NASA is about to launch a telescope that can witness the creation of stars and planets 13.8 billion years ago
The James Webb Space Telescope is scheduled for launch in 2021. The Webb telescope will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.
Several innovative technologies have been developed for Webb. These include a primary mirror made of 18 separate segments that unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium. Webb’s biggest feature is a tennis court sized five-layer sunshield that attenuates heat from the Sun more than a million times. The telescope’s four instruments – cameras and spectrometers – have detectors that are able to record extremely faint signals. One instrument (NIRSpec) has programmable microshutters, which enable observation up to 100 objects simultaneously. Webb also has a cryocooler for cooling the mid-infrared detectors of another instrument (MIRI) to a very cold 7 kelvins (minus 447 Fahrenheit) so they can work.