Thermal-Vakuum-Tests für die OPS-SAT-Mission der ESA

OPS-SAT is an ESA nanosatellite launched in December 2019. The spacecraft is open for third-party experiments, which can use almost all functions provided by the spacecraft and take full control of it. Depending on the experiment and usage of the payload, the power consumption of the spacecraft may be as small as a few watts but can exceed 30 W at full load. The peak power production lies in the same order of magnitude, which is highly demanding for thermal regulation. This article describes the preparation and execution of the OPS-SAT Thermal Vacuum (TVAC) test campaign and discusses the limitations and restrictions that had to be taken into account, such as technical limitations with respect to mounting the spacecraft inside the TVAC chamber. Additionally, the procedure of identifying a comprehensive test scenario is discussed. The general approach of TVAC tests and the results of one full test cycle are presented, and the key findings are discussed. The goal is to address the problems and limitations that were encountered during the TVAC test campaign and to provide some ideas and suggestions for improvement for the future.