Why we never went back

Some thoughtful words from Sagan's Brain as the last space shuttle orbits Earth: "By and large, in the 1960s America was not terribly interested in geological discoveries on the Moon. The Apollo program was not really about science, and for most people, the science was probably of tertiary concern. Politically it was about beating the Soviets, for sport and for security, but viscerally, we recognized its deeper meaning. ... But after only 6 successful landings, we pulled back to plan our next move. The Russians were working on space stations, so we had to get into that game, too. In a sense, the very thing that had driven us to such great heights in the age of Apollo -- competition with the Russians -- drew us back to spend the next three and half decades orbiting the Earth. Meanwhile, dreams of a rapid expansion of space exploration, with moon bases and Mars landings, evaporated. ... So, here we are. Will we press on to greater voyages, sending out at long last our cosmic argonauts to plumb the depths of interplanetary space? Or will we wait for the next generation to pick up the mantle we have borne just a little way from where we started?"