LEO effects on candidate solar cell cover materials

In 1984, the LDEF (Long Duration Exposure Facility) was placed in LEO (Low Earth Orbit) for a mission planned to last approximately one year. Due to a number of factors, retrieval was delayed until 1990. An experiment, prepared under the direction of JPL, consisted of a test plate with thirty (30) individual thin silicon solar cell/cover samples. The covers consisted of conventional cerium doped microsheet platelets and potential candidate materials, such as FEP Teflon, silicon RTV's, glass resins, polyimides, and a silicone-polyimide copolymer encapsulant. The effects of the LDEF mission environment (micrometeorite/debris impacts, atomic oxygen, UV, and particulate radiation) on the samples are discussed.