The James Webb Space Telescope (JWST) is a space telescope that is part of NASA’s Next Generation Space Telescope program, developed in coordination between NASA, the European Space Agency, and the Canadian Space Agency.
It is scheduled to launch in October 2018 and will be located near the Earth–Sun L2 lagrangian point. The telescope will offer unprecedented resolution and sensitivity from the long-wavelength (orange to red) visible light through the mid-infrared (0.6 to 27 micrometer) range.
JWST’s capabilities will enable a broad range of investigations across the fields of astronomy and cosmology.
One particular goal involves observing some of the most distant events and objects in the universe, such as the formation of the first galaxies. These types of targets are beyond the reach of current ground and space-based instruments. Some other goals include understanding the formation of stars and planets, and direct imaging of exoplanets and novas.
In gestation since 1996, the telescope is named after James E. Webb, the second administrator of NASA, who played an integral role in the Apollo program.
NASA has described JWST as the scientific successor to the Hubble Space Telescope, but not a replacement, because the capabilities are not identical.
JWST will have the ability to see high-redshift objects, typically both older and farther away than previous instruments could assess.
The result was to extend the life of Hubble until JWST, as the next generation telescope, could go online. This led to a radically altered design for JWST to obtain images deeper into the infrared than Hubble, and beyond the capabilities of the Infrared Space Observatory and the Spitzer Space Telescope.
In contrast to Hubble Space Telescope, which has a 2.4-meter (7.9 ft) mirror, the JWST features 18 larger and segmented 6.5-meter-diameter (21 ft 4 in) primary mirrors. A large sunshield will keep JWST’s mirror and four science instruments below 50 K (−220 °C; −370 °F).