Description: Future NASA Space Science Missions will incorporate detectors, sensors, shields, and telescopes that must be cooled to cryogenic temperatures. An enabling technology for these missions is advanced cryocoolers that can provide continuous and distributed cooling with minimal input power. On this program, Creare proposes to develop and demonstrate an innovative cryocooler that produces refrigeration at temperatures of 30 to 70 K and rejects heat at a temperature of 150 to 190 K with extremely high efficiency. The heat rejected can be absorbed by an upper stage cryocooler or rejected to space through a small cryo-radiator. The overall mass of the cryocooler and electronics is 3 kg, the size of the cryocooler is 6 liters, the area of the cryo-radiator is 0.5 square meters and the input power is significantly less than current state-of-the-art cryocoolers. In addition, the cryocooler technology is extremely reliable and scalable, and produces no perceptible vibration. The key innovation is a cryogenic compressor which has heritage to the cryogenic circulator developed by Creare and operated on the Hubble Space Telescope for 6.5 years. On the Phase I project, we will optimize the cryocooler design for a particular mission class and predict the performance of the cryocooler using component-level test data. On the Phase II project, we will build and test a brassboard cryocooler and cryo-radiator. The Phase II testing will be structured to achieve a TRL of 5, and will include testing with a cold-end temperature of 35 K and a heat rejection temperature of 150 K.

Benefits: The proposed cryocooler is compact, efficient, and lightweight, making it ideal as the cold stage of a multi-stage thermal management system. Military applications for this cooling system include space-based surveillance and missile defense, and high-bandwidth, superconducting communication devices. Commercial applications include cooling for communication satellites, superconducting circuits, and cryogenic computers.

The successful completion of this program will provide mission planners with an extremely high performance, lightweight, and compact cryocooler that can meet requirements for multiple missions. The cryocooler is reliable, emits no vibration, and can be used for remote and distributed cooling. The latter feature is expected to reduce size, mass, and costs of the overall payload. The primary application will be for cooling detectors, sensors, shields, and telescopes for space science missions. NASA applications include future astronomical observatories utilizing infrared, far infrared, submillimeter, and X-ray detectors, such as the Wide Field Infrared Survey telescope (WFIRST), Single Aperture Far-IR (SAFIR) telescope, Space Infrared Interferometric Telescope (SPIRIT), Submillimeter Probe of the Evolution of Cosmic Structure (SPECS), and the International X-Ray Observatory (IXO).