it can be argued that we find money for the items that are high national priorities. And one factor in the changing fortunes of the Mission to Planet Earth program is undeniably the shifting agendas that affect NASA funding. Nevertheless, the more moderate Earth Science Enterprise program will still give scientists their first real opportunity to study the planet's various oceanographic and atmospheric processes as an integrated system instead of individual components - a critical step toward understanding exactly how our planet operates and how our actions impact its health.

In short, Goddard's work in the early 1990s helped bring NASA out of the dark post-Challenger era and helped create in a new energy, enthusiasm and curiosity about both planet Earth and other bodies in the universe. We now had the technology to reach back to the very beginning of time and the outer reaches of the universe. The Hubble...

This image combines satellite data from several satellite sources, to show an anomaly in sea height and sea surface temperature in the year preceding the last strong El Niño climate condition.

....servicing mission made possible the beautiful images of far-away galaxies, stars, nebulae and planets that now flow into publications on a regular basis. These images have not only provided valuable clues to scientific questions about the cosmos, they have also fired the imaginations of both children and adults, generating a new enthusiasm for space exploration and finding out more about the galaxy and universe we call home.

At the same time, we had the technology to begin to piece together answers about where El Nino weather patterns came from, how our oceans and atmosphere work together to create and control our climate, and how endangered our environment really is. These advances provided critical support for NASA at a time when many things about the agency, and the Goddard Space Flight Center, were changing.

Better, Faster, Cheaper

As we head into the twenty-first century, the world is changing at a rapid pace. The electronic superhighways of computers and communications are making the world a smaller place, but the marketplace a more global one. Concerns about the United States' competitiveness are growing as international competition increases. The crisis-driven days of the space race are also over, and cost now is a serious concern when Congress looks at whether or not additional space projects should be funded.

This need to be more cost-efficient is driving changes both within Goddard itself and in its relationships with outside industry. Goddard recently underwent a major [47] administrative reorganization in the hopes of making better use of its engineers' time. Instead of being scattered around the Center, its almost 2,000 engineers are being organized almost entirely into either a new Applied Engineering and Technology (AET) directorate or a new Systems, Technology, and Advanced Concepts (STAAC) Directorate. In essence, AET will provide the hands-on engineering support for whatever projects are underway at the Center, and STAAC will work on advanced concepts and systems engineering for future projects.

Again, this change in matrix structure within Goddard is not a new concept. The Center has gone back and forth a couple of times between putting engineers with scientists on project teams and trying to follow a stricter discipline-oriented organization. The advantages of a project-based organization are that the engineers get to really focus on one job at a time and build synergistic relationships with the scientists with whom they are working. These relationships often lead to innovative ideas or concepts that the individual engineers or scientists might not have come to on their own. The disadvantage of this structure, which is a greater concern in times of tighter budgets, is that even if those engineers have excess time during lulls in the project, it can't easily be taken advantage of by anyone else in the Center. Their talent is tied up in one place, which can also lead to territorial "fiefdoms" instead of a more ideal Center-wide cooperation.[56]

At the present time, the changes are administrative only. The engineers are still being co-located with their scientist colleagues. How or if that changes in the future remains to be seen, as does the success of the reorganization in general. After all, the impact of any administrative change is determined more...

An image of a planetary nebula, produced by a dying star, taken from The Hubble Space Telescope. (NASA Photo PRC96-07).

....by how it is implemented than how it looks on paper, and the success of that can only be determined once the change has been made.[57]

Another issue facing Goddard is the recurring question of who should be building the spacecraft. One of the strengths of Goddard has always been its in-house ability to design and build both spacecraft and instruments. The Center's founders created this in-house capability for two reasons. First, there was little in the way of a commercial spacecraft industry at the time Goddard was started. Second, although most of the satellites actually would be built by contractors, the founders of NASA believed that the agency had to have hands-on knowledge of building spacecraft in order to manage those contracts effectively.

[48]

The Tropical Rainfall Measuring Mission (TRMM) satellite, shown here in one of Goddard's clean rooms. is part of NASA's Earth Science Enterprise effort to study Earth's climate as an integrated global system.

Over the years, the commercial spacecraft industry has grown and matured tremendously, leading to periodic discussions as to whether NASA should leave the spacecraft building jobs entirely to the private sector. After all, there is general agreement that the government, in the form of NASA, should not do what industry is capable of doing. In truth, however, the issue isn't quite that simple.

In the late 1970s, Goddard's senior management all but stopped in-house satellite building at the Center, focusing the engineers' efforts on instrument building, instead. The rationale was that industry was capable of building satellites and NASA should be working on developing advanced technology sensors and instruments. Yet even aside from the argument that keeping in-house competence was necessary to effectively manage contracts with industry, there were flaws to this rationale.

For one thing, building satellites in-house had a significant indirect effect on the employees at Goddard. The ability to help design spacecraft helped attract bright young engineers to the Center, which is always an important concern in a field where industry jobs generally pay better than NASA positions. Furthermore, knowing that some of the spacecraft sitting on top of launch vehicles had been built in-house gave Goddard employees a sense of pride and involvement in the space program that instrument building alone could not create. Taking away that element caused a huge drop in the Center's morale. Indeed, when Tom Young became the Center's director in 1980, one of his first moves was to restore the building of in-house satellites in the hopes of rebuilding morale.[58]

The commercial space industry has matured even further in the past 20 years, and the question about whether Goddard still should be building in-house satellites has been raised again in recent years. In the end, the answer is probably "Yes". The question lies more in the type and number of satellite projects the Center should undertake. The goal is for Goddard to pursue one or two in-house projects that involve advanced [49] spacecraft technology and to contract out projects that involve more proven spacecraft concepts. At the same time, Goddard is taking advantage of the expertise now present in the commercial satellite industry by introducing a new "Rapid Spacecraft Procurement Initiative," with the goal of reducing the development time and cost of new spacecraft. By "pre-qualifying" certain standard spacecraft designs from various commercial satellite contractors, Goddard hopes to make it possible for some experiments to be integrated into a spacecraft and launched within as short a time frame as a year. Not every experiment can be fit into a standard spacecraft design, but there are certainly some which could benefit from this quick-turnaround system.The contracts developed by Goddard for this initiative are now being used by not only other NASA Centers, but by the Air Force, as well.[59]

A more complex issue is how involved NASA should be in even managing the spacecraft built by industry. Historically, Goddard has employed a very thorough and detailed oversight policy with the contracts it manages. One of the reasons the Center developed this careful, conservative policy was to avoid failure in the high-profile, high-dollar realm of NASA. As a result, the concern of NASA engineers tends to be to make sure the job is done right, regardless of the cost. While industry engineers have the same interest in excellence and success, they sometimes have greater pressure to watch the bottom line. Goddard managers quote numerous examples of times contractors only agreed to conduct additional pre-launch tests after Goddard engineers managing the contract insisted on it. They also recall various instances where Goddard finally sent its own engineers to a contractor's factory to personally supervise projects that were in trouble.

Industry, on the other hand, can argue that Goddard's way of building satellites is not necessarily the only right way and this double-oversight slows down innovation and greatly increases the cost of building satellites. And in an era of decreasing federal budgets, deciding how much oversight is good or enough becomes an especially sticky issue. Currently, the trend seems to be toward a more hands-off, performance-based contract relationship with industry. Industry simply delivers a successful satellite or doesn't get paid. Some argue that a potential disadvantage to this approach is that it could rob industry engineers of the advice and experience Goddard might be...

COBE under construction at the Goddard Space Flight Center. Originally designed to be launched aboard the Space Shuttle, the satellite had to be redesigned to fit on a Delta rocket after the Space Shuttle Challenger accident in 1986. (NASA Photo GSFC PAO#4).

[50] ....able to offer. Goddard's scientists and engineers have a tremendous corporate memory and have learned many lessons the hard way. So sharing that expertise might prove more cost-effective in the long run than the bottom line salary and labor allocation figures of a more hands-off system might suggest.

In the end, there is truth in what all parties say. It's hard to say what the "right" answer is because, for all our progress in the world of space, we are still feeling our way and learning from our mistakes as we keep reaching out to try new things.

The exact nature and scope of NASA's mission has been the subject of frequent debate since the end of the Apollo program. But NASA certainly has an edict to do those things that for reasons of cost, risk, or lack of commercial market value, industry can or will not undertake. In the early 1960s, the unknowns and risk of...

An image from the SeaWiFS shows varying chlorophyll levels along the eatern seaboard of the United States.

....failure were far too high and the potential profit far too uncertain for industry to fund the development of anything but communication satellites. Today, that situation is changing. In some cases, a commercial market for the data is developing. In others, the operations once considered too risky for anyone but NASA to perform are now considered routine enough to contract out to private companies, which are also much more capable than they once were.

Some tracking and data functions that were a part of the Goddard Space Flight Center since its inception, for example, were recently moved down to the Marshall Space Flight Center, where they will be managed by a private company under contract to a supervising Space Operations Management Office at the Johnson Space Center.[60]

NASA is also starting to relinquish its hold on the launching of rockets itself. In years past, all launches were conducted at government facilities for reasons of both safety and international politics. But that is beginning to change. The state of Virginia is already in the process of building a commercial space port at the Wallops Island facility in partnership with private industry. The payloads and launch vehicles using the space port will be developed privately, and the consortium will contract with NASA to provide launch range, radar, telemetry, tracking and safety analysis services.[61]

NASA has also used a privately developed, airplane-launched rocket called the "Pegasus" to send a number of small [51] satellites into space. It should be noted, however, that the Pegasus vehicle went through a series of developmental problems before it became a reliable system. The same is true of the SeaWIFS satellite, which is currently providing very useful data on ocean color but which was developed under a very different type of contract than most scientific satellites. The SeaWIFS spacecraft was developed independently by the Orbital Sciences Corporation and NASA paid only for the data it uses. While the satellite is now generating very good data, it ran into many developmental difficulties and delays that caused both NASA and the contractor a lot of aggravation. On the one hand, because NASA paid the majority of the money up front, there was less incentive for the contractor to keep on schedule. On the other hand, the up-front, fixed-price lease meant that the contractor absorbed the costs of the problems and delays when they occurred.[62]

Fixed-price contracts work well in many arenas. The complication with scientific satellites is that these spacecraft are not generally proven designs. It's difficult to foresee ahead of time what problems are going to arise in a research project that's breaking new ground.

Indeed, there are a lot of uncertainties amidst the tremendous atmosphere of change facing Goddard, NASA and the world at large, and it remains to be seen how they will all work out. Most likely, it will take a number of missteps and failures before the right mix and/or approach is found. The process will also undoubtedly entail the same pendulum swings between different approaches that has characterized Goddard throughout its history. And since external circumstances and goals are constantly changing, there may never be one "correct" mix or answer found.

In the end, our efforts in space are still an exploration into the unknown. On the cutting edge of technology and knowledge, change is the only constant - in theories of the universe as well as technology, priorities, and operating techniques. Once upon a time, Goddard's biggest challenge was overcoming the technical obstacles to operating in space. Today, Goddard's challenge is to find the flexibility to keep up with a rapidly changing world without losing the magic that has made the Center so successful over the past forty years.

The new frontier for Goddard is now much broader than just space itself. The Center has to be open to reinventing itself, infusing new methods and a renewed sense of entrepreneurial innovation and teamwork into its operations while continuing to push boundaries in technology development, space and Earth exploration for the benefit of the human race. It has to be flexible enough to work as part of broader NASA, university and industry and international teams in a more global and cost-constrained space industry and world. It has to find a way to reach forward into new areas of research, commercial operations, and more efficient procedures without losing the balance between cost and results, science and engineering, basic research and applications, inside and outside efforts. And, most importantly, Goddard has to accomplish all of these things while preserving the most valuable strength it has - the people that make it all possible.

Chapter 3:
The Tools

[52]

A Delta rocket lifts off carrying Goddard's 8th Orbiting Solar Observatory satellite.

[53] In its first forty years, Goddard successfully launched more than 200 Earth-orbiting satellites. That is an amazing success record, and yet the very fact of that success makes it easy to take the magnitude of that accomplishment for granted. Because the Center's satellites were so successful, few people really give much thought to how difficult it is to build, launch, stabilize, power, and operate a satellite or.collect and transmit its data back down to Earth.

Yet the truth is that conducting research in the harsh and remote realm of space is a staggeringly difficult task, and every successful NASA mission is the result of the sweat and ingenuity of thousands of engineers, scientists, and support personnel who designed and built the tools to make it possible. Even today, the job [54] is a demanding one as we stretch to design more capable satellites and take on more challenging missions. But in the early days of the space program it was a truly Herculean task. Little was known about not only rocket and spacecraft technology, but also the environment in which these tools would have to operate. The early engineers and scientists in the early space program didn't know what materials would work best, how they needed to be assembled to do the job, or what obstacles the tools would have to overcome. In addition, scientific satellites had one other liability. Until the advent of the...

One of Goddard's Interplanetary Monitoring Platform satellite departs the launch pad in 1971.

...Space Shuttle and modular, servicable spacecraft, satellites could not be fixed by astronauts in space. All the potential problems of a mission had to be anticipated and fixes built in ahead of time. Once something was in space, it was difficult to change.

The Challenge of Space Flight

Scientific satellites, from the earliest Explorers to the most complex modern observatories, have two critical aspects to their design. First, there are the scientific instruments that collect the actual data from space.Second, there are the "housekeeping" systems that operate the spacecraft and get that data back to Earth. The housekeeping systems have to provide power, temperature modulation, and control of the spacecraft, and allow for data reception and transmission. This sounds pretty straightforward, but providing these services in a lightweight package in space is an extremely difficult task.

Satellites are complicated vehicles to launch and control. The launch vehicles themselves have to be programmed to follow intricate computer-calculated trajectories that will place a satellite in a very precise and specific orbit. Some satellites are launched so that they will orbit north to south, over the poles of the Earth, while others follow a more equatorial orbit. Still others are launched into a geosynchronous orbit, which means that the spacecraft will stay "parked" over one spot on the Earth. In order to follow a geosynchronous orbit, [55] however, a satellite has to be much further away from Earth. While the Space Shuttle and many Earth-orbiting satellites are positioned about 200 miles above the Earth, a geosynchronous satellite orbits almost 23,000 miles away.

Whether orbits are close or far, however, they have to be achieved with extreme precision. A polar-orbiting satellite, for example, might be designed to have an orbit with "an inclination of 101.56 degrees and a period of 115 minutes." An Interplanetary Monitoring Platform (IMP) satellite launched in 1964 failed because the final stage of its launch vehicle burned for one second shorter than it should have. That one second loss resulted in an orbit only 50,000 miles high instead of the planned 160,000 miles.[1]

To reach and maintain orbits with this kind of accuracy is not easy. NASA launches its rockets on a coast so that failed or discarded rocket stages will fall harmlessly into the ocean. But the reason most of NASA's launches take place from Cape Kennedy on the east coast is that the Earth rotates to the east, helping the satellites gain orbital speed. Polar-orbiting satellites are an exception to this rule. They typically are launched from NASA's Western Test Range at the Vandenberg Air Force Base in California because they can climb into a polar orbit over water if they launch from the west coast.

In either case, when the launch vehicle reaches the correct point and altitude for the orbit the researchers want, another rocket must fire correctly to kick the spacecraft into its orbital path. Most satellites also have an additional propulsion system on board in case their orbit needs to be adjusted or changed. And even in a stable orbit, many satellites use small intermittent chemical rockets, high-pressure gas jets, or electric currents to maintain a particular attitude and orientation.

Technicians mounting a satellite package onto a Delta launch vehicle.

Although some of the very earliest satellites simply spun around as they made their orbit, researchers soon began looking at ways they could stabilize satellites. Spin-stabilization was critical for providing good pictures of the Earth, for example, as well as for astronomical research, where the satellite needed to keep looking at one particular object for a length of time. One step further in complexity was to not only stop the spacecraft from spinning, but also to keep one particular side of it facing the Earth throughout its orbit. In many cases, scientists had to know where the satellite was pointing in order to [56] evaluate the significance of what it was seeing or the data it was receiving.

Over the years, satellites have been designed with various gyros, de-spin devices and pointing mechanisms to accomplish these ends. One device to stop a satellite from spinning, for example, was called a "yo-yo," because it employed the same technique as the children's toy. String-like devices would deploy in the opposite direction to the way the satellite was spinning, slowing it down. To keep a satellite pointed in one direction, engineers often employ Earth-tracking or star tracking systems. Star trackers fix on particular stars and send commands to the control units to adjust the spacecraft if the position of those stars drifts relative to the satellite. Earth tracking systems work the same way, except they use the curve of the Earth instead of stars as their reference point.[2]

Of course, each of these systems had to be developed, and none worked perfectly the first time. Indeed, even today the...

Goddard's facilities include data and tracking control centers for its many scientific satellites. It also serves as the hub of NASA's internal communication, NASCOM, network.

....stabilizing mechanisms in satellites can fail, causing them to "tumble" and go out of commission. A recent such failure with a commercial communication satellite, for example, caused 90% of the hip-pocket "pagers" in the United States to stop working for more than 24 hours. While the satellite was not a NASA spacecraft, the incident underscores the challenges engineers still face in stabilizing and operating satellites in space.[3]

A satellite's instruments have to be controlled, as well. The individual instruments must be able to "talk" to each other and to the data and communication functions of the spacecraft. In some cases, individual instruments have to be turned on and off at various times. Other instruments have to be kept from ever pointing directly at the Sun. Instruments also have to be calibrated for accuracy and that information has to be linked with the actual data collected when it is sent back to the ground.

All of these operations have to be remotely controlled from Earth, which means the satellite has to be able to receive commands from ground stations. By the same token, the satellite has to have a way of recording the data it's collecting, putting it in a format and frequency that can be transmitted, and sending it back to stations on Earth. Because few of these transmitters or sensors existed on the market, the Goddard and industry engineers working on early satellites often had to develop the technology themselves. Goddard's achievements in the development of microchip technology for space applications, [57] for example, stemmed from its need to make spacecraft components as lightweight as possible.

To run all these systems, a satellite needs a way of generating power for the months to years it's in orbit. Most spacecraft rely on solar cells to recharge on-board batteries. But solar panels have their own complications, ranging from deployment of the arrays and the need to keep the collecting side of the panels pointed at the Sun to the basic problem of packing large panels into a tiny space aboard the satellite until it reaches orbit. The cost of making the panels flexible and lightweight is that they also tend to be somewhat fragile, and several satellites have had to cope with damaged solar panels once in orbit.

In addition, all of the satellite's systems have to work in the extremely harsh environment of space, where temperatures away from the Sun are nearly absolute zero, and temperatures facing the Sun climb as high as 1200 degrees Kelvin. Thermal dynamics, therefore, is a critical issue in both spacecraft and instrument design. On one of the early Orbiting Geophysical Observatories (OGOs), for example, the spacecraft's attempts to compensate for the extreme temperature differences between the front and back sides of long booms extending from the main spacecraft caused serious problems with the control system. Engineers finally figured out that they needed to drill holes in the booms to allow some solar heat to reach the back side in order for the system to work.[4]

Since solar panels have to be packaged into small areas until a satellite gets into space, they can be a particularly troublesome part of the satellite. Here astronaut Kathy Thornton releases a damaged solar panel that was replaced during the first Hubble Space Telescope Servicing Mission in 1993.

Spacecraft also have to operate in a zero-gravity vacuum, which creates its own set of difficulties. For one thing, a vacuum creates problems with dissipating heat, because the heat can't be carried away by passing air. In addition, some parts of a satellite are soldered together. It's not uncommon to get some small remnants of soldering material that break off as a soldered object is moved around. In a television set, that is not a big deal. But in a....

[58]

Even small specks of dirt can cause satellites to malfunction in the vacuum of space. So components are assembled in "clean rooms" like this one at the Goddard Space Flight Center. In the foreground of this image, instruments are being fitted into a white pallet that will then go inside the Space Shuttle's cargo bay.

....zero-gravity environment, those soldering balls can float all around the spacecraft, causing a variety of problems. Even worse, they can cause a problem like a short-circuit and then float away again, so engineers trying to trouble-shoot the system can't even find evidence of what caused the problem.

There are other difficulties, as well. High-voltage instrumentation has to be either turned off or protected during its passage through the electrically-charged ionosphere and for the first few hours of its orbit while the satellite "out-gasses" the trapped molecules from the Earth's atmosphere so the high-voltage terminals don't arc and short-circuit. In astronomical satellites, a single fingerprint on a lens can render the instrument useless. The sensitivity of satellites to even the tiniest specks of dirt or grease is why they are built and tested in special "clean rooms." Goddard has several of these facilities, including one large enough to house several satellites the size of the Hubble Space Telescope.

Another inherent problem in building any aspect of a satellite, especially in the early days, was the tremendous constraint designers faced on power and weight. The key to success was lightweight construction, which meant systems were not as robust as they could be for an Earth-bound machine. Tape recorders tended to be very temperamental because of their many moving parts, and more than one satellite ended up having to transmit its data in real time because its data recorders failed. Power was also limited, even with solar panels and batteries on board, in part because satellites had to be so small and lightweight. But trying to force large amounts of data through the systems on little power created other problems, such as a tremendous amount of heat which then had to be dissipated somehow. Indeed, engineers who worked at Goddard in the 1960s say the challenge of space came down to batteries and tape recorders, and reliability was achieved only through redundancy. Because systems were prone to difficulties or failure, engineers and scientists always tried to include back-up systems in a satellite's design.[5]

All of this is to say that designing and operating a satellite is an extremely difficult task, even when everything works well. So the fact that Goddard has successfully launched and operated over 200 satellites to date is an amazingly impressive feat.

The difficulties involved in building satellites also meant that it has always been a struggle to keep a developmental satellite project within [59] its initial budget. In the early days, a "good" project, according to former director John Townsend, only overran its budget by 30% or so. A "bad" satellite project could overrun as much as 200 - 400%.[6]

In part, these overruns were a product of the conflicting pressures inherent in any space project. Managers have to balance the demands of schedule, budget, and reliability, and all three are difficult to attain. A project can be kept on schedule and budget, but reliability may suffer. If the goal is to make a spacecraft absolutely reliable, it may take additional money or take longer than scheduled to test and complete. And if a project absolutely must launch on a particular date, its cost or risk of failure may go up or reliability may go down. In forty years of space exploration, this triad of opposing pressures - cost, schedule, and risk - has never been completely resolved. Indeed, the acceptance of the fact that it cannot be resolved is a recognition of the nature of the enterprise. Each project simply falls in a slightly different place within the triangle.

Another reason it was difficult to keep scientific satellites within a predetermined budget is that in a research and development field, scientists and engineers cannot predict what obstacles or difficulties they are going to encounter. And with the difficulties inherent in designing instruments and spacecraft, the opportunities for problems were almost unlimited. In addition, the scientists often changed their requirements or developed "better" ways to make an instrument more effective or to get more instruments into a spacecraft.

There was, in fact, a constant but healthy tension between the scientists, who would have put every bell and whistle on a spacecraft to get as much data as possible, and the engineers, who were more interested in making sure the instruments and spacecraft worked correctly. This tension was formalized in Goddard's system of assigning both a project scientist and a project manager to each satellite project. The project scientist was responsible for the science requirements and the data the experiments would gather, and the project manager (usually an engineer) was responsible for making sure the overall system worked, as well as managing the logistics, manpower, budget and schedule for the project.

Even then, there was never quite a consensus on how the logistics and problems of a project should be solved. There were two schools of thought, for example, regarding spacecraft schedules. Dr. Harry Goett, Goddard's first director, was a firm advocate for giving projects as much time as they needed to get the satellite right.

A geodetic laser satellite nestled inside the nose cone of a Delta rocket before its 1976 launch.

[60] "We've waited two thousand years to get this data," he would argue to Headquarters. "We can wait another six months to get it right." On the other hand, some argued that the delays were caused by scientists wanting to constantly upgrade equipment instead of making do with what could be done in the time and money allotted. The end result was that there was always a pull between the constraints of budget and time and the risk of pushing research projects too quickly and having them fail in orbit. Space projects are inherently expensive, and the most expensive factor is the work force attached to it. If a project is delayed six months because of a late component, the project team still has to be kept together, even though their time is not being well spent. Therefore, the cost skyrockets above its budget. Finding a successful balance is tricky, and not every project was able to do it.[7]

A thermal vacuum test chamber a the Goddard Space Flight Center helped researchers test their satellites in simulated space conditions prior to launch.

Indeed, if something goes wrong with a satellite, it's an extremely daunting challenge, because most satellites are unreachable except by remote command. Goddard engineers learned early to incorporate something called a "safe hold mode" into their satellites so that, in the event of a problem, the non-essential systems in the satellite could be "frozen" and its solar panels turned toward the sun to keep power to the spacecraft until the problem could be solved. This technique saved many satellites that otherwise would have lost power before corrective commands could be sent up to the spacecraft.[8]

Not every problem would cause the complete loss of a satellite, but the consequences of any failure or problem were severe, because it was difficult to fix anything in space. As a result, Goddard's managers always put a tremendous emphasis on rigorous testing and evaluation of components and spacecraft before they were launched.

Test and Evaluation

After spending several years on a single project, no scientist or engineer wanted to lose either a key instrument or an entire satellite because of a faulty battery, control system, or connection. As a result, developing thorough test and evaluation facilities and procedures was a high priority from the earliest days of Goddard.

The pressure to get satellites into space, and therefore to develop test facilities, was very intense in the early days of the space race. The first test buildings at Goddard were built in a mere 18 months,.....

[61]

Goddard personnel maneuver carefully inside a dynamic test chamber in the Center's satellite and test evaluation facilities. (NASA photo G64-5909)

....and test engineers began working in the buildings before the structures were even completed. The engineers simply moved in section by section, right behind the construction crews.

The basic idea behind the test facilities at Goddard was to simulate the conditions of launch and space as closely as possible. The satellite and its components would be put in a vibration machine to simulate the rough and tumble conditions of a launch and put in a vacuum chamber to test the operation of its systems and instruments in a space-like environment. Spin-stabilized satellites were spin-balanced, like an automobile tire. A "launch phase simulator," .....

[62]

Technicians Assembling Explorer XVII, launched in 1963 to conduct atmospheric research. (NASA photo G63-4002-C).

....which was built around a large centrifuge machine, was sometimes used to simulate the vibration, acceleration and decreasing air pressure a satellite would experience during its launch into space. Another test unit could vary the magnetic field around the component or spacecraft to test the operation of instruments designed to measure magnetic fields and their influences.

Goddard's test engineers even went so far as to create an artificial Sun to test satellites in a thermal vacuum chamber. Based on solar measurements taken by a couple of early satellites, they assembled two megawatts of light (the equivalent of twenty thousand 100-watt light bulbs), focused through a series of reflectors into a concentrated beam. That "Sun" was then placed at the top of one of two forty-by-sixty foot vacuum chambers housed in the test facilities at Goddard. These "space chambers" were so large that they were built first, and the rest of the building was constructed around them.

One of Goddard's Orbiting Astronomical Observatories prior to launch.

[63] The possibility of a launch failure, especially in the early days, was great enough that Goddard developed a policy of building a prototype and two flight models of any given satellite. If the first one or the launch vehicle carrying it failed, the team could quickly launch the back-up model. In the case of the second Orbiting Astronomical Observatory (OAO II), the back-up satellite was actually a prototype that had been on display at the 1964 World's Fair in New York City. Engineers brought it back to NASA after the first OAO failed, refurbished it with new experiments and launched it successfully - which speaks to the amazing quality and reliability of even the satellite prototypes Goddard built. Indeed, Goddard was so concerned about building spacecraft correctly that it always had a separate division or directorate dedicated to "systems reliability." If Goddard's satellites had an impressive success rate, it was because reliability and quality assurance were always such a high priority at the Center. In fact, Goddard's satellites were so reliable that eventually not only the spares, but also the prototype models of a spacecraft, upgraded for flight, began to be launched into space as a matter of course.[9]

In either case, all components and spacecraft were thoroughly and rigorously tested before launch. Scientists were not always comfortable with this approach, preferring that a non-flyable prototype model be tested and shook and the flight model left alone. But the test engineers at Goddard were insistent that any one [63] satellite could have flaws and better to find the problems out on the ground than in space. To illustrate this point, the test engineers often would treat a satellite in a space chamber as if it were really in space. If a researcher said, "Oh, I know what the problem is. Take it out and let me fix it," the test personnel would shake their heads, replying, "It's in space. You can't touch it. Now what do you do?" It was their way of helping to develop the necessary mind-set for space science along with the hardware necessary to accomplish the job.[10]

Yet the meticulous and rigorous testing paid off. Between 1959 and 1976, Goddard had a 100% success rate for the 31 contractor and Goddard-built satellites it tested in its own facilities.[11] The Explorer satellites, many of which were built in-house at Goddard, had a particularly impressive success rate. In the 1960s, every Explorer that was properly placed in orbit by its launch vehicle...

Goddard's Explorer XII satellite, launched in August 1961, was designed to investigate the solar wind and the magnetosphere. (NASA Photo G-62-344).

[64] ...achieved its mission. As one of NASA's early managers summarized, "Explorer satellites were simply expected to succeed, and they did."[12]

An early sounding rocket called the Javelin on its launch pad. Sounding rockets are used to launch non-orbiting scientific payloads into the upper atmosphere.

Of course, there were problems and there were failures. Usually, the only things lost were weekends at home, sleep, pieces of hardware, and data. But in 1964, three men were killed and several others seriously injured in an accident involving an Orbiting Solar Observatory satellite. The satellite was completing some final pre-launch testing in a hangar at Cape Canaveral in Florida when the accident occurred. The OSO had just been been mated to the third stage of its launch rocket when spark of static electricity caused the rocket to fire. It was a sobering reminder that even if the spacecraft contained no people and was tested as thoroughly as possible, this was still a potentially dangerous business.[13]

Launch Vehicles

Of course, the spacecraft itself is only part of the equation. Something has to get the instruments into space (or, in some cases, the upper atmosphere). The research conducted at Goddard over the years has relied on a number of vehicles to do that, ranging from aircraft, balloons, and small sounding rockets to large intercontinental ballistic missile-sized launch vehicles and the Space Shuttle.

Sounding Rockets, Balloons and Aircraft

Space science research began right after World War II with what became known as "sounding rockets." Sounding rockets were so named because as they passed up and back through the atmosphere, they could make measurements at various altitudes in the same way as sounding equipment tested various depths in the ocean. They couldn't achieve orbit, [63] but they could reach high altitudes in the atmosphere or space for short periods of time.

Even after satellites became an option for scientists, they still continued to use sounding rockets for various types of research. For one thing, sounding rockets can make measurements in a regime which is difficult to access by either aircraft or orbiting spacecraft. For another thing, the smaller, less powerful sounding rockets were, and still are, a much cheaper way of performing some research. In a sense, sounding rockets were 'better, faster, cheaper,' thirty years before NASA adopted the saying as an organizational philosophy.

As a result, sounding rockets can provide a testbed for mew measurement approaches or instruments. An experiment is sometimes initially put on a sounding rocket. If it turns up something interesting, a satellite project is then planned to gather further data. By the same token, many instruments designed for satellites are first tested on less-expensive sounding rockets. Experiment space on satellite projects is also extremely limited, leading many scientists to use sounding rockets as a way to at least get some data in a timely manner. At the same time, sounding rockets serve as a wonderful training ground, giving new researchers an opportunity to conduct hands-on work and get familiar with the requirements and approach necessary for working in space.

Another advantage of sounding rockets is that they can take in situ measurements in areas of the atmosphere orbital satellites only passed on their way to orbit. Consequently, sounding rockets can provide...

Scientific balloons, like this one, are a cost-effective method to get lightweight research equipment into high altitudes.

...good profiles of density, moisture, temperature, or other parameters throughout the different levels of the atmosphere. In some cases, the payload of sounding rocket flights can be recovered again, although that is tougher if they are launched over the ocean. In one instance, the military helicopter pilots who flew out to recover a Wallops Island payload from the Atlantic Ocean returned and told the scientists that all they had found was a big cylinder with something attached to it floating in the water. Of course, the cylinder was the rocket payload, but it had Sunk by the time the crew was sent out a second time to try to recover it.[14]

Sounding rockets also can be launched from almost anywhere. When a supernova was sighted in 1987, for example, scientists wanted immediate gamma ray data from the high-energy explosion. But NASA's Shuttle launches had been halted [66] because of the Challenger accident, and there were no suitable satellites ready to launch on any other vehicles. So a team from Goddard's Wallops Island facility travelled to Australia and launched two sounding rockets with gamma ray detectors to investigate the phenomena.[15]

One of the reasons sounding rockets can be so flexible is that their range varies greatly. From the early Aerobees and Nike-Cajun rockets, the stable of solid-propellant rockets has grown and expanded. Researchers at Wallops would sometimes take different surplus rocket stages and put them together into new and different combinations, leading to rockets such as the Taurus-Nike-Tomahawk or the Nike-Orion.[16] Today, although there are very small meteorological rockets that stay below 100 miles, most sounding rocket launches can reach 180-240 miles in altitude. A lightly loaded Black Brant 12, however, can climb as high as 800 miles above the Earth.[17]

Small satellites can be place in orbit with the Pegasus rocket, which is drop-launched off a transport aircraft at over 35,000 feet.

Sometimes, however, scientists need endurance rather than altitude. In those cases, a scientific balloon or aircraft can provide a better testbed than a rocket. Scientific balloons are sandwich bag-thin polyethylene balloons filled with inert helium. Although launching them can be dicey, as any wind can rip the balloon bag, they offer scientists the opportunity to take instruments up as high as 26 miles for 12-24 hours. Of course, the trajectory is determined by the wind, but they can be launched from almost anywhere. Goddard took over management of scientific balloon launches from the National Science Foundation in 1982 and now launches approximately 35 balloons a year.

Aircraft are much more limited in altitude than either rockets or balloons, but they offer extremely quick turn-around times and are an excellent testbed for many different types of instruments and sensors. At Goddard's Wallops Flight Facility, five different types of aircraft are used to test new lasers, computers, and other instruments for Earth and space science research. In addition, the aircraft can be used for conducting certain types of Earth science research, including the study of ice formations, plant life, and in situ measurements after natural events such as volcanic eruptions. [18]

Vanguards and Deltas

Balloons, aircraft and small atmospheric rockets were all available before satellites came into being. The challenge that stood in the way of space flight was getting a rocket that had enough power to get a payload high [67] enough and fast enough to achieve orbit. Although NASA's Lewis Research Center focused on propulsion and the Marshall Space Flight Center would become known for building the large Saturn launch rocket, Goddard was given responsibility for developing and managing the rockets NASA planned to use to launch Goddard's scientific satellites.

When NASA opened its doors, six out of the seven rockets available for its research came from the military. The seventh was the developmental Vanguard rocket, which was transferred from its original home at the Naval Research Laboratory to Goddard as soon as the new space agency was formed. The Vanguard itself did not prove to be a highly successful rocket. Indeed, the spectacular and humiliating explosion of an early Vanguard test vehicle in December 1957 two seconds after launch was etched into the nation's memory for years to come. A Vanguard successfully launched the Vanguard I satellite into space in March of 1958, but eight out of eleven subsequent Vanguard launch attempts failed.[19]

The biggest problem with the Vanguard seemed to be the first of its three stages. So researchers at Goddard and the McDonnell Aircraft Corporation, which built the Delta rocket, decided to try substituting the first stage of a Douglas Aircraft Company Thor missile that was being used successfully by the Air Force. The hybrid rocket was designated the Thor-Delta, a name later shortened to simply "Delta."[20]

The first successful launch of a Delta rocket took place in August 1960. The...

The Delta rocket have had one of the best success rates of any expendable launch vehicle.

...original Delta's payload was limited to a few hundred pounds for a low-Earth orbiting satellite and around fifty pounds for a geosynchronous satellite, but the Delta team kept trying to improve the rocket's capability. They added small solid rocket boosters around the base of the vehicle, lengthened the first and second stage, gave it bigger third stage rocket motors, and added space for more propellant. Fifteen years later, that capacity had increased to 2,400 pounds, and today a Delta can put up about 4,000 pounds.[21]

The Delta has been an extremely successful launch vehicle, with very few failures in its 30 year history. But the Delta still almost became extinct in the 1980s [68] when a new, reusable launch vehicle appeared that was touted as the all-purpose space transportation system of the future - a vehicle more commonly known as the Space Shuttle.

The Space Shuttle

The 1986 Challenger accident may have changed NASA's plans to revert to a single-vehicle launch fleet, but the Space Shuttle still carries a fair number of scientific satellites and instruments into space. In addition to large satellites like the Hubble Space Telescope that it releases into orbit, the Shuttle carries several other types of scientific payloads.

The "Spartan" class of satellite is designed to be released overboard at the beginning of a Shuttle mission. Spartan satellites orbit freely for several days before being...

The Spartan 201 satellite being released from the Space Shuttle using the shuttle's robotic arm.

....retrieved and brought back to Earth at the end of the mission. Smaller, "Hitchhiker" payloads, on the other hand, stay attached to the Shuttle bay, allowing them to use the Shuttle's systems for power, data or communications functions.

Even smaller payloads called "Get Away Specials" (GAS) are packaged into small trash can-size containers in unused corners of the Shuttle's service bay. GAS payloads are self-contained experiments that are not connected to the Shuttle's electrical systems. The idea behind the GAS program was to offer an opportunity for extremely low-cost space experiments. Some of the GAS payloads cost as little as $3,000, making them a convenient way to test instruments in space and making space science available to college, high school and even elementary school students. As of 1997, a total of 138 GAS payloads had been taken into space by the Shuttle.[22]

Tracking, Data and Communications

The final component of an operational spacecraft system, beyond a launch vehicle and an operating satellite, is a way of getting commands up to the spacecraft and data back down to researchers on the ground. Researchers at the Naval Research Lab realized this even as they began planning for a possible satellite launch in conjunction with the 1957-58 International Geophysical Year (IGY).[23] They developed a "Proposal for a Minimum Trackable Satellite (Minitrack)" in April 1955 that suggested a series of ground stations to spot [69] the satellite in orbit. Because signal strength from the satellite would be weak and launch tracking data might not be entirely reliable, the "Minitrack" network, as it became known, consisted primarily of a "detection fence" of closely spaced stations along the 75th meridian. This would help insure that at least one station would "spot" the satellite as it popped over the horizon.

The Minitrack network became operational in October 1957 with nine original stations, and was put under the control of Goddard in 1959. The network eventually grew to about 11 stations and served as the main tracking network for unmanned satellites until 1962.[24]

The Mercury Spaceflight Network

The onset of the manned space flight program, however, created much more complicated tracking and communication needs. The satellites were in range of the Minitrack stations for only a few minutes on each orbit. A manned spacecraft had to be tracked continuously and had to have two-way communications available, as well. In 1961, Goddard tracking and data engineers were also given responsibility for designing and managing this more complex network, designated as the Mercury Space Flight Network (MSFN). Goddard's efforts in designing and maintaining this world-wide system created another invaluable center of expertise in the Center and were critical to the success of not only the Mercury missions, but also all the NASA crewed space endeavors that have followed.

Goddard's satellite tracking and data network spanned the globe.

The Mercury network consisted of 17 ground stations in locations around the world, from Cape Canaveral, Florida to Woomera, Australia. To cover gaps in between the continents, two ships were also outfitted with tracking and communications equipment and stationed in the Indian and Atlantic oceans. Even then, there were still times during the Mercury flights that the astronauts were out of communication range, although for much shorter periods of time than any of the scientific satellites.[25]

There were a number of difficulties with getting the MSFN operational. One of the biggest challenges stemmed from the need to work with so many different countries in order to get the stations built and staffed. To get permission to build the station in Guyamas, Mexico, for example, President Eisenhower finally sent his brother to personally ask Mexico's president for assistance. Even [70] then, the Guyamas station sometimes had to be guarded with troops during missions to keep protesting mobs at a distance.[26] Most of the time, however, cooperation was easy to get. Many countries even donated services, time and labor. This was the heyday of NASA and the dawn of an exciting new adventure. Simply put, people wanted to be a part of it.

All of the international stations were networked through a control center at Goddard, which then relayed the information to and from Mission Control at Cape Canaveral in Florida. Even this was a dicey operation at first, because the computers and communications systems in the early 1960s were less than reliable. So, as with the early satellites, reliability was achieved through redundancy. If there were six different voice channels going between Goddard and any given station, the system managers would try to use different cables or lines for each one so that if any one line failed, the others would still work. The system was still questionable enough, however, that....

One of two supertankers converted to floating communications facilities during the Apollo program.

....flight controllers were flown to each station around the world for every Mercury flight. That way even if the network failed, there would be controllers in contact with the flight at almost all times.

The manned space flight program was pushing the limits of technology in every area, and the Goddard and NASA personnel working on the program were well aware of how marginal their systems were. During the Mercury launches, for example, phone communications were still not reliable between Goddard and the Bermuda tracking station, even though the Bermuda station provided critical information for mission abort decisions. Christopher Kraft, flight director of the manned missions during the 1960s, recalled that "during the launch of an Atlas rocket, we had somewhere between thirty seconds and two minutes after main engine cutoff to decide whether to continue a mission or to abort. Initially, there were very few people who believed that this would be possible."[27] The tension of these Mercury launches was especially great because the Atlas rocket used for the orbital Mercury flights was not a highly reliable rocket at the time.

