SIMBOL-X is a space-based X-ray telescope operating from 0.5 keV up to 80 keV providing an improvement of roughly two orders
of magnitude in sensitivity and angular resolution compared to the instruments that have operated so far above 15 keV.
This breakthrough is reached thanks to the use of Wolter-I optics based on shells working in grazing incidence combined with a large
focal length (20 meters). With these characteristics, the size and the mass of a classical monolithic instrument would be well beyond
the capacity of the most powerful launchers. For that reason SIMBOL-X is the first operational mission relying on two satellites
flying in formation. The so-called mirror satellite carries the mirror of the telescope, while the detector satellite drives the detector
assembly. The first one moves freely on a high elliptical orbit controlling its attitude towards the target, while the latter controls its 3-
axis position and attitude so as to keep the detector assembly right at the mirror focal point and perpendicular to its axis.
This promising concept of formation flight raises a variety of problematics, such as relative navigation, communications, operations,
safety, simulation and performance evaluation. After a successful concept study, the current feasibility phase provides answers to
each of these issues.
The SIMBOL-X project is a cooperation between the French Space Agency (CNES) and the Italian Space Agency (ASI). The design
of the instrument involves a number of laboratories in France (CEA, CESR, APC), in Italy (INAF, IASF) and in Germany (MPE,