GNC challenges for SIMBOL-X formation flying mission
Аuthors
*, , , , , ,CNES, 18 av Edouard Belin, 31041, Toulouse, France
*e-mail: pierre-yves.guidotti@cnes.fr
Abstract
SIMBOL-X is a hard X-ray space-based observatory to be launched in 2013 onto a High Elliptical Orbit (HEO). This new generation telescope covers by a single instrument a continuous energy range starting at classical X-rays and extending to hard X-rays (i.e. from 0.5 to 80 keV). For mass and size reasons, a classical monolithic instrument cannot be used and this Franco-Italian mission will thus consist of two satellites. The Mirror spacecraft (MSC) will be in free flight on a HEO orbit and will target very precisely the source to observe, focusing the hard X-ray emission thanks to its mirror module. At the focal point, 20 meters behind the Mirror satellite, the Detector spacecraft (DSC) maintains its position on a forced orbit. This paper aims at presenting some of SIMBOL-X GNC challenges. The first part will introduce main formation flying phases and related system requirements. In the next section focus will be made on DSC GNC design: algorithms and equipment adapted to the previously introduced phases will be presented. The last section deals with the line-of-sight (LOS) restitution problematic: for scientific purposes the line-of-sight between the two spacecrafts shall be reconstructed a posteriori very precisely. The last section will thus describe the chosen methodology to address this challenging problem.Download