On-Orbit Longevity of Cryogenic Cooling Systems

Exothermics and their Phase 2 partner Northrop Grumman Space Technology seek to increase the reliability, producibility and performance of cryocoolers which cool Long and Very Long Wave Infrared (LWIR and VLWIR) focal planes in space surveillance systems. The materials proposed for investigation address the regenerator, a critical thermodynamic component in pulse tube and Stirling cryocoolers. In view of the need for enhanced cryocooler performance in future ballistic missile intercept scenarios, this Phase 2 SBIR will endeavor to further extend NGST's record of reliability and producibility to the lower temperatures required by future LWIR and VLWIR sensors. One of the main goals of the proposed Phase 2 SBIR effort is to examine methods for producing forms of the rare earth metals and alloys that will permit exploitation of their anticipated cryogenic performance potential at temperatures below 35K, particularly when compared to other more conventional approaches involving the use of lead screen or rare earth materials in the form of shot or spherical powders. Development and optimization of these materials will extend cryocooler performance for near term HgCdTe LWIR (35K) focal planes to wavelengths of ~ 15µ and enable Si:As VLWIR (10K) focal plane operation to wavelengths of ~ 26µ.