Thermal Design and Evaluation of the Microsatellite RISESAT

摘要

The Space Robotics Laboratory (SRL) of Tohoku University has developed a 50-kg-class microsatellite called RISESAT, which was launched in January 2019. The main missions of this satellite are to conduct earth observation using a high-resolution telescope and perform a demonstration of optical communication. To achieve these missions, it is necessary to maintain the on-board components in a specified safe temperature range. In this satellite, on-board components such as the battery and power control unit are mounted to the central pillars of the satellite structure, which are insulated from the outer panels, and are thus not easily affected by the external environment. Therefore, it is important to determine the amount of heat generation by the components as well as the heat transfer parameters between structure panels. The purpose of this study is to determine the parameters such as thermal contact conductance between structure panels and heat generation of the components. We conducted the thermal vacuum tests to improve the accuracy of the determination of these parameters. Finally, we analyzed the flight data and evaluated the validity of the parameter determination using data from the regular operations phase of the mission. The seasonal effects on the thermal design were also evaluated using data from the first 480 days after launch.