With the advent of the Gemini flights, several things changed. First, the Johnson Space Center in Houston, Texas was completed, and mission control was moved from Cape Canaveral to Building 30 at Johnson. Communications technology also had improved enough that controllers were no longer dispatched around the world. Instead, a secondary mission control center was set up at Goddard with [71] completely redundant systems to those in Houston. As it was, the Goddard center was the conduit for data and communications between Mission Control, the tracking stations and the spacecraft. But if the Houston system failed, the control center facilities at Goddard would allow the Center to pick up coverage of the mission instantaneously.[28]

Even with improved technology, the manned missions were always stressful endeavors. Managers at the control center at Goddard would keep one eye on the trajectory data of the rocket, another on the maintenance panels of the computer system for the network, and another on the network connections themselves. Not surprisingly, tension in the control center at Goddard during these flights was every bit as high as at Mission Control in Houston.

Goddard's world-wide network proved its worth on every mission. But during the Gemini 8 flight it proved critical, when the spacecraft carrying astronauts Neil Armstrong and David Scott spun out of control during a practice docking maneuver. The rest of the mission was cancelled, and the network engineers had to find the spacecraft again, recalculate its orbit and re-entry trajectories, and then move a recovery ship to an alternate landing location to rescue the astronauts, all in a matter of hours.[29]

Yet the Gemini missions were still simpler than the next task facing the manned network - keeping track of a spacecraft all the way to the Moon and back. In addition to the ground stations already in place, Goddard commissioned the modification of two huge supertankers into floating behemoths capable of carrying 30-foot parabolic antennas, increasing NASA's tracking fleet to a total of five ships. In addition, nine KC-135 aircraft were modified with special radar noses and launched to fill in the gaps between the ships and the ground stations.

A mission controller tracks the progress of a satellite in one of Goddard's mission centers.

As one Goddard manager put it, "We had the whole world cranked up in these missions." It was true. And the effort was as much a matter of national pride for NASA's partners as it was for the space agency itself. Many times services and labor were donated to the cause, which was fortunate, because the costs of such a worldwide system would have been prohibitive. As it was, the "phone bill" for NASA's system totalled somewhere around $50 million a year.

The personnel at the international tracking stations were deeply committed to the success of the missions, sometimes going to great lengths to insure they didn't let....

[72]

Goddard's NASCOM facility prior to a Space Shuttle launch.

....the network down. On a test flight of the Saturn vehicle that would launch the Apollo spacecraft, for example, the communication lines to the remote Carnarvon station in western Australia broke down. So using frontier resourcefulness, the Australians passed launch information to and from Carnarvon with the help of ranchers at "stations" over more than one thousand miles across the Australian outback, using the top wire of the ranch fences as a makeshift telegraph line[30].

That same level of dedication was present at Goddard's control center throughout its history. It is one of the reasons that although there were glitches in the system, the Manned Space Flight Network[31] never had a serious problem that affected the outcome of any of the manned missions.

The Satellite Tracking And Data Acquisition Network

At the same time as the manned missions were being conducted, the unmanned satellite program was growing by leaps and bounds, creating new tracking and data problems for researchers, as well. The bigger satellites, including the "observatory" class spacecraft like the Orbiting Solar Observatory (OSO), needed more capable ground equipment than the Minitrack network had.

As a result, Goddard developed a new world-wide web of stations known as the Satellite Tracking And Data Acquisition Network (STADAN), with as many as 21 different sites spread over every continent in the world except for mainland Eurasia. The STADAN stations had improved 40-foot and 85-foot parabolic antennas so [73] they could handle the larger amounts of data the more advanced satellites were generating. The Orbiting Geophysical Observatory (OGO) launched in 1964, for example, was downloading several full-length books worth of data on every pass over a ground station.[32]

The STADAN network also had its share of interesting events due to the unique politics of various locations around the world. The South African station was eventually closed because of controversy over the apartheid practices of the country, and the NASA personnel at the station in Tananarive, Madagascar had to be evacuated in the middle of the night after a tense stand-off with the country's dictator.[33]

The stations also provided a unique opportunity for the nations involved, however, because NASA made an effort to train and employ local workers at all the network sites. These countries then had the expertise and equipment to provide services to commercial satellite companies and networks. They could also run their own communication networks rather than having to rely on foreign personnel.

Spaceflight Tracking and Data Network

As the Apollo program came to a close, the need for such an extensive, separate manned space flight network decreased. So between 1969 and 1973, Goddard gradually consolidated the two separate networks - the MSFN and the STADAN - into a single network of ground stations known as the Spaceflight Tracking and Data Network, or STDN. By 1973, the STDN system incorporated 20 different stations around the world, including one ocean-going ship.

In 1971, the two Goddard directorates that had been managing the separate tracking networks were also reorganized to reflect the changing mission requirements. The new Mission and Data Operations Directorate managed the data processing activities and the computer-based tracking projections of the network, and the Networks Directorate oversaw the internal NASA communications network (NASCOM) and coordinated the operations of the various STDN stations.[34] Yet even more dramatic changes were coming down the pike.

Tracking and Data Relay Satellite System

The Apollo missions could be well serviced by ground stations because, aside from the beginning and end of each mission, the spacecraft was a fair distance away from Earth and, therefore, in sight of at least one or more of the widely-spaced ground sites. The Space Shuttle, on the other hand, was going to remain in low-Earth orbit. Keeping in touch with it would be a more difficult task.

The solution, however, was already being tested in space. Goddard managed the development of a series of Advanced Technology Satellites (ATS) designed to test advanced meteorological and communications satellite technology. The geosynchronous ATS spacecraft were [74] in a good position to track and communicate with anything in a near-Earth orbit because they were positioned 23,000 miles above the planet.

The ATS satellites were not part of Goddard's official tracking and data network. But the NASA networks had never had firm lines of demarcation. For example, although the Deep Space Network (DSN) that tracked planetary probes and distant missions was a separate entity from the MSFN, its antenna were used in helping to track the Apollo spacecraft. So although the ATS spacecraft were not officially part of the MSFN or STDN systems, they were still used to...

An artist's concept of one Goddard's Applications Technology Satellites. (NASA photo G-75C-44591).

....help provide communications for the Earth-orbiting Skylab missions in 1973.[35]

Goddard's ATS research in the 1970s led NASA officials to look at using geosynchronous satellites as a means of tracking not only the Space Shuttle, but all Earth-orbiting satellites of the future. The result was the Tracking and Data Relay Satellite System (TDRSS).

The TDRSS plans called for three geosynchronous satellites - one positioned over the western hemisphere, one over the eastern hemisphere and a "spare" positioned in between the first two. This would allow the system to provide 100% coverage for [75] satellites orbiting in an altitude range between 745 - 3,100 miles and 80% coverage for satellites below that altitude. Satellites further away than that would be tracked by the Deep Space Network. As a result, Goddard's extensive STDN ground network would no longer be needed.

There were numerous problems in getting the TDRSS network operational, most of which involved the financial contracting aspects of the project. But a rocket booster malfunctioned on the first satellite after it was launched from the Shuttle and, although NASA was able to use the satellite's small, on-board jets to nudge it into its correct orbit, it was never fully effective. The second TDRS spacecraft was then destroyed in the Challenger accident.

There were numerous difficulties with TDRSS ground system, as well especially with a computerized automatic scheduler that was supposed to coordinate time on the TDRSS satellites for the 20-plus scientific satellites the TDRSS might be tracking at any given time.

In addition, the original goal for the Space Shuttle was to be able to launch a new mission every two weeks, and the TDRSS ground stations at Goddard and White Sands would have to be able to support that kind of demanding launch schedule. That was a daunting goal at a time when it was sometimes difficult to keep the ground system up and running for 24 hours at a time. In the early days, Goddard had two crews working on the system simultaneously - one that was trying to operate the system and a second that was trying to trouble-shoot its problems at the...

One of the Tracking Data Relay Satellites being released from the Space Shuttle's cargo bay. (NASA photo JCS/S26-31-065).

....same time. After two years of long hours, seven-day weeks, and much lost sleep, the staff was just getting the scheduler problems resolved and the system up to the two-mission-per-month goal when the Challenger exploded. It was a devastating blow to the staff, who realized the goal they had worked so hard for would never be relevant again. The Shuttle began flying again in 1988, but the program has never attained the frequency of flights its designers originally envisioned.[36]

A Closing Circle

Interestingly enough, recent changes in technology have led NASA to return at least part of its satellite tracking and data tasks to a ground-based system. The tape recorders on satellites were once one of the weakest links of the system, prone to failure, but the advent of solid-state recorders, a technology developed by engineers at Goddard, has changed that. With increased reliability with on-board data storage, [76] the need to stay in constant touch with some satellites is decreasing. Ground station technology has also improved, making it much less expensive to operate ground system terminals.

In addition, using TDRSS for downlinking data can be expensive. A satellite does not have to have a very big TDRSS antenna in order to receive command and control orders from ground operators. But to send gigabytes of data back down to Earth requires a much larger and more powerful and complex antenna system. Because NASA is trying to shrink the size and cost of satellites, researchers began looking at other options.

NASA's new Earth Science Enterprise program, for example, will incorporate several large Earth-oriented satellites generating approximately a terabyte of data per day. A terabyte is a staggeringly large number equivalent to 10 to the power of 12 bytes, or a million....

A polar-orbiting satellite, such as Terra (EOS-AM) spaceraft depicted here, will scan the entire Earth as the Earth rotates.

....megabytes. In practical terms, this means that in four months, the program's Landsat 7 and EOS AM-1 satellites will have doubled the amount of information collected on the Earth from satellites since the beginning of the space program. The first of these satellites, called EOS AM-1, will use the TDRSS satellites for both commands and data transmission. But the rest of the satellites in the 15-year program will rely on TDRSS only to uplink commands to the spacecraft. The data will be downlinked to one of five possible ground stations.

Because the Earth Science Enterprise spacecraft will be primarily polar-orbiting satellites, the two main ground stations will be in Fairbanks, Alaska and Svalbard, Norway. A ground station in McMurdo, Antarctica will serve as a back-up facility. Two existing ground stations in the United States - the EROS data center in Sioux Falls, South Dakota and a research and a research center at Goddard's Wallops Island facility - are being upgraded so they can provide back-up support, as well.

The TDRSS satellites also will continue to support the Shuttle missions and a number of large NASA satellite, including the Hubble Space Telescope and the Compton Gamma Ray Observatory. But the advances in technology that are enabling more satellites to rely on ground stations have also changed one of the fundamental issues of satellite research. Once upon a time, the problem was how to get enough data back to Earth. With the Earth Science Enterprise, the problem isn't [77] getting enough data - it's finding a way not to drown in it.

Data

Transmitting and translating the data received from satellites has always been a tricky problem. In the earliest days, the "data" consisted of audio "tones" sent from the passing satellites. If a sensor found what it was designed to identify, it would emit a different tone than if the substance or force was not present. Satellite systems for transmitting data improved dramatically over the years, but scientific data has always required some interpretation.

Goddard offered scientists three different levels of data from their satellite experiments. Level 0 was fundamentally raw data, with only some spacecraft attitude and orbit information added. Level 1 data included instrument calibration information, and Level 2 data was generally a customized product that processed the information in a particular way for a particular scientist.[37]

At the beginning, the scientist or scientists who designed the experiments on the satellites got exclusive use of the data until they published their results. The system made a certain amount of sense, because space was a very risky research field. A scientist could devote years to developing an instrument only to have the launch vehicle carrying it explode on the launch pad, so there was pretty much general agreement that they deserved first crack at the results of a successful satellite instrument. When the scientist was "done" with his or her data, the results were cataloged in the National Space Science Data Center (NSSDC) at Goddard and became available to anyone.

Scientists pore over results from the International Ultraviolet Explorer (IUE) Satellite. IUE operations were simple enough to allow outside researchers to conduct their own observations with the satellite.

Yet in both the space and Earth science fields, individual investigators sometimes dragged their feet in making the data more generally available. In addition, the principal investigators often didn't remove their particular research modifications, or "signatures," from the results, so the data was virtually useless to anyone else.

As a result of concerns on both of these points, Goddard and NASA began looking at ways to improve the system. Space physics research results are difficult to distribute in a generic fashion, but several years ago, Goddard's began to archive its astronomy data in wave-length-specific archive centers around the country. Goddard's Space Science Directorate is in charge of the High Energy Astrophysics Science Archival Research Center (HEASARC) that catalogues X-ray and gamma ray astronomy data for users in the general science [78] community. Results of research in other wavelengths are cataloged in archive centers at other NASA Centers and universities.

Earth science data also began to be catalogued in topic-specific Distributed Active Archive Centers (DAAC) at Goddard and other research centers around the country. Goddard, for example, manages any data on climate, meteorology, or ocean biology. The University of Colorado archives data related to polar oceans and ice.

The philosophy of allowing principal investigators to "own" data has also changed. In space science, the amount of time an investigator is given sole access to data has shortened considerably. With Earth science research, results are now considered essentially public property almost as soon as the data can be verified and interpreted.

With the advent of the Earth Science Enterprise program in the late 1990s, Goddard is entering a new generation of...

The Earth Observing System Data and Information System facility was created to handle large amounts of data hat will be generated by the EOS satellites.

...data processing and dissemination. To handle the large quantity of data coming in and make it accessible to the public as quickly as possible, NASA has developed the Earth Observing System Data and Information System (EOSDIS), managed and located at Goddard. EOSDIS processes the data from the satellites and distributes it in various levels of complexity to the different DAACS, who then make it available via not only traditional networks, but also the internet. The goal is to make the science data available and usable to everyone from high school science students to sophisticated research scientists.[38]

Conclusion

Although few people give it much detailed thought, designing, building, testing, launching and operating satellites, as well as processing and distributing the information they gather, is a very complex and difficult task. There are a million ways something can go wrong and, unlike ground-based research or activities, most problems occur hundreds or thousands of miles away from the engineers who need to fix them.

Tracking and communicating with satellites has always required the cooperation of nations around the world. This fact is even more true today, as more and more satellite projects are developed as cooperative efforts between two or more countries. Every satellite that passes overhead in the night sky is being "flown" and watched after somewhere in the world. Somewhere, someone is telling the satellite which direction to turn next, which...

[79]

The Tropical Rainfall Measuring Mission (TRMM) satellite, launched in November1997, is helping scientists better undertans the transfer of heat and water vapor between the ocean and the atmosphere.

....instrument to turn on, or perhaps trying to figure out why the power has suddenly dropped in its on-board electrical system.

The efforts of NASA's Mission Control personnel in Houston, Texas are perhaps better known than the efforts of the technicians at the STDN station in Fairbanks, Alaska, the designers of the Cosmic Background Explorer's infrared instruments, or the test engineers who made sure the Explorer satellites worked. But the efforts of these professionals are every bit as important. It takes an army to get a satellite into space - an army of scientists, engineers, technicians and support personnel from industry, universities, NASA, and foreign countries, working together for a common cause.

Space holds fascinating secrets, wonderful mysteries, and the opportunity to look back on ourselves and better understand the planet we call home. But it is a demanding task master, unforgiving of mistakes or neglect. If we have discovered useful, important, or amazing things in our journeys off the planet, it is because there were people like those at Goddard who were willing to attend to the less-glorious but all-critical details - the spacecraft, the launch vehicles, the ground stations, and the information systems - to bring those discoveries within our reach.

Chapter 4:
Exploring the Heavens

[80]

This spectacular Hubble Space Telescope image shows the pillar structure and embryonic stars in the Eagle Nebula. (NASA Photo PRC-9544A).

[81] Many of the 200-plus satellites the Goddard Space Flight Center has built, managed, or operated over the past 40 years have been dedicated to exploring the heavens - the almost limitless space that extends billions of light years beyond our planet. And at the time Goddard was founded, this territory was truly a new frontier. We could look through telescopes at stars and distant galaxies, and we could theorize about the forces and dynamics at work in the universe. But a mere 50 years ago we had as little concrete knowledge about what surrounded our planet as Lewis and Clark had of what lay between them and the Pacific Ocean.

The first steps in charting the frontier beyond our planet came with the early V-2 and sounding rocket flights in the late 1940s...

[82]

An image of the Orion Nebula created by the Hubble Space Telescope's near-infrared NICMOS instrument. (NASA photo PRC97-13).

....and early 1950s. But satellites were the first ships that could explore the heavens in real detail and depth. The satellites Goddard launched into space gave physicists and astronomers the opportunity to turn theory into science, opening the door to whole new areas of experimentation and revitalizing the field of science itself.

In the process, their research has challenged many of our beliefs and sparked our collective imagination. For the scientific exploration of space is really a search for answers about where we came from, how our planet and life forms evolved, and what other life, planets, and phenomena might exist beyond our own world. In the last 40 years, we have found some answers and stumbled on even more complex mysteries and questions. Theorists now contemplate the possibility of a ten-dimensional universe, while experimental researchers are finding evidence of black holes, energy bursts hundreds of times greater than a supernova star explosion, and even evidence to support many aspects of Albert Einstein's most mind-bending theories. Recently, for example, scientists discovered possible evidence for Einstein's theory that the space-time "fabric" can be dragged, or warped, by the gravitational fields around rotating stars and planets.[1]

From a time when most of us thought that Earth must be the only inhabited planet in the universe, we have learned enough about how elements and galaxies evolve that numerous scientists now believe there has to be intelligent life somewhere else. We have found evidence that indicates the universe really may have started with a single, explosive "bang" of energy and has been expanding ever since. We have learned a tremendous amount about the birth, evolution and death of stars, the formation of planets, and other perplexing cosmic events, but we are still only probing the surface of these mysteries.

For centuries, we have been trying to put together the puzzle of how the universe works. Indeed, our curiosity to know more about our world and our universe, without any immediate practical application to our daily lives, is one of the unique characteristics of the human race. The puzzle is far from complete, but gaining the ability to explore space from space - a capability in which the Goddard Space Flight Center has played a pivotal role in developing - has uncovered many important pieces.

For the most part, the exploration of space has been pursued in two different fields of science, although the lines between [83] the different types of research are not always clear or distinct. One of the lasting legacies of the space age, in fact, is that it has prompted the integration of previously independent fields of scientific research.

One of the main focuses, and strengths, of space science at Goddard has been what might be generally termed space physics. This is the realm of physicists who investigate gravitational, magnetic and electrical fields in space and a variety of particle radiations, such as electrons, protons and the nuclei of many elements, that are emitted from the Sun, the galaxy and the cosmos beyond. In addition to giving us a better understanding of the near-space environment and the substances, forces and dynamics that affect our planet, this research can provide clues as to how other planets and galaxies are formed.

Complementing this research at Goddard is the work of astronomers, who use the electromagnetic spectrum (from radio waves to visual and ultra-violet light to gamma rays) to study the physical and chemical properties of more distant objects and phenomena in the universe. In contrast to space physicists who tend to use satellites to make "in situ," or on site, measurements, astronomers have to rely on remote sensing techniques, because the objects they are investigating are still long distances away even from a satellite in space. While a space physics satellite might measure the number of particles hitting a detector in a given period of time, an astronomy satellite looks at the radiated light or energy coming from objects at different wavelengths in the electromagnetic spectrum.

At 17 tons, the Compton Gamma Ray Observatory was the largets scientific satellite ever launched from a shuttle.

The early satellites were dominated by the space physicists, for several reasons. For one thing, many of the Goddard's satellite scientists came out of the sounding rocket community, which had focused more on space physics than astronomy. In addition, astronomy experiments generally required more sophisticated satellites that could point to particular objects for a length of time.

Space physicists also needed satellites more than their astronomy colleagues, because experiments in space physics could not be done on the ground. They required in situ measurements, which made physicists more willing to undertake the risks and rigors of satellite research than astronomers, who could still conduct a fair amount of research from ground-based observatories.

Yet space still offered astronomers something valuable. Satellites gave them not only the opportunity to observe objects...

[84]

The Pleiades constellation as seen by the Roentgen X-ray satellite.

...in greater clarity, but the chance to look at objects in portions of the spectrum that were blocked by the Earth's atmosphere. The results of these efforts have been beyond expectation. Over the past 40 years, Goddard's scientific satellites have discovered possible answers to some of our oldest questions and opened doors to worlds we didn't even know existed.

Space Physics

Goddard's early work in space science focused on simply figuring out what existed in the upper reaches of the atmosphere and beyond. Scientists had already determined that the atmosphere consisted of several different regions. Closest to the Earth was an area called the troposphere, where our weather occurs. Above that was the more stable stratosphere. Directly above the stratosphere was a highly charged region called the ionosphere. The ionosphere is what allows radio signals to travel beyond the horizon, because its electrically conductive properties reflect radio waves back down to Earth. In the mid-1950s, however, there was little information about what lay above that region.

Dr. James Van Allen, a researcher at the University of Iowa, made one of the first fundamental discoveries in this unexplored space above the atmosphere when his instruments on sounding rockets and the Explorer I and Explorer III satellites detected a mysterious "belt" of radiation above the ionosphere. Scientists had deduced that there must be energetic particles from the Sun that flowed toward the Earth. The polarized magnetic field of the Earth would split and deflect those particles at the equator, sending the positive particles travelling toward one pole and the negative particles toward the other. Among other things, these particles were thought to be the cause of the polar auroras, commonly known as the Northern and Southern lights.

What Van Allen discovered was that the dynamics of the Earth's magnetic field were more complex than scientists had thought. In an area near the equator, the Earth's magnetic field not only deflected particles but also trapped some of the lower energy particles, creating high-altitude "belts" of radiation around the Earth at lower latitudes.

The existence of the "Van Allen Radiation Belts," as they were called, forced scientists to revise their theories of how the Sun's particle radiations affected the Earth's atmosphere.[2] In the process, they made another fundamental discovery that...

[85]

An artist's concept of the planned orbits of the various the International Solar-Terrestrial Physics Program satellites un relation to the Earth's magnetosphere. [Click

....occupied much of space physicists' satellite research in the 1960s - the existence of a previously unpredicted region above the ionosphere called the magnetosphere.

The discovery of the Van Allen Belts focused attention on the interaction between the Sun and the Earth's magnetic field. Many of Goddard's early satellites focused on this area and, as more data emerged, a new picture began to emerge. The Sun, it appeared, radiated particles in a steady stream into space. Dubbed the solar wind, these particles were deflected around the Earth by the Earth's magnetic field in much the same way as water is deflected around the bow of a boat. In 1963, a Goddard satellite called Interplanetary Monitoring Platform (IMP) 1, detected a distinct, turbulent "bow shock" area where the solar wind hit the magnetic field of the Earth. Additional Goddard satellites determined that this flow also created a magnetospheric "tail" behind the Earth, similar to the wake created by a boat. Inside that wake, confined by the solar wind, was the region known as the magnetosphere.

Understanding the dynamics of the magnetosphere - why particles were trapped at certain latitudes and not at others, how it was affected by events on the Sun such as solar flares, and how it affected other processes in the atmosphere and in interplanetary space - was the subject of many of Goddard's satellite research projects in the 1960s. In fact, understanding the larger-scale dynamics of the interactions between the Sun and the Earth has continued to be a goal of numerous satellite research projects even up through today.

Technicians work one of Goddard's Interplanetary Monitoring Platform satellites prior to launch. (NASA Photo G-66-7252)

[86] Explorers

In many ways, the Explorers class of satellites epitomized the Goddard Space Flight Center. The first Explorer was developed and launched before Goddard was formed, but Goddard's scientists, engineers, technicians and support staff were responsible for making the Explorer series.the amazing success story that it is. To date, there have been more than 75 successful Explorer missions, and the new Small Explorer series promises to carry that tradition on into the 21st century. The Explorer satellites were innovative, most of them were relatively small and simple, and many of them were built in-house at Goddard. They conducted research in almost all the space science disciplines, from particle and field research to high energy astronomy. In the early days, however, the Explorers were perhaps best known for their particle and field research in the magnetosphere and interplanetary space.

One of the early concerns of NASA's managers, for example, was micrometeorites and the threat they might pose to both unmanned and manned space missions. Several early Explorers[3] included micrometeorite detectors, which discovered that the threat of damage from these particles was much lower than some scientists had feared.

Another concern was the possible radiation hazard solar cosmic ray events might pose for astronauts, especially on the Apollo Moon missions. Cosmic rays are actually energetic particles that travel through space. Scientists now have identified three distinct types of cosmic rays, each of which brings us information on a different aspect of the universe. One type, known as "anomalous cosmic rays," offer a sample of the interstellar gas in the nearby region of our Galaxy. So-called "galactic cosmic rays," travel at much higher speeds, reaching us from distant regions of the Galaxy and perhaps from beyond. "Solar cosmic rays" emanate from solar flares and other events on the Sun.[4]

During the Apollo program, however, NASA was concerned primarily with solar cosmic rays. When events such as solar flares occur on the Sun, a greater number of solar cosmic rays are released into space. One of the goals of Goddard's Interplanetary Monitoring Platform[5] (IMP) series of satellites was to determine how great a hazard these events might create for humans travelling in space.

The IMP series of Explorers, which project scientist Frank McDonald named in honor of his children, consisted of 10 separate satellites that investigated galactic and solar cosmic rays, the interplanetary medium, and the distant magnetosphere. They also provided real-time monitoring for possibly hazardous cosmic radiation events during the Apollo missions.

Another Explorer satellite played an important role in measuring the results of the Starfish high-altitude nuclear bomb test in 1962. The test had been an effort to analyze the effects of an explosion in the upper atmosphere, but the blast cloud had travelled much higher than the test designers had intended, and both the military [87] and NASA were noticing difficulties with a couple of their satellites. At the request of President John F. Kennedy, Goddard initiated an intense effort to modify a satellite from another mission to go up and measure what the results of the test actually had been. Designated Explorer 15, the satellite discovered that the explosion had created an artificial radiation belt around the Earth. Goddard also discovered that the radiation from the blast was also responsible for damaging several satellites that were in orbit at the time, including the Alouette spacecraft and a Telstar communication satellite.[6]

Other early Explorers made important discoveries about the composition and boundaries of the Earth's magnetosphere, ionosphere and upper atmosphere and how these regions were affected by the solar "weather" and other cosmic events.[7] By the end of the 1960s, these and other satellites had given scientists a fairly good general description of the magnetosphere, the features of the Sun-Earth relationship, and the interplanetary medium. The task since then has been to refine and expand that picture with more detail and depth.[8]

The Orbiting Geophysical Observatory Projects

The Explorers were not the only satellites geared toward helping scientists understand the near-Earth environment and how it is affected by the Sun. The Orbiting Geophysical Observatory (OGOs) projects that Goddard managed were an attempt to get a more integrated picture of the dynamics at work by co-locating many different experiments on a single satellite. The OGO I satellite, launched in September 1964, for instance, included 20 different instruments.

An artist's concept of Goddard's Orbiting Geophysical Observatory, which incorporated 20 different research experiments. (NASA Photo G-62-2835).

The OGO series actually incorporated two unique concepts. One was the inclusion of so many different experiments on a single spacecraft, which was a radical change from the smaller, more focused, Explorers. The second was that the OGO spacecraft and interfaces with experiments were designed to be standardized. In addition to cost savings, this "streetcar" design would allow experiments that weren't ready by the deadline for one launch to "catch" the next spacecraft in the series, like catching the next streetcar on a commuter schedule.

The OGO concept was a learning experience for the scientists and engineers involved, and it never worked as well as its designers would have liked. Having so many experiments on one satellite created numerous interference problems, and the success of the instruments varied widely. [88] The performance improved over time, and eventually six different OGO satellites were launched, the final one in 1969. But while the OGO concept was abandoned, the OGO work laid the groundwork for future standardized spacecraft designs. This standardized spacecraft approach has remained a recurring theme at NASA, first with the Multi-mission Modular Spacecraft (MMS) of the late 1970s, and even more recently with the Rapid Spacecraft Procurement Initiative.[9]

International Sun-Earth Explorer

Another approach to getting a more integrated picture of Sun-Earth dynamics was the International Sun-Earth Explorer...

Originally launched to investigate solar-Earth phenomena, the orbit of this spacecraft, renamed the International Cometary Explorer, was modified to intercept the Giacobini-Zinner comet in 1985.

....(ISEE) satellite series, a joint project between Goddard and the European Space Agency (ESA). The ISEE A satellite, built at Goddard, and ISEE B satellite, built by the ESA, were launched together on a single Delta rocket in October 1977. By placing the satellites in similar orbits at a variable distance from each other, scientists could pinpoint fluctuations in the boundaries of the Earth's magnetosphere. Ten months later, a third ISEE satellite built by Goddard was launched into a complementary orbit and gathered additional data on the same phenomena being measured by the first two satellites.[10]

In 1982, a Goddard project engineer named Robert Farquhar realized that a near pass of the Giacobini-Zinner comet predicted for 1985 created a golden opportunity for scientists to learn more about the composition and evolution of a comet nucleus. So the orbit of ISEE 3 was altered to fly by the comet. In a complex three-year maneuver, the ISEE 3 satellite was moved into an orbit that swung through the Earth's magnetospheric tail, sling-shotted around the Moon to put it into an orbit around the Sun, and came in close enough range to gather data from the comet in 1985. Renamed the International Cometary Explorer (ICE), the satellite was also able to observe the solar wind upstream of Halley's comet on that comet's visit in 1986.

International Solar-Terrestrial Physics

As satellite technology improved, it allowed us to add more detail to [89] our understanding of the dynamics between the Sun and Earth. We know that there are particles from the Sun that flow continuously toward and around the Earth, creating the boundaries of our magnetosphere.

The number of particles flowing toward Earth is not constant, however. Active solar events such as flares and coronal mass ejections (CMEs) release high quantities of energetic particles that shoot toward Earth at speeds up to two million miles an hour. Influxes of these particles result in geomagnetic storms around the Earth that cause a number of strange effects. These storms are believed to be the cause of the spectacular Northern and Southern lights, but they can cause numerous problems. They can interfere with telephone, television and radio signals, damage the electronics in spacecraft, disturb compasses and marine navigation instruments, and create power outages. As a result, we have more than just a scientific interest in learning more about these events, especially as our society has become more reliant on electronic technology. If we can figure out the dynamics that lead to these storms, we can take measures to mitigate their effect.[11]

In 1988, Goddard was given responsibility for a comprehensive international effort to explore these "solar-terrestrial" dynamics with much more precision and depth. The collaborative program was called the International Solar-Terrestrial Physics (ISTP) program, and its goal was to observe the impact and behavior of the...

The Geotail spacecraft was designed to conduct research on the effect of the solar wind on the magnetospheric "tail" on the side of the Earth away from the Sun.

....solar wind and its interaction with the Earth simultaneously from different perspectives. The program's initial goal was to look at these interactions from three different spacecraft called Wind, Polar, and Geotail, simultaneously for at least six months in space. In 1992, the program was expanded to include plans for two additional spacecraft called SOHO and Cluster.

The first of the ISTP spacecraft was "Geotail," a joint project between the Japanese ISAS and NASA. Launched in 1992, it looked at the dynamics and effect of the solar wind in the magnetospheric "tail" on the night side of the Earth.

[90]

The Wind satellite (left) and Polar satellite (right), were part of the International Solar-Terrestrial Physics (ISTP) program. The goal of the international ISTP effort was to use several different satellites, in different orbits, to study the various effects of the Sun on Earth.

NASA's Wind spacecraft was launched initially into an unusual orbit around the Earth, with the furthest point in the orbit almost a million miles away. Researchers then moved the satellite's orbit to a spot known as the Earth-Sun Libration point, or Lagrangian point L1. L1 is a point approximately 1/100th of the distance from the Earth to the Sun, where the centrifugal and gravitational forces of the two balance each other. The goal of the Wind satellite was to gather data on the solar wind before it reaches the Earth's magnetosphere - first at the point where it encounters the "bow shock" of the Earth's magnetosphere and then, at point L1, before the solar wind reaches the influence of the Earth at all. In 1998, the satellite's orbit was changed once again to a "petal" orbit of successive elliptical loops around the Earth to explore the solar wind in additional locations.

The third spacecraft in the ISTP series is the NASA-ESA Solar and Heliospheric Observatory (SOHO). In 1995 it was launched into an orbit around the L1 point to study the physical processes in the Sun that affect the release of solar cosmic rays and the solar wind itself.

A fourth project, developed by the ESA, was named "Cluster" because it was actually a set of four spacecraft designed to gather three-dimensional information on the shape and dynamics of magnetic structures. Unfortunately, the Ariane-5 booster rocket carrying the Cluster spacecraft exploded during its launch in 1996. But in 1997, the ESA announced that it would launch a replacement, Cluster II, on two Soyuz rockets in mid-2000.

The last ISTP spacecraft, called "Polar," was launched in 1996. It was placed into into a polar orbit of the Earth to observe the activity of solar particles once they entered the Earth's magnetosphere, ionosphere, and atmosphere.

The ISTP program was an ambitious one, and coordinating the efforts of numerous research institutions and countries on several different satellites was challenging from both a management and technical perspective. For example, Goddard had development responsibility for both the Polar and Wind satellites. The idea was to get all five satellites into orbit at the same time, but both Polar and Wind were behind schedule and encountering technical difficulties. Goddard's management decided to solve the problem by finishing the Wind satellite first and then tackling the Polar spacecraft. This caused some difficulties with Goddard's partners, because, most of the instruments built by Goddard [91] scientists just happened to be on the Wind spacecraft. But eventually, both Wind and Polar were successfully launched and are still returning useful data.

Yet despite the challenges of a multi-spacecraft, international effort, the ISTP program has achieved major breakthroughs in scientific observations of the Sun and its effect on the Earth, including the processes by which solar plasmas and particles are transported to the Earth. These findings are adding valuable pieces to the puzzle of the sun's relationship with our home planet.[12]

ACE/SAMPEX/FAST

Although they are not part of the official ISTP program, Goddard has also developed and launched three additional satellites to enhance our understanding of cosmic rays. The first of these missions was a Small Explorer (SMEX) satellite called the Solar, Anomalous and Magnetospheric Particle Explorer (SAMPEX).

Launch of the Advanced Composition Explorer in August 1997.

An artist's concept of the Fast Auroral Snapshot (FAST) explorer, launched in 1996 to explore the polar aurora of the Earth.

It was put into orbit with an air-launched Pegasus rocket in 1992 to study the composition of particles arriving from the solar atmosphere and interstellar space and how they are transported into our atmosphere. A second SMEX satellite, called the Fast Auroral Snapshot Explorer (FAST) is taking a closer look at the plasma physics of the polar auroras. The auroras are created by accelerated electrons from particles in the magnetosphere hitting the upper atmosphere, just as a television picture is created by a beam of electrons hitting the inside of the front screen. The goal of the FAST satellite, which was launched in 1996, is to better understand exactly how those particles are accelerated.[13]

A third satellite, the Advanced Composition Explorer (ACE),was launched in 1997 and is in orbit around L1, almost a million miles away from Earth. Its nine instruments are measuring the type, charge, mass, energy, direction of travel and time of arrival of ...

[92]

A series of SOHO images reveals the ejection of matter from the solar corona.

....anomalous, galactic and solar cosmic rays in an attempt to find clues as to their source and the processes that brought them here.

Because the different kinds of cosmic rays contain matter from vastly different times and places, researchers hope the satellite can help us better understand the formation and evolution of the solar system, among other things. The effort is not that different from the earlier satellites such as the Interplanetary Monitoring Platforms (IMPs); the difference is that technological advances have given the ACE instruments collecting power 10 to 1,000 times greater than previous satellite instruments.

The goal of space physics satellites has not changed dramatically over the past forty years. Scientists are still looking to satellites to gather data on the particles, magnetic fields and dynamics in both the near-Earth environment and interstellar space. And their goal is still to understand what exists beyond our atmosphere, how those particles and fields affect us here on Earth, and what all of this can tell us about the formation of our own solar system and other planetary systems that lie beyond our reach. What has changed is the technology. The early Explorer satellites drew the rough outlines of the picture. As we have developed better and more capable satellites, we have continued fill in the colors, the details, and the depth of what is turning out to be a very complex picture, indeed.

Understanding the Sun

One of the critical steps in filling in the details of the Sun's relationship with the Earth has been to learn more about the Sun itself, and several Goddard satellites have been devoted to this goal. Actually, the Sun offers a unique opportunity for several fields of study. In addition to its direct impact on Earth, the Sun is also a star. In the universal scheme of things it may only be a very average-sized star, but it is a star, and the only one close enough for us to observe in any great detail. So in learning more about our Sun's internal processes and its impact on our own planet [93] and solar system, we can infer a great deal about the dynamics of stars in remote parts of our Galaxy and beyond. And because the Sun is relatively close to Earth, scientists can obtain in situ measurements of the particles it releases as well as remote images of its processes in various wavelengths of the electromagnetic spectrum.

The Sun consists of a complex nuclear furnace surrounded by several different layers of gaseous plasma. Most of the elements in the universe are created within stars when nuclei of "lighter" elements fuse together to make heavier and more complex elements. Hydrogen, for example, is the simplest element known, with only a single proton in its nucleus. Helium is next, with two protons. Hydrogen can be turned into helium in high-speed collisions between nuclei that then release tremendous amounts of energy, but those collisions require temperatures of at least five million degrees. The formation of more complex elements require even higher temperatures, which is why scientists think most elements heavier than iron are formed in supernova explosions of dying stars.

The energy of our own Sun is a result of hydrogen nuclei fusing into helium at its core. That energy travels outward through the Sun, slowly degrading from gamma rays to X-rays and then ultra-violet and finally to visible light as it nears the visible surface, or photosphere, of the Sun. The process is a slow one. Light travels from the photosphere to Earth in approximately eight minutes, but that energy was created by fusion reactions that took place thousands of years ago in the Sun's core.

Near the surface of the Sun, energy begins to be transported by convection as well as radiation. Scientists have long surmised that dark "Sun spots" on the surface of the Sun were masses of cooler gas where strong magnetic fields limit the typical convective currents that would otherwise keep bringing heat up from lower regions.

So-called solar plumes extend into space from the polar regions of the Sun, seen in SOHO image.

At times, eruptions called solar flares explode outward from the photosphere, sometimes associated with huge ejections of up to 100 million tons of mass from the Sun. The particles released in those eruptions and Coronal Mass Ejections (CMEs) travel outward into space at speeds up to two million miles an hour, contributing significantly to the solar wind and sometimes causing numerous problems on Earth.

The region above the photosphere is called the chromosphere, an area of decreasing density analogous to the Earth's upper atmosphere. Above that is the Sun's corona, a region whose density is so low that we generally cannot see it from Earth except when a solar eclipse blocks out the...

A finely resolved image of Sun spots returned by SOHO.

[94] ...scattered sunlight in the Earth's atmosphere. During an eclipse, the corona appears as a white halo around the edges of the Sun. High-speed, feathery jets of plasma, called polar plumes, can also be observed shooting out from the sun's corona at its poles, where its magnetic field lines are more open.

Scientists have been observing the processes of the Sun since at least the days of Galileo. But many of the sun's internal processes can only be studied by looking at the radiation they create, and ground observatories are limited in the type of electromagnetic wavelengths they can see. Rocket and satellite solar astronomy allowed scientists to view the sun's processes in ultraviolet, X-ray and gamma ray wavelengths that would have been blocked by the Earth's atmosphere. This opened up an invaluable window to understanding the Sun, because many of the critical solar processes involve these short wavelengths in essential ways.[14]

Orbiting Solar Observatory

The first Goddard satellites that were designed specifically to look at the Sun were the Orbiting Solar Observatories (OSOs). The...

The Solar Maximum Mission satellite as photographed by an astronaut during the 1984 Space Shuttle mission to repair the ailing satellite. (NASA Photo G84-1158)

....first OSO spacecraft was launched in 1962 and successfully measured electromagnetic radiation from the Sun over time in ultraviolet, X-ray and gamma ray regions of the spectrum. The next two OSO satellites, however, both ran into trouble. The second OSO was destroyed in a pre-launch accident and the third stage of the Delta launch vehicle carrying the next OSO satellite fired prematurely. The result, according to Goddard's matter-of-fact mission notes, was that "the satellite thus entered the Atlantic Ocean rather than planned 350-mile circular orbit at 33-degree inclination."[15]

Eventually, eight OSO satellites were launched into orbit, all with the same basic goal of observing the Sun's processes in wavelengths not visible on Earth. OSO V, VI and VI had an additional focus on studying solar flares because of the potential threat these events might pose to astronauts in space. These OSO satellites provided the first close, extended look at the sun in important regions of the spectrum that could not be observed by any ground-based methods, and they provided the first steps toward understanding the complex processes of the star that has a critical impact on life here on Earth.

Solar Max

Activity on the Sun increases and decreases over the course of a cycle that typically lasts about 11 years, although there are exceptions to that time frame. In 1980, Goddard launched a satellite to try to get a more comprehensive [95] understanding of solar events, particularly solar flares. The satellite was called the Solar Maximum Mission (SMM) because its 1980 launch was timed to coincide with the peak activity of the Sun's 11-year cycle. The Solar Max satellite incorporated gamma ray, X-ray and ultraviolet spectrometers to look at solar flares across all the higher energy portions of the spectrum. These results were coordinated with ground observations in the visible and radio wavelengths in an effort to compile a comprehensive picture of the dynamics involved in these powerful solar events across the entire electromagnetic spectrum. The picture was filled out even further by the ISEE 3 satellite, which took in situ measurements of the particles released by the solar flares the SMM satellite and ground stations were observing.

The SMM marked the first time a satellite had been designed and launched specifically to look at solar flares. It also demonstrated one of the advantages satellites offered scientists. In addition to allowing observations of particles and radiations which cannot be seen or measured from the ground, satellites make it possible for scientists from different disciplines to work together, on the ground and in space, to get a much bigger and more comprehensive picture of cosmic phenomena.

