Comparison Study of Combined and Single Space Environmental Degradation Effects on Thermal Control Materials

This paper presents a comparison study of single and combined space environmental effects by electrons, protons and near ultraviolet (NUV) radiation on thermal control coatings. The space environment includes many hazardous factors. Because of synergistic effects among different environmental factors and the expensive nature of the open space experiments, ground-based combined environmental test methods are necessary to simulate orbital environmental effects. In many cases, the combined environmental effect from two or more factors Is not equal to the sum of single environmental effects. By studying the effects from single environmental factors, a better knowledge of their influence on the degradation of materials could be acquired. Space environmental degradation of thermal control coatings of S781 white paint, SR107-ZK white paint, silvered FEP, and OSR used on the outer satellite surfaces was simulated by exposing them to combined irradiation with electrons, protons and NUV In addition, irradiation with single factors with the same parameters was performed for comparison studies. Low energy proton irradiation has been found to affect the thermal control coatings the most. The effects from combined irradiation were found to be lower than from the sum of single environmental factors.