Performance of Hughes’ “SBIRS Low” FDS Cryocooler

Abstract

A cryocooler for use in long-term space environment adapted from earlier designs has been chosen as the baseline cryocooler for SBIRS Low FDS. First two of four units have been designed, assembled and acceptance tested. The first unit has been placed into a simulated space life test environment. This cryocooler design operates on the Stirling cycle in the split configuration. It utilizes “heat intercept” concept to enhance its performance. Heat Intercept has been demonstrated at JPL previously by Dr. Dean Johnson and Dr. Ron Ross and its use here and on an earlier prototype bears out the concept. The cooler is intended to be used at two discrete cold end temperatures for two different focal plane arrays in a space-based infrared telescope. Intended loads are: a) 0.9 Watt heat lift at 35K rejecting to 293K for 80 Watts of input power with the aid of a 170K heat intercept of less than 3 Watts and b) 0.9 Watts heat lift at 60K rejecting to 293K for 60W of input power with the aid of a 170K heat intercept of less than 3 Watts. Specified performance has been demonstrated and both units have survived a simulated space launch environment. Description of cryocooler geometry, test methods and performance data are presented.