Cryogenic space observatory

Abstract. This paper describes the status of NASA s Space Infrared Telescope Facility (SIRTF) program. SIRTF will be a cryogenicaily cooled observatory for infrared astronomy from space and is planned for launch early in t next decade. It will be the first cryogenic space observatory to make extensive use of the powerfrd infrared detector array tednology discussed at this conference. We summarise a newly developed SIRTF mission concept and show how the availability of detector arrays has shaped the scientific rationale for SIRTF, and how the arrays themsdves have become part of the definition of the SIRTF misaon. 

On the last three decades, several space experiments with parts at very low temperatures have been flown. Among these, we mention IRAS (Infrared Astronomical Satellite) launched in 1983 (see Fig. 14.1), COBE (Cosmic Background Explorer) launched in 1989, ISO (Infrared Space Observatory) launched in 1995 and Astro-E (X-ray Observatory), launched in 2000 with instrumentation at 65 mK [35], Some cryogenic space missions are in the preparation or in final phase in Europe, USA and Japan. For example, ESA is going to fly Planck (for the mapping of the cosmic background radiation) and Herschel (called before FIRST Far Infrared and Submillimetre Telescope ) [36], These missions will carry experiments at 0.1 and 0.3 K respectively. 

J. Fischer, T. Klaassen, N. Hovenier, G. Jtikob, A. Poglitsch, O. Sternberg, Cryogenic far-infrared laser absorptivity measurements of the herschel space observatory telescope mirror coatings. Appl. Opt. 43(19), 3765-3771 (2004). doi 10.1364/A0.43.003765. http //ao.osa.oig/abstract. cfm URI=ao-43-19-3765... 

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