Many of the advances in miniaturization that make low-power devices possible were developed as spin-offs of space exploration. (Heinlein wrote a great article about this back in the eighties.) Satellites were what made us aware of the hole in the ozone layer, and are still used to monitor the weather patterns that alert us to global warming trends. And our study of other planets (like Venus) may help us to understand better how to take care of this one.
I'm not saying we should invest frivolously in space exploration while millions starve here on Earth. But I don't think it's an either-or proposition. Space research is basic science research, and pays off for everyone in knowledge gained, often unpredictably. I would like it to be a goal that unites us, constructively, rather than so many of the goals we seem to have that divide us, destructively.
Ok, soapbox off.... Maybe I should go read some Steve Jordan, rather than crabbing at people about space research, eh?