The Solar Max satellite also marked the first time a satellite was successfully repaired in space. The SMM was the first of Goddard's Multi-mission Modular Spacecraft (MMS) designed to be serviceable in orbit by Space Shuttle astronauts.[16] The concept got the opportunity to be tested eight months after SMM's launch, when three fuses in the satellite's attitude control system failed. The failures made it impossible for the spacecraft to point precisely at observation targets on the Sun, severely compromising the potential success of the mission.

So in 1984, astronauts aboard the Shuttle Challenger retrieved the satellite into the Shuttle's cargo bay, replaced the damaged components, and released the spacecraft back into orbit. Although the repair mission was ultimately successful, it underscored the difficulties of such an endeavor. The SMM spacecraft had been designed with a special attach point that could be mated with a docking device carried by an astronaut to retrieve the satellite and bring it back into the Shuttle cargo bay. But a screw head near the satellite's attach point was apparently sticking up out of place, and the astronaut was unable to get a lock on the spacecraft. To make matters worse, the astronaut grabbed onto one of the satellite's solar arrays in an attempt to get a better hold on the satellite, sending the spacecraft tumbling out of control.

Down at the control center at Goddard, engineers began a frantic effort to restabilize the spacecraft. Engineers estimated that the batteries on the tumbling satellite would be dead within eight hours, after which it would have to be brought back to Earth for repair or abandoned in space. To conserve power, the engineers decided to turn off even the satellite's transmitters. This meant that they would have no information on the health of [96] the crippled satellite, but they were desperate to buy more time to gain control of the spacecraft. After 19 tense hours, controllers managed to use the Earth's magnetic field and the magnetic torquers on the satellite to stop the spacecraft's tumbling, point it toward the Sun to re-power its batteries, and restabilize its movement. The Shuttle astronauts were then able to use the orbiter's robotic arm to capture the satellite the next day. The Solar Max repair mission underscored the difficulty of conducting science in the unforgiving realm of outer space.But the resourcefulness of the ground controllers at Goddard and the Shuttle astronauts made the mission a success. The effort also gave Goddard's engineers valuable experience in space repair missions - experience that would prove critical to the success of the first Hubble servicing mission a decade later. [17]

SOHO/TRACE/ULYSSES/SPARTAN 201

The next maximum activity time in the sun's 11-year cycle is expected around...

This image from the TRACE satellite shows the fine structure loops of plasma that are contained by large-scale magnetic fields on the surface of the Sun. (NASA Photo PAOT98_03.TIF)

....2001. So in the last couple of years, several new satellites have been launched to look at the Sun in even more detail as it transitions from a low-activity time to the height of its active cycle. The biggest of these is the Solar and Heliospheric Observatory (SOHO) satellite, a joint ESA-NASA project that was launched in 1995 as part of NASA's International Solar-Terrestrial Physics (ISTP) program. The SOHO satellite is orbiting the L1 Lagrangian point, which gives it a view of the Sun unobstructed by the Earth. The 12 SOHO instruments each gathered a particular type of information to help give scientists a better picture of the inner workings and dynamics of the Sun and its complex magnetic field, as well as what causes its plumes, flares, and coronal mass ejections.

Complementing the SOHO satellite is the Transition Region And Coronal Explorer (TRACE). TRACE is a Small Explorer satellite built by Goddard and launched in April 1998. The TRACE instruments don't have as wide a range as SOHO's instruments, but they can take images of the photosphere, transition region and corona of the Sun in much finer detail. Between the two satellites, scientists hope to obtain simultaneous measurements of all the temperature ranges of the solar atmosphere as it moves toward the height of its activity cycle.

Complementing this research is a NASA-ESA satellite called "Ulysses," which is in a unique polar orbit around the Sun. Most satellites have orbits that are still [97] within what is called "the plane of the ecliptic," which means on the same horizontal plane as the rest of our solar system. Our solar system, looked at from a distance, would appear as a flat disk. All the planets rotate around the Sun in pretty much the same horizontal plane, and most satellites stay within that same horizontal path as they orbit the Earth. But to orbit the poles of the Sun, the Ulysses satellite had to be flung out of that plane, into an orbit that operated perpendicular to the rest of the solar system. It was a difficult maneuver that required sling-shotting the satellite around Jupiter before turning it back to the Sun in order to give it the energy to break away from the flat disk of the solar system. But its orbit has allowed the Ulysses satellite to obtain valuable information about the dynamics of the Sun at its poles, which appear to play a major role in the creation of the solar wind.

Goddard also developed the Spartan 201 satellite, which is a short-duration spacecraft released overboard by Shuttle astronauts at the beginning of a mission and then retrieved and brought back to Earth when they return. The Spartan 201 satellites have carried various instruments to look at specific aspects of the sun's perplexing corona.

The combined efforts of these satellites have discovered some amazing things about how our Sun works. One of the mysteries of the Sun, for example, is the temperature difference between its outermost layer, the corona, and the chromosphere layer beneath it. Because the majority of the...

The Spartan 201 satellite after release from the Space Shuttle cargo bay. The Spartan satellites are retrieved by the Shuttle before the end og the mission.

....Sun's energy is generated at the core, one might assume that its layers should be progressively cooler as its energy travels outward and dissipates. But that's not what happens. Earlier satellites had discovered that while the sun's photosphere and chromosphere are about 6,000 and 10,000 degrees Kelvin, the corona beyond them is a blistering two million degrees Kelvin. How the corona can be so much hotter than the regions below it has mystified solar physicists for many years.

Based on observations from these latest satellites, scientists have concluded that at least one source of the corona's high temperature is a process called "magnetic reconnection." In essence, the surface of the Sun has a very complex magnetic field structure that is constantly changing. As these magnetic structures continually "snap" and break down, they appear to release energy up into the corona, in the form of heat.

[98]

This image from SOHO satellite shows the active and granular surface of the Sun. A large disturbance erupting disturbance is visible on the left side of the image.

But the picture satellites are bringing back to us is even more complicated than that. Indeed, one of the main discoveries these solar satellites have made is just how amazingly complex the sun's processes are. Recent observations from the SOHO satellite, for example, have detected streams of plasma that move across the sun's surface and dive deep into its interior, almost as the jet stream, trade winds, and ocean currents circulate around the Earth. Those streams don't all move at the same speed or direction, however, and the Sun itself appears to rotate at different speeds in different places. In its interior, the Sun rotates as a unified object, but on its visible surface the Sun rotates slower at its poles than it does at its equator. Scientists now think this churning interaction between different rotation patterns and charged plasma currents may be what creates the Sun's complex magnetic field and causes the turbulent eruptions of solar flares and coronal mass ejections.

Instruments on SOHO and Ulysses have also looked at the polar plumes and coronal holes near the sun's poles, which scientists now believe play a significant role in the creation of the solar wind. Once, scientists assumed that the solar wind streamed out from the Sun in all directions. Satellite data has now shown that the picture is much more complex. The Sun's surface, chromosphere and corona are highly structured with very complex magnetic fields. At places, the fields cause plasma to "loop" out and back, trapping it on the Sun. In other places, "holes" in the fields allow plasma to escape a high speeds, becoming the solar wind. And the turbulent interactions of the various parts of these magnetic fields may be the cause of more explosive ejections of material, such as solar flares or coronal mass ejections, which release tremendous amounts of plasma in a short period of time. One such solar storm in January 1997, for example, released a magnetized cloud that stretched 30 million miles across, pounding the Earth's magnetosphere with particles for 30 hours, interrupting communications and causing spectacular polar auroras. With the new generation of solar satellites, scientists are beginning to put together enough pieces to start to make sense of this complex solar puzzle. Before long, we may actually learn enough to not only understand these storms, but to predict them.[18]

[99] Exploring the Universe

The Sun offers a unique opportunity to study the processes of a star at close range, allowing scientists to examine both the particles and the electromagnetic radiation it emits. Goddard scientists also designed instruments for space probes and planetary missions to examine the magnetic fields and particles of other planets and regions within our solar system. To figure out the composition and behavior of material, planets or stars beyond our immediate surroundings, however, scientists rely on analyzing the light and energy that reaches us in various wavelengths of the electromagnetic spectrum. Another main focus of Goddard's scientific satellites over the years has been building spacecraft to explore the universe in different regions of this spectrum.

The electromagnetic spectrum progresses from radio waves, with the lowest energy and lowest temperatures, to microwave radiation, to infrared light, to visible light, to ultraviolet light, to X-rays, and finally to gamma rays, which have the highest energy and occur at the highest temperature of any waves in the spectrum. The upper end of the scale contains very short wavelengths with a higher frequency, while the lower end consists of much longer wavelengths with a lower frequency. In a sense, the spectrum behaves much like a rope held between two people. To get the rope to undulate in big motions doesn't require much energy. But to get it to move up and down in frequent oscillations requires quite a lot of energy.

This ROSAT image shows the round shape of the Vela supernova explosion, which occurred about 11,000 years ago, abot 1500 light-years away from Earth. The remnant shapeof the event can be detected in ROSAT's X-ray image because a supernove explosiob heats the interstellar gas enough to generate a glow in the X-ray region of the spectrum.

Energy is also linked to temperature. High energy events have high temperatures, while lower energy events are much cooler. So each particular point on the spectrum correlates to a very particular temperature as well as energy or light level. Scientists spend a lot of effort looking at the Sun in X-rays and gamma ray regions, for example, because some of the processes they want to study take place at very high temperatures - which means they can be observed only at the high frequency end of the electromagnetic spectrum.

Each element of the periodic table also has a particular "fingerprint" in the electromagnetic spectrum. If nitrogen is present somewhere, for example, emissions from that location will show a particular spike at a very precise wavelength in the spectrum. Other elements will spike at different unique wavelengths. This is how scientists can determine the chemical composition of gas clouds, comets, or other matter in the galaxy.

Yet in exploring the universe, one more factor comes into play. When we look at a distant star, galaxy, or nebula, the light or energy we are receiving has travelled up to...

[100]

An X-ray image from the ROSAT satellite against a visible light image of a small galaxy group, showing the presence of a hot gas that would not be visible to the eye.

...13 billion light years to reach us. So when we look at any of these objects or phenomena, we are really looking back in time. What we see is the light that star generated many years ago, and the further away the source is, the dimmer it will appear. The universe is also expanding. So the stars in distant galaxies are not only old, they are actually moving away from us. And the more distant they are, the faster they are receding. This movement affects the light we see.

Light waves, like sound waves, change as they travel toward or away from us. Just as a train whistle appears to get higher in pitch as it approaches and lower in pitch as it recedes into the distance, the light from objects in the universe will get longer in wavelength if those objects are moving away from us. If astronomers detect an infrared source in our own galaxy, it probably began as an infrared source. But that infrared light is coming from an object in a distant galaxy, it may have begun as visible or even ultraviolet light. Scientists call this phenomenon "red shift" because the starlight from distant galaxies "shifts" down toward the redder, longer wavelength end of the spectrum as the galaxies move away from us. The more distant they are, the faster they're moving, and the greater the redshift.

So when scientists look for light from the very early days of the universe, for example, they are looking for light that is very old and has come from very far away. It may have been extremely bright at one time, but now we are more likely to detect it as a dim light and in the lower, infrared and microwave portions of the spectrum. Radiation from closer, more highly energetic events in the universe, by contrast, will be detected in the higher ends of the spectrum. Unfortunately for scientists, the Earth's atmosphere blocks many of these portions of the spectrum. So it has only been since the advent of satellite technology that we have been able to fully explore many of the universe's greatest mysteries.

The real benefits of these efforts, however, have come from the coordination of many people, projects, and data. Individual objects or phenomena may be especially bright in one particular region of the spectrum, and observations in new regions, such as X-ray wavelengths, may tell us things about objects we never knew before. But one of the biggest advantages of conducting satellite astronomy across the entire electromagnetic spectrum is that it gives scientists the ability to look at the same objects and phenomena in many different wavelengths.

[101] Many so-called X-ray stars, for example, are also visible to the eye. What X-ray satellites told scientists was that these stars were also emitting peculiar, high-temperature energy, which meant there was something different about these stars than visible stars that did not show up in X-ray wavelengths. Radio astronomers detected pulsars several years before X-ray satellites discovered that these phenomena also had high-energy emissions. The Crab Nebula, the remnant of a star that exploded almost one thousand years ago, can be observed in almost every wavelength. Yet each different wavelength provides a slightly different piece of information that helps us put together a more accurate and complete picture of any particular object or phenomenon in the universe.

So while some findings may be touted as "X-ray," "gamma ray" or "ultraviolet" discoveries, all of these depend heavily on observations in other wavelengths. One of the greatest difficulties in figuring out the source of the exotic "gamma ray bursts" that satellites have detected for...

The Crab Nebula as it appears in four different wavelengths of the electromagnetic spectrum: visible light, near ultraviolet, far ultraviolet, and X-rays.

...three decades, for example, was that scientists were unable to link these high-energy bursts with any visual objects or phenomena until 1997. And even then, only three or four out of thousands of gamma ray bursts have been identified.

Clearly, there is much left to learn. But Goddard's achievements in space-based astronomy, along with ground-based astronomy efforts over the last 40 years, has already shown us a universe that is more dazzling, complex, mysterious and powerful than we ever even imagined.

Radio Astronomy

The lowest energy portion of the spectrum consists of radio waves. It is also one of the few regions of the spectrum other than visible light where the waves can penetrate the dust clouds in our galaxy and the water vapor, dust, ozone and other elements of our atmosphere. As a result, radio astronomy has played an important role in the exploration of the universe, uncovering signs of many phenomena and objects that are invisible to the eye. Astronomers were studying intergalactic radio wave signals even before there were satellites. But from the ground, radio signals may be affected by the ionosphere and extraneous man-made radio noise. Radio astronomy satellites offered a chance to monitor signals from the solar system, galaxy and the cosmos without any of those interferences.

Goddard's first radio astronomy satellite, Explorer 38, was launched in July 1968 to look at radio signals from the Earth's magnetosphere, Jupiter, and other [102] cosmic sources. In order to receive the weak radio wave signals, the satellite had twin antenna booms that were extended from the main body of the spacecraft once it was in orbit. Tip to tip, the antenna were taller than the Empire State Building. Seven years later, Goddard launched another radio astronomy satellite, Explorer 49, to look for radio signals at slightly different wavelengths.

Among other things, radio astronomy can identify certain elements whose "fingerprints" fall in the radio wave portion of the spectrum. Goddard's Submillimeter Wave Astronomy Satellite (SWAS), for example, is being designed to examine the chemical composition of interstellar galactic clouds to help determine the process of star formation. The SWAS satellite is the third mission in Goddard's Small Explorer (SMEX) program, and is scheduled for launch in early 1999. [19]

Microwave/Infrared Astronomy

COBE

Some of Goddard's most significant astronomical research has been conducted in the microwave/infrared region of the spectrum, right above radio signal wavelengths. It's a very difficult region to explore, because it involves such low temperatures. The phenomena scientists are trying to detect have temperatures as low as three degrees Kelvin, or almost absolute zero. The heat most instruments and detectors generate is higher than that and would obscure any signals at these wavelengths. So an infrared or microwave satellite has to have cryogenically cooled instruments, which is a very cumbersome and difficult proposition. Yet this portion of the spectrum offered our best window back to the dawn of time, which prompted scientists to try to solve the difficulties inherent in exploring it.

Over a 15-year period, a Goddard team succeeded in designing, building and launching a satellite capable of exploring portions of the universe in this challenging region of the spectrum. The Goddard-built satellite, called the Cosmic Background Explorer (COBE), went in search of data to test the "Big Bang" theory of the origin of the universe - and found it.

The origins of the COBE satellite actually date back to at least 1965, when two researchers at Bell Telephone Labs in Holmberg, New Jersey detected a background microwave "noise" coming in equally from all directions of the universe, not related to any particular object or event.

The Cosmic Background Explorer satellite under construction in a clean room.

[103] Scientists realized that this low-energy background noise might hold the secret to how our universe was formed.

Several different theories had been put forth as to how the universe began and how it was evolving. One of the most popular was the "Big Bang" theory, which held that all the matter and energy in the universe was created in one initial explosion and had been expanding ever since. According to the theory, matter and energy had been changing and evolving in various combinations since then, but no additional major inputs of energy or matter had occurred in the 14 billion years since that initial explosion.

If the Big Bang theory was correct, the very beginning moments of the universe would have consisted of a cosmic oven of tiny particles of matter and anti-matter colliding into each other at tremendous rates. Each collision would have annihilated the matter, creating energy, but the temperature of this primordial soup would have been so hot that that energy, in turn, would be constantly creating new matter and anti-matter. As the energy decreased and dissipated from the initial explosion, a point would have been reached when new matter would no longer be created. At that point, there was evidently a little more matter than anti-matter. The matter clumped together to form galaxies, and the remaining energy became the cosmic background radiation.

If no additional energy inputs had occurred in the billions of years since then, that background radiation should...

After the Challenger accident, the COBE satellite had to be redesigned into a much smaller, lighter pckage so it could be launched on a Delta rocket.

....behave like a "blackbody," which emits heat and in a uniform and specific manner at all points. If there had been some other source of heat or energy during the evolution of the universe, that smooth blackbody curve of radiation would have distinctive bumps in it where the energy increased.

To find out the behavior of this cosmic background radiation, scientists had to develop instruments that could detect wavelengths typical of a body with a temperature of three degrees Kelvin - the wavelength at which that very old cosmic background radiation would be at its brightest. A young Goddard scientist named John Mather had done his doctoral thesis on cosmic background radiation, and in 1974 he proposed a follow-on experiment that might work on such a satellite. The result was COBE - a project that eventually...

[104]

The thin bright horizontal line represents the disc of our galaxy as recorded by COBE in far infrared light.

....involved the efforts of almost 1500 people, cost between $300-400 million, and took 15 years to complete - but which unlocked the door to the dawn of time.

The COBE satellite consisted of three main instruments, all of which had to be cryogenically cooled to almost absolute zero. The Far Infrared Absolute Spectrophotometer (FIRAS) would examine the cosmic background radiation to see if it behaved like a blackbody in the three-degree Kelvin temperature range. If it did, the radiation should increase in a smooth curve approaching the wavelength equivalent to three degrees Kelvin, peak at the 2.78 degrees Kelvin wavelength, and then decrease in a similarly smooth manner as the wavelength and frequency increased beyond that.

A second instrument, called the Differential Microwave Radiometer (DMR) was designed to make an all-sky map of the brightness of the background radiation to look for evidence of how galaxies developed from the homogeneous soup of the universe's earliest stages. Miniscule temperature fluctuations in the cosmic background radiation would reveal places where matter was denser than others, pointing out where and how galaxies began to form.

The third instrument, called the Diffuse Infrared Background Experiment (DIRBE), was designed to search for residual light from the earliest galaxies. If there had been galaxies in the early universe, it was so long ago that we probably couldn't detect individual light sources. But there might be a distinct residual "afterglow" from those galaxies at very long wavelengths. Scientists hoped the DIRBE instrument could detect this faint evidence of celestial bodies in the primordial universe.[20]

As with numerous other Goddard satellite projects, COBE was a tremendous challenge, requiring great technological leaps and innovation. Engineers and scientists could not write a specification for the instruments or spacecraft to operate them because nobody knew how to build them. It had never been done before. So the COBE team simply set out to design its own systems and instruments. It was not an easy process. Instruments would work on the bench and then fail when they were put into the cryogenic containers. Problems in weight, power, and cryogenic systems plagued the effort. If they didn't know before, researchers soon found out that there was a good reason no one had done this before. As Dr. Mather later put it, "The team's naivete was a blessing and a strength. We didn't know how hard it was going to be, so we went ahead and did it."

[105] The satellite was originally designed to be launched into its 560-mile high orbit from the Space Shuttle. But the 1986 Space Shuttle Challenger explosion, just as the COBE team was nearing launch readiness, changed that. The Shuttle fleet was grounded and would probably never launch from the the west coast site COBE needed. Scrambling to save the project, the COBE team decided to redesign the satellite to fit on board a smaller Delta rocket that could be launched from the west coast. Among other things, that meant the satellite had to be much lighter and smaller.

In an intense two-and-a-half year effort, COBE was successfully redesigned to fit the alternate launch vehicle. Ironically, the emergency effort and limitations actually made the effort easier in some ways. There was no question of expanding weight or size, and there was no time to discuss multiple options at length. Choices had to be made quickly and decisively. The team was also helped by the fact that, in the wake of Challenger, NASA saw COBE as something that could offer the agency a much-needed success story. Consequently, the effort suddenly became a high-priority project. Team members who had had to split their time with other projects were put on COBE full-time, and the team was relocated so the engineers and scientists could all work together in the same place.

In January 1989, COBE was successfully launched into orbit. The effort to get it there had been tremendous, and some Goddard employees jokingly referred to COBE as "the project that ate the Center," because so many people were involved in it by the time the satellite was finally launched. But when the results started coming in, everyone realized the effort had been well worth it.

As the data from the FIRAS instrument began to come in, the project scientists were rendered almost speechless. The data points and the predicted curve were not just close ... they were identical. The results were so astounding that when they were presented to the American Astronomical Society in January 1990, they drew a standing ovation from the....

The redesigned COBE satellite launched on 18 November 1989.

[106] ....normally reserved society scientists. There could be no doubt about it. COBE's data pointed clearly to a universe whose energy had been generated in one initial explosion and had been radiated out in a uniform manner at all points ever since.

It took a little longer to get firm results from the DMR instrument but eventually it indicated that there might be enough of a temperature differential in the cosmic background radiation to account for the clumping of matter into galaxies. The DIRBE results took even longer to analyze but, in early January 1998, the team scientists finally announced that they had, in fact, found evidence of an infrared background glow from the earliest stars and galaxies.

Do these results mean that we have conclusively settled the question of the universe's origins? No. If anything, the lesson of the past 40 years has been that the more we learn about space, the more we realize how much we have left to learn. Every step we take into the cosmos seems to reveal an even more complex universe than the one we previously thought we inhabited. The task of COBE was a staggeringly difficult one. Its scientists were like archaeologists trying to peer back more than 13 billion years in time and detect the faint whisper of clues that still lingered, ghost-like, in a world at the dawn of time. And the project uncovered an astounding piece of evidence no one had ever been able to see before. But there are still unanswered questions and anomalies in the Big Bang theory.

Because we know there is much left to learn, Goddard is already planning a follow-on mission to the COBE satellite. Scheduled for a launch date around the year 2000, the Microwave Anisotropy Probe (MAP) satellite will explore the tiny temperature differences discovered by COBE in even greater detail. Among other things, scientists hope that by learning more about the density and arrangement of matter in the early years of the universe, we can begin to predict whether or not the universe will keep expanding.[21]

Visual/Ultraviolet Satellites

Orbiting Astronomical Observatories

The very first astronomy satellites concentrated on the visual and ultraviolet regions of the spectrum. In part, this was because scientists had yet to realize the potential of some of the other wavelengths, but it was also because the very high and low frequency wavelengths required more complex technology to explore.

But even these first astronomy satellites came after the initial round of simple, particle and field-detecting spacecraft,....

Goddard's Orbiting Astronomical Observatory was one of the first significant attempts to pursue visual and ultraviolet astronomy from a satellite platform. (NASA Photo G-71-2148)

[107]....because astronomy satellites in general were harder to develop. Goddard had inherited some very good optical technicians from the Naval Gun Factory that had been located next to the Naval Research Lab, but developing a spacecraft for a telescope was harder. An astronomy satellite had to be stabilized and have the ability to point at one object for a relatively long period of time.

Goddard's first astronomy satellite was also its first attempt at a larger, observatory-class spacecraft. Called the Orbiting Astronomical Observatory (OAO), it was designed to explore the sky in both the visual and ultraviolet regions of the spectrum. Ultraviolet light is one of the wavelengths blocked by the Earth's atmosphere, and it was one of the regions astronomers were most interested in pursuing in the early 1960s. The astounding high energy world of neutron stars and black holes had yet to be discovered. The OAO satellite, however, was a tremendous technological leap that incorporated new sensor technology, new experiment technology and complicated ground system software that required constant updating. Experimenters on the ground who were commanding the OAOs were often only a couple of orbits ahead of the spacecraft, which made it a high-stress project.

The first OAO was launched in April 1965 but developed problems soon after reaching orbit. The high-voltage system on the star trackers that it needed to stabilize itself began arcing, and its battery overheated. After a mere 20 orbits, the satellite failed. It was not until December 1968 that the first successful astronomical satellite, OAO-2, reached orbit. OAO-2 allowed the Smithsonian Astrophysical Observatory to compile the first complete ultraviolet map of the sky, creating a catalog for use by astronomers. The satellite also provided new information on the composition of interstellar dust and hot stars.

Four years later Goddard launched OAO-3, also known as the "Copernicus" observatory, which lasted eight years and was an extremely successful astronomy satellite. Copernicus reached much farther into the ultraviolet region of the spectrum than the earlier OAOs had and gave scientists information much more detailed information about the chemical composition of certain stars and interstellar gases.

The OAO satellites were complex to operate and somewhat limited in their abilities, because they were pioneers in the space astronomy effort. But they provided valuable information and laid the groundwork for further discoveries by the Hubble Space Telescope and Goddard's International Ultraviolet Explorer.[22]

The Hubble Space Telescope

The origins of the Hubble Space Telescope date back to the late 1960s, when NASA managers began thinking about follow-on projects to the OAO satellites. Originally called the "Large Space Telescope," the facility was renamed before launch in honor of Edwin P. Hubble, an astronomer who determined in 1929 that the speeds with which galaxies are moving...

[108]

The Hubble Space Telescope was launched from the Space Shuttle in 1990.

....away from us is proportional to their distance. This "Hubble's Law," is a crucial tool still used by astronomers in trying to determine not only the location of distant galaxies, but also the size and shape of the universe itself.

NASA Headquarters decided to award management of the Hubble project to the Marshall Space Flight Center, although the scientific instruments and ground system would be Goddard's responsibility. Goddard would also be responsible for operating the telescope once it was launched. To reassure the external scientific community, which feared NASA scientists might have too much of an inside edge on this powerful astronomical tool, selection and processing of individual experiments using the telescope were delegated to an independent Space Telescope Science Institute set up specifically for that purpose in Baltimore, Maryland.[23]

Goddard scientists and engineers had fought hard to get full responsibility for developing the telescope, and there were hard feelings over the decision that lingered between the two NASA Centers for years. As one scientist described it, the fight over Hubble wasn't just a disagreement, "It was a war." But with the decision made, Goddard's team shrugged their collective shoulders and, as usual, got down to the work at hand. But the decision to split the responsibility between the two centers would come back to haunt the agency.

The Space Shuttle Challenger explosion delayed the launch of the Hubble, which was designed to be launched from a Shuttle. But in April 1990, the telescope was finally put into orbit, amidst great hope and expectation. This was the largest telescope ever put into space, and it was expected to return images clearer and more detailed than anyone had ever witnessed before. But as operation of the telescope was turned over to Goddard and the first images began to appear, it became obvious that something was wrong. The images were blurry.

Coming so soon after the Challenger disaster, the flaw in the Hubble telescope was a devastating blow to NASA's credibility in the scientific community and the public at large. Goddard engineers knew what was at stake. But they were at a severe disadvantage in terms of trouble-shooting the problem, because they had only been nominally involved in building of the actual telescope.

Goddard quickly put together a team to start working on a fix. In addition to Goddard personnel, the team included [109] representatives from the Marshall SpaceFlight Center and the Space Telescope Science Institute. Lockheed, which had built the spacecraft, and the Perkin-Elmer company[24], which had an excellent reputation in optics and had built the telescope's primary mirror, also sent experts to Goddard to join the trouble-shooting team.

The team members agreed they had three top priorities. First, they had to figure out what was wrong with the telescope. Second, they had to figure out what it would take to fix it. And third, they had to figure out how scientists could use the telescope until they could get it fixed.

The team soon discovered that the error was caused by a tiny flaw in the telescope's primary mirror. A piece of tooling used to test the mirror's accuracy had been installed backwards, causing the two-and-a-half meter diameter mirror to be 2.34 microns flatter at its edges than it should have been. The discrepancy was microscopic, equivalent to 1/50th the width of a human hair. But it was enough.

The good news was that the Hubble telescope had been designed to be serviced in space, so it had modular instruments and components that could be pulled out and replaced. The bad news was that because the error was in the telescope's primary mirror, it affected the operation of all five of the telescope's instruments.

One of the instruments, the Wide Field/Planetary Camera, was scheduled to be replaced in a servicing mission, anyway. So a corrective optical lens could be built into the upgraded replacement camera. But replacing all the instruments would be far too costly.

A group headed by researchers at the Space Telescope Science Institute that also included engineers from Goddard, Marshall, and the European Space Agency (ESA) began studying other possible solutions. In the meantime, scientists and engineers began looking at what science could be done with the telescope until it was repaired.

Even the blurry images were better than anything that had been available before, which was encouraging. And scientists soon found that the telescope's performance was acceptable for bright objects. It was faint objects that caused the biggest problem. Some of the images were also degraded because the telescope's flexible solar arrays, which had been designed and built by the Europeans, had developed a "jitter"...

Images of Supernova 1987A and its circum stellar rings from the Wide Field and Planetary Camera (image at left) and from the Space Telescope Imaging Spectrograph (STIS) (images at right). The STIS data show multiple images, each representing the emission from a distinct chemical constituent. (NASA Photo PRC97-114)

[110] ....as the spacecraft transitioned from night to day. Researchers found ways to work around the jitter, developed software to help correct the fuzzy focus on the images, and concentrated the initial work of the telescope on brighter objects in the universe. But while these adjustments were remarkably innovative and allowed some very good science data to be drawn out of the telescope, they couldn't completely compensate for the flaw. In order to get the promised science out of the telescope and restore NASA's credibility in the eyes of the scientific community and the American public, the team needed to actually fix the source of the problem.

In just a few months, the Hubble team came up with a radical idea for a solution. The scientists and engineers proposed...

Astronauts practice in a weightless water tank facility for the Solar Maximum repair mission. The experience gained from that 1984 mission helped make the 1993 Hubble servicing mission possible. (NASA photo S83-42898).

....replacing the least-used instrument on the Hubble with a module that would contain a corrective optics system for the remaining three instruments. The Corrective Optics Space Telescope Axial Replacement (COSTAR), as they called it, would contain ten separate mirrors, ranging in size from a dime to a quarter, that would refocus the light reflected from the primary mirror before it entered the three "axial" instruments.[25] In order to work, these tiny mirrors would have to be accurately polished to 1/50th of a wavelength of white light.

It was a risky proposition. Even if the complicated COSTAR instrument could be built with that degree of accuracy, it would have to be installed in space, and it had to work perfectly. NASA couldn't afford another embarrassing failure. Some NASA managers suggested limiting the effort to the less challenging task of replacing the Wide Field/Planetary Camera, which was the instrument that took all the visible light photographs. But team leaders argued that Goddard and NASA owed the scientific community a fully working telescope. The COSTAR project was approved.

With only 80 employees and more experience in large-screen television systems than space instruments, Tinsley Optical Laboratories in Richmond, California was an unlikely candidate to make the COSTAR mirrors. But it turned out that the processes for building both products were surprisingly similar, and every employee of the small company took on an almost personal responsibility for making sure the mirrors were made correctly.

[111] The Hubble repair mission became the number one priority at Goddard, as well. The team had a target date of June 1993 for the repair mission to take place, with a outside deadline of June 1994. Eventually, the team committed to having the mission ready to launch by 1 December 1993.

To make that date, there was a lot that had to be done. The problem with the solar arrays had to be found, and new arrays had to be built. Meanwhile, the telescope had developed problems with its gyros, which would have to be replaced, as well. To make all these repairs in orbit also would require more Extra-Vehicular Activity (EVA) time on the part of the Shuttle astronauts than any mission to date, and the work would be challenging.

The Goddard-managed recovery team convinced managers at the Johnson Space Center to assign the astronauts for the repair mission a full year earlier than usual, giving them almost two years to prepare for the mission. Johnson also agreed to put only veteran Shuttle astronauts on the mission, so nobody on the mission would be adjusting to space for the first time while the team tried to work on the telescope.

The astronauts shuttled back and forth between Goddard and Johnson, learning the spacecraft's systems and rehearsing the servicing effort as well as every contingency and emergency managers could envision. They even spent a record 400 hours in Johnson's neutral-buoyancy water tank practicing the five EVA missions the repair would require.

All of this activity, of course, had to be done in the fishbowl of scrutiny following the discovery of the Hubble flaw. By the time the servicing mission was launched, no fewer than 18 external review committees were overseeing the team's efforts.

But on 1 December 1993 the team was ready, as promised, and the Space Shuttle Endeavor thundered off its launch pad on an 11-day mission to retrieve and fix the Hubble telescope. As the astronauts prepared to...

Two image of the spiral galaxy M100 from the Hubble Space Telescope. The image on the left was taken a few days before the first servicing mission. The image on the right, taken after servicing, shows a vast improvement in clarity. (NASA Photo PR94-01)

[112] ....head home a week and a half later, the mission appeared to have been a success. The proof, however, would lie in the images transmitted back to Earth once the telescope was back in orbit.

Goddard scientists and engineers watching at the Space Telescope Science Institute held their breaths as they waited for the first images, knowing that the consequences of another error would be terrible. As one team manager put it, "We felt like the future of the Agency was riding on this effort. We really did." They needn't have worried. A crystal-clear image of a star appeared on the main computer screen, sending cheers and applause through the room. An effort that some experts had given no more than a 50% chance of success had succeeded beyond everyone's wildest expectations.

In recognition of the challenge, the effort, and the accomplishment, the Hubble team was given numerous awards. The team was even awarded the 1993 Collier Trophy - recognizing the servicing mission as the greatest aeronautical achievement in the nation that year.

With the flaw repaired, the Hubble Space Telescope finally began fulfilling its long-awaited promise. The images its high-resolution camera and instruments have brought us since 1994 have been nothing short of awe-inspiring. From the towering pillars of starbirth in the Eagle Nebula to the artistically spectacular shock waves from exploding and dying stars, the Hubble has brought the distant universe to our doorstep in brilliant, breath-taking technicolor.

The Hubble provides extraordinarily clear images, illuminating far more detail about a wide variety of phenomena in the solar system, the galaxy and the universe than scientists ever had before. In 1994, the Hubble captured the collision of a comet into the planet Jupiter. It has been able to distinguish the shape of galaxies at distances so far away, and therefore so far back in time, that we can start to see a pattern in how galaxies evolve. It has also let us see at least the visible and ultraviolet results from the collisions of galaxies and the death of giant stars.

In fact, the visible and ultraviolet images[26] from the Hubble have been able to give scientists a lot more detail about the life cycle of stars. It has generated clear images of dusty stellar nurseries, newborn stars with potential solar system material massing around them, bright, Sun-like stars in nearby galaxies, swollen giant stars approaching destruction, and the remnants of supernovae at different stages following these stars' explosions.

The gas clouds surrounding smaller dying stars are cool enough that they lend themselves well to analysis in the ultraviolet and visual ranges, and Hubble has produced a virtual catalog of the different shapes these "planetary" nebulae can take. Some nebulae are round, but others are shaped more like hourglasses, butterflies, goblets, rectangles, or streaming jets. Scientists are still puzzling over this phenomenon because, up until their death, all these stars have the same basic round shape.

[113] The Hubble Space Telescope's capabilities were improved even further by another planned servicing mission in 1997. These upgrades included the addition of a Near-Infrared Camera and Multi-Object Spectrometer (NICMOS), which will offer much greater detail in the cooler infrared region. Another upgrade is called the Space Telescope Imaging Spectrograph (STIS). Among other things, this instrument is useful in finding possible galactic black holes, because one of the signatures of this phenomenon is a swirling motion of the galaxy surrounding it. As the galaxy swirls, part of it is moving away from us, shifting its light lower in the spectrum, while another part moves toward us, shifting its light higher. The STIS spectrometer can create an extremely detailed cross-section image of a galaxy, measuring shifts in wavelength at 500 different points across the galaxy simultaneously. By comparison, previous spectrometers looking at these celestial bodies could sample only a dozen or so points. Scientists hope the more detailed images provided by the STIS will help identify swirling and other types of galactic movement.

Even before the STIS instrument was put on the Hubble, however, the technology developed for it was put to work here on Earth. The digital imaging technology used in the instrument has provided doctors with a new technique that facilitates non-surgical biopsies on women who may have breast cancer.

Additional servicing missions are planned for the Hubble in 2000 and 2002.

A Hubble image of planetary nebulae with striking bipolar structure. (NASA Photo PR97-38).

Scientists hope that these improvements will allow the telescope to extend its useful life until at least 2005. A study is currently underway for a "Next Generation Space Telescope" (NGST), which scientists hope will succeed the Hubble. If it is approved, the NGST will have much greater light collecting power than even the Hubble possesses and will be optimized to look in infrared light at the earliest galaxies of the ancient universe.

The STIS captured this text-book case of the Z-shaped spectral signature that reveals the presence of a super massive black hole in galaxy M84. (NASA Photo PRC97-12)

Of course, the more "invisible" wavelengths are every bit as important in piecing together the puzzle of our universe as those we can see. But the Hubble is particularly popular because we are, in the end, a visual species. The data from the Hubble's instruments have given scientists many valuable new insights about the universe. But the photographs and enhanced infrared and ultraviolet images from the telescope have reached far beyond the scientific community. They have sparked the imagination of millions of people who now gaze up at the night sky with a reawakened sense of curiosity and wonder. For without even a single word of...

[114]

An infrared image of the Egg Nebula, taken by the Near-Infrared Camera and Multi-Object Spectrometer instrument on the Hubble Space Telescope. (NASA Photo PRC97-11)

....explanation, the Hubble images have made us realize how powerful, beautiful and mysterious the universe can be.[27]

International Ultraviolet Explorer

While the Hubble Space Telescope was still in its embryonic planning stages, another satellite project devoted exclusively to exploring the ultraviolet realm was taking shape. The ultraviolet discoveries of the OAO satellites in the 1960s had made scientists eager to explore further into this previously invisible realm of the spectrum with a telescope specifically designed for that purpose.

The satellite was called the International Ultraviolet Explorer (IUE), which was put into orbit in 1978. Although some components came from other places, the spacecraft was constructed in-house at Goddard. Having learned some difficult operating lessons from the larger, more cumbersome OAOs, the scientists decided to design the IUE to have a geosynchronous orbit. While this would dramatically simplify ground operations for the satellite, because it would be in sight of a ground station all the time, it meant that the spacecraft had to be small and light enough to reach an orbit 23,000 miles above the Earth. It would also have to have very high-resolution cameras and an extremely precise pointing system, accurate to within a few arc-seconds.

Another unique aspect of the IUE was that it was developed as an international project between NASA, the European Space Agency (ESA), and the British Science Research Council. The detectors and solar panels were supplied by the Europeans, and the telescope and spacecraft were designed and built by Goddard. The OAO's star tracker problems taught Goddard's engineers that a better way was needed to stabilize an astronomy satellite. So they worked with the Bendix Corporation to develop an inertial gyro system for the IUE that turned out to work so well that the spare was used in the Hubble Space Telescope. In fact, the IUE continued to work flawlessly for 11 years with only two of its initial six gyros, and the team even managed to operate the satellite for the last six months of its 19-year life with only one remaining gyro.

Technology also had advanced far enough by the mid-1970s, when the IUE was being built, that it could incorporate a vastly simpler ground computer system. The interface between an experimenter's software system and the satellite's system was designed to be "transparent," so that outside astronomers could use the IUE telescope [115] as easily as they used their own ground-based observatories, making adjustments in real time. This change meant that observers no longer had to be experts in satellite instrumentation. As a result, it opened up a whole new era in space science and generated a lot more support for satellite research in the astronomy community.

The IUE was scheduled to launch in mid-January 1978. Only a couple of weeks before that, however, a short circuit was discovered somewhere in its internal wiring system. On New Year's Eve, the satellite was sitting in many pieces on the floor of Goddard's clean room as engineers and technicians searched for the trouble spot. Even if the problem was solved quickly, there wouldn't be time to complete another full test on the satellite if it was going to make its launch date. But the technician in charge of the repair solemnly promised the engineers and scientists in charge that the satellite would be fixed and reassembled not only perfectly, but on time. It was, and on 26 January 1978 the IUE satellite was launched into orbit.

Observing time on the IUE was shared between the United States and European partners. Goddard controlled the satellite 16 hours a day, and the Europeans controlled it the remaining eight hours.

Goddard's International Ultraviolet Explorer was one of the most successful satellites in NASA's history. Designed for a 5-year mission, it was a facility used by thousands of astronomers for nearly 19 years.

The IUE was originally designed for a five-year mission. To everyone's surprise, it...

[116]

Data depicting Comet 1983D. The ultraviolet spectrum of Comet 1983D, as obtained by the International Ultraviolet Explorer.

....kept returning useful data for almost 19 years, adding a tremendous amount to our understanding of our solar system, our galaxy, and the universe.

One very basic and important contribution of the IUE was that it allowed scientists to fill in observations of thousands of celestial objects in a previously unobtainable portion of the spectrum. But there were also some objects and phenomena that could be studied particularly well in ultraviolet wavelengths. The temperature of many of the gas clouds surrounding stars, in between stars, and in between galaxies, for example, means that they create a signature in the ultraviolet range. As a result, the IUE was able to teach scientists a lot about the temperature, density, and behavior of this circum-stellar, inter-stellar, and inter-galactic matter. Among other things, IUE data indicated that just outside of our galaxy was a "halo" of hot gas that scientists had not known existed.

