The European Space Agency (ESA) is Europe’s gateway to space. Its mission is to shape the development of Europe’s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world.
Find out more about space activities in our 23 Member States, and understand how ESA works together with their national agencies, institutions and organisations.
Exploring our Solar System and unlocking the secrets of the Universe
Go to topicProtecting life and infrastructure on Earth and in orbit
Go to topicUsing space to benefit citizens and meet future challenges on Earth
Go to topicMaking space accessible and developing the technologies for the future
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Galileo's worldwide ground segment as of March 2013. The sheer scale and reach of Galileo means that its ground segment has a worldwide footprint, as one of the most complex developments ever undertaken by ESA.
Grey circles - Galileo Control Centres, located in Germany and Italy
Yellow circles - Telemetry, Tracking and Command (TT&C) Stations – the space/ground interface for telemetry acquisition and telecommand uplink to the satellite platforms, as well as two-way ranging
Red circles - Uplink Stations – a network of stations to uplink the corrections to the satellites for rebroadcast to users as part of the navigation message
Blue circles - Galileo Sensor Stations – spaced across the globe to receive navigation signals from the constellation for rebroadcast to the control centres, enabling continuous clock synchronisation,
signal quality and satellite ranging measurements
Green circles - MEOLUTs, Medium-Earth Orbit Local User Terminals, not part of Galileo’s navigation infrastructure but instead used to relay search and rescue messages to local authorities as part of the international Cospas–Sarsat programme
Orange circle - Galileo Security Monitoring Centre
Dark blue circle - Galileo Timing and Geodetic Validation Facility
Brown circle - In-orbit Test Centre.
For more details, see the dedicated article in ESA Bulletin 156