Verification of an Actively Shuttered Dust-Resilient Radiator for Lunar Applications

Thermal control devices for the lunar surface must consider the effects of lunar dust in terms of thermal performance, as well as reliability of the mechanism over an extreme range of temperatures. The development challenge is increased when attempting to design such a device as a generic, scalable product to operate at any latitude across the lunar surface. Radiator functionality is influenced by lunar environmental temperatures and must consider IR heating during the lunar day as well as heat losses during the Lunar night. The Lunar Thermal Shutter (LTS), developed by ESR with the support of Almatech and Spacemech, enables closure of a radiator to minimize heat losses at night. In addition, the LTS is also intended to protect from contamination during events and phases of the day with high expected dust deposition, such as the passing of the day/night terminator, landing, or activities of astronauts, rovers or robotic equipment. The paper describes advancements of the LTS made following three years of development, focusing on the status of thermal vacuum and dusty vacuum tests, where this device is intended to be suitable for use in various lunar applications, including on landers (such as for example Argonaut), rovers and other longer duration lunar surface applications. Thermal analysis cases are summarized including the results of correlation with thermal vacuum testing completed in August 2024 that included assessment of turn-down ratios over temperature.