MODULAR APPROACH TO SPACEBORNE STIRLING CRYOCOOLERS

Lockheed has advanced a family of spaceborne cryocoolers based on the split Stirling cycle technology developed at Oxford University. The de signs use flexure supports, clearance gaps, and modular use of a dynam ic balancer for the compressor and/or displacer. They have achieved a no-load temperature of 24 K, cooling loads of 1.7 W, compressor input powers of 46 W/W at 55 K, and are inherently designed for long lifetim es. A hybrid digital/analog electronic controller controls the system, minimizes induced vibration, and maintains temperature stability. Thi s paper discusses reliability, induced vibration, efficiency, and inst rument integration of different configurations, including system integ ration of each, and presents experimental data.