Study on thermal stabilization of a GEO-stationary telescope baffling system by integral application of phase change material

Abstract

Within the last two decades, the utilization of phase change material (PCM) for latent heat storage and thermal control of spacecrafts has become of growing interest for the scientific community. Some applications have been successfully flown in the past. However, all concepts developed so far envisioned the PCM to be applied as an additional capacitor, encapsulated in its own housing, leading to mass, efficiency and accommodation challenges. Recently, the application of PCM within the scan cavity of a GEOS type satellite has been suggested, in order to tackle thermal issues due to direct sun intrusion (Choi, M., 2014). However, the application of PCM in such complex mechanical structures is extremely challenging. A new concept to tackle this issue is currently under development at the FH Aachen University of Applied Sciences. The concept “Infused Thermal Solutions (ITS)” is based on the idea to 3D print metallic structures in their regular functional shape, but double walled with lattice support structures, allowing the infusion of a PCM layer directly into the voids and eliminating the need for additional parts and interfaces. Together with OHB System, the FH Aachen theoretically studied the application of this technology to the Meteosat Third Generation (MTG) Infra Red Sounder (IRS) instrument. The study focuses on the scan cavity and entrance baffling assembly (EBA) of the IRS. It consists of thermal analyses, 3D-redesign and bread boarding of a scaled and PCM infused EBA version. In the thermal design of the alternative EBA, PCM was applied directly into the EBA, simulating the worst hot case sun intrusion of the mission. By applying 4kg of PCM (to a 60kg baffle) the EBA temperature excursions during sun intrusion were limited from 140K to 30K, leading to a significant thermo-opto-elastic performance gain. This paper introduces the ITS concept development status.