Design concept
Capabilities
Hardware and software architecture
Exchanges

The SPOT 4 operations control centre (CMP)

From 1998, the SPOT 4 satellite will provide continuity of service as part of the SPOT family of earth observation spacecraft. These services began in 1986 with the launching of SPOT 1.

Like its predecessors, SPOT 4 will be managed from the Toulouse space centre operated by the French space agency CNES. More specifically, CNES will control the satellite bus plus its passengers and the main payload comprising two HRVIR imaging instruments.

From the moment it is placed in orbit by the Ariane launcher and throughout its five-year lifetime, the satellite will be controlled by the SPOT operations control centre, or CMP (from the French "Centre de Mise et Maintien à Poste").

top of page, article

Design concept

The SPOT operations control centre, or CMP, was designed and developed by CNES to meet the requirements of various spacecraft using the same satellite bus as SPOT 4. The centre's capabilities can be briefly described as follows:

Software development began in 1990, with CNES awarding contracts to companies in France, Italy and Belgium.

The CMP software suite was developed using C, C++, Fortran and Ada. The complete suite represents some 600,000 instructions.

top of page, article

Capabilities

The CMP comprises three separate entities performing three distinct roles :

The CCS is designed to perform all of these operations simultaneously.

synoptique état général satellite synoptique de l'état global satellite synoptique HRVIR 1 synoptique déploiement primaire du générateur solaire 
Mimic panels
(each enlargement : about 60 K)

syn4.gif (15597 octets)
Mimic panels displaying equipment status
(animated sequence : about 808 K)

All of these activities involve regular exchanges with widely-scattered centres making up the SPOT 4 system, including:

These entities use two additional subsystems that are also vital for the CMP:

top of page, article

Hardware and software architecture

archi3_0.gif (21467 octets)

Satellite control centre (CCS)

The CMP hardware architecture is designed around Hewlett-Packard Series 9000 computers running under Unix.

All the CMP computers are interconnected via an Ethernet network.

synoptique TM - TC mesures de localisationThe satellite control centre, or CCS, uses an H-P 9000/735 controlled through an X terminal (for command transmission and telemetry reception). Four additional X terminals can be connected to the CCS computer to display telemetry parameters on mimic diagrams. For the SPOT 4 CCS, the operations engineers require just one X terminal.

A second CCS computer using the same configuration is ready to take over should the nominal computer fail.

top of page, article

Housekeeping management centre (CGS)

The housekeeping management centre, or CGS, comprises three computers:

top of page, article

Vegetation programming centre (CPV)

The Vegetation programming centre, or CPV, comprises two computers:

top of page, article

Exchanges

The CCSs are linked to the 2-GHz TT&C network via two X.25 lines operating at 19 200 baud.

Data exchanges between the CMP machines use NFS.

All exchanges with SPOT 4 centres outside Toulouse use an FTP-based common communications protocol.

top of page, article

image2.jpg (6379 octets)

  page updated on the 00-06-06