This paper describes a Stirling Cycle Refrigerator that has been built and tested by Stirling Technology Company (STC) for the NASA Marshall Space Flight Center (MSFC). Its intended application is the space station food refrigerator freezer.
The Stirling Cycle Refrigerator described herein has few moving parts, is nontoxic to both humans and the environment, is insensitive to gravity, and has a moderate efficiency. Its temperature setpoint is adjustable, making it adaptable to other space station applications including a -70 °C freezer and freeze drier, a -183 °C freezer, and a -196 °C snap freezer.
Test results have been very promising, with a Coefficient of Performance (COP) of 1.1 at -26 °C (-15 °F) and a heat load of 130 watts. Reliability tests on individual components and the entire Stirling Cycle Refrigerator system show a 10-year life is possible.
In addition, the benefits of using this technology for the space station refrigerator freezer will be described.