How the James Webb Space Telescope Cryogenic Cooler Works

While most of the instruments on the James Webb Space Telescope are passively cooled, the Mid-Infrared Instrument (MIRI) requires cooling to 6° K, far below what passive cooling can achieve. This is accomplished by a two-stage cryocooler, which has to operate without vibration that would disturb the aiming of the telescope and last for its estimated twenty-year life.