With its minimum lifetime of two years (extendible to four years), SAX will be able to perform more than 2000 pointings.
While the Narrow Field Instrument (NFI) will be the prime instruments most of the time, the Wide Field Cameras (WFC) will be periodically used to scan the galactic plane to monitor the temporal behaviour of sources above 1 mCrab and to detect transient phenomena; thanks to their large field of view, the WFCs will be operated to monitor selected objects when the NFI perform their sequence of pointed observations.
We expect to detect about 10-20 bright X-ray transients per year during the WFC observations. The observing programme will be held flexible in order to accommodate those TOO (Target Of Opportunity) for follow-up observations with the NFI. Furthermore the operation capability of SAX will allow to acquire the target within a few hours of its discovery.
The observations will be organized on the basis of a `Core Programme', devoted to systematic studies with particular regard to scientific objectives that exploit SAX capabilities, and a `Guest Observer' programme.
The time reserved to the Core Programme is 80% the first year of the mission, decreasing in the following years. Participation in the Core Programme is open to members of the national communities participating in the mission and will be regulated, along with application for Guest Observer time, by the selection of proposals. This policy will allow the achievement of complex and systematic programmes, leaving however ample time for smaller projects.
In order to allow the scientific community to exploit fully the SAX data (about 1 Gbyte of data produced every day), software for the scientific data analysis is under development, which will be immediately portable on ULTRIX platforms (and easily adapted to other UNIX systems).
SAX data will be distributed on tapes, both on the standard 1"1/2 media or DAT cassettes. A Scientific Data Center (SDC) will be set up in Rome near the OCC (Operations Control Centre), to maintain the data archive, perform routine calibration, maintain and distribute the scientific software and provide assistance to guest observers.