Webb’s Sun Shield
A giant, five-layered sunshield protects the James Webb Space Telescope and its instruments from the light and heat of the Sun. At 21×14 metres, this is about the size of a tennis court. The sunshield keeps the telescope in perpetual shadow for operations at –233°C, to prevent the instruments’ own infrared emission from overwhelming the signals from the astronomical targets. The mid infrared instrument MIRI is further cooled to –266°C.