It’s sad to see the space shuttle Discovery being flown to the Smithsonian. Not that the shuttle hadn’t outlived its usefulness, but there’s no replacement for it, meaning that manned space exploration, at least by Americans, is over for now and likely for a long time to come. The space program, for me and millions of other space geeks who grew up when Americans were orbiting the earth, landing on the moon, and making regular jaunts into space, was the most exciting example of this nation’s ambition and confidence. Yes, it was fabulously expensive, and yes, NASA made some catastrophic errors, but we dared to spend and dared to send Americans into space despite the risks.. Nothing tells the tale of our declining ambitions and our increasing self-doubt as eloquently as the contraction of NASA’s mission.