The Flight Operation Segment (FOS) is responsible for command and control of the satellite and is operated from ESA’s European Space Operations Centre (ESOC) in Darmstadt, Germany.

Figure 1: ESA's European Space Operations Centre

The FOS consists of the Ground Station and Communications Network, Flight Operations Control Centre and a General Purpose Communication Network.

The FOS provides the capability to monitor and control the satellite during all mission phases including the Flight Dynamics System facility responsible for orbit determination and prediction, and for the generation of attitude and orbit control telecommands.

The main functions of the FOS include:

Mission planning
Long term planning of spacecraft and payload activities, covering the complete orbit cycle and repeating indefinitely. Short term planning, nominally every 2 weeks, in the form of updated mission schedules.

Spacecraft status monitoring
Processing housekeeping telemetry, providing information about the status of all spacecraft subsystems and attitude.

Spacecraft control
Taking control actions by means of telecommands, based on the spacecraft monitoring and following the mission plan.

Orbit determination and control
Using tracking data and implementing orbit manoeuvres, ensuring required orbital conditions are achieved.

Attitude determination and control
Using processed attitude sensor data from spacecraft monitoring and by commanded updates of control parameters through the on-board attitude control system.

On-board software maintenance
Integrating software images received from the spacecraft manufacturer (pre-launch and post-launch) into the telecommand process.

Communications
Communicating (TM/TC) with one satellite at a time.