The Submillimeter-Wave Astronomy Satellite: Instrument Thermal Design and Verification

A large telescope aperture, stringent thermal stability and temperature range requirements, and a passively-cooled 150°K module presented major challenges in thermal design and hardware fabrication of this Small Explorer science instrument. This paper details SWAS thermal system design, problems that were revealed in thermal testing, and the hardware changes that brought the design into an acceptable condition. Thermal test techniques that helped verify design adequacy are described, as well as the analytical methods used to correlate the thermal model and predict flight performance.