U.S. scientists say they\'ve built a full-size prototype of a solar-powered robot designed to search for potentially rich deposits of water ice on the moon. The rover, dubbed Polaris, is being developed by Astrobotic Technology Inc., a spinoff company of Carnegie Mellon University that develops robotics technology for planetary missions. Intended for an expedition to the moon\'s northern pole, Polaris would launch from Cape Canaveral, Fla., atop a SpaceX Falcon 9 launch vehicle, a university release said Wednesday. The test prototype will allow researchers to test and improve the robot\'s computer vision, navigation and planning software, and another software program than can plot the rover\'s position on the moon to within 10 feet. Ice on the moon could be a source of water, fuel and oxygen for future expeditions. \"It is the first rover developed specifically for drilling lunar ice,\" said William \"Red\" Whittaker, head of Astrobotic and founder of the Field Robotics Center at Carnegie Mellon\'s Robotics Institute. Polaris can move at about a foot a second on 2-foot-diameter composite wheels and can carry a drill and science payload of up to 150 pounds, the researchers said.