The Astrobotic approach to lunar mobility places the two drive motors in the main rover body where they are protected from dust and from the boiling heat of noontime lunar temperatures. By contrast, Mars rovers and some NASA-designed lunar rover prototypes have motors in each wheel hub, which is not practical for equatorial missions on the Moon. This image shows the exterior of the prototype and two tubes extending down to the front and back right wheels -- a chain drive from the shoulder motor powers the wheels. Recently, the team installed the two drive motors in the third prototype to begin bringing it into operation. The motors are brushless, with planetary and harmonic gears to bring down the rpm and provide very high torque. The rover will travel about 5 centimeters per second. For added simplicity, there are no steering motors to turn the wheels. Instead, the two shoulder motors can spin in opposite directions to "skid steer" the robot.