The Mars Decision

Tere was a bittersweet quality to the recent celebrations of the fiftieth anniversary of the first lunar landing. It was an occasion of justifiable American pride — after all, sending men to the Moon in the late 1960s and early 1970s was not only a feat of human ingenuity and daring but a spectacular national accomplishment, one that, as Jules Verne had sagely predicted a century earlier, only Americans could pull off. But in the half-century since Apollo 11, NASA’s human spaceflight program has stagnated. It has had very few memorable successes and certainly performed no comparably glorious feats.Why not? At the time of the Moon landing, it was generally expected that the United States would quickly go on to Mars. Even several of the Apollo astronauts believed, as they described in their memoirs, that after going to the Moon they might help the United States reach the Red Planet. Many explanations have been offered over the years for why American astronauts have not been sent on to Mars — or anywhere else of note — in the years since Apollo. Three explanations in particular stand out for being widely believed. Each of these explanations is intuitively plausible. Each has a kernel of truth. But these explanations are so incomplete as to be misleading.