Development of a high-performance cryogenic radiator with V-groove radiation shields
A feasibility demonstration model of a new-technology, high-performance, cryogenic radiative cooler has been successfully tested in a helium-cooled vacuum chamber. Thermal isolation of the radiator cold stage from the warm spacecraft and instrument is achieved by a novel arrangement of lightweight radiation shields which form large V-groove cavities, and by the use of low-conductance structural supports. The vacuum chamber experiments demonstrate the thermal isolation capability of the radiator design. Analytical model predictions are all within 1 K of the measured test temperatures. Utilization of this design enables reasonably sized radiative coolers (less than 0.3 sq m) to achieve operating temperatures below 60 K at earth, Mars, and beyond for useful cooling loads below 75 mW. The design can be scaled to accommodate larger heat loads. The reduction in operating temperature of over 15 K relative to any radiative cooler flown in the past will allow the V-groove isolation radiator to meet the challenging instrument cooling requirements of many future space missions.