By analyzing the gas clouds surrounding the nuclei of active galaxies, the IUE was able to help measure the size, temperature and behavior of these high-energy objects. In addition, the satellite played a key role in observing the Supernova 1987A that occurred in the nearby Large Magellanic Cloud galaxy. Scientists were not sure, at first, which of two closely located stars in the galaxy had exploded. The IUE accurately detected which star had exploded, which was significant because Supernova 1987A was the closest supernova to occur since the invention of the telescope. Scientists knew that the star which had exploded had been one they had observed before, but the two possible candidates were different types of stars. IUE's results told scientists that the star that had exploded was the "blue supergiant" star - a fact which surprised researchers but provided significant new information about stars and supernova explosions. IUE also continued to help study the Supernova's debris as it expanded from the initial explosion.

The satellite also confirmed that many other stars in the galaxy had chromospheres, just like our own Sun. In addition, it provided important information about how gas flows behave in binary star systems, disproving one previous theory about how matter flowed to and from companion stars.

The IUE satellite taught us many things about events in our own solar system, as well. Although radio astronomers had previously found radiation belts around the planet Jupiter, IUE made the first [117] extensive study of auroral activity on the planet.

IUE was also extremely helpful in allowing us to better understand comets. Once, scientists thought comets were little more than dirty ice balls. And the IUE did determine that Halley's comet had tremendous water reserves, spewing off up to ten tons of water per second during its last flyby of our Sun. But the IUE also detected sulfur emissions from the IRAS-Araki-Alcock comet's nucleus, providing solid evidence that comets were much more complex than scientists had once thought. In fact, quantitative evidence of numerous elements has now been detected in comets, lending support to the idea that comets might be cosmic "Johnny Appleseeds," seeding planets in the galaxy with water and other elements necessary for life. Whether or not this is true may depend on whether comets originate inside or outside our solar system - a question that will take further study of comets in order to answer.

By the time the IUE was finally shut down in September 1996, it had accommodated almost four thousand guest observers. Those scientists, in turn, had generated more than 3500 scientific papers from IUE data, making it the most prolific satellite project in NASA's history.[28]

Extreme Ultraviolet Explorer

As technology progressed even further, it allowed scientists to contemplate telescopes that could observe the universe in more difficult wavelengths, such as the extreme ultraviolet range. Some scientists believed that there would be no use in investigating this short range between ultraviolet and X-ray wavelengths, because hydrogen and helium atoms in their normal state block these emissions. Because hydrogen and helium atoms are the most plentiful elements in the universe, it might stand to reason that a satellite looking for this type of emission from distant sources might not find very much.

But some scientists argued that from a scientific standpoint, we should observe the universe in all available wavelengths, and that we wouldn't know for sure what could be seen in the extreme ultraviolet world unless we at least made the attempt to look. NASA consequently approved another Explorer project, called the Extreme Ultraviolet Explorer (EUVE). The EUVE satellite was built in-house at Goddard, using instruments developed at the University of California, Berkeley, and launched in 1992.

While the number of extreme ultraviolet sources observable in the universe has, indeed, proven to be small, the satellite has discovered many more than most scientists expected. So far, the EUVE has identified approximately 900 stars and 11 galaxies with radiation in the extreme ultraviolet range. What that means is that there are at least portions of interstellar and intergalactic matter that are hotter and/or less dense than expected, allowing extreme ultraviolet radiation to penetrate them and reach the EUVE telescopes. The EUVE observations have enabled us to study very hot gases around stars and [118] galaxies, helping us in our ongoing effort to piece together an accurate puzzle of what our universe is and how it operates.[29]

The High Energy Universe

In the early 1960s, most scientists thought that most exciting promise of satellite-based astronomy lay in the ultraviolet wavelengths. But by the end of the decade, scientists realized that the higher regions of the spectrum had even more potential for significant and paradigm-changing discoveries. Some of Goddard's most significant contributions to astronomy, in fact, have been in this high-energy astronomy field.

A group of scientists from the Naval Research Lab (NRL) began exploring X-rays coming from the Sun in 1948, using short-duration sounding rocket...

A ROSAT X-ray image showing the remnants Tycho's Supernova of 1572.

....flights to get above the Earth's X-ray-absorbing atmosphere. The first X-ray source from outside the solar system was discovered in 1962 by a sounding rocket research group headed by Riccardo Giacconi, from American Science and Engineering, and Bruno Rossi, from the Massachusetts Institute of Technology. The researchers thought they were going to look at solar-induced X-rays from the Moon, but they detected another object in the sky emitting X-rays in far greater quantities than the Sun. Because the source was a star in the Scorpio constellation, it was named Sco X-1. Their results, confirmed a month later by the NRL group, cracked open the door to a universe that until then had been completely hidden from view. They also sparked interest in developing follow-on satellite research projects to probe further into this "invisible" universe.

Throughout the 1960s, bizarre new sources of high-energy radiation were found. One particularly puzzling find was an X-ray source in the Crab Nebula, a gas cloud that was the remnant of a supernova explosion that occured almost a thousand years ago.

A supernova is one possible result when a star uses up the nuclear fuel at its core and "dies." The energy from nuclear reactions at the core of a star are what keep it from collapsing under the weight of its own gravitational field. When those reactions cease, the star will collapse on itself. If it's a small to medium-sized star, like our own Sun, it will become what's known as a "white dwarf." A white dwarf [119] is about one-one-hundredth the size of the original star, which means that our Sun would end up about the size of Earth. That much compression generates a tremendous amount of heat, turning the star "white-hot" - hence the object's name.

A star five times the size of our Sun will collapse with even more force, generating a tremendous "supernova" explosion that propels most of its material out into intergalactic space. This explosion is so powerful that it can generate energy as intense as the light from 10 billion suns. The shock waves from the explosion can spread as far as 100 light years, seeding the galaxy with heavier elements and heating the interstellar gas enough to trigger the formation of new stars. The material that is left is compressed so far that the atoms themselves are crushed. The positively-charged protons in the nuclei capture the negatively-charged electrons circling them, becoming neutrons. The resulting object is known as a "neutron" star. The collapsed matter in this kind of star is great that a particle 1/10th of an inch in diameter would weigh as much as an aircraft carrier.

When an even larger star explodes, the gravitational weight of the remaining material can be so dense that it collapses in on itself indefinitely, creating a strange phenomenon known as a black hole. The gravitational pull of a black hole is so great that neither matter nor light can escape from it. Black holes are still not well understood, but rocket and satellite research over the last 30 years has taught scientists a great deal more about their existence and behavior.

Astronomers actually had observed white dwarfs as far back as 1862, and had come up for an explanation for the objects by 1933. But until the late 1960s, neutron stars and black holes existed in theory only. The first real evidence of a neutron star was finally found in the Crab Nebula, which had perplexed astronomers ever since they had detected X-ray emissions coming from the cloud in 1962. The X-rays were puzzling because the Crab Nebula was the remnant of a supernova that occurred in 1054 A.D. High energy emissions from an explosion that long ago should have dissipated by now. So the continuing presence of X-ray emissions was a mystery.

The mystery was solved in 1968 when radio astronomers discovered a very strong, regular and rapid pulsing signal coming from deep within the Nebula. At first, the odd signals were nicknamed "LGMs," because some people thought they might be "little green men" signalling us from a distant galaxy. But scientists soon realized that the pulsing signals were from a new class of object that was apparently rotating at a rate that would tear most objects apart - thirty times a second in the case of the Crab Nebula. In order for something to hold together at that rate, it would have to have a staggeringly high density level. This was the clue that led scientists to the discovery of neutron stars.

Scientists deduced that, in the process of being compressed from large star into an ultra-dense remnant core in a supernova...

[120]

This X-ray image shows the Crab Nebula with its intense spinning neutron star, or pulsar, at its core. The white area indicates the position of the pulsar which emits a high level of X-ray radiation. The yellow area marks the milder X-ray signature across the rest of the nebula.

....explosion, the normal rotation of the star must be accelerated greatly - in some cases as much as 100 million times. The magnetic field of the star also must be amplified by the compression, creating a stream of strong radio waves that emanated from each pole. Because the star was rotating at such high speed, these signals appeared to us as pulses, leading astronomers to name these objects "pulsars."

The discovery of the pulsar-type of neutron star explained the mysterious high-energy emissions from the Crab Nebula and gave scientists another hint about the complexities and amazing phenomena that lay undiscovered in the "invisible" realm of the high-energy universe. It also made astronomers even more interested in exploring this realm from the unencumbered perspective of space.[30]

Uhuru

The first three satellite projects dedicated to high-energy astronomy were Explorers developed and managed by Goddard. Explorer 42 was the first of the Small Astronomy Satellite (SAS) series, as the three were called. It was launched by a joint team from NASA and the University of Rome, Italy on 12 December 1970, from a platform off the coast of Kenya. Since the satellite was also launched on Kenya's day of independence, it was named "Uhuru," which is the Swahili word for "freedom."

The Uhuru satellite provided the first detailed and accurate view of the X-ray sky, cataloging 161 X-ray sources with luminosities as great as one thousand times the strength of our Sun. That catalog was a significant contribution to the astronomical community. In fact, it was cited more than any other scientific paper in the year it was published.[31]

The Uhuru satellite also discovered that many, if not all, X-ray stars were part of binary systems in which a very strong, dense collapsed star was actually pulling matter off of a nearby larger star, producing X-ray emissions in the process. Some of these collapsed stars were neutron stars, but Uhuru made an even more significant breakthrough by studying a particularly strong binary X-ray system called Cygnus X-1. In looking at the satellite data, scientists realized that they had found what would prove to be the first tangible evidence of a black hole. In a black hole, matter is pulled off a companion star and pulled into the hole's immense gravity field. As the matter swirls down into the hole it is compressed, heating it to temperatures of tens of millions or even a billion degrees, creating flashes of X-ray and [121] gamma ray energy before it finally disappears into the black hole.[32]

Other X-Ray Satellites

Several satellites have pursued X-ray astronomy since Uhuru. In 1975, Goddard launched SAS-3, which looked more closely at some of the X-ray sources mapped by the Uhuru satellite. That work was followed in 1977 by the first of three High Energy Astronomy Observatory (HEAO) satellites. The HEAO projects were managed by the Marshall Space Flight Center, but Goddard provided the project scientist on the first two HEAO satellites, which focused on X-ray astronomy.

HEAO A, like Uhuru, was a scanning mission that mapped the sky in numerous X-ray frequencies. The second observatory, HEAO B, carried the largest X-ray telescope ever built. Two X-ray telescopes had flown successfully aboard Skylab,...

One of the advantages of exploring the universe in numerous regions of the electromagnetic spectrum is that different wavelengths can tell scientists different things about the same object. This image shows a single black hole as it appears in optical/UV, X-ray, and gamma ray wavelengths of the spectrum.

[122] ....giving scientists the confidence that a focusing X-ray telescope could work on a satellite like HEAO. Since HEAO B's November 1978 launch date was the centennial of physicist Albert Einstein's birth, the satellite was named the "Einstein Observatory." This observatory became an extremely successful project. One of the secondary objectives of project managers was to bring X-ray astronomy into the mainstream of the astronomical community, so the Einstein Observatory was designed to incorporate guest observers. Eventually over 400 guest astronomers used the satellite's telescope.[33]

The results of these satellites have changed our entire view of the cosmos. The HEAO satellites indicated to scientists that all stars are X-ray sources at some level. Because supernovae, neutron stars and even the matter surrounding black holes emit most of their energy in the X-ray region, these satellites gave astronomers the opportunity to study these incredibly powerful events and objects in the universe for extended periods of time.

X-ray satellites have also found important clues to the structure of both our own Milky Way galaxy and other galaxies in the universe. Before the Einstein Observatory was launched, only three other normal galaxies outside our own had been detected in the X-ray region of the spectrum. By the end of the HEAO project, well over 100 galaxies that gave off X-ray radiation had been identified.

The satellites also found evidence that explosive activity was present in almost all galaxy nuclei, including our own. Some galaxies are more energetic than others, however. Some of the most energetic of these are called "quasars," or "quasi-stellar objects," because they are so distant that they initially appeared to be single stars. These quasars can be detected as far away as ten billion light years and are so powerful that one the size of our solar system would put out more energy than ten trillion of our Suns. The source of this incredible energy is still something of a mystery, but scientists are beginning to find evidence that indicates these galaxies may have tremendous black holes at their centers.

In fact, it's possible that all galaxies begin life as quasars. Early star clusters spiralling toward the center may form a giant star that eventually collapses and forms a black hole. After the black hole at its core devours all the star material near it, the galaxy may settle down, becoming a "normal" galaxy like our own. These quasar galaxies may provide clues to the formation of galaxies in the early universe, because the energy we detect from them originated so far back in time.[34]

Investigations with X-ray satellites have also given us a better understanding of how galaxies interact with one another. Many of the universe's galaxies, it turns out, are clumped together in clusters. Especially in dense clusters, the galaxies can collide with each other. The friction from these collisions may slow a galaxy down, causing it to spiral in toward the center of the cluster where its stars may be [123] torn apart by a larger galaxy there that "feeds" on inward-spiralling galaxies. Over time, this would result in galaxy clusters with a giant galaxy at the center surrounded by much dimmer galaxies. This theory was given a boost when HEAO A found evidence of just this type of galaxy cluster.

This process is occurring in our own galaxy, as well. X-ray satellites have shown us that the Milky Way has an active galactic nucleus sending out bright X-ray signals that may be a from a black hole. Our galaxy has also experienced collisions with other, smaller galaxies. Scientists recently discovered a small galaxy that had collided with ours in the Sagittarius constellation, for example. The odd thing about this galaxy was that even though scientists estimated it had orbited around that location about ten times, it was still intact. For a small galaxy not to be ripped apart by the gravitational forces of a larger galaxy with which it collides, it must contain very dense material. It may be that this small galaxy contains a large amount of "dark matter" - one of the great remaining mysteries of the universe.

Dark matter, which may make up as much as 90% of the matter in the universe, cannot be observed. But something beyond the matter we can see must exist in space, or even our own spiraling galaxy cluster should fly apart. Dark matter also may provide the answer to whether our universe will continue to expand or will eventually start collapsing back in on itself. Based on the observable matter we know, there is not enough density in our universe for it to stop expanding. But if there is enough dark matter, with enough mass, the universe may actually have enough density to stop expanding at some point in the distant future.[35]

Recent X-ray Satellites

Scientists at Goddard and elsewhere are continuing to work together to learn more about how stars and galaxies evolve and behave. Goddard has provided part of the scientific payload on two Japanese satellites designed to further explore the X-ray region of the spectrum. And in 1996, Goddard launched the Rossi X-Ray Timing Explorer (XTE) satellite to take a more precise look at collapsed stars and massive black holes in quasars and galaxies. The XTE satellite is the first U.S-sponsored X-ray mission since HEAO B, and it was designed as an observatory satellite, in that 100% of its observation time is open to guest observers.

The XTE set out to find answers to some of the many remaining questions about the X-ray universe, such as the cause of a mysterious X-ray background radiation, similar to the infrared and microwave background radiation explored by the COBE satellite. And although previous missions have identified active galactic nuclei and neutron stars, scientists still are trying to understand the dynamics of these objects.

Yet in the process of trying to better understand these known objects, the XTE satellite has discovered some even more amazing phenomena. It found a young pulsar spinning twice as fast as any pulsar ever discovered - a remnant of a supernova [124] four thousand years ago in a nearby galaxy called the Large Magellanic Cloud. This new pulsar is turning at 60 times per second, or twice the rate of the Crab Nebula pulsar, which had been the most energetic pulsar found up until the XTE's discovery. Scientists estimate that this new pulsar may have been turning as rapidly as 150 times per second when it was created. The magnetic field of the new pulsar, on the other hand, is even weaker than that of the Crab Nebula, leading scientists to wonder if neutron stars might progress through a predictable evolutionary process. When they are created, pulsars appear to rotate at very high speeds and have relatively weak magnetic fields. Over time they slow down, and their magnetic fields appear to increase. Indeed, the magnetic fields of these stars may be the reason they slow down over time.

In exploring this phenomenon, the XTE satellite also uncovered a neutron star with what appears to be the most intense magnetic field ever found in the universe. This discovery may confirm the existence of a special class of neutron stars called "magnetars," with magnetic fields estimated to be one thousand trillion times the strength of the Earth's magnetic field. The neutron star associated with this magnetic field is only spinning once every 7.5 seconds, in contrast to faster-rotating neutron stars with weaker magnetic fields. A neutron star born with that great a magnetic field might slow down so quickly that it would be undetectable at the X-ray and radio wave frequencies where most neutron stars are found. So this discovery might account for the large number of supernovae remnants in the galaxy which do not appear to have neutron stars at their centers. It may also help us understand the rate at which stars die and seed the galaxy with the heavier elements necessary for life as we know it.

There is still much we don't understand, however. So the exploration continues. The Advanced X-Ray Astrophysics Facility (AXAF), a large X-ray telescope observatory with high-resolution instruments at least 100 times more sensitive than those on the first HEAO X-ray telescope, is currently scheduled for launch in late 1998. AXAF was originally designed as one of four "great observatories," to explore the universe in all parts of the electromagnetic spectrum. The other three are the planned Space Infrared Telescope Facility (SIRTF), the Hubble Space Telescope, and the Compton Gamma Ray Observatory (GRO). AXAF and SIRTF have been downsized considerably from their original designs, but both should still bring back important clues that will help us better understand our galaxy and our universe.[36]

Gamma Ray Satellites

Some of the most perplexing and exotic phenomena in the universe are those that emit radiation at the highest frequencies of the electromagnetic spectrum. Gamma rays, which are produced by reactions within an atom's nucleus, are produced deep within the core of stars, but they rarely reach the surface. In most cases, we have only found observable [125] gamma rays associated with phenomena such as in the birth or death of a star, or around black holes. But phenomena that create emissions at these extraordinarily high frequencies are very unusual in the universe. Out of 500 pulsars detected in the radio and X-ray regions of the spectrum since 1968, for example, only six emit gamma rays.[37]

Yet gamma rays are evidence of some of the most powerful energy events known to scientists, so they are as fascinating as they are mystifying. As we have improved our satellites and instruments, we have begun to understand a little more about what creates these rare, high-energy sources in the universe. But it is still a strange, perplexing and exciting frontier.

The gamma ray universe has been explored by scientists with Goddard satellites as far back as 1961, when a gamma ray telescope was put into orbit aboard the Explorer 11 satellite. Explorer 11 detected the first gamma ray sources outside our own solar system and helped rule out one of the major competing theories for the evolution of the universe. According to the "steady state" theory of the universe, the universe was neither expanding nor contracting, but stretched infinitely into space and time. Celestial bodies moving away from us would be replaced by the...

An all-sky image from Goddard's Compton Gamma Ray Observatory mapping the location and intensity of over 800 gamma-ray bursts. The cause of these incredibly high-energy events is still a puzzling mystery to scientists.

[126] ....formation of new matter, which would create new stars and galaxies. Explorer 11, however, found that the intensity of gamma rays in the universe was a thousand times weaker than what should have existed if the steady-state theory were true.[38]

Explorer 11 was an important first step into this high-energy field, even though it located only one or two gamma ray sources during its time in orbit. The next step was taken in 1972, when Goddard launched Explorer 48, which was the second spacecraft in the Small Astronomy Satellite (SAS) series. SAS 2 carried a gamma ray telescope and detected numerous additional gamma ray sources. Even more importantly, it laid the groundwork for a larger gamma ray observatory, HEAO 3. This third High Energy Astronomical Observatory, launched in 1979, conducted the first extensive sky survey of gamma ray sources.

HEAO 3 also provided some important clues about what exists at the center of our galaxy. In addition to a continuous spectrum of gamma rays coming out of our galaxy's nucleus, HEAO 3 detected a spike of gamma ray energy at one particular and precise wavelength. An energy surge at that precise frequency happens when electrons meet anti-electrons, or positrons, and annihilate each other. The spike of energy detected by HEAO 3 told scientists that there must be a strong source of positrons, or "anti-matter" at that location, and the most likely source of these extremely high-energy particles is a black hole. In other words, these results told scientists that there might well be a black hole at the center of our galaxy.[39]

HEAO 3 and SAS 2 were both relatively small satellites with specialized instruments. The next step, then, was to explore the high energy universe across a broad range of the gamma ray portion of the spectrum. This was the mission of Goddard's Compton Gamma Ray Observatory (CGRO), a 17-ton satellite that was launched from the Atlantis Space Shuttle in April 1991. The Compton was named in honor of Dr. Arthur Holly Compton, an astrophysicist whose Nobel prize-winning discoveries about high energy processes are central to the techniques used by the observatory's instruments.

The Compton Observatory's instruments were ten times more sensitive than those on HEAO 3, allowing it to make numerous important contributions to our understanding of gamma ray sources in the universe. One of the most perplexing sources of gamma rays, for example, is something called a "gamma ray burst." These short-lived bursts of high energy...

An image showing the gamma ray emissions detectable from our own Moon with Goddard's EGRET on board the Compton Gamma Ray Observatory. (NASA Photo PAO_E97_01.JPG)

[127] ....radiation were first detected by Air Force satellites in the 1960s but have remained a mystery ever since. In a few seconds, one of these bursts can put out more gamma ray energy than our Sun could produce in one thousand years.

Since its launch, the Compton has detected more than a thousand of these bursts. It has also discovered that the bursts are not limited to our galaxy, but are spread evenly across the sky. This has tremendous significance, because it means the bursts are coming from very far distances. For something to appear that energetic after travelling that far a distance, its initial energy has to be staggeringly high. Scientists now believe that gamma ray bursts may originate from locations as far away as 12 billion light years, which means they date back almost as far as the universe itself. Perhaps the most mystifying thing about gamma ray bursts, however, is that no known phenomenon could explain a burst of energy that high.

Several theories have been proposed about the source of gamma ray bursts, including the collision of two neutron stars, or the collapse of a massive giant star into black hole. This second theory was given additional weight recently by a group of researchers from the University of Cambridge in the U.K. Massive stars have very short life spans, so they die pretty much where and when they are born. If gamma ray bursts are linked to the death of these stars, they should correlate with the location and near-time of these stars' birth.

A map of gamma ray emission from the central region of the Milky Way, obtained by the Compton Gamma Ray Observatory.

Gamma ray sources are typically very hard to pinpoint, but an Italian-Dutch satellite called BeppoSAX, launched in 1996, gave scientists the ability to nail down the location of these bursts with much more accuracy. The Cambridge scientists plotted the location of three gamma ray bursts detected so far and found that they were located in star-forming regions. The results are far from conclusive, but this evidence certainly gives some additional credence to the theory that gamma ray bursts may be caused by massive stars falling into black holes. In any event, the Cambridge research indicated that gamma ray bursts are extremely rare events, occuring in any galaxy perhaps as seldom as once every 40 million years.[40]

The gamma ray burst picture got even more complicated when scientists realized that a gamma ray burst detected by the Compton Observatory on 14 December 1997 had put out more energy in a few seconds than any event since the beginning of the universe. For a few seconds, the energy of the burst was as bright as the rest of the universe combined and, in a core region about 100 miles across, it would [128] have created conditions similar to those that existed one millisecond after the Big Bang. Scientists estimate that the burst originated about 12 billion light years from Earth, and released hundreds of times more energy than a Supernova explosion. Scientists are baffled as to the possible source for such a tremendous burst. All they know is that something obviously exists in the universe that has the ability to produce more energy than any current theory can explain. But this kind of event and mystery is what propels science forward.

Goddard's Compton Observatory also discovered traces of Cobalt 57 that scientists believe was produced by the 1987a Supernova explosion in the Large Magellanic Cloud. This evidence helped confirm that heavier elements in the universe are, indeed, formed in the process of supernovae explosions. In addition, the CGRO satellite has uncovered new objects and phenomena, such as gamma-ray quasars (as opposed to quasars that emit their energy in X-ray wavelengths), identifying a new class of active galactic nuclei.[41]

Conclusion

Astronomers have been exploring the heavens for centuries. But the ability to go into the heavens themselves has taken us into a whole new dimension. In the past 40 years, rocket and satellite technology has changed dreams and theory into science and knowledge. Because of the efforts of the people at Goddard and its many industry, university, NASA, and international partners, we now can see into the Sun to explore how it works and how it affects life here on Earth. We can map the fields and forces surrounding our own planet and probe the atmospheres of planets further out in our solar system. We have uncovered stars, galaxies and mysterious high-energy phenomena that would have boggled the minds of astronomers even 100 years ago.

In the process, we have found evidence that has supported some important scientific theories and disproven others. We have peered back to the dawn of time and discovered worlds and events that have forced us to change many of our ideas about the galaxy and universe in which we live. In fact, we have sometimes ended up almost falling over ourselves trying to keep up with new discoveries and information that keep changing the picture of our universe just as we thought we understood what was going on.

The truth is, the universe is an astoundingly complex and almost infinitely large territory that we may never fully understand. Columbus, Magellan, and Lewis and Clark may have faced the same element of the unknown as Goddard's space scientists, but a continent or an ocean is a much more limited area than a galaxy or universe. The amazing thing is the amount of headway we've actually been able to make into this mysterious and unforgiving territory in only 40 short years.

In some cases, Goddard's efforts have helped scientists find answers about objects or phenomena, such as the existence and boundaries of Earth's magnetosphere or...

[129]

A map of the whole-sky in gamma rays. The prominent white band represents emission from the disc of the Milky Way. Bright spots above and below are high-energy sources, such as quasars.

...the origins of pulsars. In others, the Center's work has uncovered pieces of information that we only know must fit into the puzzle somewhere - we just don't know yet how or where, or even how significant these pieces may turn out to be.

But as Goddard scientists point out, astronomer Tycho Brahe made observations in the late 16th century about the orbits of the planets without being able to make any bigger conclusions about them. A few years later, however, mathematician Johannes Kepler used that information to come up with his laws of planetary motion. Those laws later provided Issac Newton with the basis for his universal law of gravity, which transformed science and made modern cosmology possible. In other words, progress and learning are ongoing, incremental processes that require many building blocks to be in place before a building takes shape. And while we are putting together the pieces, we can't always see ahead to see what the building will look like.

Even when a building appears or an "Aha" moment occurs, it's still not the end of the cycle. We continue to build, because we continue to be curious, and there is always something new to learn. It's one of the most wonderful things about life as we know it. The universe we live in is so large and so intricate that as long as our curiosity and spirit of adventure remain alive, there will always be new territory to explore and new wonders to uncover. One of the marvels of space, we have discovered, is that it's not simply a new or final frontier. It's an endless frontier, with the ability to to inspire both our minds and our souls with the power of its elements, the depth of its mysteries, and the beauty of its music.

Chapter 5:
Exploring the Earth

[130]

This image of Earth was created using data from four different satellites. It shows fires burning on land areas (red dots) and a large aerosol cloud over the Atlantic ocean formed by the burning biomass in Africa. It also indicates dust and cloud cover around the globe. Satellite data and images such as this one are beginning to give us a more comprehensive view of the Earth's interrelated systems and climate.

[131] When scientists first began using rockets for research, their eyes were focused upward, on the mysteries that lay beyond our atmosphere and our planet. But it wasn't long before they realized that this new technology could also give them a unique vantage point from which to look back at Earth.

Scientists working with V-2 and early sounding rockets for the Naval Research Laboratory (NRL) made the first steps in this direction almost ten years before Goddard was formed. The scientists put aircraft gun cameras on several rockets in an attempt to determine which way the rockets were pointing. When the film from one of these rockets was developed, it had recorded images of a huge tropical storm over Brownsville, Texas. Because the rocket....

[132]

Otto Berg's montage photo, taken from a gun camera on board an early research rocket, was perhaps the first weather photo ever taken from space. Note the storm clouds in the upper portion of the image.

....was spinning, the image wasn't a neat, complete picture, but Otto Berg, the scientist who had modified the camera to take the photo, took the separate images home and pasted them together on a flat board. He then took the collage to Life magazine, which published what was arguably one of the earliest weather photos ever taken from space.[1]

Space also offered unique possibilities for communication that were recognized by industry and the military several years before NASA was organized. Project RAND[2] had published several reports in the early 1950s outlining the potential benefits of satellite-based communication relays, and both AT&T and Hughes had conducted internal company studies on the commercial viability of communication satellites by 1959.[3]

These rudimentary seeds, already sown by the time Goddard opened its doors, grew into an amazing variety of communication, weather, and other remote-sensing satellite projects at the Center that have revolutionized many aspects of our lives. They have also taught us significant and surprising things about the planet we inhabit. Our awareness of large-scale crop and forest conditions, ozone depletion, greenhouse warming, and El Nino weather patterns has increased dramatically because of our ability to look back on Earth from space. Satellites have allowed us to measure the shape of the Earth more accurately, track the movement of tectonic plates, and analyze portions of the atmosphere and areas of the world that are hard to reach from the ground.

In addition, the "big picture" perspective satellites offer has allowed scientists to begin investigating the dynamics between different individual processes and the development and behavior of global patterns and systems. Ironically, it seems we have had to develop the ability to leave our planet before we could begin to fully understand it.

Geodesy

From the very earliest days of the space program, scientists realized that satellites could offer an important side-benefit to researchers interested in mapping the gravity field and shape of the Earth, and Goddard played an important role in this effort. The field of geodesy, or the study of the gravitational field of the Earth and its relationship to the solid structure of the planet, dates back to the third century B.C., when the Greek astronomer Eratosthenes combined astronomical observation with land measurement to try to prove that the Earth was, in fact, round. Later astronomers and scientists had used other methods of triangulation to try to estimate the exact size of the Earth. [133] Astronomers also had used the Moon, or stars with established locations, to try to map the shape of the Earth and exact distances between points more precisely. But satellites offered a new twist to this methodology.

For one thing, the Earth's shape and gravity field affected the orbit of satellites. So at the beginning of the space age, Goddard's tracking and characterizing the orbit of the first satellites was in and of itself a scientific endeavor. From that orbital data, scientists could infer information about the Earth's gravity field, which is affected by the distribution of its mass. The Earth, as it turns out, is not perfectly round, and its mass is not perfectly distributed. There are places where land or ocean topography results in denser or less dense mass accumulation. The centrifugal force of the Earth's rotation combines with gravity and these mass concentrations to create bulges and depressions in the planet. In fact, although we think of the Earth as round, Goddard's research showed us that it is really slightly pear-shaped.

Successive Goddard satellites enabled scientists to gather much more precise information about the Earth's shape as well as exact positions of points on the planet. In fact, within 10 years, scientists had learned as much again about global positioning, the size and shape of the Earth, and its gravity field as their predecessors had learned in the previous 200 years.

Laser reflectors on Goddard satellites launched in 1965, 1968, and 1976, for example, allowed scientists to make much more precise measurements between points, which enabled them to determine the exact location or movement of objects. The laser reflectors developed for Goddard's LAGEOS satellite, launched in 1976, could determine movement or position within a few centimeters, which allowed scientists to track and analyze tectonic plate movement and continental drift. Among other things, the satellite data told scientists that the continents seem to be inherently rigid bodies, even if they contain divisive bodies of water, such as the Mississippi River, and that continental plate movement appears to occur at a constant rate over time. Plate movement information provided by satellites has also helped geologists track the dynamics that lead up to Earthquakes, which is an important step in predicting these potentially catastrophic events.

The satellite positioning technique used for this plate tectonic research was the precursor to the Global Positioning System (GPS) technology that now uses a...

A technician working on reflectors for one of Goddard's laser geodynamic satellites.

[134] ...constellation of satellites to provide precise three-dimensional navigation for aircraft and other vehicles. Yet although a viable commercial market is developing for GPS technology today, the greatest commercial application of space has remained the field of communication satellites.[4]

Communication Satellites

For all the talk about the commercial possibilities of space, the only area that has proven substantially profitable since 1959 is communication satellites, and Goddard played an important role in developing the early versions of these spacecraft. The industry managers who were conducting research studies and contemplating investment in this field in 1959 could not have predicted the staggering explosion of demand for communications that has accompanied the so-called "Information Age." But they saw how dramatically demand for telephone service had increased since World War II, and they saw potential in other communications technology markets, such as better or broader transmission for television and radio signals. As a result, several companies were even willing to invest their own money, if necessary, to develop communication satellites.

The Department of Defense (DoD) actually had been working on communication satellite technology for a number of years, and it wanted to keep control of what it considered a critical technology. So when NASA was organized, responsibility for communication satellite technology development was split between the new space agency and the DoD. The DoD would continue responsibility for "active" communication satellites, which added power to incoming signals and actively transmitted the signals back to ground stations. NASA's role was initially limited to "passive" communication satellites, which relied on simply reflecting signals off the satellite to send them back to Earth.[5]

Echo

NASA's first communication satellite, consequently, was a passive spacecraft called "Echo." It was based on a balloon design by an engineer at NASA's Langley Research Center and developed by Langley, Goddard, JPL and AT&T. Echo was, in essence, a giant mylar balloon, 100 feet in diameter, that could "bounce" a radio signal back down to another ground station a long distance away from the first one.

Echo I, the world's first communication satellite, was successfully put into orbit on 12 August 1960. Soon after launch, it reflected a pre-taped message from President Dwight Eisenhower across....

The world's first communications satellite was an inflatable mylar sphere called "Echo" that simply reflected transmissions back to Earth. The spacecraft was readily visible to the eye. (NASA Photo G-63-3202)

[135].....the country and other radio messages to Europe, demonstrating the potential of global radio communications via satellite. It also generated a lot of public interest, because the sphere was so large that it could be seen from the ground with the naked eye as it passed by overhead.

Echo I had some problems, however. The sphere seemed to buckle somewhat, hampering its signal-reflecting ability. So in 1964, a larger and stronger passive satellite, Echo II, was put into orbit. Echo II was made of a material 20 times more resistant to buckling than Echo I and was almost 40 feet wider in diameter.

Echo II also experienced some difficulties with buckling. But the main reason the Echo satellites were not pursued any further was not that the concept wouldn't work. It was simply that it was eclipsed by much better technology - active communication satellites.[6]

Syncom, Telstar, and Relay

By 1960, Hughes, RCA, and AT&T were all advocating the development of active communication satellites. They differed in the kind of satellite they recommended, however. Hughes felt strongly that the best system would be based on geosynchronous satellites. Geosynchronous satellites are in very high orbits - 22,300 miles above the ground. This high orbit allows their orbital speed to match the rotation speed of the Earth, which means they can remain essentially stable over one spot, providing a broad range of coverage 24 hours a day. Three of these satellites, for example, can provide coverage of the entire world, with the exception of the poles.

The Syncom satellite proved that high-altitude, geosynchronous satellites could still be used effectively for communications.(NASA Photo G-63-3266)

The disadvantage of using geosynchronous satellites for communications is that sending a signal up 22,300 miles and back causes a time-delay of approximately a quarter second in the signal. Arguing that this delay would be too annoying for telephone subscribers, both RCA and AT&T supported a bigger constellation of satellites in medium Earth orbit, only a few hundred miles above the Earth.[7]

The Department of Defense had been working on its own geosynchronous communication satellite, but the project was running into significant development problems and delays. NASA had been given permission by 1960 to pursue active communication satellite technology as well as passive systems, so the DoD approached NASA about giving Hughes a sole-source contract to develop an experimental geosynchronous satellite. The result was Syncom, a geosynchronous [136] satellite design built by Hughes under contract to Goddard.

Hughes already had begun investing its own money and effort in the technology, so Syncom I was ready for Goddard to launch in February 1963 - only 17 months after the contract was awarded. Syncom I stopped sending signals a few seconds before it was inserted into its final orbit, but Syncom II was launched successfully five months later, demonstrating the viability of the system. The third Syncom satellite, launched in August 1964, transmitted live television coverage of the Olympic Games in Tokyo, Japan to stations in North America and Europe.

Although the military favored the geosynchronous concept, it was not the only technology being developed. In 1961, Goddard began working with RCA on the "Relay" satellite, which was launched 13 December 1962. Relay was designed to demonstrate the feasibility of medium-orbit, wide-band communications satellite technology and to help develop the ground....

The Relay satellite, which Goddard helped RCA build and launch, was a medium-altitude orbit satellite design. (NASA Photo G-63-3970)

....station operations necessary for such a system. It was a very successful project, transmitting even color television signals across wide distances.

AT&T, meanwhile, had run into political problems with NASA and government officials who were concerned that the big telecommunications conglomerate would end up monopolizing what was recognized as potentially powerful technology. But when NASA chose to fund RCA's Relay satellite instead of AT&T's design, AT&T decided to simply use its own money to develop a medium orbit communications satellite, which it called Telstar. NASA would launch the satellite, but AT&T would reimburse NASA for the costs involved. Telstar 1 was launched on 10 July 1962, and a second Telstar satellite followed less than a year later. Both satellites were very successful, and Telstar 2 demonstrated that it could even transmit both color and black and white television signals between the United States and Europe.

In some senses, Relay and Telstar were competitors. But RCA and AT&T, who were both working with managers at Goddard, reportedly cooperated very well with each other. Each of the efforts was seen as helping to advance the technology necessary for this new satellite industry to become viable, and both companies saw the potential profit of that in the long run.

By 1962, it was clear that satellite communications technology worked, and there was going to be money made in its use. Fearful of the powerful monopoly satellites could offer a single company, Congress passed the Satellite Communications Act, setting up a [137] consortium of existing communications carriers to run the satellite communications industry. Individual companies could bid to sell satellites to the consortium, but no single company would own the system. NASA would launch the satellites for Comsat, as the consortium was called, but Comsat would run the operations.

In 1964, the Comsat consortium was expanded further with the formation of the International Telecommunications Satellite Organization, commonly known as "Intelsat," to establish a framework for international use of communication satellites. These organizations had the responsibility for choosing the type of satellite technology the system would use. The work of RCA, AT&T and Hughes had proven that either medium-altitude or geosynchronous satellites could work. But in 1965, the consortiums finally decided to base the international system on geosynchronous satellites similar to the Syncom design.[8]

Applications Technology Satellites

Having helped to develop the prototype satellites, Goddard stepped back from operational communication satellites and focused its efforts on developing advanced technology for future systems. Between 1966 and 1974, Goddard launched a total of six Applications Technology Satellites (ATS) to research advanced technology for communications and meteorological spacecraft. The ATS spacecraft were all put into geosynchronous orbits and investigated microwave and millimeter wavelengths for.....

Goddard's sixth Applications Technology Satellites undergoes final prelaunch testing at Cape Canaveral in Florida. (NASA Photo G-74-7446)

....communication transmissions, methods for aircraft and marine navigation and communications, and various control technologies to improve geosynchronous satellites.

Four of the spacecraft were highly successful and provided valuable data for improving future communication satellites. The sixth ATS spacecraft, launched 30 May 1974, even experimented with transmitting health and education television to small, low-cost ground stations in remote areas. It also tested a geosynchronous satellite's ability to provide tracking and data transmission services for other satellites. Goddard's research in this area, and the expertise the Center developed in the process, made it possible for NASA to develop the Tracking and Data Relay Satellite System (TDRSS) the agency still uses today.[9]

After ATS-6, NASA transferred responsibility for future communication [138] satellite research to the Lewis Research Center. Goddard, however, maintained responsibility for developing and operating the TDRSS tracking and data satellite system.[10]

Meteorological Satellites

Statistically, the United States has the world's most violent weather. In a typical year, the U.S. will endure some 10,000 violent thunderstorms, 5,000 floods, 1,000 tornadoes, and several hurricanes.[11] Improving weather prediction, therefore, has been a high priority of meteorologists here for a very long time.

The early sounding rocket flights began to indicate some of the possibilities space flight might offer in terms of understanding and forecasting the weather, and they prompted the military to pursue development of a meteorological satellite. The Advanced Research Projects Agency (ARPA)[12] had a group of scientists and engineers working on this project at the U.S. Army Signal Engineering Laboratories in Ft. Monmouth, New Jersey when NASA was first organized. Recognizing the country's history of providing weather services to the public through a civilian agency, the military agreed to transfer the research group to NASA. These scientists and engineers became one of the founding units of Goddard in 1958.

Television and Infrared Observation Satellites

These Goddard researchers were working on a project called the Television and Infrared Observation Satellite (TIROS). When it was launched on 1 April 1960, it became the world's first meteorological satellite, returning thousands of images of cloud cover and spiralling storm systems. Goddard's Explorer VI satellite had recorded some crude cloud cover images before TIROS I was launched, but the TIROS satellite was the first spacecraft dedicated to meteorological data gathering and transmitted the first really good cloud cover photographs. [13]

Clearly, there was a lot of potential in this new technology, and other meteorological satellites soon followed the first TIROS spacecraft. Despite its name, the first TIROS carried only television cameras. The second TIROS satellite, launched in November 1960, also included an infrared instrument, which gave it the ability to detect cloud cover even at night.

The TIROS capabilities were limited, but the satellites still provided a tremendous service in terms of weather forecasting. One of the biggest obstacles meteorologists faced was the local, "spotty" nature of the data...

Dr. Joanne Simpson, who is pictured here with two male colleagues, is a pioneer in the study of clouds, typhoons and other tropical storms and, in fact, has flown through six hurricanes to gather meteorological data. Currently, she is chief scientist for meteorology at Goddard [Note: This photo caption was obtained from Goddard's 40th anniversary cd-rom. Chris Gamble, html editor].

[139] ...they could obtain. Weather balloons and ocean buoys could only collect data in their immediate area. Huge sections of the globe, especially over the oceans, were dark areas where little meteorological information was available. This made forecasting a difficult task, especially for coastal areas.

Sounding rockets offered the ability to take measurements at all altitudes of the atmosphere, which helped provide temperature, density and water vapor information. But sounding rockets, too, were limited in the scope of their coverage. Satellites offered the first chance to get a "big picture" perspective on weather patterns and storm systems as they travelled around the globe.

