Evolution of the spot-helios Command-Control Ground Segment design and architecture

The Command-Control Ground Segment (CMP) of the satellite HELIOS1A has now been operating since July 7th, 1995 and participated successfully to the final acceptance of the whole system. The SPOT4 CMP participates to the Technical describe the Qualification of the SPOT4 system. The commonality between both CMPs is greater than 90% for the Housekeeping management part. From the CMP SPOT4 software basis, a SPOT1-SPOT2 CMP has been completed. It has replaced the present SPOT1/2 Mission and Control Center, which had important operating and maintenance costs, since the mid of May 1997. In the end, a family of CMP for earth observation and remote sensing satellites is being derived from an unique product, and will be operated by common teams. The CNES division, in charge of Earth Observation CMP development, take benefit of: - the experience of the technical and operational qualification phases for the SPOT4/HELIOS1A CMP, - the experience of the development and adaptation phases for the SPOT1/SPOT2 CMP, - the prospects for the up-coming next generation of earth observation satellites (SPOT5, HELIOS2) CMP, - its collaboration with the operating teams, to design a new architecture for the CMP. This paper will provide first a brief description of the CMP basic functions, capabilities and its situation in the different systems of satellites ground segments. It will then detail the foreseen objectives and the means to reach them (separation of ''mission'' functions and ''Housekeeping management'', improvement of the product, flexibility for the new systems). It will finally describe the chosen architecture and the necessary design steps.