The robotic chopper currently exists as just a tech demo, and it'll take some testing to prove that this small automaton (it's 3.6 feet from blade to blade) is ready for the Red Planet. If it makes the cut, though, it could let Mars rovers cover much more ground than they have so far -- JPL estimates that these machines could travel three times further in a given day. The project could easily be worthwhile if it means both completing missions faster and discovering things about Mars that would otherwise go unnoticed.