During tests that have taken place over the last few months, a hybrid pulse tube Joule-Thomson cryocooler using the Company's long-life, high reliability, heritage flight hardware achieved cooling levels to 4.4 Kelvin (-451.75 F). The tests were conducted as part of a company-funded independent research and development project. Northrop Grumman's flight-proven cryocooler hardware consisted of a 3-stage pulse tube cooler that uses high-pressure helium gas. This multi-stage approach enables efficient cooling of optics and system components and also makes it possible for another cooling element of the hardware to operate between 4 K and very low 50mK temperatures. Cooling to very low cryogenic temperatures enables x-ray, infrared, microwave and gamma ray sensors to provide more and better astronomical data. History has proven the product — since 1998, 12 of the 13 U.S.-manufactured long-life pulse tube or Stirling cryocoolers in space have been built by Northrop Grumman. None has failed or changed performance in orbit.
(Image: mechanical engineering model of the IXO spacecraft, which will enable scientists to study the high-energy universe, with the goal of discovering more black holes, the formation and evolution of galaxies, and the life cycle of matter and energy. Courtesy Northrop Grumman)