Red Rover last week entered the first of several field tests in the lunar-like terrain of a Pittsburgh-area slag heap (waste rock left over from an abandoned steel mill). The robot is powered by two brushless motors mounted inside its body, which drive planetary and harmonic drives that turn bicycle-style chains connected to the wheels. Red Rover steers by turning the motors at different speeds; it can rotate in place by turning one motor in reverse of the other. The robot shown in the video is the third prototype. The next prototype will be a "proto-flight" version with a greater array of space-appropriate parts, followed by a flight version for the expected December 2012 launch. The team is evaluating how fast the robot should move on the Moon. Some robot motion in this video is accelerated somewhat from the actual slag-heap experience.