Material Passes Tests for James Webb Space Telescope Sunshield

The James Webb Space Telescope (JWST) will observe primarily the infrared light from faint and very distant objects. But all objects, including telescopes, also emit infrared light in the form of heat energy. To avoid swamping the very faint astronomical signals with radiation from the telescope, the telescope and its instruments must be very cold, at an operating temperature of under 50 K (-370 ºF).