Because weather forecasting was an operational task that usually fell under the management of the Weather Bureau, there was some disagreement about who should have responsibility for designing and operating this new class of satellite. Some people at Goddard felt that NASA should take the lead, because the new technology was satellite-based. The Weather Bureau, on the other hand, was going to be paying for the satellites and wanted control over the type of spacecraft and instruments they were funding. When the dust settled, it was decided that NASA would conduct research on advanced meteorological satellite technology and would manage the building, launching and testing of operational weather satellites. The Weather Bureau would have final say over operational satellite design, however, and would take over management of spacecraft operations after the initial test phase was completed.[14]

The TIROS satellites continued to improve throughout the early 1960s.

Early meteorology satellite and violent storms pioneer. [Note: no photo caption in the book. Chris Gamble, html editor]

Although the spacecraft were officially research satellites, they also provided the Weather Bureau with a semi-operational weather satellite system from 1961 to 1965. TIROS III, launched in July 1961, detected numerous hurricanes, tropical storms, and weather fronts around the world that conventional ground networks missed or would not have seen for several more days.[15] TIROS IX, launched in January 1965, was the first of the series launched into a polar orbit, rotating around the Earth in a north-south direction. This orientation allowed the satellite to cross the equator at the same time each day and provided coverage of the entire globe, including the higher latitudes and polar regions, as its orbit precessed around the Earth.

The later TIROS satellites also improved their coverage by changing the location of the spacecraft's camera. The TIROS satellites were designed like a wheel of cheese. The wheel spun around but, like a toy top or gyroscope, the axis of the wheel kept pointing in the same direction as the satellite orbited the Earth. The cameras were placed on the satellite's axis, which allowed them to take continuous pictures of the Earth when that surface was actually facing the planet. Like dancers doing a do-si-do, however, the surface with the cameras would be pointing parallel to or away from the Earth for more than half of the satellite's orbit. TIROS IX (and the operational TIROS satellites), put the camera on the rotating section of the wheel, which was kept [140] facing perpendicular to the Earth throughout its orbit. This made the satellite operate more like a dancer twirling around while circling her partner. While the camera could only take pictures every few seconds, when the section of the wheel holding the camera rotated past the Earth, it could continue taking photographs throughout the satellite's entire orbit.

NIMBUS/ESSA/NOAA

In 1964, Goddard took another step in developing more advanced weather satellites when it launched the first NIMBUS spacecraft. NASA had originally envisioned the larger and more sophisticated NIMBUS as the design for the Weather Bureau's operational satellites. The Weather Bureau decided that the....

Goddard test and evaluation personnel conduct vibration testing of a Nimbus research weather satellite. (NASA photo G-67-2656).

....NIMBUS spacecraft were too large and expensive, however, and opted to stay with the simpler TIROS design for the operational system. So the NIMBUS satellites were used as research vehicles to develop advanced instruments and technology for future weather satellites. Between 1964 and 1978, Goddard developed and launched a total of seven Nimbus research satellites.

In 1965, the Weather Bureau was absorbed into a new agency called the Environmental Science Services Administration (ESSA). The next year, NASA launched the first satellite in ESSA's operational weather system. The satellite was designed like the TIROS IX spacecraft and was designated "ESSA 1." As per NASA's agreement, Goddard continued to manage the building, launching and testing of ESSA's operational spacecraft, even as the Center's scientists and engineers worked to develop more advanced technology with separate research satellites.

The ESSA satellites were divided into two types. One took visual images of the Earth with an an Automatic Picture Transmission (APT) camera system and transmitted them in real time to stations around the globe. The other recorded images that were recorded and then transmitted to a central ground station for global analysis. These first ESSA satellites were deployed in pairs in "Sun-synchronous" polar orbits around the Earth, crossing the same point at approximately the same time each day.

In 1970, Goddard launched an improved operational spacecraft for ESSA [141] using "second generation" weather satellite technology. The Improved TIROS Operational System (ITOS), as the design was initially called, combined the functions of the previous pairs of ESSA satellites into a single spacecraft and added a day and night scanning radiometer. This improvement meant that meteorologists could get global cloud cover information every 12 hours instead of every 24 hours.

Soon after ITOS 1 was launched, ESSA evolved into the National Oceanic and Atmospheric Administration (NOAA), and successive ITOS satellites were redesignated as NOAA 1, 2, 3, etc. This designation system for NOAA's polar-orbiting satellites continues to this day.

In 1978, NASA launched the first of what was called the "third generation" of polar orbiting satellites. The TIROS-N design was a much bigger, three-axis-stabilized spacecraft that incorporated much more advanced equipment. The TIROS-N series of instruments, used aboard operational NOAA satellites today, provided much more accurate sea-surface temperature information, which is necessary to predict a phenomenon like an El Nino weather pattern. They also could identify snow and sea ice and could provide much better temperature profiles for different altitudes in the atmosphere.

But while the lower-altitude polar satellites can observe some phenomena in more detail because they are relatively close to the Earth, they can't provide the continuous "big picture" information a geosynchronous satellite can offer. So for the past 25 years, NOAA has operated two weather satellite systems - the TIROS series of polar orbiting satellites at lower altitudes, and two geosynchronous satellites more than 22,300 miles above the Earth.[16]

Satellite imagery showing snow and sea ice cover at the north and south poles of the Earth.

The polar-orbiting ITOS satellites were an improved version of the original TIROS weather satellites.

ATS/SMS/GOES

While polar-orbiting satellites were an improvement over the more equatorial-orbiting TIROS satellites, scientists realized that they could get a much better perspective on weather systems from a geosynchronous spacecraft. Goddard's research teams started investigating this technology with the launch of the first Applications Technology Satellite (ATS-1) in 1966. Because the ATS had a geosynchronous orbit that kept it "parked" above one spot, meteorologists could get progressive photographs of the same area over a period of time as often as every 30 minutes. The "satellite photos" showing changes in cloud cover that we now almost take for granted during nightly newscasts are made possible by geosynchronous weather satellites. Those cloud movement images also allowed meteorologists to infer wind currents and speeds. This information is particularly useful in [142] determining weather patterns over areas of the world such as oceans or the tropics, where conventional aircraft and balloon methods can't easily gather data.

Goddard's ATS III satellite, launched in 1967, included a multi-color scanner that could provide images in color, as well. Shortly after its launch, ATS III took the first color image of the entire Earth, a photo made possible by the satellite's 22,300 mile high orbit.[17]

In 1974, Goddard followed its ATS work with a dedicated geosynchronous weather satellite called the Synchronous Meteorological Satellite (SMS). Both SMS -1 and SMS-2 were research prototypes, but they still provided meteorologists with practical information as they tested out new technology. In addition to providing continuous coverage of a broad area, the SMS satellites collected and relayed weather data from 10,000 automatic ground stations in six hours, giving forecasters more timely and detailed data than they had ever had before.

The Synchronous Meteorological Satellite was the first geosynchronous weather satellite. This design evolved into the GOES series of spacecraft.

Goddard launched NOAA's first operational geostationary[18] satellite, designated the Geostationary Operational Environmental Satellite (GOES) in October 1975. That satellite has led to a whole family of GOES spacecraft. As with previous operational satellites, Goddard managed the building, launching and testing of the GOES spacecraft.

The first seven GOES spacecraft, while geostationary, were still "spinning" designs like NOAA's earlier operational ESSA satellites. In the early 1980s, however, NOAA decided that it wanted the new series of geostationary GOES spacecraft to be three-axis stabilized, as well, and to incorporate significantly more advanced instruments. In addition, NOAA decided to award a single contract directly with an industry manufacturer for the spacecraft and instruments, instead of working separate instrument and spacecraft contracts through Goddard.

Goddard typically developed new instruments and technology on research satellites before putting them onto an operational spacecraft for NOAA. The plan for GOES 8,[19] however, called for incorporating new technology instruments directly into a spacecraft that was itself a new design and also had an operational mission. Meteorologists across the country were going to rely on the new instruments for accurate weather forecasting information, which put a tremendous amount of added pressure on the designers. But the contractor selected to build the instruments underestimated the cost and complexity of developing the [143] GOES 8 instruments. In addition, Goddard's traditional "Phase B" design study, which would have generated more concrete estimates of the time and cost involved in the instrument development, was eliminated on the GOES 8 project. The study was skipped in an attempt to save time, because NOAA was facing a potential crisis with its geostationary satellite system.

NOAA wanted to have two geostationary satellites up at any given point in order to adequately cover both coasts of the country. But the GOES 5 satellite failed in 1984, leaving only one geostationary satellite, GOES 6, in operation. The early demise of GOES 4 and GOES 5 left NOAA uneasy about how long GOES 6 would last, prompting the "streamlining" efforts on the GOES 8 spacecraft design. The problem became even more serious in 1986 when the launch vehicle for the GOES G spacecraft, which would have become GOES 7, failed after launch. Another GOES satellite was successfully launched in 1987, but the GOES 6 spacecraft failed in January 1989, leaving the United States once again with only one operational geostationary weather satellite.

By 1991, when the GOES 8 project could not predict a realistic launch date, because working instruments for the spacecraft still hadn't been developed, Congress began to investigate the issue. The GOES 7 spacecraft was aging, and managers and elected officials realized that it was entirely possible that the country might soon find itself without any geostationary satellite coverage at all.

A computer-generated image of Hurricane Fran, using data from the GOES weather satellites.(NASA Photo PAO H96_01.JPG)

To buy the time necessary to fix the GOES 8 project and alleviate concerns about coverage, NASA arranged with the Europeans to "borrow" one of their Eumetsat geostationary satellites. The satellite was allowed to "drift" further west so it sat closer to the North American coast, allowing NOAA to move the GOES 7 satellite further west.

Meanwhile, Goddard began to take a more active role in the GOES 8 project. A bigger GOES 8 project office was established at the Center and Goddard brought in some of its best instrument experts to work on the project, both at Goddard and at the contractor's facilities. Goddard, after all, had some of the best meteorological instrument-building expertise in the country. But because Goddard was not directly in charge of the instrument sub-contract, the Center had been handicapped [144] in making that knowledge and experience available to the beleaguered contractor.

The project was a sobering reminder of the difficulties that could ensue when, in an effort to save time and money, designers attempted to streamline a development project or combine research and operational functions into a single spacecraft. But in 1994, the GOES 8 spacecraft was finally successfully launched, and the results have been impressive. Its advanced instruments performed as advertised, improving the spacecraft's focusing and atmospheric sounding abilities and significantly reducing the amount of time the satellite needed to scan any particular area. [20]

Earth Resources Satellites

As meteorological satellite technology developed and improved, Goddard scientists realized that the same instruments used for obtaining weather information could be used for other purposes, as well. Meteorologists could look at radiation that travelled back up from the Earth's surface to determine things like water vapor content and temperature profiles at different altitudes in the atmosphere. But those same emissions could reveal potentially valuable information about the Earth's surface, as well.

Objects at a temperature above absolute zero emit radiation, many of them at precise and unique wavelengths in the electromagnetic spectrum. So by analyzing the emissions of any object, from a star or comet to a particular section of forest or farmland, scientists can learn important things about its chemical composition. Instruments on the Nimbus spacecraft had the ability to look at reflected solar radiation from the Earth in several different wavelengths. As early as 1964, scientists began discussing the possibilities of experimenting with this technology to see what it might be able to show us about not only the atmosphere, but also resources on the Earth.

The result was the Earth Resources Technology Satellite (ERTS), launched in 1972 and later given the more popular name "Landsat 1." The spacecraft was based on a Nimbus satellite,with a multi-channel radiometer to look at different wavelength bands where the reflected energy from surfaces such as forests, water, or different crops would fall. The satellite instruments also had much better resolution than the Nimbus instruments. Each swath of the Earth covered by the Nimbus scanner was 1500 miles wide, with each pixel in the picture representing five miles. The polar-orbiting ERTS satellite instrument could focus in on a swath only 115 miles wide, with each pixel representing 80 meters. This resolution allowed scientists to view a small enough section of land, in enough detail, to conduct a worthwhile analysis of what it contained.

Images from the ERTS/Landsat satellite, for example, showed scientists a 25-mile wide geological feature near Reno, Nevada that appeared to be a previously undiscovered meteor crater. Other images collected by the satellite were useful in discovering water-bearing rocks in Nebraska, Illinois and New York and determining that water pollution drifted off the Atlantic [145] coast as a cohesive unit, instead of dissipating in the ocean currents.

The success of the ERTS satellite prompted scientists to want to explore this use of satellite technology further. They began working on instruments that could get pixel resolutions as high as five meters, but were told to discontinue that research because of national security concerns. If a civilian satellite provided data that detailed, it might allow foreign countries to find out critical information about military installations or other important targets in the U.S. This example illustrates one of the ongoing difficulties with Earth resource satellite research. The fact that the same information can be used for both scientific and practical purposes often creates complications with not only who should be responsible for the work, but how and where the information will be used.

In any event, the follow-on satellite, "Landsat-2," was limited to the same levels of resolution. More recent Landsat spacecraft, however, have been able to improve instrument resolution further.[21]

Landsat 2 was launched in January 1975 and looked at land areas for an even greater number of variables than its ERTS predecessor, integrating information from ground stations with data obtained by the satellite's instruments. Because wet land and green crops reflect solar energy at different wavelengths than dry soil or brown plants, Landsat imagery enabled researchers to look at soil moisture levels and crop health over wide areas, as well as soil temperature, stream flows, and snow depth. Its data was used by the U.S. Department of Agriculture, the U.S. Forest Service, the Department of Commerce, the Army Corps of Engineers, the Environmental Protection Agency and the Department of Interior, as well as agencies from foreign countries.[22]

A Landsat image of the Muir glacier in southeastern Alaska taken in September 1986. The red color indicates areas of vegetation.

The Landsat program clearly was a success, particularly from a scientific perspective. It proved that satellite technology could determine valuable information about precious natural resources, agricultural activity, and environmental hazards. The question was who should operate the satellites. Once the instruments were developed, the Landsat spacecraft were going to be collecting the same data, over and over, instead of exploring new areas and technology. One could argue that by examining [146] the evolution of land resources over time, scientists were still exploring new processes and gathering new scientific information about the Earth. But that same information was being used predominantly for practical purposes of natural resource management, agricultural and urban planning, and monitoring environmental hazards. NASA had never seen its role as providing ongoing, practical information, but there was no other agency with the expertise or charter to operate land resource satellites.

As a result, NASA continued to manage the building, launch, and space operation of the Landsat satellites until 1984. Processing and distribution of the satellite's data was managed by the Department of Interior, through an Earth Resources Observation System (EROS) Data Center that was built by the U.S. Geological Survey in Sioux Falls, South Dakota in 1972.

A Landsat image of Salt Lake City and a portion of the Great Salt Lake in Utah.

In 1979, the Carter Administration developed a new policy in which the Landsat program would be managed by NOAA and eventually turned over to the private sector. In 1984, the first Reagan Administration put that policy into effect, soliciting commercial bids for operating the system, which at that point consisted of two operational satellites. Landsat 4 had been launched in 1982 and Landsat 5 was launched in 1984. Ownership and operation of the system was officially turned over to the EOSAT Company in 1985, which sold the images to anyone who wanted them, including the government. At the same time, responsibility for overseeing the program was transferred from NASA to NOAA. Under the new program guidelines, the next spacecraft in the Landsat program, Landsat 6, would also be constructed independently by industry.

There were two big drawbacks with this move, however, as everyone soon found out. The first was that although there was something of a market for Landsat images, it was nothing like that surrounding the communication satellite industry. The EOSAT company found itself struggling to stay afloat. Prices for images jumped from the couple of hundred dollars per image that EROS had charged to $4,000 per shot, and EOSAT still found itself bordering on insolvency.

Being a private company, EOSAT also was concerned with making a profit, not archiving data for the good of science or the government. Government budgets wouldn't allow for purchasing thousands of archival images at $4,000 a piece, so the EROS Data Center only bought a few [147] selected images each year. As a result, many of the the scientific or archival benefits the system could have created were lost.

In 1992, the Land Remote Sensing Policy Act reversed the 1984 decision to commercialize the Landsat system, noting the scientific, national security, economic, and social utility of the Landsat images. Landsat 6 was launched the following year, but the spacecraft failed to reach orbit and ended up in the Indian Ocean.

This launch failure was discouraging, but planning for the next Landsat satellite was already underway. Goddard had agreed to manage design of a new data ground station for the satellite, and NASA and the Department of Defense initially agreed to divide responsibility for managing the satellite development. But the Air Force subsequently pulled out of the project and, in May 1994, management of the Landsat system was turned over to NASA, the U.S. Geological Survey (USGS), and NOAA. At the same time, Goddard assumed sole management responsibility for developing Landsat 7.

The only U.S. land resource satellites in operation at the moment are still Landsat 4 and 5, which are both degrading in capability. Landsat 5, in fact, is the only satellite still able to transmit images. The redesigned Landsat 7 satellite is scheduled for launch by mid-1999, and its data will once again be made available though the upgraded EROS facilities in Sioux Falls, South Dakota. Until then, scientists, farmers and other users of land resource information have to rely on Landsat 5 images through EOSAT, or they have to turn to foreign companies for the information.

The French and the Indians have both created commercial companies to sell land resource information from their satellites, but both companies are being heavily subsidized by their governments while a market for the images is developed. There is probably a viable commercial market that could be developed in the United States, as well. But it may be that the demand either needs to grow substantially on its own or would need government subsidy before a commercialization effort could succeed. The issue of scientific versus practical access to the information would also still have to be resolved.

No matter how the organization of the system is eventually structured, Landsat imagery has proven itself an extremely valuable tool for not only natural resource management but urban planning and agricultural assistance, as well. Former NASA Administrator James Fletcher even commented in 1975 that if he had one space-age development to save the world, it would be Landsat and its successor satellites.[23] Without question, the Landsat technology has enabled us to learn much more about the Earth and its land-based resources. And as the population and industrial production on the planet increase, learning about the Earth and potential dangers to it has become an increasingly important priority for scientists and policy-makers alike.[24]

Atmospheric Research Satellites

One of the main elements scientists are trying to learn about the Earth is the [148] composition and behavior of its atmosphere. In fact, Goddard's scientists have been investigating the dynamics of the Earth's atmosphere for scientific, as well as meteorological, purposes since the inception of the Center. Explorers 17, 19, and 32, for example, all researched various aspects of the density, composition, pressure and temperature of the Earth's atmosphere. Explorers 51 and 54, also known as "Atmosphere Explorers," investigated the chemical processes and energy transfer mechanisms that control the atmosphere.

Another goal of Goddard's atmospheric scientists was to understand and measure what was called the "Earth Radiation Budget." Scientists knew that radiation from the Sun enters the Earth's atmosphere. Some of that energy is reflected back into space, but most of it penetrates the atmosphere to warm the surface of the Earth. The Earth, in turn, radiates....

The Earth Radiation Budget Satellite was launched in 1984 to investigate the balance of solar radiation in the Earth's atmosphere.

....energy back into space. Scientists knew that the overall radiation received and released was about equal, but they wanted to know more about the dynamics of the process and seasonal or other fluctuations that might exist. Understanding this process is important because the excesses and deficits in this "budget," as well as variations in it over time or at different locations, create the energy to drive our planet's heating and weather patterns.

The first satellite to investigate the dynamics of the Earth Radiation Budget was Explorer VII, launched in 1959. Nimbus 2 provided the first global picture of the radiation budget, showing that the amount of energy reflected by the Earth's atmosphere was lower than scientists had thought. Additional instruments on Nimbus 3, 5, and 6, as well as operational TIROS and ESSA satellites, explored the dynamics of this complex process further. In the early 1980s, researchers developed an Earth Radiation Budget Experiment (ERBE) instrument that could better analyze the short-wavelength energy received from the Sun and the longer-wavelength energy radiated into space from the Earth. This instrument was put on a special Earth Radiation Budget Satellite (ERBS) launched in 1984, as well as the NOAA-9 and NOAA 10 weather satellites.

This instrument has provided scientists with information on how different kinds of clouds affect the amount of energy trapped in the Earth's atmosphere. Lower, thicker clouds, for example, reflect a portion of the Sun's energy back into space, creating a...

[149]

In a single pass across Hurricane Alley, the Tropical Rainfall Measuring Mission provided graphic information: tropical storm Howard and hurricanes Isis, Vearl, and Danielle.

....cooling effect on the surface and atmosphere of the Earth. High, thin cirrus clouds, on the other hand, let the Sun's energy in but trap some of the Earth's outgoing infrared radiation, reflecting it back to the ground. As a result, they can have a warming effect on the Earth's atmosphere. This warming effect can, in turn, create more evaporation, leading to more moisture in the air. This moisture can trap even more radiation in the atmosphere, creating a warming cycle that could influence the long-term climate of the Earth.

Because clouds and atmospheric water vapor seem to play a significant role in the radiation budget of the Earth as well as the amount of global warming and climate change that may occur over the next century, scientists are attempting to find out more about the convection cycle that transports water vapor into the atmosphere. In 1997, Goddard launched the Tropical Rainfall Measuring Mission (TRMM) satellite into a near-equatorial orbit to look more closely at the convection cycle in the tropics that powers much of the rest of the world's cloud and weather patterns. The TRMM satellite's Clouds and the Earth's Radiant Energy System (CERES) instrument, built by NASA's Langley Research Center, is an improved version of the earlier ERBE experiment. While the satellite's focus is on convection and rainfall in the lower atmosphere, some of that moisture does get transported into the upper atmosphere, where it can play a role in changing the Earth's radiation budget and overall climate.[25]

[150] Ozone

An even greater amount of atmospheric research, however, has been focused on a once little-known chemical compound of three oxygen atoms called ozone. Ozone, as most Americans now know, is a chemical in the upper atmosphere that blocks incoming ultraviolet rays from the Sun, protecting us from skin cancer and other harmful effects caused by ultraviolet radiation.

The ozone layer was first brought into the spotlight in the 1960s, when designers began working on the proposed Supersonic Transport (SST). Some scientists and environmentalists were concerned that the jet's high-altitude emissions might damage the ozone layer, and the federal government funded several research studies to evaluate the risk. The cancellation of the SST in 1971 shelved the issue, at least temporarily, but two years later a much greater potential threat emerged.

In 1973, two researchers at the University of California, Irvine came up with the astounding theory that certain man-made chemicals, called chlorofluorocarbons (CFCs), could damage the atmosphere's ozone layer. These chemicals were widely used in everything from hair spray to air conditioning systems, which meant that the world might have a dangerously serious problem on its hands.

In 1975, Congress directed NASA to develop a "comprehensive program of research, technology and monitoring of phenomena of the upper atmosphere" to evaluate the potential risk of ozone damage further. NASA was already conducting atmospheric research, but the Congressional mandate supported even wider efforts. NASA was not the only organization looking into the problem, either. Researchers around the world began focusing on learning more about the chemistry of the upper atmosphere and the behavior of ozone layer.

Goddard's Nimbus IV research satellite, launched in 1970, already had an instrument on it to analyze ultraviolet rays that were "backscattered," or reflected, from different altitudes in the Earth's atmosphere. Different wavelengths of UV radiation should be absorbed by the ozone at different levels in the atmosphere. So by analyzing how much UV radiation was still present in different wavelengths, researchers could develop a profile of how thick or thin the ozone layer was at different altitudes and locations.

In 1978, Goddard launched the last and most capable of its Nimbus-series satellites. Nimbus 7 carried an improved version of this experiment, called the Solar Backscatter Ultraviolet (SBUV) instrument. It also carried a new sensor called the Total Ozone Mapping Spectrometer (TOMS). As opposed to the SBUV, which provided a vertical profile of ozone in the atmosphere, the TOMS instrument generated a high-density map of the total amount of ozone in the atmosphere.

A similar instrument, called the SBUV-2, has been put on weather satellites since the early 1980s. For a number of years, the Space Shuttle periodically flew a Goddard instrument called the Shuttle Solar Backscatter Ultraviolet (SSBUV) experiment that was used to calibrate the SBUV-2 [151] satellite instruments to insure the readings continued to be accurate. In the last couple of years, however, scientists have developed data-processing methods of calibrating the instruments, eliminating the need for the Shuttle experiments.

Yet it was actually not a NASA satellite that discovered the "hole" that finally developed in the ozone layer. In May 1985, a British researcher in Antarctica published a paper announcing that he had detected an astounding 40% loss in the ozone layer over a Antarctica the previous winter. When Goddard researchers went back and looked at their TOMS data from that time period, they discovered that the data indicated the exact same phenomenon. Indeed, the satellite indicated an area of ozone layer thinning, or "hole,"[26] the size of the Continental U.S.

How had researchers missed a development that drastic? Ironically enough, it was because the anomaly was so drastic. The TOMS data analysis software had been programmed to flag grossly anomalous data points, which were assumed to be errors. Nobody had expected the ozone loss to be as great as it was, so the data points over the area where the loss had occurred looked like problems with the instrument or its calibration. .

Once the Nimbus 7 data was verified, Goddard's researchers generated a visual map of the area over Antarctica where the ozone loss had occurred. In fact, the ability to generate visual images of the ozone layer and its "holes" have been among the significant contributions NASA's ozone-related satellites have made to the public debate over the issue. Data points are hard for most people to fully understand. But for non-scientists, a visual image showing a gap in a protective layer over Antarctica or North America makes the problem not only clear, but somehow very real.

The problem then became determining what was causing the loss of ozone. The problem was a particularly sticky one, because it was going to relate directly to legislation and restrictions that would be extremely costly for industry. By 1978, the Environmental Protection Agency (EPA) had already moved to ban....

This series of Total Ozone Mapping Spectrometer maps shows the development of an ozone "hole" over Antarctica. Red indicates areas of thicker ozone; blues and violets indicate areas of ozone thinning.

[152]....the use of CFCs in aerosols. By 1985, the United Nations Environmental Program (UNEP) was calling on nations to take measures to protect the ozone and, in 1987, forty-three nations signed the "Montreal Protocol, agreeing to cut CFC production 50% by the year 2000.

The CFC theory was based on a prediction that chlorofluorocarbons, when they reached the upper atmosphere, released chlorine and flourine. The chlorine, it was suspected, was reacting with the ozone to form chlorine monoxide - a chemical that is able to destroy a large amount of ozone in a very short period of time. Because the issue was the subject of so much debate, NASA launched numerous research efforts to try to validate or disprove the theory. In addition to satellite observations, NASA sent teams of researchers and aircraft to Antarctica to take in situ readings of the ozone layer and the ozone "hole" itself. These findings were then supplemented with the bigger picture perspective the TOMS and SBUV instruments could provide.

The TOMS instrument on Nimbus 7 was not supposed to last more than a couple of years. But the information it was providing was considered so critical to the debate that Goddard researchers undertook an enormous effort to keep the instrument working, even as it aged and began to degrade. The TOMS instrument also hadn't been designed to show long-term trends, so the data processing techniques had to be significantly improved to give researchers that kind of information. In the end, Goddard was able to keep the Nimbus 7 TOMS instrument operating for almost 15 years, which provided ozone monitoring until Goddard was able to launch a replacement TOMS instrument on a Russian satellite in 1991.[27]

A more comprehensive project to study the upper atmosphere and and the ozone layer was launched in 1991, as well. The satellite, called the Upper Atmosphere Research Satellite (UARS), was one of the results of Congress's 1975 mandate for NASA to pursue additional ozone research. Although its goal is to try to understand the chemistry and dynamics of the upper atmosphere, the focus of UARS is clearly on ozone research. Original plans called for the spacecraft to be launched from the Shuttle in the mid-1980s, but the Challenger explosion back-up delayed its launch until 1991.

Once in orbit, however, the more advanced instruments on board the UARS satellite were able to map chlorine monoxide levels in the stratosphere. Within months, the satellite was able to confirm what the Antarctic....

The Upper Atmosphere Research Satellite was launched in 1991 to take an intensive look at components and processes in the Earth's upper atmosphere.

[153] ....aircraft expeditions and Nimbus-7 satellite had already reported - that there was a clear and causal link between levels of chlorine, formation of chlorine monoxide, and levels of ozone loss in the upper atmosphere.

Since the launch of UARS, the TOMS instrument has been put on several additional satellites to insure that we have a continuing ability to monitor changes in the ozone layer. A Russian satellite called Meteor 3 took measurements with a TOMS instrument from 1991 until the satellite ceased operating in 1994. The TOMS instrument was also incorporated into a Japanese satellite called the Advanced Earth Observing System (ADEOS) that was launched in 1996. ADEOS, which researchers hoped could provide TOMS coverage until the next scheduled TOMS instrument launch in 1999, failed after less than a year in orbit. But fortunately, Goddard had another TOMS instrument ready for launch on a small NASA satellite called an Earth Probe, which was put into orbit with the Pegasus launch vehicle in 1996. Researchers hope that this instrument will continue to provide coverage and data until the next scheduled TOMS instrument launch.

All of these satellites have given us a much clearer picture of what the ozone layer is, how it interacts with various other chemicals, and what causes it to deteriorate. These pieces of information are essential elements for us to have if we want to figure out how best to protect what is arguably one of our most precious natural resources.

Using the UARS satellite, scientists have been able to track the progress of CFCs up into the stratosphere and have detected the build-up of chlorine monoxide over North America and the Arctic as well as Antarctica. Scientists also have discovered that ozone loss is much greater when the temperature of the stratosphere is cold. In 1997, for example, particularly cold stratospheric temperatures created the first Antarctic-type of ozone hole over North America.

Another factor in ozone loss is the level of aerosols, or particulate matter, in the upper atmosphere. The vast majority of aerosols come from soot, other pollution, or volcanic activity, and Goddard's scientists have been studying the effects of these particles in the atmosphere ever since the launch of the Nimbus I spacecraft in 1964. Goddard's 1984 Earth Radiation Budget Satellite (ERBS), which is still operational, carries a Stratospheric Aerosol and Gas Experiment (SAGE II) that tracks aerosol levels in the lower and upper atmosphere. The Halogen Occultation Experiment (HALOE) instrument on UARS also measures aerosol intensity and distribution.

The light green to bold orange colors in this image taken by NASA's Upper Atmosphere Research Satellite show the increase in sulfur dioxide levels following the June 1991 eruption of Mt. Pinatubo in the Philippines.

[154] In 1991, both UARS and SAGE II were used to track the movement and dispersal of the massive aerosol cloud created by the Mt. Pinatubo volcano eruption in the Philippines. The eruption caused stratospheric aerosol levels to increase to as much as 100 times their pre-eruption levels, creating spectacular Sunsets around the world but causing some other effects, as well. These volcanic clouds appear to help cool the Earth, which could affect global warming trends, but the aerosols in these clouds seem to increase the amount of ozone loss in the stratosphere, as well.

The good news is, the atmosphere seems to be beginning to heal itself. In 1979 there was no ozone hole. Throughout the 1980s, while legislative and policy debates raged over the issue, the hole developed and grew steadily larger. In 1989, most U.S. companies finally ceased production of CFC chemicals and, in 1990, the U.N. strengthened its Montreal Protocol to call for the complete phaseout of CFCs by the year 2000. Nature is slow to react to changes in our behavior but, by 1997, scientists finally began to see a levelling out and even a slight decrease in chlorine monoxide levels and ozone loss in the upper atmosphere.[28]

Continued public interest in this topic has made ozone research a little more complicated for the scientists involved. Priorities and pressures in the program have changed along with Presidential administrations and Congressional agendas and, as much as scientists can argue that data is simply data, they cannot hope to please everyone in such a politically charged arena. Some environmentalists argue that the problem is much worse than NASA is making it out to be, while more conservative politicians have argued that NASA's scientists are blowing the issue out of proportion.[29]

But at this point a few things are clearer. The production of CFC chemicals was, in fact, harming a critical component of our planet's atmosphere. It took a variety of ground and space instruments to detect and map the nature and extent of the problem. But the perspective offered by Goddard's satellites allowed scientists and the general public to get a clear overview of the problem and map the progression of events that caused it. This information has had a direct impact on changing the world's industrial practices which, in turn, have begun to slow the damage and allow the planet to heal itself. The practical implications of Earth-oriented satellite data may make life a little more complicated for the scientists involved, but no one can argue the significance or impact of the work. By developing the technology to view and analyze the Earth from space, we have given ourselves an invaluable tool for helping us understand and protect the planet on which we live.

Oceanographic Satellites

One of the biggest advantages to remote sensing of the Earth from satellites stems from the fact that the majority of the Earth's surface area is extremely difficult to study from the ground. The world's oceans cover 71% of the Earth's [155] surface and comprise 99% of its living area. Atmospheric convective activity over the tropical ocean area is believed to drive a significant amount of the world's weather. Yet until recently, the only way to map or analyze this powerful planetary element was with buoys, ships or aircraft. But these methods could only obtain data from various individual points, and the process was extremely difficult , expensive, and time-consuming.

Satellites, therefore, offered oceanographers a tremendous advantage. A two-minute ocean color satellite image, for example, contains more measurements than a ship travelling 10 knots could make in a decade. This ability has allowed scientists to learn a lot more about the vast open stretches of ocean that influence our weather, our global climate, and our everyday lives.[30]

Although Goddard's early meteorological satellites were not geared specifically toward analyzing ocean characteristics, some of the instruments could provide information about the ocean as well as the atmosphere. The passive microwave sensors that allowed scientists to "see" through clouds better, for example, also let them map the distribution of sea ice around the world. Changes in sea ice distribution can indicate climate changes and affect sea levels around the world, which makes this an important parameter to monitor. At the same time, this information also has allowed scientists to locate open passageways for ships trying to get through the moving ice floes of the Arctic region.

By 1970, NOAA weather satellites also had instruments that could measure the temperature of the ocean surface in areas where there was no cloud cover, and the Landsat satellites could provide some information on snow and ice distributions. But since the late 1970s, much more sophisticated ocean-sensing satellite technology has emerged.[31]

The Nimbus 7 satellite, for example, carried an improved microwave instrument that could generate a much more detailed picture of sea ice distribution than either...

Goddard's Nimbus 7 satellite carried a Coastal Zone Color Scanner, which detected the distribution of phytoplankton around the world. Phytoplankton is a critical component of the global carbon cycle and its distribution has important implications for global climate change predictions.

[156]...the earlier Nimbus or Landsat satellites. Nimbus 7 also carried the first Coastal Zone Color Scanner (CZCS), which allowed scientists to map pollutants and sediment near coastlines. The CZCS also showed the location of ocean phytoplankton around the world. Phytoplankton are tiny, carbon dioxide-absorbing plants that constitute the lowest rung on the ocean food chain. So phytoplankton generally mark spots where larger fish may be found. But because they bloom where nutrient-rich water from the deep ocean comes up near the surface, their presence also gives scientists clues about the ocean's currents and circulation.

Nimbus 7 continued to send back ocean color information until 1984. Scientists at Goddard continued working on ocean color sensor development...

This image from the Coastal Zone Color Scanner depicts ocean temperatures in the Atlantic Ocean off North America. Reds are the warmest, and blues and violets are the coolest. Swirls indicate eddies in the Gulf Stream.

....throughout the 1980s, and a more advanced coastal zone ocean color instrument was launched on the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite in 1997. In contrast to most scientific satellites, SeaWiFS was funded and launched by a private company instead of by NASA. Most of the ocean color data the satellite provides is purchased by NASA and other research institutions, but the company is selling some data to the fishing industry, as well.[32]

Since the launch of the Nimbus 7 and Tiros-N satellites in 1978, scientists have also been able to get much better information on global ocean surface temperatures. Sea surface temperatures tell scientists about ocean circulation, because they can use the temperature information to track the movement of warmer and cooler bodies of water. Changes in sea surface temperatures can also indicate the development of phenomena such as El Nino climate patterns. In fact, one of the most marked indications of a developing El Nino condition, which can cause heavy rains in some parts of the world and devastating drought in others, is an unusually warm tongue of water moving eastward from the western equatorial Pacific Ocean.

NOAA weather satellites have carried instruments to measure sea surface temperature since 1981, and NASA's EOS AM-1 satellite, scheduled for launch in 1999, incorporates an instrument that can measure those temperatures with even more precision. The launch of Nimbus 7 also gave researchers the ability to look at surface winds, which help drive ocean circulation. [157] With Nimbus 7, however, scientists had to infer surface winds by looking at slight differentiations in microwave emissions coming from the ocean surface. A scatterometer designed specifically to measure surface winds was not launched until the Europeans launched ERS-1 in 1991. Another scatterometer was launched on the Japanese ADEOS spacecraft in 1996. Because ADEOS failed less than a year after launch, Goddard researchers have begun an intensive effort to launch another scatterometer, called QuickSCAT, on a NASA spacecraft. JPL project managers are being aided in this effort by the Goddard-developed Rapid Spacecraft Procurement Initiative, which will allow them to incorporate the instrument into an existing small spacecraft design.Using this streamlined process, scientists hope to have QuickSCAT in orbit by the end of 1998.[33]

In the 1970s, researchers at the Wallops Flight Facility also began experimenting with radar altimetry to determine sea surface height, although they were pleased if they could get accuracy within a meter. In 1992, however, a joint satellite project between NASA and the French Centre National d'Etudes Spatiales (CNES) called TOPEX/Poseidon put a much more accurate radar altimeter into orbit. Goddard managed the development of the TOPEX radar altimeter, which can measure sea surface height within a few centimeters. In addition to offering useful information for maritime weather reports, this sea level data tells scientists some important things about ocean movement.

The first Earth Observing System satellite under construction. (NASA Photo G98-019-008)

For one thing, sea surface height indicates the build-up of water in one area of the world or another. One of the very first precursors to an El Nino condition, for example, is a rise in ocean levels in the western equatorial Pacific, caused by stronger-than-normal easterly trade winds. Sea level also tells scientists important information about the amount of heat the ocean is storing. If the sea level in a particular area is low, it means that the area of warm, upper-level water is shallow. This means that colder, deeper water can reach the surface there, driving ocean circulation and bringing nutrients up from below, leading to the production of phytoplankton. The upwelling of cold water will also cool down the sea surface temperature, reducing the amount of water that evaporates into the atmosphere.

All of these improvements in satellite capabilities gave oceanographers and scientists an opportunity to integrate on-site surface measurements from buoys or ships with the more global perspective available from space. As a result, we are finally beginning to piece together a more complete picture of our oceans and the role they play in the Earth's biosystems and climate. In fact, one of the most significant results of ocean-oriented satellite research was the realization that ocean and atmospheric processes were intimately linked to each other. To really understand the dynamics of the ocean or the atmosphere, we needed to look at the combined global system they comprised.[34]

El Nino and Global Change

The main catalyst that prompted scientists to start looking at the oceans and atmosphere as an integrated system was the El Nino event of 1982-83. The rains and drought associated with the unusual weather pattern caused eight billion dollars of damage, leading to several international research programs to try to understand and predict the phenomenon better. The research efforts included measurements by ships, aircraft, ocean buoys, and satellites, and the work is continuing today. But by 1996, scientists had begun to understand the warning signals and patterns of a strong El Nino event. They also had the technology to track atmospheric wind currents and cloud formation, ocean color, sea surface temperatures, sea surface levels and sea surface winds, which let them accurately predict the heavy rains and severe droughts that occurred at points around the world throughout the 1997-98 winter.

The reason the 1982-83 El Nino prompted a change to a more integrated ocean-atmospheric approach is that the El Nino phenomenon does not exist in the ocean or the atmosphere by itself. It's the coupled interactions between the two elements that cause this periodic weather pattern to occur. The term El Nino, which means "The Child," was coined by fishermen on the Pacific coast of Central America who noticed a warming of their coastal ocean waters, along with a decline in fish population, near the Christ Child's birthday in December. But as scientists have discovered, the sequence of events that causes that warming begins many months earlier, in winds headed the opposite direction.

In a normal year, strong easterly trade winds blowing near the equator drag warmer, upper-level ocean water to the western edge of the Pacific ocean. That build-up of warm water causes convection....

This image of the sea surface temperature anomaly during the 1982-1983 El Niño eventwas created from satellite data.

[159] ....up into the tropical atmosphere, leading to rainfall along the Indonesian and Australian coastlines. It also leads to upwelling of colder, nutrient-rich water along the eastern equatorial Pacific coastlines, along Central and South America. In an El Nino year, however, a period of stronger-than-normal trade winds that significantly raises sea levels in the western Pacific is followed by a sharp drop in those winds. The unusually weak trade winds allow the large build-up of warm water in the western tropical Pacific to flow eastward along the equator. That change moves the convection and rainfall off the Indonesian and Australian coasts, causing severe drought in those areas and, as the warm water reaches the eastern edge of the Pacific ocean, much heavier than normal rainfall occurs along the western coastlines of North, Central, and South America. The movement of warm water toward the eastern Pacific also keeps the colder ocean water from coming up to the surface, keeping phytoplankton from growing and reducing the presence of fish further up on the food chain.

In other words, an El Nino is the result of a change in atmospheric winds, which causes a change in ocean currents and sea level distribution, which causes a change in sea surface temperature, which causes a change in water vapor entering the atmosphere, which causes further changes in the wind currents, and so on, creating a cyclical pattern. Scientists still don't know exactly what causes the initial change in atmospheric winds, but they now realize that they need to look at a global system of water, land and air interactions in order to find the answer. And satellites play a critical role in being able to do that.

