English: Engineers at Marshall Space Flight center in Huntsville, AL remove the James Webb Space Telescope’s backplane from the cryogenic test chamber. During the recent testing, the backplane went through several cycles from room temperature to minus 400 degrees Fahrenheit. The X-ray & Cryogenic Facility at Marshall is the world’s largest X-ray telescope test facility and offers a unique, cryogenic, clean-room optical test environment. Cryogenic testing of the backplane took place in a 7,600-cubic-foot, helium-cooled vacuum chamber, chilling the Webb support structure from room temperature to simulate the frigid atmosphere of space. The backplane holds the 18 beryllium mirrors nearly motionless while the telescope peers into deep space.