Ball aerospace 4-6 K space cryocooler

This paper describes the design, development, testing and performance at Ball Aerospace of a long life, 4-6 K temperature space cryocooler. For temperatures to 4 K and below, Ball has developed a hybrid Stirling/Joule-Thomson (J-T) cooler. The hybrid cooler has been verified in test to 3.5 K on a Ball program and a 6 K Development Model is in development on the NASA/JPL Advanced Cryocooler Technology Program (ACTDP). This paper will include the test status on the Stirling Precooler and the Thermal System Breadboard. The ACTDP cooler provides simultaneous cooling at 6 K (typically, for either doped Si detectors or as a sub-Kelvin precooler) and 18 K (typically, for optics or shielding) with cooling stages also available at 40 and 180 K (typically, for thermal shields or other components). The ACTDP cooler is under development for the NASA Terrestrial Planet Finder (TPF), Constellation X-Ray (Con-X), and other future missions. The 4-6 K cooler is highly leveraged off previous Ball space coolers including multiple life test and flight units.