Lunar X Prize hopeful to search for water ice at moon's poles
10 October 2012
A Carnegie Mellon University spin-off has completed assembly of a full-size prototype of a solar powered robot that will search for water ice at the moon's poles.
Solar-powered Polaris can accommodate a drill to bore one metre into the lunar surface
Astrobotic, a Carnegie Mellon University (CMU) spinoff that develops robotics technology for planetary missions, is developing Polaris for an expedition to the moon's northern pole. It would launch from Cape Canaveral atop a SpaceX Falcon 9 launch vehicle. The company, in partnership with CMU, seeks to win the Google Lunar X Prize of more than $20m.
Polaris is a flight prototype, but has the same configuration as the rover that will eventually land on the moon. This will enable Astrobotic team members to spend the coming months testing and improving the robot's computer vision, navigation and planning software, and software that can plot the rover's position on the moon within ten feet. It includes a number of flight-worthy components, including wheels and chassis beams constructed of light, but tough composite materials.
"It is the first rover developed specifically for drilling lunar ice," said William Whittaker, Astrobotic CEO and founder of the Field Robotics Centre at CMU's Robotics Institute. Other robots built by the Field Robotics Center have developed technologies necessary for lunar drilling, but none of those machines was ever meant to leave Earth. "What Polaris does is bring those many ideas together into a rover configuration that is capable of going to the moon to find ice," he added.
Observations by NASA and Indian spacecraft suggest that a substantial amount of water ice could exist at the lunar poles. That ice could be a source of water, fuel and oxygen for future expeditions.
To find the ice, a rover thus must operate as close to the dark poles as possible, but not so far that it can't use solar arrays for power, Whittaker said. Polaris thus has three large solar arrays, arranged vertically to capture light from low on the horizon. The solar arrays will be capable of an average of 250W.
Polaris also makes use of software, pioneered in CMU's NASA-funded Hyperion robot, that keeps track of the rover's position relative to the sun's rays to maximise solar energy and husbands battery power for use in the long shadows and dark regions found at the poles.
The rover will weigh 150kg and can accommodate a drill and science payload of up to 70kg.
Composite structural materials are essential for Polaris in order that it can accommodate the heavy drill, as well as the large batteries it will need for low-light operations. The carbon fibre and Kevlar materials are also important to the mission because they won't release gases in the moon's hard vacuum and affect the operation of onboard gas sensors.