Investigation of Thermo‐optical Characteristics of Thermo‐regulating Covers on Geostationary Orbit

This report presents the results of an investigation of thermo‐optical characteristics, i.e. the total solar absorptance, αs and solar emittance, e of thermal control coatings (TCC) exposed to the space environment at a geostationary orbit (GEO). Experiments results from samples that were flown on space vehicles (SV) “Yamal‐100” and “Yamal‐200” for 8 and 4 flight years, respectively, are presented here. The results from experiments flown for 6 and 2 flight years were presented in an earlier article [1].The αs and e characteristics were measured by a calorimetric method through monitoring the temperatures of the coating samples that were used as microcalorimeters (MC) and a mathematical treatment of the temperature data. The temperature sensors were attached to the back side of the flown samples.