An El Nino weather pattern is the biggest short-term "coupled" atmospheric and oceanographic climate signal on the planet after the change in seasons, which is why it prompted researchers to take a more interdisciplinary approach to studying it. But scientists are beginning to realize that many of the Earth's climatic changes or phenomena are really coupled events that require a broader approach in order to understand. In fact, the 1990s have seen the emergence of a new type of scientist who is neither oceanographer or atmospheric specialist, but is an amphibious kind of researcher focusing on the broader issue of climate change.[35]

Global Warming

One of the other important topics these researchers are currently trying to assess is the issue of global warming. Back in 1896, a Swedish chemist named Svante Arrhenius predicted that the increasing carbon dioxide emissions from the industrial revolution would eventually cause the Earth to become several degrees warmer. The reason for this warming was due to what has become known as the "greenhouse effect." In essence, carbon dioxide and other "greenhouse gases," such as water vapor, allow the short-wavelength radiation from the Sun to pass through the atmosphere, warming the Earth. But the gases absorb the longer-wavelength energy travelling [160] back from the Earth into space, radiating part of that energy back down to the Earth again. Just as the glass in a greenhouse allows the Sun through but traps the heat inside, these gases end up trapping a certain amount of heat in the Earth's atmosphere, causing the Earth to become warmer.

The effect of this warming could be small or great, depending on how much the temperature actually changes. If it is only a degree or two, the effect would be relatively small. But a larger change in climate could melt polar ice, causing the sea level to rise several feet and wiping out numerous coastal communities and resources. If the warming happened rapidly, vegetation might not have time to adjust to the climate change, which could affect the world's food supply as well as timber and other natural resources.

This satellite image shows global water vapor levels, which are an important factor in global warming studies.

The critical question, then, is how great a danger global warming is. And the answer to that is dependent on numerous factors. One, obviously, is the amount of carbon dioxide and other emissions we put into the air - a concern that has driven efforts to reduce our carbon dioxide-producing fossil fuel consumption. But the amount of carbon dioxide in the air is also dependent on how much can be absorbed again by plant life on Earth - a figure that scientists depend on satellites in order to compute. Landsat images can tell scientists how much deforestation is occurring around the world, and how much healthy plant life remains to absorb CO_2. Until recently, however, the amount of CO_2 absorbed by the world's oceans was unknown. The ocean color images of SeaWiFS are helping to fill that gap, because the phytoplankton it tracks are a major [161] source of carbon dioxide absorption in the oceans.

Another part of the global warming equation is how much water vapor is in the atmosphere - a factor that is driven by ocean processes, especially in the heat furnace of the tropics. As a result, scientists are trying to learn more about the transfer of heat and water vapor between the ocean and different levels of the atmosphere, using tools such as Goddard's TRMM and UARS satellites.

All of these numbers and factors are fed into atmospheric and global computer models, many of which have been developed at the Goddard Institute for Space Studies (GISS) in New York City. These models then try to predict how our global climate may change based on current emissions, population trends, and known facts about ocean and atmospheric processes.

While these models have been successful in predicting short-term effects, such as the global temperature drop after the Mt. Pinatubo volcano eruption, the problem with trying to predict global change is that it's a very long-term process, with many factors that may change over time. We have only been studying the Earth in bits and pieces, and for only a short number of years. In order to really understand which climate changes are short-term variations and which ones are longer trends of more permanent change, scientists needed to observe and measure the global, integrated climate systems of Planet Earth over a long period of time. This realization was the impetus for NASA's Mission to Planet Earth, or the Earth Science Enterprise.[36]

Earth Science Enterprise

In some senses, the origins of what became NASA's "Mission to Planet Earth" (MTPE) began in the late 1970s, when we began studying the overall climate and planetary processes of other planets in our solar system. Scientists began to realize that we had never taken that kind of "big picture" look at our own planet, and that such an effort might yield some important and fascinating results. But an even larger spur to the effort was simply the development of knowledge and technology that gave scientists both the capability and an understanding of the importance of looking at the Earth from a more global, systems perspective.

Discussions along these lines were already underway when the El Nino event of 1982-83 and the discovery of the ozone "hole" in 1985 elevated the level of interest and support for global climate change research to an almost crisis level. Although the "Mission to Planet Earth" was not announced as a formal new NASA program until 1990, work on the satellites to perform the mission was underway before that. In 1991, Goddard's UARS satellite became the first official MTPE spacecraft to be launched.

Although the program has now changed its name to the Earth Science Enterprise, suffered several budget cuts, and refocused its efforts from overall global change to a narrower focus of global climate change (leaving out changes in solid land masses), the basic goal of the program echoes what was initiated in 1990. In essence, the Earth Science Enterprise aims to integrate satellite, [162] aircraft and ground-based instruments to monitor 24 interrelated processes and parameters in the planet's oceans and atmosphere over a 15-year period.

Phase I of the program consisted of integrating information from satellites such as UARS, the TOMS Earth Probe, TRMM, TOPEX/Poseidon, ADEOS and SeaWiFS with Space Shuttle research payloads, research aircraft and ground station observations. Phase II is scheduled to begin in 1999 with the launch of Landsat 7 and the first in a series of Earth Observing System (EOS) satellites. The EOS spacecraft are extremely large research platforms with many different instruments to look at various atmospheric and ocean processes that affect natural resources and the overall global climate. They will be polar-orbiting satellites, with orbital paths that will allow the different satellites to take measurements at different times of the day. EOS AM-1 is scheduled for launch in late 1998. EOS PM-1 is scheduled for launch around the year 2000. The first in an EOS altimetry series of satellites, which will study the role of oceans, ocean winds and ocean-atmosphere interactions in climate systems, will launch in 2000. An EOS CHEM-1 satellite, which will look at the behavior of ozone and greenhouse gases, measure pollution and the effect of aerosols on global climate, is scheduled for launch in 2002. Follow-on missions will continue the work of these initial observation satellites over a 15-year period.

There is still much we don't know about our own planet. Indeed, the first priority of the Earth Science Enterprise satellites is simply to try to fill in the gaps in what we know about the behavior and dynamics of our oceans and our atmosphere. Then scientists can begin to look at how those elements interact, and what impact they have and will have on global climate and climate change. Only then will we really know how great a danger global warming is, or how much our planet can absorb the man-made elements we are creating in greater and greater amounts.[37]

It's an ambitious task. But until the advent of satellite technology, the job would have been impossible to even imagine undertaking. Satellites have given us the ability to map and study large sections of the planet that would be difficult to cover from the planet's surface. Surface and aircraft measurements also play a critical role in these studies. But satellites were the breakthrough that gave us the unique ability to stand back far enough from the trees to see the complete and complex forest in which we live.

Conclusion

For centuries, humankind has stared at the stars and dreamed of travelling among them. We imagined ourselves zipping through asteroid fields, transfixed by spectacular sights of meteors, stars, and distant galaxies. Yet when the astronauts first left the planet, they were surprised to find themselves transfixed not by distant stars, but by the awe-inspiring view their spaceship gave them of the place they had just left - a dazzling, mysterious planet they affectionally nicknamed the "Big Blue Marble." As our horizons expanded into the universe, so did our perspective [163] and understanding of the place we call home. As an astronaut on an international Space Shuttle crew put it, "The first day or so we all pointed to our countries. The third or fourth day we were pointing to our continents. By the fifth day we were aware of only one Earth."[38]

Satellites have given this perspective to all of us, expanding our horizons and deepening our understanding of the planet we inhabit. If the world is suddenly a smaller place, with cellular phones, paging systems, and Internet service connecting friends from distant lands, it's because satellites have advanced our communication abilities far beyond anything Alexander Graham Bell ever imagined. If we have more than a few hours' notice of hurricanes or storm fronts, it's because weather satellites have enabled meteorologists to better understand the dynamics of weather systems and track those systems as they develop around the world. If we can detect and correct damage to our ozone layer or give advance warning of a strong El Nino winter, it's because satellites have helped scientists better understand the changing dynamics of our atmosphere and our oceans.

We now understand that our individual "homes" are affected by events on the far side of the globe. From both a climatic and environmental perspective, we have realized that our home is indeed "one Earth," and we need to look at its entirety in order to understand and protect it. The practical implications of this information sometimes make the scientific pursuit of this understanding more complicated than our explorations into the deeper universe. But no one would argue the inherent worth of the information or the advantages satellites offer.

Earthrise, as seen by the Apollo astronauts on the Moon. Ironically, it has only been since we left our planet that we have really begun to understand it.

The satellites developed by Goddard and its many partners have expanded both our capabilities and our understanding of the complex processes within our Earth's atmosphere. Those efforts may be slightly less mind-bending than our search for space-time anomalies or unexplainable black holes, but they are perhaps even more important. After all, there may be millions of galaxies in the universe. But until we find a way to reach them, this planet is the only one we have. And the better we understand it, the better our chances are of preserving it - not only for ourselves, but for the generations to come.

Chapter 6:
The Endless Frontier

[164]

A cluster of young stars and the glowing nebula around them are about 200,000 light-years from Earth in the Small Magellanic Cloud.

[165] When the Goddard Space Flight Center opened its doors, we were standing on the brink of a great new adventure - one that would change our lives and vastly expand our understanding of the world and universe in which we live. The journey would not be an easy one. It would involve many thousands of people, in many different locations, and the cooperation of countries around the world. It would require enormous ingenuity, a tremendous investment of time and money, and the sacrifice of human lives. The people who undertook this endeavor had to have the determination to persevere through failure and frustration, the dedication to devote hours, months, and years to a single effort, and the vision to imagine not only creative solutions [166] but the results that would make the effort worthwhile.

Because it was created at the dawn of the space age and has lived through the many changing tides and eras of NASA, Goddard in many ways parallels the history of the U.S. space program itself. It began in a scramble to catch up with the Russians after the launch of Sputnik, pulling scientists and engineers from numerous military and civilian research institutions into a hybrid organization that could master the challenges of space flight and exploration. The effort was funded by a nation suddenly worried about not only its prestige, but its military security. Yet President Eisenhower made it very clear that the exploration of this new territory was to be a civilian effort. Despite the fact that it was the height of the Cold War, NASA and Goddard were formed with the directive that "the activities in space should be devoted to peaceful purposes for the benefit of all mankind."[1]

The challenges this group of researchers faced were so extensive that even the people who organized NASA initially failed to realize how complex the effort would be. Goddard, it was thought, could manage all the tasks necessary for the scientific and human exploration of space. This notion soon changed, but it left Goddard with a unique legacy of diversity. Goddard remained one of the only places in the world where the entire cycle of a space project could be completed, from theory to launch to final analysis of the data received. The Center has one other distinction within NASA, as well. In an agency dedicated primarily to the engineering challenge of travelling into space, Goddard has remained the only full NASA Center dedicated to science[2].

These two distinguishing characteristics of Goddard: its wide diversity of projects and responsibilities, and its role in conducting scientific research, have created unique and impressive strengths within the Center. Goddard's blend of science and engineering has given it the ability to not only conceive of experiments but also to design the technology and equipment necessary to execute those ideas. This in-house satellite building capability, which stressed innovative thinking and design, led to the development of numerous valuable concepts and spacecraft, including the highly successful Explorer series, the concept of modular satellites that could be serviced in space, and the....

A technician checks Goddard's Radio Astronomy Explorer satellite prior to its launch on July 4, 1968.

[167] .....new state-of-the-art Small Explorer class of research satellites. The blend of science and engineering at the same Center also gave Goddard's scientists and engineers the ability to work closely together to design and build a wide variety of complex instruments that made Goddard's scientific achievements possible.

At the same time, Goddard's diversity and wide range of responsibilities have created a unique set of challenges for the Center throughout its history. Scientific research was not the exclusive domain of NASA, which meant that Goddard managers were constantly having to balance not only the conflicting needs and priorities of their own engineers and scientists, but also the work of the Center's own scientists with the needs of a greater, international research community. Goddard's work in the areas of Earth Science and so-called "applications" was sometimes even more complex, because NASA's role in these areas was even more unclear. In addition, no matter how much scientists argue that data is simply data, research on our own planet is often complicated by the inescapable practical ramifications of what that research uncovers.

Yet many of Goddard's challenges simply reflected the larger challenges inherent in this new realm of space exploration. If managing Goddard's many satellite projects was a complex task, it was because space flight itself was an incredibly complex and expensive endeavor that required the cooperation of many people. A small team of design engineers might get a new airplane off the ground, but to get a spacecraft into orbit required the combined efforts of an army of professionals and support staff at NASA Centers, universities, private industry, and in countries around the world. Striking the right balance between the sometimes conflicting needs and priorities of such a diverse group of people and organizations was simply a difficult thing to do.

The Evolving Space Age: Goddard's First Forty

When Goddard opened its doors, the challenges facing Goddard's scientists and engineers were mostly technical ones. Limited launch vehicle capability meant that satellites had to be extremely small and lightweight. High amounts of data had to be processed and transmitted to the ground with very little power. Launch vehicles themselves were unreliable, causing Goddard to build back-up models for each of its satellites. And all of this was being attempted when computers were in their infancy and reliable telephone service was still questionable with many ground tracking stations.

Students prepare a Get Away Special can experiment to be carried in the cargo bay of the Space Shuttle.

Explorer 1 took the United States into space for the first time when it was launched successfully on 1 February1958.

Today, technology has advanced beyond anything those pioneers could even have imagined. In some cases, these advances have allowed the design of much larger and more complex satellites. In 1959, the first Explorer satellite carried into orbit by a Jupiter C rocket was a slender cylinder that was about 70 inches long and weighed 22 pounds. In 1991, the Compton Gamma Ray Observatory launched by the Space Shuttle was 70 feet long and weighed more than 17 tons. Tracking systems also advanced from many different ground stations around the world [168] to a network of geosynchronous tracking and data relay satellites.

New technology - some of which was developed at Goddard - has also resulted in advancements such as solid state tape recorders and computers that are a fraction of the size and weight of their predecessors and yet hold many times more memory and power. Ironically, these advances have allowed building once again of small, easily launched satellites that are still vastly more capable and can store data reliably enough that it can be retrieved by a simple network of ground stations.

The Polar satellite under construction, Polar was one of several satellites included in the International Terresrtial Program effort to look at Sun-Earth connections.

Advances in computer and spacecraft technology have created a new era in the type and amount of data satellites can gather, as well. From the days when scientists had to decipher simple audio tones from satellites passing overhead, we have satellites sending back breathtaking images of distant galaxies and complex streams of data from the inside of the Sun. The new EOS satellites are scheduled to transmit a mind-boggling terabyte of data every day, creating a whole new challenge in data processing and storage. Once the problem was trying to get enough data. Today the challenge is not to drown in it.

Technology has also improved the usefulness of satellites to the general scientific community. In the early days, the only people who could get useful data from physics or astronomy satellites were the scientists who had designed the instruments. By the mid-1970s, Goddard's engineers were able to build astronomy satellites with "transparent" software that could allow guest observers to use the platforms as easily as a ground telescope, opening up space science to a much broader community of researchers.

These advances in technology have allowed us to vastly expand the horizons of our world. When Goddard was founded, scientists were simply trying to find out what lay beyond our immediate atmosphere. Today, Goddard's satellites have reached back to the dawn of time and have cracked open doors to invisible and distant reaches of the universe, answering some of our most basic questions and uncovering new worlds and phenomena we never even dreamed existed.

We have discovered not only radiation belts and a magnetosphere that surround our planet, but a complex relationship between the Sun and the Earth that begins....

[169]

A montage of some fof Goddard's launch vehicles and satellites from the1980s.

.....with even more complex reactions and events within the Sun itself. We have learned much more about the composition and behavior of comets, leading scientists to wonder whether these cosmic ice balls might be capable of seeding a galaxy with elements necessary for life as we know it.

We have also developed the capability to look at our galaxy and the distant universe in parts of the electromagnetic spectrum that are blocked by the Earth's atmosphere. From this perspective, we have discovered that the universe is a vastly more complex and fascinating place than we ever imagined it was. We have discovered pulsars, quasars, neutron stars and other, more mystifying, phenomena such as gamma ray bursts and black holes. We have found echoes of our genesis in the distant glow of the universe, and evidence of primordial elements from a time when the stars were young. We have even found ourselves witnessing the birth, life, and death of stars in distant galaxies, giving us a window to our own past, present and future.

In the same breath, we have discovered that our view from space has given us an entirely new perspective on our home planet Earth. Our satellites have allowed vastly improved global communications, reliable weather prediction, and monitoring of valuable natural resources. They have also allowed scientists to learn much more about the complex systems [170] that make life possible here on Earth, as well as potential threats to the health of those systems. If global warming, ozone, and El Nino climate patterns are now household terms and concerns, it is in no small part because of satellites Goddard helped put into space and atmospheric models the Center's scientists have developed from those satellites' data.

A computer-enhanced image of Hurricane Linda created from GOES satellite data.

Satellite technology made it possible to turn theories and dreams into science and knowledge, rejuvenating the field of science itself. In the process, it has also created whole new disciplines of scientists. The advent of sounding rocket and satellites created space physicists who could delve into solar physics and "fields and particles" research around Earth and other planets in the solar system. Years later, the results from various Earth-oriented satellites would lead to the creation of climatologists - scientists who combined atmospheric and oceanographic research to look at the inter-related systems that affect global climate changes here on Earth.

The New Millenium: Goddard's Next 40

Today, Goddard stands at the threshold of a new millenium and a new era of space exploration. The Center has grown and evolved dramatically in its first 40 years, but so has the world. And the challenges faced by those trying to explore the mysteries of that world and the universe beyond it have changed, as well. Once, constraints of technology drove Goddard's scientists and engineers to be extremely creative and innovative in their methods. The need for innovation and flexibility is as great today as it ever was, but the driving force is economic, not technological. In a post-Cold War world of shrinking budgets, scientists and engineers simply need to find ways to do more for less.

The players involved in the exploration of space also have evolved and changed. When Goddard was founded, no one really knew how to build a satellite. [171] Today, industry has matured greatly, making it possible to consider new kinds of relationships and agreements. Indeed, one of the legacies of Goddard's 40 years of effort is the expertise its scientists, engineers, and technicians developed and passed on to the Center's industry partners in their many joint efforts. This shared experience is one of the reasons industry has developed the ability to do some of the tasks once reserved for NASA alone.

At the cutting edge of technology and knowledge, change is the only constant. And as with any other development at Goddard over the past 40 years, the changes the Center faces today are a kind of scientific research in and of themselves. If history is any guide, it will take numerous attempts and adjustments before the correct mix of method and structure is found. It's even possible that, in the ever-changing world of technology and scientific exploration, the "correct" approach or mix may never be achieved. But it was the willingness to try new approaches that allowed Goddard's early employees to overcome the enormous challenges and obstacles they faced in conquering even the basics of space flight. Indeed, many would argue that an openness to new ideas or approaches is critical for any scientific progress to occur at all.

In the 1960s, Goddard's employees were driven by a collective enthusiasm for exploration and a belief that their efforts were going to make a difference not only for science, but for the security and life of American citizens. It is harder to keep....

A small part of the Hubble Deep Field South. One of the deepest views of space ever made.

.....that level of enthusiasm without the direct external threat the Russians provided. But the need for that innovation and enthusiasm is as great as it ever was.

If we are to continue to explore our own planet and the universe in which we live, we have to keep our spirit of innovation alive and find ways of making the best use of people's talents, time and energy. It is not an easy task. And in some cases, it may be hard to explain the economic value of the effort. But it is our curiosity about the world beyond the horizon that brought us out of the caves and has driven civilization forward ever since. Indeed, our curiosity and thirst for knowledge are part of what make us human. We may not be able to express this fact in dollars and cents on a balance sheet. But we sense almost instinctively that our minds, imaginations, and souls need sustenance every bit as much as our bodies. If we cease our search for new lands and ideas; if we stop trying to expand our minds and inspire our imaginations; we stagnate, and a life force within us begins to die.

[172]

As we move into a new millenium, the data satellites generate increase in quality and quantity, generating a need for new data processing and archive centers like this EOSDIS facility at Goddard.

Yet to learn more about the world in which we live and to keep new ideas flowing through our minds, we need people willing to undertake the challenge of stepping into the unknown and exploring a territory that is as demanding and unforgiving as it ever was. For some things have not changed in the past 40 years. Space is still a new and unknown frontier, as full of risk, challenge and frustration as it was the day we began to explore it. And that exploration is still a complex and expensive endeavor that requires the cooperation of many different people, institutions, and countries.

The technical obstacles may not be as great as they once were, but the goalposts have moved. Getting into space is no longer sufficient. The task now is to go further and to do it with fewer resources. To accomplish this task requires people with the the same dedication, enthusiasm and passion that made the first successful satellites possible. And this, more than any other single accomplishment or project, is the legacy of the Goddard Space Flight Center. For 40 years, whether it has been in ramshackle warehouses, the muddy swampland of Beltsville, or the neat buildings that now adorn its sprawling campus, Goddard has been a place of enthusiasm, innovation and dogged determination to develop satellites that could improve our lives and bring the universe within our reach.

The sagas of the Apollo and Space Shuttle astronauts may be better known, but the researchers, administrative support staff and other support personnel at Goddard have experienced their own share of adventure in 40 years of space exploration. The control room at Goddard was every bit as tense as Mission Control at Cape Canaveral or the Johnson Space Center, whether or not any particular spacecraft had people on board. Setting up [173] and maintaining the worldwide network to track satellites and the Apollo missions involved its own unique challenges, from coping with political unrest to making use of makeshift telegraph lines across miles of Australian outback territory.

There were technicians and support personnel who frantically trouble-shot computer tracking systems or pieced together satellites that developed problems shortly before launch. There were engineers who spent sleepless nights coordinating the repair of the Hubble Space Telescope. There were scientists who were willing to devote 10 or 15 years of their career to a single research project, knowing the spacecraft might blow up two minutes after launch. There were disappointments, failures, and even tragedies.

Success came at a price. And the price was dedication. Sometimes, it was simply the refusal to give up, and the willingness to risk failure in the hope of finding out something worthwhile. But for 40 years, it has been this intangible, unquantifiable element of passion and dedication that has enabled Goddard to make the contribution to space science and to American society that it has.

The world is more complex than it once was. And so is the field of space flight. There are new pressures, new constraints, and new relationships. Forty years after its founding, one of Goddard's biggest challenges is still maintaining a balance between project teams and Center-wide cooperation, scientists and engineers, inside and outside communities, industry and government, U.S and international efforts, and the cost, schedule, and reliability of the projects it undertakes. At the same time, it needs to keep the flexibility and willingness to consider new approaches and ideas, the passion for exploration, and the enthusiasm for innovation that made space flight possible in the first place.

Our journeys into space comprise the greatest adventure the human race has ever undertaken. We watched, transfixed, as the Echo satellite moved across the night sky and Neil Armstrong became the first human to set foot on the Moon. We find ourselves moved beyond words by images from the Hubble Space Telescope that make us hear and feel the music of the spheres and the power of cosmos. Each new discovery reminds us once again that the universe is a truly majestic and mysterious realm. Our explorations in space keep the wondering child inside us alive as we take step after step into a magical, technicolor world we only know is far more vast and complex than the land we call home.

And yet, our journeys into space have given us a whole new perspective on the land we call home, as well. From space, we are all residents of a single planet Earth, and we have begun to realize how interconnected we all really are.

The effort that has brought us this perspective has not been an easy one, but no exploration ever is. We have mapped certain portions of this unforgiving cosmic territory and have begun to venture into others. Along the way, we have achieved spectacular [174] successes and endured heart-breaking setbacks. But we are still only scratching the surface of the mysteries that lie in this strange new frontier. There is no single list of questions left to answer about our planet, our solar system or our universe, because the more we learn, the more we realize how much left there is to learn. As we discover answers to one question, we find clues to another we hadn't yet thought to ask.

Over the past 40 years, we have discovered that space is not only a new frontier, but an endless one. And exploring it will continue to be one of our greatest ongoing challenges and adventures - a quest of the mind, the imagination, and the human spirit to improve our lives, preserve our home planet, and expand our understanding of ourselves and the vast, mysterious and powerful universe in which we live.

The Hubble Space Telescope opened a window to wonders of the universe that still lie waiting to be discovered and explored. Under the Hubble's lens, this nearby galaxy shows itself to be comprised of numerous distinctive elements, including clumpy gas clouds, darkened dust lanes, and young luminous central star clusters.

REFERENCES

Chapter 1

1. Alfred Rosenthal, Venture Into Space (Washington, D.C.: National Aeronautics and Space Administration, 1968), 20-21; Homer Newell, Beyond the Atmosphere (Washington, D.C.: National Aeronautics and Space Administration, 1980), 55-56.

2. When President Eisenhower originally proposed the civilian space agency, it was called the National Aeronautics and Space Agency, but the name was later changed to the National Aeronautics and Space Administration. (Shirley Thomas, Men of Space (New York: Chilton Books, 1965), 84.

3. Newell, Beyond the Atmosphere, 408.

4. Today, NASA refers to this part of its mission as human space flight. But in the early days, the astronaut program was known both formally and informally as the "manned space flight program." So in some instances I use the term "manned space flight" when referring to this part of NASA in a historical context, even though that term is now outdated.

5. Newell, Beyond the Atmosphere, 246; Sam Keller, interview with author, Washington, D.C., 15 October 1997.

6. According to Homer Newell, "on 22 July 1965 (NASA Associate Administrator Robert) Seamans removed Goett from the directorship ... with the concurrence of both (James) Webb and (Hugh) Dryden." Newell, Beyond the Atmosphere, 256; Harry Goett, interview with author, Los Altos Hills, California, 13 February 1998.

7. Thomas, Men of Space, 94.

8. Christopher Kraft, as quoted in Kathleen M. Mogan, Frank P. Mintz, ed., Keeping Track: A History of the GSFC Tracking and Data Acquisition Networks: 1957 to 1991 (Greenbelt, MD: NASA Publication, undated), 104.

9. Andre Gide, as quoted in Julia Cameron, The Artist's Way: A Spiritual Path to Higher Creativity (New York: G.P. Putnam's Sons, 1992, p.199).

Chapter 2

1. John C. Mather and John Boslough, The Very First Light (New York: Basic Books, 1996), 12-13.

2. Homer Newell, Beyond the Atmosphere (Washington, D.C.: National Aeronautics and Space Administration, 1980), 25-26.

3. Alfred Rosenthal, Venture Into Space (Washington, D.C.: National Aeronautics and Space Administration, NASA SP-4301, 1968), 6-13.

4. Homer Newell, Beyond the Atmosphere , 31-32.

5. William R. Corliss, NASA Sounding Rockets, 1958-1968 (Washington, D.C.: National Aeronautics and Space Administration, NASA SP-4401, 1971), 29; Newell, Beyond the Atmosphere, 51.

6. William Corliss, "The Evolution of the Satellite Tracking and Data Network (STADAN)," Goddard Historical Note Number 3, X-202-67-26 (Greenbelt, Maryland: Goddard Space Flight Center, January 1967), 12.

7. Rosenthal, Venture Into Space, 16; Newell, Beyond the Atmosphere, 31, 54.

8. Newell, Beyond the Atmosphere, 55-56; Rosenthal, Venture Into Space, 20-22; Robert Rosholt, An Administrative History of NASA, 1958-1963 (Washington, D.C.: National Aeronautics and Space Administration, 1966), 3-8; John W. Townsend, Jr., interview with author, Cabin John, Maryland, 15 October 1997.

9. For more detailed information on the formation of NASA, see Rosholt, An Administrative History of NASA, 1958-1963, and Newell, Beyond the Atmosphere, 87-99.

10. Rosholt, An Administrative History of NASA, 1958-1963, 13.

11. Rosenthal, Venture Into Space, 22; John E. Naugle, First Among Equals (Washington, D.C., National Aeronautics and Space Administration, 1991), 13-14; J.H. Capshew, "Within Goddard's Orbit: Satellites, Space Research and NASA," unpublished manuscript, 28 September 1989, Chapter 2, 12. (note: cover says do not quote or cite without author's permission)

12. The Army had successfully launched a Jupiter C missile into space and retrieved its nose cone after re-entry sometime before the beginning of November 1957 (Rosenthal, The Early Years, 126); John E. Naugle, First Among Equals , 6; Dr. Frank B. McDonald, "IMPs, EGOs, and Skyhooks," Journal of Geophysical Research, Vol. 101, A5, 1 May 1996, 10,523; John Clark, phone interview with author, 18 May 1998.

13. Alfred Rosenthal, ed. NASA Space Missions Since 1958 (Washington D.C.: National Aeronautics and Space Administration, 1982), 1-14; "NASA Major Launch Record," Launch summary, 1958-1992, unpublished document, prepared by Chao Yang, Goddard Space Center Technical Library, 1997.

14. John W. Townsend, Jr., Interview, 15 October 1997.

15. "Press release by Senator J. Glenn Beall, Maryland, at Washington D.C. Office, 1 August 1958," from NASA Headquarters History Office Archives.

16. Rosenthal, Venture Into Space, 284-85.

17. Alfred Rosenthal, The Early Years, (Washington, D.C.: National Aeronautics and Space Administration, undated), 17-20, 27-28; Rosenthal, Venture Into Space, 27-28; Rosholt, An Administrative History of NASA, 47; Capshew, "Within Goddard's Orbit, Chapter 3, 5-12; John Townsend, interview, 15 October 1997.

18. Rosenthal, Venture Into Space, 286-289; T. Keith Glennan, Memorandum, 1 May 1959, from NASA Headquarters History Office archives.

19. Rosenthal, Venture Into Space, 209.

20. McDonald, "IMPs, EGOs, and Skyhooks," 10,523-10,524; Rosenthal, Venture Into Space, 290-291; John Townsend, interview, 15 October 1997; Roland Van Allen, interview with author, GSFC, Greenbelt, Maryland, 6 October 1997; Memorandum, from John W. Townsend to T. Keith Glennan, 6 March 1959, from NASA Headquarters History Office archives.

21. Townsend, interview, 15 October 1997; Roland Van Allen, interview, 6 October 1997; Frank McDonald, "Imps, EGOs, and Skyhooks,"10,523-10,524; Frank McDonald, phone interview with author, 5 May 1998.

22. Rosenthal, The Early Years, 28.

23. John W. Townsend, interview, 15 October 1997; Samuel Keller, interview with author, Washington, D.C., 15 October 1997.

24. Alberta Moran, interview with author, GSFC, Greenbelt, MD, 10 July 1997.

25. The Space Science Board name was changed to the Space Studies Board around 1989. The Board contributes ideas for missions, but does not make decisions about which experiments are selected for the missions.

26. John E. Naugle, First Among Equals, 37, 51-53, 57-59, 67-69, 82-85.

27. NASA Space Missions Since 1958, 135, 112, 28.

28. John E. Naugle, First Among Equals , 61.

29. John W. Townsend, interview, 15 October 1997; Frank McDonald, interview,16 October 1997; Les Meredith and Dave Blanchard, interview with author, GSFC, Greenbelt, Maryland, 21 October 1997.

30. Samuel Keller, interview, 15 October 1997; John New, interview with author, Lanham, Maryland, 15 October 1997.

31. Frank McDonald, interview, 16 October 1997; John Townsend, interview, 15 October 1997.

32. Newell, Beyond the Atmosphere, 114-115; Rosenthal, An Administrative History of NASA, 248-49.

33. Robert Jastrow, interview with author, Los Angeles, California, 11 February 1998; Robert Jastrow, The Enchanted Loom, (New York: Simon & Shuster, 1981), 9; "Establishment of an Institute for Space Studies," Memorandum, from Robert Jastrow to the Director of Space Flight Programs, with initialled note "approved subject to attached memo by Dr. Glennan" by Abe Silverstein, 13 December 1960, from NASA Headquarters History Office archives; Newell, Beyond the Atmosphere, 237-240.

34. John Townsend, interview, 15 October 1997; John Clark, phone interview with author, 18 May 1998.

35. NASA Space Missions Since 1958, 75, 87,

36. NASA Space Missions Since 1958, 29, 32, 96, 100, 107; Andrew J. Butrica, ed., Beyond the Ionosphere (Washington, D.C.: National Aeronautics and Space Administration, 1997), 104.

37. Newell, Beyond the Atmosphere, 109.

38. Newell, Beyond the Atmosphere, 251-157; Harry Goett, interview with author, Los Altos Hills, California, 13 February 1998; George Pieper, interview with author, GSFC, Greenbelt, Maryland, 14 October 1997; John W. Townsend, interview, 15 October 1997.

39. A Reduction in Force, or RIF, is the formal term for layoffs of civil servants. (George Pieper, interview, 19 November 1997, comments, 31 August 1998.)

40. Frank Ceppolina, interview with author, GSFC, Greenbelt, Maryland, 12 January 1998.

41. Wallace H. Tucker, The Star Splitters: The High Energy Astronomy Observatories (Washington, D.C.: National Aeronautics and Space Administration, 1984); Margorie Townsend, interview with author, Washington, D.C., 22 November 1997; Nancy Roman, phone interview with author, 27 January 1998; NASA Space Missions Since 1958, 454-455, 513-516.

42. Nancy Roman, phone interviews with author, 27 January 1998 and 23 February 1998; Jesse Mitchell, phone interview with author, 4 March 1998; Albert Opp, phone interview with author, 25 February 1998; John Clark, phone interview with author, 18 May 1998; George Pieper, interview with author, Greenbelt, Maryland, 19 November 1997.

43. In a sense, support for funding any NASA project is affected by national priorities. But the Earth Science research results themselves were more likely to be used as a basis for regulation or legislation than space science results, and therefore, as the scientists relate, were more often attacked by both sides of any related policy debate, particularly with regard to environmental issues. This link to legislation or regulation gave Earth Science projects an additional element of complexity that Space Science projects typically did not have.

44. Robert Cooper, interview with author, Greenbelt, Maryland, 20 October 1997; Vince Salomonson, interview, 19 November 1997; Robert Price, interview, 16 January 1998; John Klineberg, interview with author, Palo Alto, California, 26 November 1997; John Clark, phone interview with author, 18 May 1998; W.Henry Lambright, "Administrative Entrepreneurship and Space Technology: The Ups and Downs of 'Mission to Planet Earth," 97-104..

45. Jim Gravura, phone interview with author, 3 March 1998.

46. "Compton Gamma-Ray Observatory: Exploring the Mysteries of Time," Fact Sheet, from GSFC Public Affairs Office files.

47. Wallops underwent several name changes over the years. In 1946, it became the "Pilotless Aircraft Research Division (PARD)" of Langley. When the NACA became NASA in 1958, it became an independent NASA Center and was renamed the Wallops Island Station. When it was absorbed into Goddard in 1982, it was renamed once again, as the Wallops Flight Facility. James Hansen, Engineer in Charge (Washington, D.C.: National Aeronautics and Space Administration, NASA SP-4305, 1987), 267-270, 567; Arnold Torres, Ray Stanley and Keith Koehler, interview with author, Wallops Island, 23 October 1997; Harold D. Wallace, Jr. Wallops Station and the Creation of an American Space Program, (Washington, D.C.: National Aeronautics and Space Administration, NASA SP-4311, 1997), 6-16.

48. Goddard Space Flight Center organizational charts, from the GSFC Library.

49. Goddard Space Flight Center organizational charts, from the GSFC Library, Greenbelt, Maryland; Dave Shrewsberry, interview with author, GSFC, Greenbelt, Maryland, 15 January 1998; Jon Busse, phone interview with author, 3 March 1998; Arnold Torres, Ray Stanley and Keith Koehler, interview, 23 October 1997; Tom Young, interview with author, GSFC, Greenbelt, Maryland, 18 November 1997.

50. Charles Gunn, interview with author, Falls Church, Virginia, 15 January 1998; John Clark, interview, 18 May 1998.

51. Dave Shrewsberry, interview with author, GSFC, Greenbelt, Maryland, 15 January 1998; "NASA's Small Explorer Program: Faster, Better, Cheaper," Fact Sheet FS-96(07)-014, from GSFC Public Affairs Office files, July 1996.

52. John Mather, The Very First Light, xvii.

53. Bill Robie, For the Greatest Achievement, (Washington, D.C.: Smithsonian Institution Press, 1993), frontespiece.

54. W.Henry Lambright, "Administrative Entrepreneurship and Space Technology: The Ups and Downs of 'Mission to Planet Earth,' Public Administration Review, Vol. 54, No. 2, March/April 1994, 100.

55. Robert Price, interview with author, GSFC, Greenbelt, Maryland, 16 January 1998; Vince Salomonson, interview with author, GSFC, Greenbelt, Maryland, 20 October 1997; W.Henry Lambright, "Administrative Entrepreneurship and Space Technology: The Ups and Downs of 'Mission to Planet Earth,' Public Administration Review, Vol. 54, No. 2, March/April 1994, 97-104.

56. Orlando Figueroa, interview with author, GSFC, Greenbelt, Maryland, 14 January 1998; Brian Keegan, interview with author, GSFC, Greenbelt, Maryland, 21 November 1997; Joe Rothenberg, interview with author, NASA HQ, Washington, D.C., 15 January 1998; Steve Holt, interview with author, GSFC, Greenbelt, Maryland, 14 January 1998.

57. Arnold Torres, Ray Stanley and Keith Koehler, interview, 23 October 1997.

58. Tom Young, interview, 18 November 1997.

59. Tom Huber, interview with author, GSFC, Greenbelt, Maryland, 20 November 1997; Joe Rothenberg, interview, 15 January 1998; "Response to Initial Set of NASA Advisory Council Questions for GSFC," 15 September 1997, Viewgraphs, from Joe Rothenberg files; Jim Adams, telephone interview with author, 16 July 1998.

60. "Space Operations Management," memorandum from Daniel S. Goldin to Directors, NASA Field Installations, 18 October 1995, from the files of Arthur Fuchs, GSFC; Arthur Fuchs, interview with author, GSFC, Greenbelt, Maryland, 12 January 1998.

61. Arnold Torres, Ray Stanley and Keith Koehler, interview, 23 October 1997.

62. Tony Busalacchi, phone interview with author, 28 February 1998; Arnold Torres, Ray Stanley and Keith Koehler, interview, 23 October 1998.

Chapter 3

1. Alfred Rosenthal, edl, NASA Space Missions Since 1958, (Washington, D.C.: National Aeronautics and Space Administration, 1982), 435; Alfred Bester, The Life and Death of a Satellite, (Boston: Little, Brown and Co., 1966), 60-61.

2. John Boeckel, interview with author, GSFC, Greenbelt, Maryland, 17 October 1997; Margorie Townsend, interview with author, Washington, D.C., 22 November 1997; John New, interview with author, Lanham, Maryland, 15 October 1997; Homer Newell, Beyond the Atmosphere, 144-149; Frank McDonald, interview with author, GSFC, Greenbelt, Maryland, 16 October 1997.

3. Karen Kaplan, "Outer Space Outage Signals Growing Dependence on Satellites," Los Angeles Times, 21 May 1998, A1,A31.

4. John Boeckel, interview, 17 October 1997.

5. John Boeckel, interview, 17 October 1997; Roland Van Allen with author, GSFC, Greenbelt, Maryland, interview, 16 October 1997; John New, interview, 15 October 1997; Margorie Townsend, interview, 22 November 1997; Bester, The Life and Death of a Satellite, 74-76.

6. John W. Townsend, interview with author, Cabin John, Maryland, 15 October 1997.

7. Harry Goett, interview with author, Los Altos Hills, California, 13 February 1998; John W. Townsend, interview with author, 15 October 1997; John Boeckel, interview, 17 October 1997; John New, interview, 15 October 1997; Homer Newell, Beyond the Atmosphere, 165-170.

8. A good example of this danger was SeaSat A - a satellite Goddard did not build, but which the Center was handling through its tracking and data network. Three months after its launch in June 1978, the spacecraft developed problems. Engineers realized it was ailing when it passed over Goddard's ground tracking station. They frantically began trouble-shooting the problem, but by the time the spacecraft came within range of the next ground station that could uplink commands to fix it, the satellite's batteries had gone dead.NASA Space Missions Since 1958, 700-701; Robert Cooper, interview with author, Greenbelt, Maryland, 20 October 1997; Robert Price, interview with author, GSFC, Greenbelt, Maryland, 16 January 1998; Tom Huber, interview with author, GSFC, Greenbelt, Maryland, 20 November 1997.

9. Nancy Roman, phone interview with author, 23 February 1998; Frank McDonald, interview with author, GSFC, Greenbelt, Maryland, 16 October 1997; John New, interview, 15 October 1997; Frank McDonald, "IMPs, EGOs and Skyhooks," Journal of Geophysical Research, Vol. 101, No. A5,, 10,526; Goddard Space Flight Center Organizational Charts, from the GSFC Technical Library, Greenbelt, Maryland.

10. John New, interview, 15 October 1997.

11. John New, interview, 15 October 1997; Harry Goett, interview, 13 February 1998.

12. Homer Newell, Beyond the Atmosphere, 159-160, 170.

13. Alfred Bester, Life and Death of a Satellite, 177-180.

14. Jon Busse, phone interview with author, 3 March 1998.

15. Arnold Torres, Ray Stanley and Keith Koehler, interview with author, Wallops Island, Virginia, 23 October 1997; Jon Busse, interview, 3 March 1998, William R. Corliss, NASA Sounding Rockets 1958-1968 (Washington, D.C.: National Aeronautics and Space Administration, NASA SP-4401, 1971), 2-3.

16. "NASA Sounding Rocket Launch Vehicles," Fact Sheet, from Suborbital Projects Directorate files, Wallops Island, Virginia.

17. Arnold Torres, Ray Stanley and Keith Koehler, interview, 23 October 1997.

18. Arnold Torres, Ray Stanley and Keith Koehler, interview, 23 October 1997; Scientific Balloon and Aircraft Fact Sheets, from GSFC Public Affairs Office files.

19. Homer Newell, Beyond the Atmosphere, 133-134; NASA Space Missions Since 1958, 3-17; Charles Gunn, interview with author, Falls Church, Virginia, 16 January 1998.

