System of systems

The Mission Data Systems (MDS) is a ‘system of systems’ comprising multiple sub-systems, including the Mission Control System (MCS), the flight dynamics system, a specially designed spacecraft simulator and the mission planning system.

These work together to enable engineers at ESOC to process satellite telemetry – information sent from the spacecraft reporting on its health and status – and prepare the telecommands that must be sent up to effect daily operations. These include commands instructing the satellite where it should point itself, when to turn its thrusters on or off, when on-board platform and payload systems should function, and when to download the mission’s precious scientific data.

To ensure the success of what might be a billion-euro mission, the Mission Data Systems must provide high reliability, quick response, clarity of information and guaranteed availability of data – with all activities conducted in an unforgiving, real-time environment.

Finally, all systems together must be validated in a realistic, end-to-end (i.e. spacecraft-to-ground) testing campaign.

Building a team

During the pre-launch period, an experienced Spacecraft Operations Manager (SOM) is appointed to lead the Flight Control Team, and serve as the central figure responsible for leadership, technical management and mission operations success.

The team typically comprises from six to as many as fifteen experienced system engineers, analysts and other experts (depending on the complexity of the spacecraft and the mission) provided from within ESA or by industrial contractors. The team begins training, studying the spacecraft, its systems and its scientific goals, learning in immense detail how every step of the mission should proceed.

The Flight Control Team is also responsible for the design requirements for all the ground segment systems to be used for the mission, and is responsible for the final acceptance testing of the ground segment, including the Mission Data Systems, the Operations Control Centre facilities and ground station network.

Based on the operations concept and the scientific goals, the Flight Control Team develops a series of detailed flight control procedures and flight ‘rules’. These cover every aspect of the mission’s operations, and will serve as primary reference throughout the satellite’s life in space.

Engineers from the Flight Control Team meet with the Project Team from ESTEC and with the satellite manufacturer on numerous occasions as the mission progress through various stages of readiness. These include a series of technical reviews of the satellite, the ground segment and the flight teams’ preparations.

ESOC’s partnership with European industry

The costs for the lifetime operation of a satellite mission typically comprise no more than 8% of the overall mission budget (most of the budget is allocated to manufacturing and testing the satellite and procuring the launch).

Of the mission’s operations budget, the majority flows to European industry, which

• Provides trained experts to work on flight control teams or in specialist areas like flight dynamics or tracking station engineering

• Furnishes sophisticated ground-segment hardware and software

• Delivers operational services like network management and 24 hours/day mission support

Money spent by European taxpayers on spacecraft operations represents an excellent investment in unique infrastructure and in future-oriented jobs, thereby creating strong benefits to ESA Member States.