What will astronauts need to survive the dangerous journey to Mars?
On movie missions to Mars, getting there is the easy part. The Martian’s Mark Watney was fine until a dust storm left him fending for himself. Douglas Quaid’s jaunt to the Red Planet in Total Recall was smooth sailing until he came under fire at Martian customs and immigration. But in real life, just getting to Mars and back will be rife with dangers that have nothing to do with extreme weather or armed gunmen. “The mission to Mars is likely going to be four to six individuals [living] together in a can the size of a Winnebago for three years,” says Leticia Vega, associate chief scientist for the NASA Human Research Program in Houston. Time on the planet will be sandwiched between a six- to nine-month journey there plus the same long trip back. Once outside of Earth’s protective gravitational and magnetic fields, microgravity and radiation become big worries. Microgravity allows fluid...