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 designs use flexure supports, clearance gaps, and modular use of a dynamic 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 lifetimes. A hybrid digital/analog electronic controller controls the system, minimizes induced vibration, and maintains temperature stability. This paper discusses reliability, induced vibration, efficiency, and instrument integration of different configurations, including system integration of each, and presents experimental data.