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Session 54 - Next Generation Space Telescope.
Oral session, Thursday, January 08
International Ballroom Center,
The Next Generation Space Telescope (NGST) would meet the challenge set out by the HST and Beyond committee report (Dressler et al., AURA). The requirement is for a telescope optimized for the 1-5 \mum band with an aperture of at least 4 m, diffraction limited at 2 \mum. The ``stretch'' goal is for an aperture of 8 m and a wavelength range of 0.5 to 20 or 30 \mum. The instruments would be cameras and moderate resolution (R=100--1000) multi-object spectrometers. The telescope would be radiatively cooled to 40 K. InSb detectors can cover the 0.5 - 5 \mum range at about 30 K, and Si photoconductors can reach 26 \mum at about 6 K, and other detectors such as HgCdTe may also be useful. With such detectors, already demonstrated for the SIRTF (Space Infrared Telescope Facility), sensitivities in the sub-nanojansky range can be achieved, corresponding to magnitude(AB) 32 or beyond. With a wide field of view ( 4 arcmin) and excellent image quality, the NGST would be a very powerful telescope.
The NGST would be launched to a deep space orbit (Sun-Earth Lagrange point L2, or beyond) to enable deep radiative cooling and simple uninterrupted operations. An Atlas IIAS launch vehicle could place 2800 kg in this orbit. The mission would be built for a construction cost of less than $500 M (FY96 dollars). Two mission concept study contracts and two mirror technology demonstration contracts have been let, and an ad hoc science working group has been selected. Discussions have begun with the European Space Agency and the Canadian Space Agency about possible contributions to the NGST mission, which could extend the capabilities or reduce the cost to the US. Prospects look bright for a start of construction in 2003 and a launch in 2007.
The author(s) of this abstract have provided an email address for comments about the abstract: dmiller@hst.nasa.gov
