So, why potatoes? As Scientific American points out, a single potato can contain 10 percent of an average person's required daily caloric needs. They also thrive in harsh, dry environments. With that said, the team will need to test all 100 varieties of potato to see if they provide enough calories and can withstand the extremely dry, desolate landscape found on Mars. NASA plans to continue this experiment at least until March, and possibly longer, according to Scientific American.