Combined Low-Energy Environment Stimulation Test of Geosynchronous Satellite Thermal Control Coatings

Geosynchronous orbit environment effects of 15 years on solar absorptance of thermal control coatings such as S781 white paint, SR107-ZKwhite paint, silvered fluorinated ethylene propylene F46, and optical solar reflectors on the outer satellite are simulated by a combined low-energy irradiation test. Severe degradation is found in organic white paint whereas optical solar reflectors and silvered fluorinated ethylene propylene F46 remains quite stable. By comparison with flight test results, the effectiveness of the simulation method has been shown. Based on the degradation trend data, the least-square regression method was used to obtain an empirical formula. The secondorder exponential decaying formulas are found to be quite good to fit degradation curves of four kinds of materials. Extrapolation for a longer test time has been made, and the results have been verified. The error of using 8 year test results to extrapolate 15 year degradation is verified to be less than 1%.