COROT TELESCOPE (COROTEL)

摘要

The space Corot telescope has been developed by Thales Alenia Space Cannes (previously named Alcatel Alenia Space) and has been delivered to the French Space agency (CNES). The satellite has been successfully launched from Baikonour the 27th of December 2006. This telescope is a very precise and stable imaging instrument that is pointed towards fixed areas in the sky for periods of at least 5 months, in order to carry out two kinds of missions : (ⅰ) Stellar seismology, (ⅱ) Search for exoplanets (by transit detection). Corot is likely to be the first space instrument capable of detecting Earth like planets orbiting around other stars and providing accurate stellar data in relation with their internal constitution. The target stars will have visible magnitudes lower than 9 for the seismology mission, and lower than 13 for the detection of Earth-like planets. COROT is a low cost mission and has a polar circular orbit with an altitude around 800 Km (unfortunately not at L2 orbit). In order to comply with the above objectives, the instrument shall deliver a very stable signal from a stable source. More particularly, this stringent stability requirement implies : (ⅰ) a high level of straylight (coming from earth) rejection, (ⅱ) a high pointing stability, (ⅲ) a high level of performance for the thermal control subsystem in term of temperature and gradient stability associated with the use of hyper stable materials. On the other hand, this instrument is carried by a low size satellite of the PROTEUS family, allowing a faster and cheaper development. This paper focuses on the proposed opto mechanical design for the telescope, its baffling concept and its performance which are now demonstrated in flight.