Thermal design of the sample handling assembly in the sampling and caching subsystem on the Mars 2020 rover

The Mars 2020 Rover is scheduled to land on Mars on February 18, 2021. One of the primary mission objectives for the Mars 2020 Rover is to collect a set of Martian regolith samples for potential future return to Earth. Regolith and rock samples will be collected and placed into sample tubes using a coring drill, located at the end of a large Robotic Arm, on the outside of the rover. Filled sample tubes will be transferred from the outside of the Rover into the Adaptive Caching Assembly (ACA), located inside the Rover chassis, via the Bit Carousel. Once the filled sample tube is brought into the ACA, the Sample Handling Assembly (SHA) will transfer it to all of the internal processing stations of the ACA for volume assessment, sealing and finally drop-off on the Martian surface. The ACA is a volume within the rover chassis that is not temperature-controlled. Actuators inside the SHA and its End Effector (EE) must be warmed to above -55°C and -25°C, respectively,
prior to use. This paper discusses the thermal design of the SHA that uses heaters and temperature sensors to warm up and maintain the temperature-sensitive arm components within temperature limits during operation. Thermal performance predictions for Mars surface operations are also presented.