Results of Space-Environment Exposure of the Flexible Optical Solar Re ector

摘要

This paper presents exposure results for the flexible optical solar reflector, a sample material in the InternationalnSpace Station Service Module/Micro-Particles Capturer and Space Environment Exposure Device experimentnmission. The flexible optical solar reflector, which has a conductive layer and a mirror layer coated on anpolyetherimide base film, is a thermal control filmmaterial for spacecraft. It achieves lowsolar absorptance and highninfrared emittance. Results indicate a mass increase: the flexible optical solar reflector was not eroded by atomicnoxygen in low Earth orbit. Thermo-optical properties show no significant change. In fact, flexible optical solarnreflector is confirmed to retain its initial properties after exposure on an International Space Station orbit forn46months.Transmission electronmicroscopy observation of the cross sections including the exposed surface showednthat a new layer had formed over the flight sample. Qualitative analysis of the new layer indicates that the layernmainly comprises silicon and oxygen. The layer is chemically produced by deposited silicone contamination andnatomic oxygen, which would be SiO2. This experiment also provides actual quantitative contamination data on thenInternational Space Station, contributing to improvement of contamination control on the International SpacenStation in the future.