The On-Board Control Procedures Subsystem for the Herschel and Planck Satellites

The on-board control procedures (OBCP) subsystem of Herschel and Planck satellites' central data management unit (CDMU) application SW (ASW) provides means to control the spacecraft through small script-like programs written in a specific language called on-board command language (OCL). The implementation for Herschel and Planck satellites is an adaptation from previous experiences on instruments like Rosetta/OSIRIS, Venus Express/VMC and Dawn/FC, but it had also been adapted successfully for the GOCE satellite already. The purpose of having on-board control procedures is to allow the ground operators to be able to prepare and up-link complex operations sequences (more complex than simple sequences of mission time-line telecommands) to be executed on-board during the mission operational phase. This is possible because the OBCPs run in a quite separate subsystem, so the creation of a new procedure does not require modification, uplink and re-validation of the whole on-board software. The OBCP subsystem allows these control procedures to be developed, tested on ground, and executed on the spacecraft.