20. John W. Townsend, interview with author, Cabin John, Maryland, 15 October 1997; Charles Gunn, interview, 16 January 1998;

21. Charles Gunn, interview, 16 January 1998; "The Delta Expendable Launch Vehicle," Fact Sheet, from GSFC Public Affairs Office files.

22. Don Margolies and Jim Barrowman, interview with author, GSFC, Greenbelt, Maryland, 13 January 1998; Dave Shrewsberry, interview with author, GSFC, Greenbelt, Maryland, 15 January 1998; "Science Research with the Spartan," "The Hitchhiker Project," Shuttle Small Payloads Capabilities," "NASA's Get Away Special Program," Fact Sheets/booklets from GSFC Special Payloads Division and Public Affairs Office files; "Get Away Special (GAS) Flight History," Memorandum, from Susan Olden to Dave Shrewsberry, et. al., 9 December 1997.

23. For more information on the IGY, see Chapter Two.

24. This number is approximate because the network was never static. New stations continued to be added and others closed as the tracking needs developed and changed. Information on minitrack network from: William R. Corliss, "The Evolution of the Satellite Tracking and Data Network (STADAN)," Goddard Historical Note Number 3, X-202-67-26 (Greenbelt, Maryland: Goddard Space Flight Center, January 1967) 1-41; Kathleen M. Mogan and Frank P. Mintz, ed., Keeping Track: GSFC Tracking and Data Acquisition Networks: 1957 to 1991 (Greenbelt, Maryland: Goddard Space Flight Center, (undated), 5-14, 79-81.

25. Verne Stelter, interview with author, GSFC, Greenbelt, Maryland, 20 October 1997;

26. Keeping Track, 89, 104.

27. Keeping Track, 41, 101.

28. Verne Stelter, interview, 20 October 1997; Keeping Track, 38-41.

29. Keeping Track, 39; "NASA Major Launch Record," from GSFC Library files.

30. Verne Stelter, interview, 20 October 1997; Keeping Track, 96.

31. The name of the network was changed from the Mercury Space Flight Network to the Manned Space Flight Network at the beginning of the Gemini program.

32. Keeping Track, 42-49, 57-66.

33. John Clark, phone interview with author, 18 May 1998; Verne Stelter, interview, 20 October 1997; Marjorie Townsend, interview, 22 November 1997; Keeping Track, 104.

34. Keeping Track, 56; GSFC Organizational Charts, from the GSFC Library files.

35. Keeping Track, 61.

36. Verne Stelter, interview, 20 October 1997; Pete Bracken, interview with author, GSFC, Greenbelt, Maryland, 17 October 1997; Dale Harris, interview with author, GSFC, Greenbelt, Maryland, 19 November 1997; Art Fuchs, interview with author, GSFC, Greenbelt, Maryland, 12 January 1998; Keeping Track, 70-75.

37. Roland Van Allen, interview with author, GSFC, Greenbelt, Maryland, 16 October 1997; Pete Bracken, interview, 17 October 1997; Rick Obenschain, interview with author, GSFC, Greenbelt, Maryland, 20 November 1997; "Product Levels - Layman's Definitions," Email Memorandum, from H.K. Ramapriyan to Rick Obenschain, 24 November 1997.

38. Steve Holt, interview with author, GSFC, Greenbelt, Maryland, 14 January 1998; Rick Obenschain, interview, 20 November 1997; "EOS Data and Information System (EOSDIS) Overview," viewgraphs, from Rick Obenschain files; "The Earth Observing System Data and Information System," Fact Sheet, from GSFC Public Affairs Office files.

Chapter 4

1. K.C. Cole, "Study of Black Holes Backs Einstein's Theory of Gravity," Los Angeles Times, 7 November 1997, A-1, A-32-33, (referencing research with Goddard's Rossi X-ray Timing Explorer (RXTE)).

2. Homer Newell, Beyond the Atmosphere (Washington, D.C.: National Aeronautics and Space Administration, NASA SP-4211,1980), 39, 82-84, 329.

3. These missions included Explorers 7, 13, 16 and 23. For specific launch dates, see Appendix A.

4. Frank McDonald, interview with author, GSFC, Greenbelt, Maryland, 16 October 1997; Steve Maran, email comments, 14 July 1998; "Advanced Composition Explorer," booklet, from Don Margolies' files, GSFC.

5. Frank McDonald originally named the series Interplanetary Monitoring Probes, but it was soon changed from Probes to Platforms.

6. Frank McDonald, interview, 16 October 1997; George Pieper, phone interview with author, 20 July 1998, comments, 31 August 1998; John W. Townsend, phone interview with author, 28 August 1998.

7. Frank McDonald, interview, 16 October 1997; Frank McDonald, "IMPs, EGOs, and Skyhooks," Journal of Geophysical Research, Vol. 101, No. A5, 1 May 1996, 10,521-10,530; "NASA Major Launch Record," from GSFC library files; Alfred Rosenthal, ed., NASA Space Missions Since 1958 (Washington, D.C.: National Aeronautics and Space Administration, 1982).

8. Newell, Beyond the Atmosphere, 338-340.

9. NASA Space Missions Since 1958, 135, 179, 212, 270, 306, 382; John Clark, phone interview with author, 18 May 1998; Alfred Rosenthal, Venture Into Space, (Washington, D.C.: National Aeronautics and Space Administration, 1968), 47, 231,-232; Tom Huber, interview with author, GSFC, Greenbelt, Maryland, 20 November 1997; Robert Bordeaux, interview with author, Fulton, Maryland, 21 October 1997. (For more information on the Rapid Spacecraft Procurement Initiative, see Chapter 2.)

10. NASA Space Missions Since 1958, 675, 710; Frank McDonald, "IMPs, EGOs, and Skyhooks," 10,528.

11. "Advanced Composition Explorer," GSFC booklet, from Don Margolies files, 9-19; "Our Sun: A Look Under the Hood," Fact sheet, from GSFC Public Affairs Office files; Dick Thompson, "Eyes on the Storm-Tossed Sun," Time, 8 September 1997, 68-69.

12. John Klineberg, interview with author, Palo Alto, California, 24 November 1997; "The Geotail Mission," "Polar Satellite Will Study Effects of Solar Plasma," "ISTP Unites Scientists for Study of Sun-Earth System," "Wind Spacecraft to Study Solar Breeze," Fact Sheets, from GSFC Public Affairs Office files; Solar and Heliospheric Observatory (SOHO) fact sheet/educational aid, from SOHO project office files; "Advanced Composition Explorer (ACE)," booklet, from Don Margolies files; "GGS Polar Mission Profile," Booklet, produced by Lockheed Martin Astro Space, Princeton, New Jersey, undated.

13. "SMEX Project History," Fact Sheet, from SMEX project Web Page; "FAST Satellite Probes Mysteries of the Aurora," Fact Sheet, from GSFC Public Affairs Office files.

14. Newell, Beyond the Atmosphere, 363-369; Steve Maran, interview with author, GSFC, Greenbelt, Maryland, 14 January 1998; "Our Sun: A Look Under the Hood," NASA Fact Sheet FS-1997-01-002-HQ-S, January 1997, from GSFC Public Affairs Office Files, .

15. NASA Space Missions Since 1958, 178.

16. For more information on Multi-mission Modular Spacecraft, see Chapter 3.

17. Pete Bracken, interview with author, GSFC, Greenbelt, Maryland, 17 October 1997; Frank Ceppolina, interview with author, GSFC, Greenbelt, Maryland, 12 January 1998; Major NASA Satellite Missions and Key Participants, Vol. IV - 1984 and 1985 (Greenbelt, Maryland: Goddard Space Flight Center, 1985), 10-15.

18. Stephen Maran, interview, 14 January 1998; NASA Missions Since 1958, 746-748; Stephen Maran, "A New Look at Old Sol," Natural Science, June 1997, 154-161; "Heat Source of Sun's Corona Said Found by SOHO Satellite," Press Release, from the Royal Astronomical Society, 27 March 1998; "SOHO Data on Coronal Ejections May Tell Where Solar Wind Begins," Press Release, from the Royal Astronomical Society, 27 March 1998; "Tiny Explosions, Size of Earth, Said Found on Sun by SOHO Satellite," Press Release, from the Royal Astronomical Society, 26 January 1998; Dick Thompson, "Eyes on the Storm-Tossed Sun," Time, 8 September 1997, 68-69; R. Cowen, "Deepening Insight into Solar Outbursts," Science News, Vol. 152, 20-27 December 1997, 390; R. Cowen, "Spacecraft Probes Beneath Sun's Surface," Science News, Vol 152, 6 September 1997, 150; Alexander Hellemans, "SOHO Probes the Sun's Turbulent Neighborhood," Science, Vol. 277, 25 July 1997, 479; David Ehrenstein, "SOHO Traces the Sun's Hot Currents," Science, Vol. 277, 5 September 1997, 1438; Randy Showstack, "Scientists Unveil New Theory and Findings About Solar Eruptions," EOS, 16 December 1997, 581; "New Satellite Shows Sun in Stunning Detail," Press Release, from NASA HQ, 29 May 1998; "Our Sun: A Look Under the Hood," Fact Sheet, January 1997, from GSFC Public Affairs Office Files; "Advanced Composition Explorer," GSFC booklet, from Don Margolies files; "Transition Region and Coronal Explorer," Fact Sheet, from GSFC TRACE project web page; "Spartan 201: NASA's Mission to Explore the Sun's Corona," Fact Sheet, from GSFC Spartan project web page; "The Ulysses Mission - A Deep Space Voyage to High Latitudes over the Solar Pole," Fact Sheet, from the Ulysses/NASA internet web page; "SOHO Illuminates the Sun," Fact Sheet/Educational Reference Guide, from SOHO project office files, GSFC.

19. NASA Space Missions Since 1958, 321-326, 547-548; Dave Blanchard, interview with author, GSFC, Greenbelt, Maryland, 22 October 1997; John Clark, phone interview with author, 18 May 1998; "SWAS Spacecraft Probes Mysteries of Star Formation, Fact Sheet FS-96(07)-012, July 1996, from GSFC Public Affairs Office files; Wallace H. Tucker, The Star Splitters (Washington, D.C.: National Aeronautics and Space Administration, 1984), 6-7, 91.

20. John C. Mather, interview with author, GSFC, Greenbelt, Maryland, 24 October 1997; John C. Mather and John Boslough, The Very First Light, (New York: Basic Books, 1996), 113-114; John C. Mather, "Cosmic Background Explorer Observes the Primeval Explosion," GSFC Booklet, undated.

21. John C. Mather, interview, 24 October 1997; Steve Holt, interview with author, GSFC, Greenbelt, Maryland, 14 January 1998; Mather, The Very First Light; "COBE: Revealing Secrets of the Big Bang, Fact Sheet, from GSFC Public Affairs Office files; "Astronomers Discover an Infrared Background Glow in the Universe," NASA Press Release, 9 January 1998.

22. John W. Townsend, interview with author, Cabin John, Maryland, 15 October 1997; Nancy Roman, phone interview with author, 23 February 1998; George Pieper, interview with author, GSFC, Greenbelt, Maryland, 14 October 1997; John Boeckel, interview with author, GSFC, Greenbelt, Maryland, 17 October 1997; Tom Huber, interview with author, GSFC, Greenbelt, Maryland, 20 November 1997; NASA Space Missions Since 1958, 202-203, 340-341, 452, 517-518.

23. For more discussion on how and why the Hubble program was set up the way it was, see Chapter 2.

24. Perkin-Elmer is now called Raytheon Optical Systems.

25. "Axial" refers to the four instruments located in long modules along the "axis" of the telescope. The Wide Field/Planetary Camera, in contrast, was a wedge-shaped instrument that was located below these instruments, in the lower part of the cylindrical-shaped telescope.

26. Phenomena observed in ultraviolet and infrared wavelengths do not initially appear as a nice, pretty picture. Scientists take the data and enhance it with different colors to visually represent the contrasting intensities and patterns indicated

27. Joe Rothenberg, interview with author, NASA HQ, Washington, D.C., 15 January 1998; Frank Ceppolina, interview , 12 January 1998; John Klineberg, interview with author, Palo Alto, California, 26 November 1997; Tom Huber, interview with author, GSFC, Greenbelt, Maryland, 20 November 1997; George Pieper, interviews with author, GSFC, Greenbelt, Maryland, 14 October 1997 and 19 November 1997; Nancy Roman, phone interview with author, 23 February 1998; Hubble Space Telescope 1st Servicing Mission Reference Guide, published for NASA by Lockheed Missiles & Space Company, Inc., Sunnyvale, California, 1993; Hubble Space Telescope 2nd Servicing Mission Media Reference Guide, published for NASA by Lockheed Martin Missiles & Space, Sunnyvale, California, 1997; "NASA embarks on Historic Hubble First Servicing Mission," Goddard News, Special Edition, HST 1993; "Hubble Space Telescope Second Servicing Mission (SM-2)," Hubble Facts, Fact Sheet FS-96(12)-025-GSFC, from GSFC Public Affairs Office files; "Hubble Space Telescope New and Improved," Starcatcher, from the Space Telescope Science Institute, Baltimore, Maryland, undated; "Planetary Nebula Gallery," Educational Resource Material EW-1997(12)-008-GSFC, published by GSFC, Greenbelt, Maryland, 1997; "Stars," Educational Resource Material EW-1997(02)-001-GSFC, published by GSFC, Greenbelt, Maryland, 1997; Kathy Sawyer, "Images of Stars' Dazzling Deaths Radiate a Message of Rebirth," The Washington Post, 22 December 1997, A3; Gloria B. Lubkin, "Stellar Techniques in Mammography," Physics Today, June 1995, 21-22; K.C. Cole, "Hubble Finds Biggest Star Yet," The Los Angeles Times, 8 October 1997, B2, B8.

28. Tom Huber, interview, 20 November 1997; Nancy Roman, phone interview, 23 February 1998; Les Meredith, interview with author, GSFC, Greenbelt, Maryland, 21 October 1997; George Pieper, interviews with author, 14 October 1997 and 19 November 1997; Yoji Kondo, telephone interview with author, 24 June 1998; Yoji Kondo, "Space Astronomy and IUE," written comments, 17 April 1998; "The International Ultraviolet Explorer (IUE)," Fact Sheet NF-189, June 1993, from GSFC Public Affairs Office; Jim Sahli, "IUE 'Lights Out'," Goddard News, November 1996, 5, 7.

29. Yoji Kondo, telephone interview with author, 24 June 1998; "EUVE: Probing a Newly Opened Window," Fact Sheet, undated, from GSFC Public Affairs Office; "EUVE Operations," Fact Sheet, March 1992, from GSFC Public Affairs Office.

30. Tucker, The Star Splitters, 7-8; 85; 99; 111-117; Newell, Beyond the Atmosphere, 357-363; Steve Holt, interview, 14 January 1998; Nancy Roman, phone interview, 23 February 1998; Edward K.L. Upton, interview with author, Los Angeles, California, 12 April 1998.

31. Tucker, The Star Splitters, 24.

32. Margorie Townsend, interview with author, Washington, D.C., 22 November 1997; Tucker, The Star Splitters, 24; 129-132.

33. NASA Space Missions Since 1958, 664-665, 720-721; Tucker, The Star Splitters, 27, 79-81.

34. Tucker, The Star Splitters, 103, 133-135, 147-150; "Medal Awarded to Early Black Hole Investigator, Donald Lynden-Bell," Press Release, from the Astronomical Society of the Pacific, 18 May 1998; "X-Ray Timing Explorer Clocks High-Energy Universe," NASA Facts Online Fact Sheet, from GSFC Internet World Wide Web Pages.

35. Tucker, The Star Splitters, 151-164; "Forecast for the Universe is Stormy, Professor Says," Press Release, from the University of Missouri, 16 April 1998; "Invader Galaxy Apparently Contains Much Dark Matter," Press Release, from the Johns Hopkins University, 13 February 1998; "Mysterious Glow from Colliding Galaxies," Press Release, from the Massachusetts Institute of Technology, 23 February 1998.

36. Steve Holt, interview with author, 14 January 1998; Steve Maran, interview with author, GSFC, Greenbelt, Maryland, 14 January 1998; "Strongest Known Magnetic Field? Magentar Said Discovered," Press Release from the University of Alabama, Huntsville, 20 May 1998; "Record-Setting Pulsar Said Found by NASA's RXTE Satellite," Press Release from the Los Alamos National Laboratory, 26 January 1998; Tucker, The Star Splitters, 81, 113; "X-Ray Timing Explorer Clocks High Energy Universe," NASA Facts Online Fact Sheet, June 1995, from GSFC Internet World Wide Web pages; "ASCA (Astro D): February 1993," Fact Sheet, undated, from GSFC Laboratory for High Energy Astrophysics World Wide Web pages.

37. "Compton Gamma-Ray Observatory: Exploring the Mysteries of Time," Fact Sheet FS96(07)-015, July 1996, from GSFC Public Affairs Office files.

38. Mather, The Very First Light, 48-49; "Goddard Projects Summary August 1959 - December 1967," GSFC Booklet, undated, 8-9.

39. Tucker, The Star Splitters, 138-139.

40. Ralph A.M.J. Wijers, et. al, "Gamma Ray Bursts from Stellar Remnants: Probing the Universe at High Redshift," Monthly Notices of the Royal Astronomical Society, 294, 11 February 1998, L13-L-17; "Gamma Ray Bursts Said to Come from Very Early Universe," Press Release, from the Royal Astronomical Society, 6 February 1998.

41. Steve Maran, interview, 14 January 1998; Al Opp, telephone interview with author, 25 February 1998; "Compton Gamma Ray Observatory (CGRO)," fact sheet, 4 June 1997, from GSFC Laboratory for High Energy Astrophysics World Wide Web pages; "Compton Gamma-Ray Observatory: Exploring the Mysteries of Time," fact sheet, July 1996, from GSFC Public Affairs Office files; "Compton Gamma-Ray Observatory: Exploring the Mysteries of Time," NASA Facts On Line NF-180-June 1993, from GSFC World Wide Web pages; "Most Energetic Event in Universe Said to be Detected," Press Release, 30 April 1998, from the California Institute of Technology; "Most Powerful Explosion Since the Big Bang," NASA Headquarters Press Release, 5 May 1998.

Chapter 5

1. Rough photographs of Earth taken from Viking rockets at altitudes of 60-70 miles actually appeared in the October 1950 issue of National Geographic (Seeing the World from 80 Miles Up," National Geographic, 98:511-28, October 1959). The photos in Life magazine came a year later but were broader in coverage because they were taken from an altitude of 135 miles. (Life, 31:165-66, 15 October 1951); Les Meredith, interview with author, GSFC, Greenbelt, Maryland, 21 October 1997.

2. Project Rand would later become the non-profit, research and development-oriented RAND corporation.

3. Andrew J. Butrica, ed., Beyond the Ionosphere, (Washington, D.C.: National Aeronautics and Space Administration, 1997), 96-103.

4. Homer Newell, Beyond the Atmosphere, (Washington, D.C.: National Aeronautics and Space Administration, 1980), 186-200, 332-3; Vincent V. Salomonson and Louis S. Walter, "The Contributions of Spaceborne Observing Systems to the Understanding of the Solid Earth and Land Surface Processes," Proceedings of the Symposium on the State of Earth Science from Space: Past, Progress, Future Prospects, Space Policy Institute of George Washington University, published in a compendium by the American Institute for Physics (G. Asrar, ed.), May 1994, 3-18; Paul Lowman, interview with author, GSFC, Greenbelt, Maryland, 17 October 1997; Alfred Rosenthal, NASA Space Missions Since 1958, (Washington, D.C.: National Aeronautics and Space Administration, 1982), 182, 301, 648-9.

5. Beyond the Ionosphere, 100.

6. "The Goddard Space Flight Center Family of Satellites," GSFC Booklet, April 1963 from Roland Van Allen's files; NASA Space Missions Since 1958, 32, 120; Beyond the Ionosphere, 99-105; Al Jones, phone interview with author, 23 February 1998.

7. This debate about which approach to take for communication satellites continues to this day. Numerous companies are currently investing in a new round of extremely high capability satellite systems that will vastly improve mobile phone and communications service, but they are taking three different approaches. Hughes is pursuing a geostationary orbit for its system, which will need 8 satellites. Two other companies are planning medium-Earth orbits for their networks, which will require 10-12 spacecraft. Several other companies are planning networks of low-Earth orbiting satellites, which will consist of anywhere from 28 to 840 satellites. (Al Jones, phone interview, 23 February 1998; William J. Cook, "1997: A New Space Odyssey," US News & World Report, Vol. , 3 March 1997, 45-52.

8. Beyond the Ionosphere, 100-124; Al Jones, phone interview, 23 February 1998; John W. Townsend, interview with author, Cabin John, Maryland, 15 October 1997; Harry Goett, interview with author, Los Altos Hills, California, 13 February 1998; NASA Space Missions Since 1958, 81, 96, 100, 102, 107, 118, 129.

9. For more information on TDRSS, see Chapter 3.

10. Al Jones, interview, 23 February 1998; NASA Space Missions Since 1958, 234, 249, 285, 328, 409, 571; L.J. Allison, ed., "Meteorological Satellites," NASA TM 80704, June 1980, 7-8; Keeping Track, 71-73, 107.

11. "Our Atmosphere," Fact Sheet, undated, from GSFC Public Affairs Office files.

12. This agency has, at different times, been known as both "ARPA," for the "Advanced Research Projects Agency," and "DARPA," for the "Defense Advanced Research Projects Agency." At the time referenced here, the agency was known as ARPA.

13. William Bandeen, interview with author, GSFC, Greenbelt, Maryland, 19 November 1997; NASA Space Missions Since 1958, 15, 21-23, 29.

14. John W. Townsend, interview, 15 October 1997; William Bandeen, interview, 19 November 1997; John Clark, phone interview with author, 18 May 1998; Harry Goett, interview, 13 February 1998.

15. United States Department of Commerce Press Release, WB 61-20, 13 November 1961, from the files of William Bandeen.

16. William Bandeen, interview, 19 November 1997; John W. Townsend, interview with author, Cabin John, Maryland, 15 October 1997; "TIROS I Plus Ten," ESSA, Vol. 5, No. 1,January 1970, 17-23; L.J. Allison, ed., "Meteorological Satellites," NASA TM 80704, June 1980, 1-7.

17. Guenter Warnecke and Wendell S. Sunderlin, "The First Color Picture of the Earth Taken from the ATS-3 Satellite," Bulletin of the American Meteorological Society, Vol. 49, No. 2, February 1968, 75-83.

18. The difference between geosynchronous and geostationary satellites is small. A geostationary satellite will remain in exactly the same spot as the Earth rotates. A geosynchronous satellite will remain in approximately the same spot, but its orbit will oscillate slightly north to south around the equator. How much the orbit varies depends on the satellite.

19. The satellite actually became known as GOES-8 after it was successfully launched. Satellites are typically referred to with letter designations in development and only given numerical designations once they reach orbit. I refer to this project as GOES 8 throughout to avoid confusion, since that is how the satellite is now known.

20. Rick Obenschain, interview with author, GSFC, Greenbelt, Maryland, 20 November 1997; Vincent V. Salomonson, interview with author, GSFC, Greenbelt, Maryland, 19 November 1997; William Bandeen, interview, 19 November 1997; William Bandeen, phone interview, 1 July 1998; John Klineberg, interview with author, Palo Alto, California, 26 November 1997; Jim Greaves, phone interview with author, 1 July 1998; GOES 8 project report and Launch Date records,undated, from Jim Greaves files.

21. William Bandeen, interview, 19 November 1997; Les Meredith, interview, 21 October 1997; John Boeckel, interview with author, GSFC, Greenbelt, Maryland, 17 October 1997; Rudy Hanel, interview with author, Brookeville, Maryland, 24 October 1997; Vincent V. Salomonson, interview, 19 November 1997; Lewis J. Allison, et. al., "Remote Sensing of the Atmosphere from Environmental Satellites, GSFC Report X-901-77-132 Preprint, June 1977, 25-26; NASA Space Missions Since 1958, 511-512.

22. NASA Space Missions Since 1958, 594-95.

23. "Landsat: Time Present, Time Past, and Now Time Future," booklet NP-1997 (09)-025-GSFC, from Darrell Williams files.

24. William Bandeen, interview, 19 November 1997; Les Meredith, interview, 21 October 1997; John Boeckel, interview, 17 October 1997; Rudy Hanel, interview, 24 October 1997; Rick Obenschain, interview, 20 November 1997; Vincent V. Salomonson, interview, 19 November 1997; Donald T. Lauer, Stanley A. Morain, and Vincent V. Salomonson, "The Landsat Program: Its Origins, Evolution, and Impacts," Photogrammetric Engineering & Remote Sensing, Vo. 53, No. 7, July 1997, 831-838.

25. Mark Schoeberl, interview with author, GSFC, Greenbelt, Maryland, 16 January 1998; William R. Bandeen, "Experimental Approaches to Remote Atmospheric Probing in the Infrared from Satellites," GSFC Report X-622-68-146 preprint, May 1968, 1-2; "Clouds and the Energy Cycle," Fact Sheet NF-207, January 1994, from GSFC Public Affairs Office files; NASA Space Missions Since 1958, 23, 227, 253, 330, 364; Major NASA Satellite Missions and Key Participants, Vol.. IV - 1984 and 1985, (Greenbelt, Maryland, Goddard Space Flight Center, 1986), 25-26; Dr. Edward J. Hurley and Ruthie Jones, "Nimbus 7: Observing the Atmosphere and Oceans," GSFC Booklet, December 1983, from William Bandeen files, 12-13; "Tropical Rainfall Measuring Mission," Fact Sheet FS-1997(03)-003-GSFC, April 1997, from GSFC Public Affairs Office files; "TRMM Mission Summary," Fact Sheet, from TRMM project web pages; "A Global Eye on Tropical Rainfall: The Tropical Rainfall Measuring Mission (TRMM)," Booklet, undated, from GSFC Public Affairs Office files.

26. Although popularly known as a "hole" in the ozone layer, the phenomenon being researched is actually just a thinning in the layer. There is no place where the ozone is completely gone.

27. Mark Schoeberl, interview, 16 January 1998; W. Henry Lambright, "NASA, Ozone and Policy-Relevant Science: The Accelerative Process," NSF Report DIR-9009827, November 1993, 1-26; Dr. Edward J. Hurley and Ruthie Jones, "Nimbus 7," 22-25; "Ozone: What is It and Why Do We Care About It?" Fact Sheet NF-198, December 1993, from GSFC Public Affairs Office files; "NASA's Ozone Studies," Fact Sheet NF-208, February 1994, from GSFC Public Affairs Office files, "Shuttle Solar Backscatter Ultraviolet (SSBUV) Instrument," Fact Sheet 193, September 1995, from GSFC Public Affairs Office files; Claire L. Parkinson, Earth From Above: Using Color-Coded Satellite Images to Examine the Global Environment (Sausalito, CA: University Science Books, 1997), 17-32.

28. Mark Schoeberl, interview, 16 January 1998; "UARS," booklet, 1998, from Mark Schoeberl files; "Upper Atmosphere Research Satellite," Fact Sheet, January 1994, from NASA Facts On Line, NASA GSFC Web Pages; "Total Ozone Mapping Spectrometer/Earth Probe," Fact Sheet, 22 September 1997, from NASA Facts On Line, NASA GSFC Web Pages; "Volcanoes and Global Climate Change," Fact Sheet NF 220, March 1994, from GSFC Public Affairs Office files; "Upper Atmosphere Research Satellite (UARS)," Fact Sheet NF-208, January 1994, from GSFC Public Affairs Office files; W. Henry Lambright, "NASA, Ozone and Policy-Relevant Science," 22-31, Kathy Pedelty, "UARS' Amazing Journey," Earth Science News, Vol. 2, No. 1, Spring/Summer 1997, 2-3, 12.

29. Mark Schoeberl, interview, 16 January 1998.

30. "Our Oceans," Fact Sheet, from data compiled from the Smithsonian Institution's Ocean Planet exhibition and from Peter Benchley and Judith Gradwohl, Ocean Planet: Writings and Images of the Sea (New York: Harry N. Abrams Inc.), undated, from GSFC Public Affairs Office files.

31. "Tony Busalacchi, phone interview with author, 28 February 1998; "Polar Ice," Fact Sheet NF 212, February 1994, from GSFC Public Affairs Office files, Lewis J. Allison, et. al, "Remote Sensing of the Atmosphere from Environmental Satellites," 20-21, 33; Claire L. Parkinson, Earth From Above, 33-53.

32. For more information on the SeaWIFS project structure, see Chapter 2.

33. For more information on the Rapid Spacecraft Procurement Initiative, see Chapter 2; Jim Adams, phone interview with author, 16 July 1998.

34. Tony Busalacchi, interview, 28 February, 1998; Vincent V. Salomonson, interview, 19 November 1997; Dorothy Zukor, interview with author, GSFC, Greenbelt, Maryland, 19 November 1997; Claire L. Parkinson, Earth From Above, 77-93; Lewis J. Allison, et. al, "Remote Sensing of the Atmosphere from Environmental Satellites," 20, 35-37; Dr. Edward J. Hurley and Ruthie Jones, "Nimbus 7," 1-13; "TOPEX-Poseidon: At-A-Glance," Fact Sheet, undated, from TOPEX/Poseidon Web Pages. "Sea-viewing Wide Field-of-view Sensor (SeaWiFS)," Fact Sheet FS-97(03)-004-GSFC, May 1997, from GSFC Public Affairs Office Files.

35. Tony Busalacchi, interview, 28 February, 1998; Claire L. Parkinson, Earth From Above, 77-84; Dorothy Zukor, interview, 19 November 1997; "Space Based Observation of Anomalies in the Equatorial Pacific," Fact sheet, undated, from GSFC World Wide Web pages, "El Nino," Fact Sheet NF 211, Rev. April 1996, from GSFC Public Affairs Office files; "El Nino," Fact Sheet, undated, from TOPEX/Poseidon Prime Mission Results Introduction Web pages; "ENSO Primer," Fact Sheet, undated, from GSFC Web pages.

36. Mark Schoeberl, interview, 16 January 1998; Tony Busalacchi, interview, 28 February 1998; "Biosphere," Fact Sheet NF-223, March 1994, from GSFC Public Affairs Office files; "The Greenhouse Effect," Fact Sheet NF-182, June 1993, from GSFC Public Affairs Office files; "Global Warming," Fact Sheet NF-222, March 1994, from GSFC Public Affairs Office files.

37. Robert Price, interview with author, GSFC, Greenbelt, Maryland, 16 January 1998; Dorothy Zukor, interview, 19 November 1997; W. Henry Lambright, "Administrative Entrepreneurship and Space Technology: The Ups and Downs of 'Mission to Planet Earth,'" Public Administration Review, Vol. 54, No. 2, March/April 1994, 97-104; Tony Busalacchi, interview, 28 February 1998; "Understanding Our Changing Planet: NASA's Mission to Planet Earth," 1997 Fact Book, from MTPE program office files; "GSFC MPTE Lead Center," viewgraph, June 1997, from Joe Rothenberg files.

38. Discovery 5 Space Mission astronaut, as quoted in Atlas of the World (Maplewood, NJ: Hammond Incorporated, 1993), back cover.

Chapter 6

1.:"The National Aeronautics and Space Act, As Amended," 13 October 1962, Sec. 102(a), as reproduced in Robert L. Rosholt, An Administrative History of NASA 1958-1963, (Washington, D.C.: National Aeronautics and Space Administration, 1966), 305.

2. The Jet Propulsion Laboratory in Pasadena, California is dedicated to scientific research, as well, but it is operated and staffed by CalTech under contract to NASA, not by NASA directly.

Bibliographic Essay

[191] The single most important group of sources for this book consists of over 70 individual interviews with scientists, engineers, administrative personnel, and managers who worked at or with Goddard over the past 40 years, along with documents they provided from their files.

Additional information on the organizational structure of Goddard and the history of its launches was obtained from Goddard's technical library, with the help of Jane Riddle and Chao Yang. Further project information was obtained from individual project offices, Goddard's "web" pages on the internet and from fact sheets and informational material provided by Goddard's Public Affairs Office. A critical resource for specific details on individual spacecraft was the NASA Space Missions Since 1958 (Alfred Rosenthal, ed., Washington, D.C., National Aeroantuics and Space Administration, 1991).

Information on the evolution of Goddard and the work the Center performed was also provided by numerous other books. These sources included: Alfred Rosenthal, Venture Into Space (Washington, D.C.: National Aeronautics and Space Administration, NASA SP-4301, 1968); Robert Rosholt, An Administrative History of NASA, 1958-1963 (Washington, D.C.: National Aeronautics and Space Administration, 1966); Homer Newell, Beyond the Atmosphere (Washington, D.C.: National Aeronautics and Space Administration, 1980); William R. Corliss, NASA Sounding Rockets, 1958-1968 (Washington, D.C.: National Aeronautics and Space Administration, NASA SP-4401, 1971); John E. Naugle, First Among Equals (Washington, D.C.: National Aeronautics and Space Administration, 1991); Alfred Bester, The Life and Death of a Satellite (Boston, MA: Little, Brown and Company, 1966); Harold D. Wallace Jr., Wallops Station (Washington, D.C.: National Aeronautics and Space Administration, NASA SP-4311, 1997); Wallace H. Tucker, The Star Splitters, (Washington, D.C.: National Aeronautics and Space Administration, NASA SP-466, 1984); Claire L. Parkinson, Earth From Above (Sausalito, CA: University Science Books); and John.C. Mather and John Boslough, The Very First Light (New York, NY: Basic Books, 1996).

[192] Additional Goddard-produced monographs and historical notes, such as Kathleen M. Mogan and Frank P. Mintz, Keeping Track: A History of the GSFC Tracking and Data Acquisition Networks: 1957-1991, and William R. Corliss, "The Evolution of the Satellite Tracking and Data Acquisition Network (STADAN), (Goddard Historical Note Number 3, January 1967) provided valuable information on the evolution of Goddard's tracking and data networks.

Other articles and research reports, such as W. Henry Lambright, "Administrative Entrepreneurship and Space Technology: The Ups and Downs of "Mission to Planet Earth," Public Administration Review, Vol. 54, No. 2, March/April 1994; and Donald T. Lauer, et. al, "The Landsat Program: Its Origins, Evolution, and Impacts," Photogrammetric Engineering and Remote Sensing, Vol. 53, No. 7, July 1997, helped trace the evolution of various long-term programs at Goddard and the factors that influenced their development.

A final group of sources for information on recent scientific research consisted of the American Astronomical Society, as well as articles in current journals and newspapers, including the Los Angeles Times, Science, Natural Science, and Science News.

Appendix A
Glossary of Acronyms

ACE

Advanced Composition Explorer

ADEOS

Advanced Earth Observing System (Japanese satellite)

AET

Applied Engineering and Technology (directorate)

AFO

Announcement of Flight Opportunity

APT

Automatic Picture Transmission

ARPA

Advanced Research Projects Agency

ATS

Applications Technology Satellite

AXAF

Advanced X-Ray Astrophysics Facility

CERES

Clouds and the Earth's Radiant Energy System (instrument)

CFC

Chlorofluorocarbons

CGRO

Compton Gamma Ray Observatory

CME

Coronal Mass Ejection

COBE

Cosmic Background Explorer

COSTAR

Corrective Optics Space Telescope Axial Replacement

CZCS

Coastal Zone Color Scanner

DAAC

Distributed Active Archive Centers

DARPA

Defense Advanced Research Projects Agency

DIRBE

Diffuse Infrared Background Experiment

DMR

Differential Microwave Radiometer

DOD

Department of Defense

DSN

Deep Space Network

EOS

Earth Observing System

EOSDIS

Earth Observing System Data and Information System

EPA

Environmental Protection Agency

ERBE

Earth Radiation Budget Experiment

ERBS

Earth Radiation Budget Satellite

EROS

Earth Resources Observation System (data center)

ERTS

Earth Resources Technology Satellite

ESA

European Space Agency

ESSA

Environmental Science Services Administration

EUVE

Extreme UltraViolet Explorer

EVA

Extra-Vehicular Activity

FAST

Fast Auroral Snapshot Explorer

FIRAS

Far Infrared Absolute Spectrophotometer

GAS

Get Away Special

GISS

Goddard Institute for Space Studies

GOES

Geostationary Operational Environmental Satellite

GPS

Global Positioning System

GSFC

Goddard Space Flight Center

HALOE

Halogen Occultation Experiment

HEAO

High Energy Astronomy Observatory

HEASARC

High Energy Astrophysics Science Archival Research Center

HST

Hubble Space Telescope

ICBM

Intercontinental Ballistic Missile

ICE

International Cometary Explorer

IGY

International Geophysical Year

IMP

Interplanetary Monitoring Probe/Platform

ISAS

(Japanese) Institute of Space and Astronautical Science

ISEE

International Sun Earth Explorer

ISTP

International Solar Terrestrial Physics (program)

ITOS

Improved TIROS Operational Satellite

IUE

International Ultraviolet Explorer

MAP

Microwave Anisotropy Probe

MMS

Multi-mission Modular Spacecraft

MSFN

Mercury/Manned Space Flight Network

MTPE

Mission to Planet Earth

NACA

National Advisory Committee for Aeronautics

NAS

National Academy of Sciences

NASA

National Aeronautics and Space Administration

NASCOM

NASA Communications Network

NICMOS

Near Infrared Camera and Multi-Object Spectrometer

NGST

Next Generation Space Telescope

NOAA

National Oceanic and Atmospheric Administration

NRL

Naval Research Laboratory

NSF

National Science Foundation

NSSDC

National Space Science Data Center

OAO

Orbiting Astronomical Observatory

OGO

Orbiting Geophysical Observatory

OSO

Orbiting Solar Observatory

ROSAT

Roentgen Satellite

RXTE

Rossi X-Ray Timing Explorer

SAGE/AEM

Stratospheric Aerosol and Gas Experiment Applications Explorer Mission

SAS

Small Astronomy Satellite

SAMPEX

Solar, Anomalous and Magnetospheric Particle Explorer

SBUV

Solar Backscatter UltraViolet (instrument)

SeaWiFS

Sea-viewing Wide Field-of-view Sensor

SIRTF

Space Infrared Telescope Facility

SMEX

Small Explorer

SMM

Solar Maximum Mission

SMS

Synchronous Meteorological Satellite

SOHO

Solar and Heliospheric Observatory

SSBUV

Shuttle Solar Backscatter UltraViolet (instrument)

SST

Supersonic Transport

STAAC

Systems, Technology and Advanced Concepts (directorate)

STADAN

Satellite Tracking And Data Acquisition Network

STDN

Spaceflight Tracking and Data Network

STGT

Second TDRSS Ground Terminal

STIS

Space Telescope Imaging Spectrograph

STSI

Space Telescope Science Institute

SWAS

Submillimeter Wave Astronomy Satellite

TDRSS

Tracking and Data Relay Satellite System

TIROS

Television Infrared Obwervation Satellite

TOMS

Total Ozone Mapping Spectrometer

TRACE

Transition Region and Coronal Explorer

TRMM

Tropical Rainfall Measuring Mission

UARS

Upper Atmosphere Research Satellite

UNEP

United Nations Environmental Program

WFF

Wallops Island Flight Facility

WSGT

White Sands Ground Terminal

Appendix B
Goddard Launches

Date

Mission

Launch Vehicle

Remarks

.

17 February 1959

Vanguard II

Vanguard SLV-4

120-inch sphere. First Earth photo from satellite.

13 April 1959

Vanguard

Vanguard SLV-6

Did Not Achieve Orbit

22 June 1959

Vanguard

Vanguard SLV-6

Did not achieve orbit

16 July 1959

Explorer (S-1)

Juno II

Did not achieve orbit

7 August 1959

Explorer 6

Thor-Able III

Particles and Meteorology

18 September 1959

Vanguard III

Vanguard SLV-71

Magnetic fields, radiation belts, micrometeorites

13 October 1959

Explorer 7

Juno II

Energetic particles, magnetic storms, micrometeorites

23 March 1960

Explorer (S-46)

Juno II

Did not achieve orbit

1 April 1960

TIROS I

Thor-Able II

First successful weather-study satellite

13 May 1960

Echo A-10

Thor-Delta

Did not achieve orbit

12 August 1960

Echo I

Thor-Delta

First passive communications satellite (100-ft sphere)

3 November 1960

Explorer 8

Juno II

Ionosphere research

23 November 1960

TIROS II

Thor-Delta

Weather satellite

4 December 1960

Explorer (S-56)

Scout

Did not achieve orbit

16 February 1961

Explorer 9

Scout

Atmospheric density research

24 February 1961

Explorer (S-45)

Juno II

Did not achieve orbit

25 March 1961

Explorer 10

Thor-Delta

Solar wind and flare research

27 April 1961

Explorer 11

Juno II

Cosmic gamma rays

24 May 1961

Explorer (S-45a)

Juno II

Did not achieve orbit

30 June 1961

Explorer (S-55)

Scout

Did not achieve orbit

12 July 1961

TIROS III

Thor-Delta

Weather satellite, discovered Hurricane Esther

16 August 1961

Explorer 12

Thor-Delta

Solar winds, magnetosphere

25 August 1961

Explorer 13

Scout

Micrometeorites (3rd stage failed to ignite)

19 October 1961

Probe A (P-21)

Scout

Electron density research

15 January 1962

Echo (AVT-1)

Thor

Suborbital test. 135-ft sphere ruptured.

8 February 1962

TIROS IV

Thor-Delta

Weather satellite

7 March 1962

OSO-1

Thor-Delta S

olar phenomena

26 April 1962

Ariel I

Thor-Delta

First international satellite

19 June 1962

TIROS V

Thor-Delta

Weather satellite

10 July 1962

Telstar I

Thor-Delta.

