In space, the telescope itself must be kept extremely cold in order to be able to detect the infrared light from faint and very distant objects. To protect the telescope from external sources of light and heat (like the sun, Earth, and moon) as well as from heat emitted by the observatory itself, a five-layer, tennis court-sized sunshield acts like a parasol providing shade. The sunshield separates the observatory into a hot, sun-facing side (reaching temperatures close to 230 degrees Fahrenheit), and a cold side (approximately minus 400 degrees Fahrenheit) where the sunlight is blocked from interfering with the sensitive telescope instruments. (Image: Desiree Stover via NASA)
