What will the first humans on Mars eat? One scientist has the answer.

A mission to Mars could launch as early as the 2030s, taking a small crew of humans on a 5-year round trip to the red planet. One of the biggest questions about this mission isn't what kind of rocket ship we'll need, but how we'll feed people for five years in vacuum, and on an alien world. NASA senior research… »9/01/11 7:30pm9/01/11 7:30pm