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3. Ground operations

BeppoSAX was launched on April 30 1996 by an Atlas-Centaur directly into a 600 km, 96 min orbit at tex2html_wrap_inline1238 inclination. The satellite will thus nearly avoid the South Atlantic Anomaly and take full advantage of the screening effect of the Earth's magnetic field in reducing the cosmic ray induced background, an aspect particularly relevant for high energy instruments (HPGSPC and PDS).

The satellite is operated directly from the Operation Control Center (OCC) in Rome, through a bidirectional (command transmission and telemetry data collection) Intelsat link between the OCC and the Telemetry and Telecommand (TT&C) station located on the equator at the Italian base near Malindi (Kenya). The satellite passes over the TT&C station every orbit for a contact period of 10 minutes. During each pass the Ground Station performs the following activities: telecommand up-linking; mass memory downloading; spacecraft doppler and ranging; spacecraft time sinchronization.

The OCC is the core of the satellite operational management with the following activities: telecommand generation and validation, orbit and attitude determination; short-term telemetry archiving; health monitoring of satellite and its sub-systems.

As part of the OCC, the Scientific Operation Center (SOC) will deal specifically with scientific operations: monitoring of payload parameters; quick-look analysis of scientific data in real time, aimed in particular to bright X-ray transients discovery and Target of Opportunity (TOO) alert; short and long term scheduling.

The Scientific Data Center (SDC) is located in Rome, at the same site as the OCC. Along with the Mission Scientist it is the main interface of the scientific community to the BeppoSAX project. Its main tasks are: collection and archiving of the proposals from the scientific community (Sect. 5.2); production of the list of observations from the approved proposals to be processed by the OCC for schedule generation; archiving of telemetry on optical disks; production and distribution of data (FOT= Final Observing Tape) to the observers; off-line analysis of quick look data for TOO follow up program's assessment; integration, development and maintainance of scientific software and calibrations along with the Institutes of the BeppoSAX Consortium; distribution of calibration data, software and general information about the mission; support to guest observers for data analysis and proposal preparation; set up of the results data base.

The Mission Scientist overviews all the scientific activities of the program, and in tight contact with the other scientific components, takes care in particular of: schedule of observations and TOO; calibrations of instruments; issue of Announcement of Opportunities and the technical description of the mission (Piro et al. 1995).


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