Radiative cryogenic cooler for the near infrared mapping spectrometer for the Galileo Jupiter Orbiter

Summaries of the thermal design, analysis, and testing of a radiative cooler for the Near Infrared Mapping Spectrometer (NIMS) for the Galileo Jupiter Orbiter are presented. The radiative cooler rejects approximately 120 milliwatts of heat at a temperature of 75K when operating in the worst-case thermal environment. The cooler is designed to operate against a relatively hostile thermal environment which varies over 145 deg of instrument scan angle and which includes planetary radiation, solar radiation, and emissions from warm spacecraft surfaces (some of which rotate periodically through the radiator field of view).