Carnegie Mellon University spinoff Astrobotic Technology has now completed a full-size prototype of a solar-powered robot designed to search for water ice at the moon's poles.
The plan is to launch the robot from Cape Canaveral on a SpaceX Falcon 9 launch vehicle, and win the $20 million Google Lunar X Prize in the process.
Polaris will carry a drill to bore one meter down into the lunar surface and is designed to operate in the low-light conditions of the poles.
"It is the first rover developed specifically for drilling lunar ice," says William Whittaker, Astrobotic CEO.
Observations by NASA and Indian spacecraft suggest that a substantial amount of water ice could exist at the lunar poles - a potential source of water, fuel and oxygen for future expeditions.
But finding it will be tricky, as the rover will need to operate close to the dark poles, while still using its three large solar arrays. Arranged vertically, these are designed to capture light from low on the horizon and should be capable of an average of 250 watts of electrical power.
Polaris is about five and a half feet tall, seven feet wide and almost eight feet long. It can move at about a foot a second on two-foot-wide composite wheels. It will weigh about 330 pounds, and can accommodate a drill and science payload of up to 150 pounds.
While the lunar day lasts about 14 Earth days, only about 10 days are suitable for water prospecting at the poles. The Astrobotic team expects Polaris could drill between 10 and 100 holes during that time - and repeat the feat indefinitely if it can, as expected, survive the long, cold lunar nights.
Astrobotic has won nine lunar contracts from NASA worth $3.6 million, including one to evaluate how Polaris can accommodate NASA's ice-prospecting instruments during a three-mile traverse near the moon's north pole.