Reliability of Space-Borne Turbo-Brayton Cryocoolers

"The Department of Defense (DoD) will require cryocoolers for future missions to cool space-based infrared sensor arrays, space-based lasers, and orbital transfer vehicles. Turbo-Brayton cryocoolers are ideal candidates for these missions because they areefficient, lightweight, highly reliable, produce negligible vibration, and have an adaptable layout that allows them to be easily integrated with sensors and spacecraft systems. Several accelerated life tests have been used to demonstrate the reliabilityof the basic turbomachine technology. However, typical missions require maintenance-free cryocoolers that operate for more than 10 years without exhibiting significant performance degradation. Long-duration life tests (10+ years) using prototypicalflight hardware are needed to demonstrate cooler reliability and lifetime. The objective of the proposed work is to develop the contamination control approach and demonstrate the reliability of a low-temperature turbo-Brayton cryocooler through a lifetest. The cooler baselined for the life test is an Engineering Model (EM) unit that has been optimized for cooling at 35 K. The successful completion of this project is critical for future DoD space programs such as SBIRS-Low. During Phase I, we willdevelop a contamination control plan. During Phase II, we will implement the plan and initiate the life test. This program will result in the development of a turbo-Brayton cryocooler that ex