(3 of 3)
Until they get the nod, the Mars partisans have to find ways to keep busy. Research teams from NASA and the Mars Society (a private advocacy group) are conducting expeditions to Devon Island in the Canadian Arctic--a place about as similar to the freeze-dried Martian wasteland as you're likely to find anywhere on Earth--to practice survival skills and exploration techniques. Teams at the Johnson Space Center are refining their mission scenarios and crunching their numbers to keep the costs as low as possible. "For now," says Zubrin, "the only thing between us and Mars is a political decision to go." That kind of hurdle, of course, is often the highest of all.