James Webb Space Telescope
The James Webb Space Telescope (JWST) is a planned orbital infrared observatory, intended (in part) to replace the aging Hubble Space Telescope. Formerly called the Next Generation Space Telescope (NGST), it was renamed after NASA's second administrator, James E. Webb, in 2002. The telescope's launch is planned for sometime between 2009 and 2011. Its orbit (at the L2 lagrangian point point, around 1.5 million km from Earth) is considerably beyond the maximum altitude achievable using the Space Shuttle, so JWST will probably be placed in orbit using a European Ariane 5 launcher. This height also means that, unlike Hubble, it will not be possible to repair or upgrade the observatory during its 5-10 year design life.Although JWST has a planned weight half that of the Hubble, its primary mirror (a 6.5 meter segmented beryllium reflector) is more than 5 times larger.
