Putting a human on Mars might be easier than anyone thought. A flight to the Red Planet currently takes at least six months, which is why we send robots—the trip is boring, fuel costs are astronomical, and cosmic radiation is nobody's friend. But NASA engineer Robert Adams has a solution: the two-burn maneuver, an all-but-forgotten secret of orbital mechanics that could cut travel time in half.
Dreamed up in 1929 by Hermann Oberth, one of the fathers of- CONTINUED with pictorial goodness. . . .