ROSAT

ROSAT was a German-British-US X-ray astronomy project with the goal to perform the first complete all-sky survey of celestial X-ray sources. The satellite and its instruments provided the capability of detailed pointed observations of selected sources with respect to spatial structure, spectrum and time variability. ROSAT carried the most sensitive X-ray telescope in the world together with a XUV wide field camera which are mounted on three-axis stabilized platform. The spacecraft was launched with a DELTA-2 rocket from the Kennedy Space Center, Cape Canaveral, Fla (USA) into a circular Earth orbit of app. 360 miles (580km) with an inclination of 53 degrees. The expected mission duration was 1.5 years, however the excellent performance of the satellite systems has been yielding scientific data for nearly 10 years until 12 January 1999. During the short visibility periods of 6 to 10 minutes over GSOC's ground station at Weilheim (15 meter S-band antenna) the operations team had to cope with the immense data traffic both in the down and uplink. Every day six consecutive orbits were serviced by GSOC within 8 hours. ROSAT provided astronomers with a wealth of knowledge on previously unquantified X-ray sources for almost ten years.