Cooled scientific instrument assembly onboard SPICA

The Space Infrared Telescope for Cosmology and Astrophysi cs (SPICA) is a 3.2m cooled (below 6K) telescope mission which covers mid- and far-IR waveband with unprecedented sensitivity. An overview of recent design updates of the Scientific Instrument Assembly (SIA), composed of the telescope assembly and the instrument optical bench equipped with Focal Plane Instruments (FPIs) are presented. The FPI international science and engineering review is on-going to determine the FPI suite onboard SPICA: at present the mandatory instruments and functions to perform the unique science objectives of the SPICA mission are now consolidated. The final decision on the composition of the FPI suite is expected in early 2013. Through the activities in the current pre-project phase, several key technical issues which impact directly on the instruments’ performances and the science requirements and the observing efficiency have been identified, and extensive works are underway both at instrument and spacecraft level to reso lve these issues and to enable the confirmation of the SPICA FPI suite. Keywords: SPICA, space telescope, Joule-T homson cooler , infrared astronomy