An anonymous reader shares an article: When President Kennedy announced the Apollo Program, he famously argued that we should go to the moon because it is hard. Solving the technical challenges of space travel is a kind of civilizational achievement on its own, like resolving an interplanetary Rubik's Cube. The argument worked, perhaps all too well. As soon as we landed on the moon, humanity's expansion into the cosmos slowed and then stopped (not counting robots). If you were to draw a graph charting the farthest distance a human being has ever been from the surface of Earth, the peak was in 1970 with Apollo 13. With the successful moon landings, we solved all of the fundamental challenges involved in launching humans into orbit and bringing them back safely. The people watching those early feats of exploration imagined we would soon be sending astronauts to Mars and beyond, but something has held us back. Not know-how, or even money, but a certain lack of imagination. Getting to space isn't the hard part -- the hard part is figuring out why we're there. Sure, we can celebrate the human spirit and the first person to do this or that, but that kind of achievement never moves beyond the symbolic. It doesn't build industries, establish settlements and scientific research stations, or scale up solutions from expensive one-offs to mass production. Furthermore, as five decades of failing to go farther than our own moon have demonstrated, that kind of symbolism can't even sustain itself, much less energize new activity.