NASA believes our return to the Moon could be sustained by extracting water from the lunar soil to produce air and even fuel. But how to get large amounts of that soil without bringing heavy, failure-prone machinery? The agency's RASSOR (pronounced "razor") excavator robot might do the trick. Rather than wield big scoops, it has a pair of arm-mounted drums that can change the robot's profile and dig with far more efficiency than RASSOR's 100-pound weight would usually allow, using one drum as a grip. The robot's sheer flexibility is also key to its working for the estimated five years of NASA's plans: if the crawler ever overturns or gets caught, it can flip over and keep the main treads out of the ground while clearing out soil-related jams. There's enough refinement needed that a RASSOR 2 follow-up should be in testing around early 2014, but the sequel will be close enough to the ideal design that long-term Moon missions could have the little hauler as a passenger.