First privately built communications satellite

18 July 1962

Echo (AVT-2)

Thor-Delta

Passive communication satellite

18 September 1962

TIROS VI

Thor-Delta

Weather satellite

29 September 1962

Alouette I

Thor-Agena

Designed and built by Canada

2 October 1962

Explorer 14

Thor-Delta

Solar wind and radiation

27 October 1962

Explorer 15

Thor-Delta

Study effects of high-altitude nuclear blast

13 December 1962

Relay I

Thor-Delta

Communications satellite

16 December 1962

Explorer 16

Scout

Micrometeoroid research

14 February 1963

Syncom I

Thor-Delta

Contact lost 20 seconds into orbit

3 April 1963

Explorer 17

Thor-Delta

Atmospheric research

7 May 1963

Telstar II

Thor-Delta

Communications satellite

19 June 1963

TIROS VII

Thor-Delta

Weather satellite

26 July 1963

Syncom II

Thor-Delta

Geosynchronous communications test satellite

27 November 1963

Explorer 18/IMP 1

Thor-Delta

First in IMP series

19 December 1963

Explorer 19

Scout

Atmospheric density research

21 December 1963

TIROS VIII

Delta

Weather, test of automatic picture transmission

21 January 1964

Relay II

Delta

Communications satellite

25 January

Echo II

Thor-Agena 4

135-ft. inflatable sphere - communications satellite

19 March 1964

Beacon Explorer A

Delta

Did not achieve orbit

27 March 1964

Ariel 2

Scout

Cooperative with U.K.

19 August 1964

Syncom III

Delta

Geosynchronous communications satellite

25 August 1964

Explorer 20

Scout

Ionosphere topside sounder

28 August 1964

Nimbus I

Thor-Agena

Weather research satellite

4 September 1964

OGO I

Atlas-Agena

20 instruments; geophysical research

4 October 1964

Explorer 21/IMP 2

Delta

Magnetic field, radiation, solar wind research

10 October 1964

Explorer 22

Scout

Beacon explorer; ionosphere

6 November 1964

Explorer 23

Scout

Meteoroid research

21 November 1964

Explorer 24/Explorer 25

Scout

First dual payload; upper atmospheric research

15 December 1964

San Marco 1

Scout

Cooperative with Italy; air density, ionosphere

21 December 1964

Explorer 26

Delta

Energetic Particles Explorer

22 January 1965

TIROS IX

Delta 1

First "cartwheel" configuration weather satellite

3 February 1965

OSO B-2

Delta

Solar phenomena; UV, X-ray, gamma ray

6 April 1965

Intelsat 1

Delta

First operational satellite for Comsat Corp

29 April 1965

Explorer 27

Scout

Beacon Explorer; Earth's magnetic field

29 May 1965

Explorer 28/IMP 3

Delta

Third in IMP series

1 July 1965

TIROS X

Delta

First US Weather Bureau-funded TIROS

25 August 1965

OSO-C

Delta

Did not achieve orbit

14 October 1965

OGO II

Thor-Agena

Near-Earth space phenomena

6 November 1965

Explorer 29

Delta

GEOS-A; geodetic research

18 November 1965

Explorer 30

Scout

Solar UV and X-rays

29 November 1965

Explorer 31/Alouette II

Thor-Agena

Cooperative with Canada; ionospheric research

3 February 1966

ESSA I

Delta

Sun-synchronous orbit; weather

28 February 1966

ESSA II

Delta 1

Paired with ESSA I, initial global weather system

8 April 1966

OAO I

Atlas-Agena

Astronomy observatory; battery malfunctioned

14 May 1966

Nimbus II

Thor-Agena

Weather research satellite

25 May 1966

Explorer 32

Delta

Atmosphere Explorer

7 June 1966

OGO III

Atlas-Agena

Geophysical and solar phenomena

23 June 1966

Pageos I

Thor-Agena

Geodetic research

1 July 1966

Explorer 33/IMP 4

Delta

-IMP - Earth's magnetosphere and magnetic tail

2 October 1966

ESSA III

Delta

Operational weather satellite

7 December 1966

ATS I

Atlas-Agena

Applications technology satellite

26 January 1967

ESSA IV

Delta

Operational weather satellite

8 March 1967

OSO III

Delta

Solar phenomena

6 April 1967

ATS II

Atlas-Agena

Tested gravity gradient control system

20 April 1967

ESSA V

Delta

Operational weather satellite

26 April 1967

San Marco II

Scout

Cooperative with Italy; from sea-based platform

5 May 1967

Ariel 3

Scout.

UK-built; atmospheric and ionospheric research

24 May 1967

Explorer 34/IMP 5

Delta

Fifth IMP; Sun-Earth relationships

19 July 1967

Explorer 35/IMP 6

Delta

IMP; lunar orbit

28 July 1967

OGO IV

Thor-Agena

Sun-Earth relationships

18 October 1967

OSO IV

Delta

Solar phenomena; 1st extreme UV pictures of Sun

5 November 1967

ATS III

Atlas-Agena

Applications Technology Satellite

10 November 1967

ESSA VI

Delta

Operational weather satellite

11 January 1968

Explorer 36

Delta

GEOS; geodetic research

4 March 1968

OGO V

Atlas-Agena

Radiation belt, bow shock research

5 March 1968

Explorer 37

Scout

Solar Explorer - UV and X-ray emissions

18 May 1968

Nimbus B

Thor-Agena

Did not achieve orbit

4 July 1968

Explorer 38

Delta

Radio Astronomy Explorer

8 August 1968

Explorer 39/Explorer 40

Scout

Dual payload; upper atmosphere research

10 August 1968

ATS IV

Atlas Centaur

Centaur 2nd burn failed; remained in parking orbit

16 August 1968

ESSA VII

Delta

Operational weather satellite

7 December 1968

OAO II

Atlas-Centaur

Astronomy observatory

15 December 1968

ESSA VIII

Delta

Operational weather satellite

22 January 1969

OSO V

Delta

Solar phenomena - X-rays, gamma rays and radio

30 January 1969

ISIS-A

Delta

Cooperative with Canada; ionosphere

26 February 1969

ESSA IX

Delta

9th and last in TOS series

14 April 1969

Nimbus III

Thor-Agena

Research weather satellite

5 June 1969

OGO VI

Thor-Agena

Last in the OGO series

21 June 1969

Explorer 41/IMP 7

Delta

7th in IMP series

9 August 1969

OSO VI

Delta

Solar phenomena; X-ray, gamma ray and radio emissions

12 August 1969

ATS V

Atlas-Centaur

Applications Technology Satellite

23 January 1970

ITOS A

Delta

2nd generation meteorological satellite

8 April 1970

Nimbus IV

Thor-Agena

Stabilized, Earth-oriented research weather satellite

30 November 1970

OAO B

Atlas-Centaur

Did not achieve orbit

11 December 1970

ITOS A

Delta

Operational weather satellite

12 December 1970

Explorer 42

Scout

Small Astronomy Satellite; 1st X-ray satellite

13 March 1971

Explorer 43/IMP 8

Delta

2nd generation IMP; solar-lunar relationships

31 March 1971

ISIS B

Delta

Cooperative with Canada; ionosphere research

24 April 1971

San Marco C

Scout

Atmospheric research, with Italy

8 July 1971

Explorer 44

Scout

Solar radiation; X-ray and UV emissions

29 September 1971

OSO H

Delta

Solar phenomena and effect on Earth

21 October 1971

ITOS B

Delta

Operational Weather Satellite; 2nd stage failed

15 November 1971

Explorer 45

Scout

Magnetosphere research

11 December 1971

Ariel 4

Scout

Ionosphere research

23 July 1972

ERTS-A

Delta

Earth Resources Technology Satellite

13 August 1972

Explorer 46

Scout

Meteoroid technology satellite

21 August 1972

OAO 3

Atlas-Centaur

"Copernicus" Astronomy observatory

22 September 1972

Explorer 47/IMP 9

Delta

Interplanetary Monitoring Platform

15 October 1972

ITOS D

Delta

Operational weather satellite

15 November 1972

Explorer 48

Scout

Small Astronomy Satellite; gamma ray research

11 December 1972

Nimbus V

Delta

Research weather satellite

16 December 1972

AEROS-A

Scout

Upper Atmosphere & Ionosphere research

10 June 1973

Explorer 49

Delta

Radio Astronomy Explorer

16 June 1973

ITOS E

Delta

Did not achieve orbit

25 October 1973

Explorer 50/IMP 10

Delta

Last Interplanetary Monitoring Platform

6 November 1973

ITOS F

Delta

Operational weather satellite

16 December 1973

Explorer 51

Delta

Atmosphere Explorer

18 February 1974

San Marco C-2

Scout

Atmospheric research with Italy

17 May 1974

SMS A

Delta

Geostationary weather research satellite

30 May 1974

ATS F

Titan II

Applications Technology Satellite

3 June 1974

Explorer 52

Scout

Hawkeye" spacecraft; solar wind

16 July 1974

AEROS-B

Scout

Upper Atmosphere & Ionosphere research

15 October1974

Ariel 5

Scout

Cosmic X-ray research

15 November 1974

ITOS-G

Delta

Operational weather satellite

10 December 1974

Helios A

Titan III

Cooperative with W. Germany; solar research

22 January 1975

Landsat 2

Delta

(2nd Earth Resources Technology Satellite

6 February 1975

SMS-B

Delta

Geostationary weather satellite

9 April 1975

GEOS C

Delta

Geodetic research

7 May 1975

Explorer 53

Scout

Small Astronomy Satellite; X-ray astronomy

12 June 1975

Nimbus VI

Delta

Research weather satellite

21 June 1975

OSO I

Delta

Solar phenomena

6 October 1975

Explorer 54

Delta

Atmosphere Explorer

16 October 1975

SMS-C/GOES-A

Delta

First operational geostationary weather satellite

20 November 1975

Explorer 55

Delta

Atmosphere Explorer

15 January 1976

Helios B

Titan III

Solar research; cooperative with Germany

4 May 1976

LAGEOS

Delta

Geodetic laser ranging research

29 July 1976

ITOS H

Delta

Operational weather satellite

20 April 1977

GEOS

Delta

Malfunction placed in unusable orbit

16 June 1977

GOES B

Delta

Operational geostationary weather satellite

12 August 1977

HEAO A

Atlas-Centaur

High Energy Astronomy Observatory

22 October 1977

ISEE A/B

Delta

Dual payload; Internat'l Sun/Earth Explorer

26 January 1978

IUE

Delta 9

International Ultraviolet Explorer; cooperative with U.K.

5 March 1978

Landsat 3

Delta

Third Earth Resources remote sensing satellite

26 April 1978

AEM-A/Explorer 58

Scout

Heat Capacity Mapping Mission (HCMM)

16 June 1978

GOES-C

Delta

Operational geostationary weather satellite

26 June 1978

Seasat-A

Atlas

Lost contact after 106 days

12 August 1978

ISEE-C

Delta

Renamed ICE in 1985 for cometary research

13 October 1978

TIROS-N

Atlas

3rd generation polar orbiting weather satellite (research)

24 October 1978

Nimbus VII

Delta

Research environmental/weather satellite

13 November 1978

HEAO-B

Atlas-Centaur

2nd High Energy Astronomical Satellite - X-rays

18 February 1979

SAGE/AEM-2

Scout

Stratospheric Aerosol & Gas Experiment Applications Explorer

27 June 1979

NOAA-6

Atlas

Operational weather satellite

20 September 1979

HEAO 3

Atlas-Centaur

High-energy astronomy/gamma ray research

30 October 1979

Magsat

Scout

Measure near-Earth magnetic fields

14 February 1980

SMM

Delta

Solar Maximum Mission

29 May 1980

NOAA-7

Atlas

Weather satellite - launch vehicle malfunctioned

9 September 1980

GOES D

Delta

Operational geostationary weather satellite

22 May 1981

GOES E

Delta

Operational geostationary weather satellite

23 June 1981

NOAA-C

Atlas

Operational weather satellite

3 August 1981

Dynamic Explorer A&B

Delta

Dual payload; Earth's magnetic field research

6 October 1981

SME

Delta

Solar Mesosphere Explorer; atmospheric research

22 March 1982

OSS-1

Shuttle Columbia/STS-3

Plasma & Solar physics, Shuttle capabilities

27 June 1982

GAS

Shuttle Columbia/STS-4

Carried first Get Away Special (GAS) experiment

16 July 1982

Landsat 4

Delta

Earth resources remote sensing satellite

28 March 1983

NOAA-8

Atlas

Operational weather satellite

4 April 1983

TDRS -A

Shuttle Challenger/STS-60

Deployed first Tracking and Data Relay Satellite

28 April 1983

GOES F

Delta

Operational geostationary weather satellite

1 March 1984

Landsat 5

Delta

Earth resources remote sensing satellite

6 April 1984

SMM Repair

Shuttle Challenger/STS-41C

Shuttle crew retrieved & repaired SMM satellite

16 August 1984

AMPTE

Delta

Three magnetospheric particle tracer explorers

5 October 1984

ERBS

Shuttle Challenger/STS-41G

Earth Radiation Budget Satellite

12 December 1984

NOAA-9

Atlas

Operational weather satellite

17 June 1985

Spartan 1

Shuttle Discovery/STS-51G

Deployed and retrieved Spartan 1

28 January 1986

TDRS-B

Shuttle Challenger/STS-51L

Did not achieve orbit

5 May 1986 G

OES-G

Delta

Did not achieve orbit

17 September 1986

NOAA-10

Atlas

Operational weather satellite; included ERBE

26 February 1987

GOES-H

Delta 1

Operational geostationary weather satellite

25 March 1987

San Marco D/L

Scout

Solar-meteorological activity relationship

24 September 1987

NOAA-11

Atlas

Operational weather satellite

29 September 1988

TDRS-C

Shuttle Discovery/STS-26

2nd Tracking and Data Relay Satellite

13 March 1989

TDRS-D

Shuttle Discovery/STS-29

3rd Tracking and Data Relay Satellite

18 November 1989

COBE

Delta 2

Cosmic Background Explorer

24 April 1990

HST

Shuttle Discovery/STS-31

Hubble Space Telescope deployed

1 June 1990

ROSAT

Delta 25

Roentgen Satellite X-ray telescope with Germany, UK

2 December 1990

BBXRT

Shuttle Columbia/STS-35

X-ray telescope

5 April 1990

CGRO

Shuttle Atlantis/STS-37

Compton Gamma Ray Observatory

14 May 1990

NOAA-12

Atlas

3rd generation operational weather satellite

2 August 1991

TDRS-E

Shuttle Atlantis/STS-43

Tracking and Data Relay Satellite

12 September 1991

UARS

Shuttle Discovery/STS-48

Upper Atmosphere Research Satellite

7 June 1992

EUVE

Delta 2

Extreme Ultraviolet Explorer

3 July 1992

SAMPEX

Scout3

First in Small Explorer series; cosmic ray research

24 July 1992

GEOTAIL

Delta 2

Joint NASA/Japan; geomagnetic tail research

22 October 1992

LAGEOS

Shuttle Columbia/STS-52

Geodetic research

13 January 1993

TDRS-F

Shuttle Endeavor/STS-54

Tracking and Data Relay Satellite

20 February 1993

Astro-D

M-3 SII (Japanese)

ASCA - X-ray astronomy

8 April 1993

Spartan 201

Shuttle Discovery/STS-56

Solar corona research

2 December 1993

HST-1st Servicing mission

Shuttle Endeavor/STS-61

Repair/servicing of Hubble Space Telescope

9 April 1994

GOES-I (GOES 8)

Atlas-Centaur

Next generation operational geostationary weather satellite

9 September 1994

Spartan 1

Shuttle Discovery/STS64

Solar wind and corona research

1 November 1994

WIND

Delta 2

Solar wind research

30 December 1994

NOAA-14

Atlas E

Operational weather satellite

23 May 1995

GOES-J

Atlas II

Operational geostationary weather satellite

13 July 1995

TDRS-G

Shuttle Discovery/STS-70

Tracking and Data Relay Satellite

2 December 1995

SOHO

Atlas II

Joint ESA/NASA; Solar Heliospheric Observatory

30 December 1995

RXTE

Delta 2

Rossi X-ray Timing Explorer

24 February 1996

Polar

Delta 2

Polar orbiting satellite; magnetospheric phenomena

4 June 1996

Cluster

Ariane-5

Did not achieve orbit

2 July 1996

TOMS-EP

Pegasus XL

Total Ozone Mapping Spectrometer Earth Probe

17 August 1996

ADEOS

H-2 (Japanese)

Japanese mission; satellite failed after 90 days

21 August 1996

FAST

Pegasus XL

Fast Auroral Snapshot Explorer

4 November 1996

SAC-B/HETE

Pegasus XL

Did not separate from rocket

11 February 1997

HST 2nd Servicing Mission

Shuttle Discovery/STS-82

Hubble Space Telescope 2nd Servicing mission

25 April 1997

GOES-K

Atlas II

Operational geostationary weather satellite

25 August 1997

ACE

Delta 2

Advanced Composition Explorer

27 November 1997

TRMM

H-2 (Japanese)

Tropical Rainfall Measuring Mission

26 February 1998

SNOE

Pegasus XL

Student Nitric Oxide Explorer

1 April 1998

TRACE

Pegasus XL

Transition Region and Coronal Explorer

13 May 1998

NOAA-K

Titan IV

Operational Weather Satellite

Appendix C
Directors of the Goddard Space Flight Center 1959-1998

1959 - 1965

Dr. Harry J. Goett

1965 - 1976

Dr. John C. Clark

1976 - 1979

Dr. Robert S. Cooper

1979 - 1982

A. Thomas Young

1982 - 1987

Dr. Noel W. Hinners

1987 - 1990

Dr. John W. Townsend

1990 - 1995

John M. Klineberg

1995 - 1998

Joseph H. Rothenberg

1998 -

Alphonso V. Diaz

Acknowledgements

[207] A book of this size and scope is never the result of a single person's effort. Creating a history of a space center takes almost as many people as building a spacecraft itself.

First and foremost, I am indebted to the tremendous number of talented, bright and accomplished people who took the time to share their memories, notes, and knowledge with me, sometimes patiently going over topics numerous times until I understood the science behind the spacecraft and the technology behind the accomplishments. In the end, the history of any organization is the history of its people, and I could not have told that story without the help of the people who had lived it first-hand, in the trenches. If I ever wondered how the United States managed to accomplish so much in a field as difficult as space exploration, the drive and enthusiasm I found among the people at Goddard has given me my answer.

I am also extremely grateful to the staff of the public affairs office, who welcomed me into their midst, found me a place to work even when there wasn't one, helped me track down people and places to interview them, and always had a spare smile for me when I walked in the door. Michelle Jackson, Kisha Wright, Nakia Reams, Jan Ruff, Mark Hess, and Diann Harwood helped make the daunting challenge of this project manageable.

My thanks to Jane Riddle, Chang Yao and Jim Sahli, as well, who helped me find launch histories and other research documents to supplement the oral histories I got from the people I interviewed. Special thanks to Terri Randall whose careful attention to detail in editing and proofreading the book was invaluable. Louise Alstork also deserves thanks for undertaking the task of creating the book's index.

In addition, I am indebted to the numerous people, including George Pieper, John Naugle, Roger Launius, Dick Stock, Bill O'Leary, Bill Bandeen, Steve Maran, Orlando Figueroa, Vince Salomonson, Tony Busalacchi, Mark Schoeberl, John Mather, Yoji Kondo, Rick Obenschain, Darrel Williams, Tom Huber, Al Diaz and Jan Ruff who volunteered to read drafts of the manuscript, offering technical accuracy checks and many helpful suggestions.

[208] The beautiful photos that illustrate this book were also a product of numerous people's efforts. My thanks to Bill O'Leary, Keith Koehler, Yoji Kondo, Ann Jenkins, Barbara Summey, Padi Boyd, Mike Carlowicz, Jim Eckles, Pat Rader, Mark deBord and especially Carol Ladd for helping to find the images that grace these pages. I also need to thank Carol Ladd and Mona Kiely for turning mere words into a beautiful work of art with their wonderful flair for graphic design and layout.

The production of this book involved many other people, as well. There are many I didn't meet or talk to, but their efforts are evident on every page, and I am grateful to each and every one of them. I also owe a special thanks to Jan Ruff, who was as much of a coach, cheerleader and trouble-shooter as she was a contract supervisor. Her guidance, support, perspective and wonderful ability to still laugh at it all were all truly invaluable gifts.

In the end, however, my greatest debt is to the thousands of people who have worked for Goddard and its contractors over the years. Without their efforts and sacrifices-the late nights, early mornings, lost weekends, lost sleep-and their willingness to endure whatever frustration, setbacks, and problems stood between them and success- there would have been no story to tell. I offer all of you not only my thanks, but my greatest admiration and respect.

Index

[ Chapter 1 : pp1-11; Chapter 2 : pp12-51; Chapter 3 : pp52-79; Chapter 4 : pp80-129; Chapter 5 : pp130-163; Chapter 6 : pp164-174]

A

Advanced Composition Explorer (ACE): 91-92
Advanced Earth Observing System (ADEOS):153, 157, 162
Advanced Research Projects Agency (ARPA): 138
Advanced X-Ray Astrophysics Facility (AXAF): 124
Aerobee, rocket: 16, 17, 66
Air Force, U.S.: 42, 67, 127, 147
Alouette I, satellite: 26
Alouette, spacecraft: 87
American Astronomical Society (AAS): 105
American Science and Engineering: 118
American Telephone & Telegraph (AT&T): 132, 134, 135-137
Announcements of flight Opportunities (AOs): 21
Antarctica: 152, 153
Apollo Program: 5, 24, 32, 33, 37, 38, 72, 73, 86, 172, 173
Apollo 1: 31, 42
Apollo 13: 42
Apollo 17:32

Telescope Mount, Skylab: 34

Applications Technology Satellites (ATS): 73, 74, 137, 141-142

ATS 111: 142
ATS-1: 141
ATS-6: 137

Applied Engineering and Technology (AET): 47
Arctic: 153
Ariane-5, booster rocket: 90
Ariel I, satellite: 25, 26
Aristotle: 13
Armstrong, Neil: 71, 173
Army, U.S.: 15, 17, 19, 27, 138, 145

Ballistics Missile Agency: 17
Corps of Engineers: 145
Signal Corps Research and Development Laboratory: 19, 27
Signal Engineering Laboratories: 138

Arrhenius, Svante: 159
Atlantic Ocean: 65, 69, 94, 144-145
Atlantis, spacecraft: 126
Atlas, rocket: 70
Atlas-Centaur, rocket: 42
Australia: 8, 72
Automatic Picture Transmission (APT): 140

B

Baltimore, Maryland: 108
Beall, J. Glenn: 18
Bell Telephone: 102
Bell, Alexander Graham: 163
Beltsville Agricultural Research Center: 18
Beltsville Space Center: 19, 172
Bendix Corporation: 114
BeppoSAX, Italian-Dutch satellite: 127
Berg, Otto: 132
Big Bang: 44, 102-103, 106, 128
Black Brant: 66
Brahe, Tycho: 129
British Science Research Council: 114
Brownsville, Texas: 131

C

Cape Canaveral: 64, 69, 70, 172
Carnarvon Station: 72
Central America: 158, 159
Centre National d'Etudes Spatiales (CNES): 157
Ceppolina, Frank: 33
Challenger, spacecraft: 39, 40, 42, 44, 45, 46, 66, 68, 75, 95, 105, 108, 152
Chin Tarters: 14
Chlorofluorocarbons (CFCs): 150, 152, 153,154
Clouds and the Earth's Radiant Energy System (CERES): 149
Cluster, spacecraft: 89, 90 Cluster II, spacecraft: 90
Coastal Zone Color Scanner (CZCS): 156
Cobalt 57: 128
Cold War: 16, 166, 170
Collier Trophy: 45, 112
Columbus, Christopher (explorer): 128
Comet Shoemaker-Levy: 112
Communications Satellite (COMSAT): 137
Compton Gamma Ray Observatory (CGRO): 40, 44, 45, 76, 124, 126-128, 167
Compton, Arthur H.: 126
Congress, U.S.: 6, 16, 28, 30, 31, 37, 46, 136,150
Copernicus Observatory: 107
Coronal Mass Ejections (CMEs): 89, 93
Corrective Optics Space Telescope Axial Replacement (COSTAR): 110
Cosmic Background Explorer (COBE): 44, 79, 102-106, 123
Cosmos Club: 19
Crab Nebula: 101, 118- 120, 124
Cygnus X-1: 120

D

Deep Space Network (DSN): 74-75
Delta, rocket: 42, 44, 67, 88, 94, 105
Department of Agriculture, U.S. (DOA): 18, 145
Forest Service, (USFS): 145
Department of Commerce (DOC): 145
Department of Defense (DOD): 16, 27, 40, 42, 134, 135, 147
Department of the Interior (DOI): 145, 146

Geological Survey (USGS): 146, 147

Differential Microwave Radiometer (DMR): 104, 106
Diffuse Infrared Background Experiment (DIRBE): 104, 106
Distributed Active Archive Centers (DAAC): 78
Dolly Madison House: 19
Douglas Aircraft Company: 67
Dryden, Hugh L.: 18

E

Eagle Nebula: 112
Earth: 2, 4, 9, 10, 11, 13, 26, 27, 33, 35, 36, 37, 38, 41, 45, 51, 53, 54, 55, 56, 58, 66, 68, 73, 76, 77, 78, 84, 85, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 100, 101,107, 112, 113, 114, 119, 124, 128, 131,132, 133, 134, 135, 139, 140, 141, 142, 144, 145, 146, 147, 149, 150, 154, 158, 159, 160, 161, 162, 163, 168, 169, 170, 173
Earth Observing System (EOS): 76, 162, 168

EOS AM-1: 76, 156, 162
EOS CHEM- 1: 162
EOS PM-1: 162

Earth Observing System Data and Information System (EOSDIS): 78
Earth Probe: 153
Earth Radiation Budget: 148
Earth Radiation Budget Experiment (ERBE):148, 149
Earth Radiation Budget Satellite (ERBS): 148, 153
Earth Resources Observation System (EROS): 76
Earth Resources Observation System (EROS) Data Center: 146, 147
Earth Resources Technology Satellite (ERTS): 35, 144-145
Earth Science: 9, 10, 161, 167
Earth Science Enterprise: 46, 76, 78, 161,162
Earth-Sun Libration: 90
Echo "Project": 27, 134-135, 173
Echo 1: 134-135
Echo II: 135
Einstein Observatory: 122
Einstein, Albert: 82, 122
Eisenhower, Dwight D.: 15, 16, 69, 134, 166
El Nino: 10, 46, 132, 141, 156, 157, 158-159, 161, 163, 170
Empire State Building: 102
Environmental Protection Agency (EPA): 145,151
Environmental Science Services Administration (ESSA): 140-141, 142, 148
ESSA 1: 140
EOSAT Company: 146, 147
Eratosthenes: 132
ERS-1: 157
Eurasia: 72
European Space Agency (ESA): 88, 90, 96, 109, 114
Explorer: 8, 43, 63, 64, 79, 86-87, 117, 120, 138, 166, 167

Atmosphere Explorers: 148
Explorer 11: 125- 126
Explorer 17: 148
Explorer 19: 148
Explorer 32: 148
Explorer 38: 101
Explorer 42: 120
Explorer 48: 126
Explorer 49: 102
Explorer 51: 148
Explorer 54: 148
Explorer I: 17, 84
Explorer III: 84
Explorer VI: 138
Explorer VII: 148
Small Explorer: 167

Extra-Vehicular Activity (EVA): 111
Extreme Ultraviolet Explorer (EUVE): 117-118

F

Fairbanks, Alaska: 76, 79
Far Infrared Absolute Spectrophotometer (FIRAS): 104, 105
Farquhar, Robert: 88
Fast Auroral Snapshot Explorer (FAST): 91
Fletcher, James C.: 147
Ft. Monmouth, New Jersey: 138

G

Galileo: 94
Gemini: 5, 24, 70
Gemini 8: 71
Geostationary Operational Environmental Satellite (GOES): 142

GOES 4: 143
GOES 5: 143
GOES 6: 143
GOES 7: 143
GOES 8: 142-143, 144
GOES G: 143

Geotail, spacecraft: 89
Get Away Special (GAS): 41, 68
Giacconi, Riccardo: 118
Giacobini-Zinner: 88
Gide, Andre: 11
Gilruth, Robert: 20
Global Positioning System (GPS): 133-134
Goddard Institute for Space Studies (GISS): 24-25, 161
Goddard Space Flight Center: 13-14, 23, 41, 46, 50
Goddard, Robert H.: 14, 19,
Goett, Harry J.: 6, 28, 30, 59
Guaymas (tracking station): 8
Guyamas, Mexico: 69, 70

H

Halley's comet: 88, 117
Halogen Occultation Experiment (HALOE): 153
Hawking, Stephen: 44
Helium: 93, 117
High Energy Astronomical Observatory
(HEAO): 34-35, 121-122, 124, 126

HEAO 3: 126
HEAO A: 121, 123
HEAO B: 121-122, 123

High Energy Astrophysics Science Archival Research Center: 77
Holmberg, New Jersey: 102
Houston, Texas: 20, 28, 70, 79
Hubble Space Telescope (HST): 8-9, 28, 33, 34, 35, 43, 44-45, 58, 68, 76, 96, 107-114, 124, 173
Hubble, Edwin P.: 107
Hubble's Law: 108
Huber, Tony: 43
Hughes Corporation: 132, 135-137
Huntsville, Alabama: 17
Hydrogen: 93, 117

I

Improved TIROS Operational System (ITOS): 141

ITOS 1:141

Indian Ocean: 69, 147
Institute for Space Studies (see also Goddard Institute for Space Studies (GISS)): 5
intercontinental ballistic missile (ICBM): 17
International Cometary Explorer: 88
International Council of Scientific Unions: 15
International Geophysical Year (IGY): 15, 17, 25, 68
International Polar Year (IPY): 15
International Solar-Terrestrial Physics (ISTP): 88-91, 96
International Sun-Earth Explorer (ISEE): 88

ISEE 3: 88, 95
ISEE A: 88
ISEE B: 88

International Telecommunications Satellite (Intelsat): 137
International Ultraviolet Explorer (IUE): 33, 107, 114-117
Interplanetary Monitoring Platform (IMP): 55, 85, 86, 92
IRAS -Araki-Alcock comet: 117

J

Japanese Institute of Space and Astronautical Science (ISAS): 89
Jastrow, Robert: 19, 24
Jet Propulsion Laboratory (JPL): 4, 16, 134, 157
Johnson Space Center: 45, 50, 111, 172
Jupiter: 97, 112, 116
Jupiter C, rocket: 17, 167
Jupiter, missile: 17

K

Kai-feng-fu: 14
Kelvin: 97, 102, 103, 104
Kennedy Space Center: 55
Kennedy, John F.: 22, 87
Kenya, Africa: 120
Kraft, Christopher: 70

L

Lagrangian: 90, 91, 96
Land Remote Sensing Policy Act: 147
Landsat: 35, 76, 145-147, 155, 156, 160
Landsat 1: 144
Landsat 2: 145
Landsat 4: 146, 147
Landsat 5: 146, 147
Landsat 6: 146, 147
Landsat 7: 76, 147, 162
Langley Research Center: 19, 134, 149
Large Magellanic Cloud: 116, 124, 128
Large Space Telescope: 107
Laser GEOdynamics (LAGEOS): 133
Lewis and Clark (explorers): 81, 128
Lewis Research Center: 19, 67, 138
Life magazine: 132
Little green men (LGMs): 119
Lockheed: 109

M

Magellan, Ferdinand (explorer): 128
Manned Space Flight Network (MSFN): 72, 73, 74
Manned Spacecraft Center: 28, 70
Mars: 37
Marshall Space Flight Center: 34, 50, 67, 108, 109, 121
Massachusetts Institute of Technology: 118
Mather, John C.: 103, 104
McDonald, Frank: 86
McDonnell Aircraft Corporation: 67
McMurdo, Antarctica: 76
Mercury: 5, 19, 20, 24, 69, 70
Mercury Space Flight Network (MSFN): 69
Meteor 3, satellite: 153
Microwave Anisotropy Probe (MAP): 106
Milky Way: 122, 123
Minimum Trackable Satellite (Minitrack): 68, 69, 72
Mission and Data Operations Directorate: 73
Mission Control: 70, 71, 79, 172
Mission to Planet Earth (MTPE): 45-46, 161
Mississippi River: 133
Mongol: 14
Moon: 1, 3, 24, 28, 31, 71, 86, 88, 118, 133, 173
Mt. Pinatubo: 154, 161
Multi-mission Modular Spacecraft (MMS): 8, 33, 88, 95

N

NASA Communications network (NASCOM): 73
National Academy of Sciences (NAS): 16, 21

Langley Aeronautical Laboratory: 40
Space Science Board: 21
National Advisory Committee for Aeronautics (NACA): 2, 6, 16, 18, 28, 40
Ames Research Center: 28

National Aeronautics and Space Act of 1958: 7, 16, 18
National Aeronautics and Space Administration (NASA): 2, 16

Headquarters: 21, 28-29, 30, 34, 37, 41

National Oceanic and Atmospheric Administration (NOAA): 141, 142-143, 146, 147, 155, 156

NOAA 1, 2, 3: 141
NOAA 10: 148
NOAA 9: 148

National Science Foundation (NSF): 16, 40, 66
Naval Gun Factory: 107
Naval Receiving Station: 19
Naval Research Laboratory (NRL): 9, 16, 18, 19, 67, 68, 107, 118, 131
Near-lnfrared Camera and Multi-Object Spectrometer (NICMOS): 113
Newton, Issac: 129
Next Generation Space Telescope (NGST): 113
Nike-Cajun: 66
Nike-Orion: 66
Nimbus: 35, 140, 144, 150, 156
Nimbus 1: 153
Nimbus 2: 148
Nimbus 3: 148
Nimbus 4: 150
Nimbus 5: 148
Nimbus 6: 148
Nimbus 7: 35, 150, 151, 155, 156-157
North America: 151, 153, 159

O

Orbital Sciences Corporation: 51
Orbiting Astronomical Observatory (OAO): 28, 63, l 07, 114

OAO-2: 107
OAO-3: 107

Orbiting Geophysical Observatory (OGO): 8, 33, 57, 73, 87-88
Orbiting Solar Observatory (OSO): 42, 64, 72, 94

OSO V: 94
OSO VI: 94
OSO VII: 94

Ozone: 150-154

P

Pacific Ocean: 81, 156, 157, 158-159
Pasadena, California: 4
Pegasus: 50-51, 91, 153
Perkin-Elmer Company: 109
Pioneer probe: 28
Polar, spacecraft: 89, 90-91

Q

QuickSCAT: 157

R

RAND: 132
Ranger probe: 28
Rapid Spacecraft Procurement Initiative (RSPI): 157
RCA: 135-137
Redstone Arsenal: 17
Reductions in Force (RlFs): 32
Relay, satellite: 136
Reno, Nevada: 144
Richmond, California: 110
Rossi, Bruno: 118, 123

S

Sagittarius: 123
Satellite Communications Act: 136
Satellite Tracking And Data Acquisition Network (STADAN): 72, 73
Saturn: 34
Saturn, rocket: 67, 72
Science Advisory Committee: 16
Sco X- 1: 118
Scorpio: 118
Scott, David: 71
Sea-viewing Wide Field-of-view Sensor (SeaWiFS): 51, 156, 160, 162
Second TDRSS Ground Terminal (STGT): 39
Secret Service, U.S.: 22
Shuttle Solar Backscatter Ultraviolet (SSBW): 150
Sioux Falls, South Dakota (see also Earth Resources Observation System (EROS) Data Center): 76, 146, 147
Skylab: 74, 121
Small Astronomy Satellite (SAS): 33-34, 120, 126

SAS 2: 126
SAS-3: 121

Small Explorer (SMEX): 43, 44, 102
Smithsonian Astrophysical Observatory (SAO):107
Solar and Heliospheric Observatory (SOHO): 89, 90, 96-98
Solar Backscatter Ultraviolet (SBUV): 150

SBUV-2: 150

Solar Maximum Mission (SMM): 8, 33, 45, 94, 95
Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX): 91
South America: 8
Soyuz, Russian spacecraft: 90
Space Infrared Telescope Facility (SIRTF): 124
Space Science Directorate: 77
Space Shuttle: 5, 8, 9, 32-33, 38-40, 41, 42-43, 45, 68, 73, 74, 76, 95, 96, 105, 108,111, 126, 150, 151, 162, 163, 167, 172
Space Telescope Imaging Spectrograph (STIS): 113
Space Telescope Science Institute (STSI): 35, 108, 109, 112
Spaceflight Tracking and Data Network (STDN): 73, 74-75, 79
Spartan: 41, 68
Spartan 201: 97
Sputnik, Russian spacecraft: 1, 16, 17, 20, 166
Sputnik I: 1, 16
Starfish, high-altitude nuclear bomb test: 86
Stratospheric Aerosol and Gas Experiment (SAGE 11): 153, 154
Submillimeter Wave Astronomy Satellite (SWAS): 102
Sun: 10, 22, 56, 57, 60, 62, 83, 84-85, 86, 88-94, 94-95, 96-98, 99, 116, 117, 118-119, 120, 127, 148, 150, 159, 160, 168, 169
Sun-Earth: 87, 88
Supernova 1987A: 116
Supersonic Transport (SST): 150
Svalbard, Norway: 76
Synchronous Meteorological Satellite (SMS): 142

SMS- 1: 142
SMS-2: 142

Syncom: 135 - 137
Syncom I: 136
Syncom II: 136
Systems, Technology, and Advanced Concepts (STAAC): 47

T

Tananarive, Madagascar: 73
Taurus-Nike-Tomahawk: 66
Television and Infrared Observation Satellite (TIROS): 19, 27, 35, 138-140, 141, 148
TIROS I: 138
TIROS III: 139
TIROS IX: 139, 140
TIROS-N: 141, 156
Telstar: 87, 136
Telstar 1: 136
Telstar 2: 136
Thor (booster): 67
Thor-Delta, rocket (see also Delta): 67
Tinsley Optical Laboratories: 110
TOPEX/Poseidon: 157, 162
Total Ozone Mapping Spectrometer (TOMS): 150-153, 162
Townsend, Jr., John W.: 18, 59
Tracking and Data Relay Satellite System (TDRSS): 9, 39, 74, 75, 76, 137
Transition Region And Coronal Explorer (TRACE): 96
Tropical Rainfall Measuring Mission (TRMM): 149, 161, 162

U

Uhuru: 120-121
Ulysses: 96-98
United Kingdom: 25, 26, 127
United Nations: 154
United Nations Environmental Program (UNEP): 152
United States: 8, 15, 16, 17, 56, 76, 138, 147
University of California, Berkeley: 1
University of California, Irvine: 150
University of Cambridge: 127
University of lowa: 84
University of Rome, Italy: 120
Upper Atmosphere Research Satellite (UARS): 153, 154, 161, 162

V

V-2, rocket: 81, 131
Vaccaro, Mike: 22, 23
Van Allen Radiation Belts: 84-85
Van Allen, James A.: 84
Vandenberg Air Force Base: 55
Vanguard Program: 16-17, 18, 30, 67
Viking: 16, 17

W

Wallops Flight Facility: 5, 40-41, 50, 65-66, 76, 157
Weather Bureau: 139, 140
Webb, James E.: 6
Western Test Range: 55
White Sands Ground Terminal (WSGT): 39
White Sands Missile Range: 5, 39
White Sands Proving Ground: 15, 75
Wide Field/Planetary Camera: 109, 110
Wilson, Alexander: 14
Wind, spacecraft: 89-91
Woomera, Australia: 69
World War II: 14, 15, 64

X

X-Ray Timing Explorer (XTE): 123-124

Y

Young, Tom: 48

About the Author

[219] Lane E. Wallace is a professional writer who lives in Los Angeles, California. She is the author of three other books: Flights of Discovery: 50 Years at the NASA Dryden Flight Research Center; Airborne Trailblazer, a history of the Langley Research Center's 737 testbed aircraft, which won the 1994 Washington Edpress Silver Award for Excellence in Print, and a commemorative history of the Defense Technical Information Center. She is also one of the authors of From Engineering Science to Big Science, an anthology published in 1998 about the NACA and NASA Collier Trophy award-winning projects.

In addition to her books, Ms. Wallace has written and co-produced a 3-part video documentary series entitled Test Flights: Flights of Discovery, exploring the human drama and adventure of flight research. She has also published over 200 articles on a wide variety of aviation and aerospace topics ranging from biplanes and air racing to new developments in NASA research and military aircraft technology. Her writing has appeared in a number of national and international magazines, including AOPA Pilot and Flight International, and she is a regular columnist for Flying magazine. Her work has also earned her an honorary membership in the United States Air Force Society of Wild Weasels, as well as a citation for "Outstanding Contributions to Preserve General Aviation" by the Torrance, California Airport Association.

Ms. Wallace graduated with honors from Brown University in 1983, with a degree in Semiotics. She is a private pilot and has owned a 1946 Cessna 120 as well as her current plane, a 1977 Grumman Cheetah. In addition to her own airplane projects, she has also worked as a volunteer for the Planes of Fame Air Museum in Chino, California and both the "Tsunami" and "Pond Racer" Unlimited air racing crews.

THE NASA HISTORY SERIES

[For a complete and updated listing of publications in the "NASA History" series, readers should turn to the following link: The NASA History Series. Chris Gamble, html editor ]