SENSORS - Efficient Low - Temperature Cryocooler (ELTC)

An Efficient Low-Temperature Cryocooler (ELTC) design was developed in the Phase I study that will provide cooling below 35 K with a Carnot efficiency greater than 10 percent. This extraordinary high efficiency is due to the incorporation of a uniqueexpansion engine design that is enabled though application of a unique expansion engine design that is enabled through application of microelectro-mechanical systems (MEMS) technology. The expansion engine provides large cold-eng cooling capacity andallows the use of a single-stage Sterling or pulse tube cryocooler as a precooler for the low temperature cold stage.The combination of features that ELTC promised are high efficiency, low weight, compactness, high reliability, cold-end heat exchanger flexibility, low vibration, and variable load capability. These features will provide and extraordinarily high payofffor future DoD surveillance missions. Satellite power and heat rejection requirements will be significantly reduced, decreasing overall weight and greatly simplifying cooling system integration. The capability to uniformly cool large area FPAs totemperatures of 35K and below will enable high resolution, large field-of-view sensor systems critical for advanced space reconnaissance missions. Development of this revolutionary cooling system will usher in an era of high resolution advanced sensors,dramatically improving our nation's satellite surveillance capabilities to meet future national security needs