If water is the key to life on Earth, it's doubly so if we want to survive in space. Water's crucial for our own human needs, and is also an excellent starting point for rocket fuel, but it's also prohibitively heavy to lift up from Earth in large quantities. Until now, NASA has mostly been concerned with just finding the stuff. That's changed: In a signal that the agency is confident it will be extracting water in the relatively near future, it's unveiled a prototype mining robot that help scrape the good liquid out of the Moon.
The Regolith Advanced Surface Systems Operations Robot (RASSOR, pronounced "razor") isn't a final design just yet. For starters, as you might have guessed by looking at the pictures, it's a prototype that's too small to do any serious mining. (In the configuration above, it's about two-and-a-half feet tall.) But its design highlights the inherent challenge of mining the Moon: Rovers need to be fairly light to lift into space, but on the Moon's 1/6 gravity, a light bot won't be able to dig effectively. To counteract that, the two bucket wheels on RASSOR rotate in opposite directions, which effectively locks the bot in place.
"We proved that if you engage one bucket, it pulls itself but when you lower the other bucket and rotate it, once they both catch in, it starts digging," RASSOR engineer A.J. Nick said in a release.
RASSOR is designed to be flexible enough to scale obstacles.
RASSOR also has relatively shallow buckets, which would essentially grind away at the soil, rather than scooping it up in big loads like a backhoe here on Earth. According to NASA, the idea is that RASSOR will be able to scoop up ice- and water-laden soil from the Moon, and transfer that soil to a device that can suck the water out of it. That device has yet to be developed, but hey, the mining bit is a start. NASA said it's hoping to develop the whole package to be around 2000 pounds, 100 for a full-size RASSOR design and the rest for processing and landing equipment.
The big goal for such a resource-processing mission is sending it to Mars, as processing water and fuel on site is currently the only way a round trip to the red planet could be possible. And with water increasingly probable on Mars, it's mostly a matter of figuring out where to dig.
"There are some areas at the poles where they think there's a lot of ice, so you'd be digging in ice," Nick said. "There's other areas where the water is actually 30 centimeters down so you actually have to dig down 30 centimeters and take off the top and that depth is really where you want to start collecting water ice."
That's not to say that it's an easy task. Even with a fully working processing plant, RASSOR is only expected to carry 40 pounds of raw material at a time, and NASA estimates it would have to dig 16 hours a day for five years to build up an appreciable stockpile of water. That's a long time indeed, but when the alternative is hoping the urine recyclers don't fizzle out, perhaps it's okay to wait.