Ultra Compact, Lightweight, Space-Borne Cryocoolers

Future space-based astronomical observatories will require long-life, vibration-free mechanical cryocoolers for sensor cooling. Of the candidate mechanical cryocoolers, the turbomachine-based reverse-Brayton cryocooler (TRBC) exhibits the most attractive combination of low vibration, high reliability, low mass, flexible integration, and high efficiency. In recent years, this technology has achieved a high level of maturity through a space flight qualification program and flight test. The opportunity now exists for breakthrough reductions in size and mass, and improvements in system integration. The goal of the proposed effort is to develop a compact, lightweight TRBC that will easily integrate with: (1) high and low temperature radiators to improve system performance; (2) other TRBCs to allow multi-stage cooling at lower temperatures; and (3) other types of coolers such as adiabatic demagnetization refrigerators to allow efficient cooling at sub-Kelvin temperatures. The key innovation is a single turbomachine that provides both the compression and expansion of the cycle gas. During Phase I, we will develop a preliminary design of a compact TRBC, identify a range of applications, and demonstrate the operation of the turbomachine at prototypical speeds.