James Webb Space Telescope (JWST) is a space observatory under construction and scheduled to launch in 2018. It is a replacement for the Hubble Space Telescope which was launched in 1990. The telescope is named after James E. Webb, who was a director at NASA and created the Apollo moon program. It will have a main mirror that is 6.5 meters (21.3 feet) wide, seven times larger than Hubble. The main mirror is composed of 18 sections that fold together.
Once operational the observatory will be looking mostly in the infrared spectrum, but also in the red part of visible light. Images will be color coded for public viewing. Because heat is visible to infrared sensors, the JWST must be kept as cool as possible. It is protected by a large sunshield, the size of a tennis court, and will be placed in a special orbit around the sun, beyond the moon, at the second Lagrange point (L2), a place of stable gravity. This keeps it in the Earth’s shadow most of the time.
January 8, 2017