Half a century after Apollo, why haven’t we been back to the Moon?

By Eric Berger The 50th anniversary of NASA’s historic landing on the Moon—this Saturday, July 20th—provokes a decidedly bittersweet feeling. Certainly, this marks an appropriate time 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 …