NASA's latest prototype has found a way to, quite literally, get water out of rocks. No word on if it can get blood from stone yet.

One of the biggest challenges of space travel has very little to do with the traveling itself, and more to do with everything that happens afterward. How will humans sustain themselves if we send them back to the moon (and, as planned, to Mars)? Food, even freeze-dried, is heavy. Water, too. Maintenance is expensive, in every sense of the word. So if manned space travel is to become a long-term reality, we'll need to find ways to cultivate the places and planets we visit: to mine their soil for nutrients, to find the water hidden in their depths, to generate the air that will make everything else possible.

NASA has an idea for doing all that, and it takes the form -- as so many innovative ideas seem to these days -- of a robot.

Meet ... the Regolith Advanced Surface Systems Operations Robot -- RASSOR, for short. The robot (pronounced as "razor") is an excavator device, designed to extract (yes) water, (yes) ice, and (yes) fuel from the soil of the moon. And from the soil of similarly dusty bodies (like, say, Mars). NASA is envisioning that RASSOR, currently in development in prototype form, will not only perform the Greek-fable-meets-rocket-science-reality task of getting water from rocks; it will also take the remaining dust and convert the chemicals it contains into two things crucial to astronauts: air for breathing, and fuel for moving. "The robot," NASA says, "would be the feeder for a lunar resource processing plant, a level of industry never before tried anywhere besides Earth."

So. How do you design a device that can do all that work? How do you create an automaton that is rover and water filtration center and power plant all rolled in one rolling vehicle? One obvious challenge is mass. On the one hand, the robot in question has to be light enough to feasibly fly on a rocket. (It takes about $4,000, NASA says, to send a single pound of payload into space.) On the other hand, though, the machine has to be heavy enough to operate in less gravity than that offered by Earth. (In the moon's case: less than 20 percent of that gravity.) It also has to be generally substantial enough to dig into soil without tipping over, and to operate -- like its fellow lunar and Martian rovers -- as a kind of multi-purpose machine.

The current prototype has solved many of those problems by applying its multi-purpose intentions to multi-purpose design. The drums that the machine will use to gather soil double as legs -- which can, in turn, help the robot to navigate dusty terrain. (They also allow the 100-pound, 2.5-foot-tall device to dig effectively, since one of those drums can act as a grip to balance the robot as it does its work.) Though the current design has given the RASSOR a tank-like shape, with tracks to balance the robot as it roves other worlds, NASA is considering replacing that base with wheels -- which would make the next RASSOR iteration a little more Martian-rover-like than the current one. But the modular capability, ostensibly, would be a constant.

So: a shape-shifting, water-mining spacebot! If you, like I, would like to see what the final version of this could look like, you don't have long to wait. NASA is expecting that the RASSOR 2 -- the next generation of the spunky little power plant -- will begin testing in early 2014.

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