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Data Storage and Data Transmission


All of the science data received by the XRT and WFC, as well as housekeeping and attitude data, are stored onboard on magnetic tape. Two tape recorders with a capacity of 700 Megabit each are available for this purpose; one tape recorder is redundant.

The spacecraft operations are controlled from the GSOC ground station in Oberpfaffenhofen, Germany. There are 5 or 6 ground contacts every day. These contacts occur in groups; 5 or 6 orbits with ground contacts are followed by 9 or 10 orbits (about 16 hours) without any ground station contact. During a contact period all the necessary telecommands for the ROSAT operations for the coming contact-free time must be loaded. At any given time about 30 pointing positions can be stored by the system. A large number of short duration observations (e.g., raster scans) lasting shorter than 15 minutes per pointing can therefore not be scheduled.

Michael Arida
Tue Jun 11 16:18:41 EDT 1996