Cryocooler Coldfinger Heat Interceptor

Abstract

Spacecraft instruments requiring cryocoolers in their design struggle to keep overall power requirements in line with feasible solar array dimensions and launch vehicle lift capacities. Intermediate temperature (150 K to 200 K) radiators to cool radiation shields or optics on spacecraft instruments provide an as yet untapped resource for reducing the cryocooler power requirements.

JPL has demonstrated significant thermal performance improvements to British Aerospace (BAe) cryocoolers by providing passive cooling below 200 K along the warm end of the cryocooler coldfinger. Inclusion of the thermal strap to cool the coldfinger has resulted in 50% reductions in cryocooler input power with no loss in refrigeration capacity for coldtip temperatures near 60 K. It is clearly shown in this paper that the advantages of a hybrid cooler/radiator design have profound benefits for spacecraft.