Simbol-X
Simbol-X was the name of an X-ray satellite that Italy and France wanted to build together. The project was discontinued in 2009 for cost reasons. Originally, Simbol-X was supposed to be transported by a Soyuz rocket into Earth orbit in 2014 . The concept of the telescope was similar to that of Xeus . The mirror with a diameter of three meters and the detector are located on two separate satellites. The distance between them of approx. 30 m in formation flight determines the focal length of the system.
The planned energy spectrum was between 0.5 keV and 80 keV, the required resolution was better than 15 arc seconds. Its performance data should exceed those of the X-ray satellites Chandra and XMM-Newton above 10 keV and be better than that of Integral below 15 keV.