The 50th anniversary of NASA’s historic landing on the Moon—this Saturday, July 20th—provokes a decidedly bittersweet feel. Certainly, this marks an appropriate moment to pause and celebrate a singular moment in our shared history, the first time humans ever set foot on another world. Neil Armstrong, Buzz Aldrin, and Michael Collins really did push back the frontier for all of humanity

And yet, for all that this technological and geopolitical tour de force achieved, there has been a decided lack of follow through by the US spaceflight enterprise since Apollo 11. On such an anniversary, this raises uncomfortable questions. Why have we not gone back? Was the Apollo Program really America’s high water mark in space? And will we actually return in the next half century?

Why we went

Beginning with Sputnik in 1957 and continuing through the flights of Yuri Gagarin and other cosmonauts, the Soviet Union ticked off an impressive succession of “firsts” in space during the middle of the Cold War. As the United States waged a hearts-and-minds campaign against the Soviets around the world, technological superiority represented a key battlefront.