In-Orbit Degradation of Thermo-Optical Material Properties on OTS-2

In May 1981 OTS-2, the European Space Agency’s (ESA) first experimental telecommunication satellite, successfully completed its three year Orbital Test Program. The main topic of this paper is the continuing evaluation of the thermal control subsystem, with particular emphasis on the estimation of in-flight degradation rates associated with the various on-board thermo-optical material properties.