Thermal Design of Astrobee Perching Arm

This paper presents the thermal design of actuators in the perching arm of Astrobee robot that will operate inside the International Space Station (ISS) starting in 2019. Since the crew's safety is of the utmost importance on the ISS, all materials used in the Astrobee robot should meet the touch temperature requirements according to the ISS safety standards to protect crew from skin burns by controlling the exposure temperature. The Astrobee perching arm consists of 2-DOF (Degrees-of-Freedom)- arm servo motors and 1-DOF gripper DC motor, which are capable of overheating in the stalled condition. Thermal properties of two types of actuators are verified by monitoring the touch temperature in worst-case operations with no thermal protection. Then, the proper thermal protection designs have been conducted and installed to guarantee the safety in all conditions.