Mission control and data handling

The ground force

Extensive facilities are required on the ground to support the Envisat Mission – both to command and control the satellite, and to handle the large volume of data provided by the onboard instruments.

ESA’s European Space Operations Centre (ESOC) in Darmstadt, Germany, will be responsible for the command and control of the satellite.

Data from the satellite’s instruments will be transmitted directly to the ground stations in Kiruna, Sweden, and Fucino, Italy and through Artemis - a satellite in a higher orbit, that relays data when Envisat is out of range of a European station.

A Payload Data Segment (PDS) comprises all services related to the acquisition, processing, distribution and archiving of Envisat data as well as user interface facilities. It will be co-ordinated by ESA’s data processing facility, ESRIN in Frascati, Italy. A huge flow of data will pass through here on a daily basis amounting to approximately 1000 Terabytes (approximately 125,000 CD-roms) over the duration of the mission.

Information for Europe

Once the ground stations receive data it will be processed into a format suitable for use by the science and commercial communities. This will be done via a number of Processing and Archiving Centres within ESA’s member states.

At that stage the data will be made available in the form of:

• Consultation of general information on Envisat mission, products and services
• Retrieval of data
• Search facilities for existing products/satellite-generated data in the PDS archives
• Requests for the production and delivery of Envisat products either as physical media or directly through electronic links
• Helpdesk

Access to all these services will be provided through the Internet.

Scientists and research institutions selected by ESA under a special ‘Announcement of Opportunity’ will process data which will be offered at the cost of reproduction.

Under an agreed data policy, ESA will also provide data to its commercial distributors at cost price, who will promote and market the material world-wide.