It's a bit long in the tooth now (from '77), I suppose, and doesn't really deal with space exploration's effects on humanity (more about the revelations that come from exploring the Solar system), but James P. Hogan's "Inherit the Stars" might still be worth your time (and it's a freebie at
Baen).
(The first sequel, "The Gentle Giants of Ganymede" is just as good. "Giants' Star" isn't quite as good, but still well worth reading. "Entoverse" isn't good and "Mission to Minerva" is best avoided)