Beating the boiling temperatures of the lunar day requires both good insulation to reject exterior radiation and an internal system to wick heat away from the electrically powered components that generate heat inside the robot.

The Astrobotic rover has several composite parts that are highly heat-conductive to route internal heat to the radiator for dumping into space. This week the conductive straps that surround each of the two drive motors entered testing. The photo below shows wires coming off the thermocouples that will measure heat flow from the tubular area that will clamp on to the motor. The base will be bolted to a heat strap leading to the radiator. In this test, it is bolted to a cold plate.

In the photo below, a 20w heat source will be placed in the tubular section in the upper left of the image. Heat will first flow to the right along the composite material's fibers. The multiple curved pieces in the upper right form a spring, which allows the motor to flex slightly as it receives shocks transmitted from the exterior drive train. The composite fibers then curve down to the base plate. The base is sheared off at an angle, so that each of the multiple layers of fibers terminate in direct contact with the cold plate (or heat strap in the actual robot) for maximum heat drainage.

In the photo below, the heat source is installed in the strap (upper right) and the cold plate is activated. The yellow tape holds thermocouples to the device to measure temperature at various points between the heat source and the cold plate.

Photos by Guillermo Gomez