The SPICA mission is a future Japanese infrared astronomical satellite to explore the universe with a cooled, large telescope.
We propose a ``warm launch'' cooled telescope; the telescope is to be launched at ambient temperature and is to be cooled in orbit to 4.5K by a modest cryogenic cooler with the help of radiative cooling. Since liquid helium and hence a heavy vacuum vessel are no longer required, the warm launch design reduces the weight of the satellite dramatically.
We propose to launch this satellite into a halo orbit around S-E L2, one of the Sun-Earth Lagrangian liberation points. The S-E L2 is an ideal orbit for infrared astronomy, since (1) radiative cooling can become very effective, and (2) long-integration observations become possible.
A 3.5 m class telescope can be put into a halo orbit around S-E L2 by the Japanese H-IIA launching vehicle. This mission focuses on high-resolution mid- to far-infrared observations with unprecedented sensitivity, since the large aperture reduces confusion noise and the cooled optics suppresses instrumental background radiation. The SPICA mission is an ideal observatory-type platform to make follow-up observations to the ASTRO-F/IRIS survey mission. The target launch year is 2010.
Postscript version of this document (387 Kbytes) (1998, SPIE Proc. 3356)
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