Biomass Thermal Vacuum Test Campaign Lessons Learned

Biomass was selected as the 7th Earth Explorer mission in Spring 2013 at the User Consultation Meeting in Graz, Austria. The overall objective of the mission is to reduce the uncertainty in the worldwide spatial distribution and dynamics of forest biomass in order to improve current assessments and future projections of the global carbon cycle. This objective will be achieved by implementation of a novel P-band SAR mission, providing global maps of forest biomass stocks, forest disturbance and growth. As part of the satellite verification activities, a thermal vacuum test was concluded in October 2024 in the SIMLES test chamber at Airbus Defence and Space Toulouse. In the absence of solar simulation, the test utilised IR lamp arrays for the purposes of heat injection at critical locations, in combination with direct test heating to simulate environmental loads on the satellite. In addition, dedicated excursions were performed during the test to assess the robustness of PI control implemented on the Star Tracker optical heads. This paper will summarise the Biomass thermal control design and will discuss the complexities of realising the idealised thermal design into a fully testable test configuration. The paper also addresses lessons learned for future satellite thermal vacuum tests.