Teams led by Lockheed Martin and TRW/Ball Aerospace have submitted proposals to NASA's Goddard Spaceflight Center to build the space agency's $500 million Next Generation Space Telescope (NGST) which is set to succeed the Hubble Space Telescope (HST).
The 5,400kg (11,900lb) NGST will feature a number of technological improvements compared with the $2 billion-plus HST. The lightweight, advanced technologies to be used include cryogenic mirrors, cryogenic actuators and detectors.
The mirrors were originally due to measure less than 8m (26ft), but NASA reduced this to 6m for cost reasons. Lockheed has opted for the conservative approach of a monolithic 6m diameter deployable mirror, while the TRW/Ball team proposes a mirror comprising six hexagonal petals that deploy in orbit.
The infrared observations will enable the NGST to study objects 400 times fainter than those seen by infrared spacecraft and Earth-bound telescopes, while at the same time matching or even surpassing the image sharpness or spatial resolution of the Lockheed-built HST.
Astronomers intend to use the NGST to observe stars and possibly galaxies being formed, helping to answer fundamental questions about the evolution of galaxies, stars and planetary systems and life cycles of matter in the universe.
The NGST is a NASA Origins programme, involving the European Space Agency, Canadian Space Agency and the Space Telescope Science Institute.
The telescope will be launched between December 2008 and June 2009 after HST's retirement. The NGST is likely to be preceded by a 50cm to 2m diameter mirror technology demonstration orbital mission. Sources say that launch dates could slip as the HST is expected to work well for many years.
Source: Flight International
