Recent discoveries of active under-ice oceans on Europa and Enceladus have kindled speculation that life may exist at the outer reaches of our solar system. But to prove it, we're going to have to employ devices like the one recently tested by Stone Aerospace researchers in Alaska.
Called VALKYRIE, the Stone Aeorospace cryobot (along with some help from NASA) is powered by a 5,000-watt laser carried through a fibre optic wire (peace treaties prevent the use of nuclear-powered devices). The upgraded system can carry more power than electric cables, allowing the automated drill to dig deeper than before. Shaped like a torpedo, it's 5.3 feet (1.6 meters) tall and 17.7 inches (45 centimeters) in diameter. It'll eventually be able to deploy smaller robots carried inside that would be released into liquid water to map the seafloor and scan for signs of life. Researchers are hoping to test a prototype of these marine robots, called Sunfish, next year in Antarctica. See a diagram here.
New Scientist reporter Lisa Grossman recently went to Alaska to witness a test of VALKYRIE. Here's how it works:
The robot's burrowing strategy is to suck in water through valves in its nose, heat it internally and shoot it back out to melt a pocket in the ice that it can slide into. The robot moves about a metre an hour, but the Europa-bound version should be bigger and speedier.
By the time I arrive at the glacier, the cryobot has drilled a hole 15 metres deep. It later extended this to 30 metres, beating the JPL team's record.
Stone and his fellow engineers also ran tests to see whether VALKYRIE can change direction. On Europa, it would have a radar mounted on its nose so it could sense obstacles in its path and veer away from them.
"None of this would be required if we thought the ice would be clean straight down, but there could be anything from specks of dust to Volkswagens sitting in there," says Stone.
VALKYRIE turns by shooting hot water out of two side-facing jets to create a sloped channel, although it's not yet working as planned. Firing its side jets initially made the robot spin as it burrowed, carving a corkscrew path in the glacier. To get round this, the team attached a pole to the top of the robot that they could grasp on the surface, keeping the robot steady inside the hole as it fired its jets. Images of the resulting channels showed that side jets were not creating a consolidated hole. Instead they were carving a Mickey Mouse shape in the ice.
The system will be put through a formidable test at some future point when its expected to drill through 9,850 feet (3,000 meters) of ice into the South Pole Lake.
[ New Scientist ]