Telecommunications & Navigation

SSTL's role in Europe's satellite-supported navigation system

SSTL has been selected by ESA to supply 22 navigation payloads for the deployment phase of Europe's satellite navigation system.

SSTL is teamed with OHB System of Bremen, Germany for the provision of the first 22 satellites in the full operational capability phase of the programme.  Within the team, OHB take the role of prime contractor and builder of the spacecraft platform and SSTL take full responsibility for the navigation payloads onboard the satellite that will form the heart of the navigation system.

SSTL's payload solution is based on European sourced atomic clocks, signal generators, high power TWTAs and antennas. Each payload will be formed of a number of subsystems that will combine to generate the navigation messages broadcast by the satellites directly to a user's receiver. 

Timing Subsystem -  the heart of the navigation payload, containing two different types of highly accurate atomic clock.

Mission Uplink Subsystem - receives the data messages sent to the satellites from the ground control system.

Galileo spacecraft: Credit OHB System AGSignal Generator Subsystem - responsible for the generation of the navigation signals.

RF Amplification Subsystem - transmits the navigation signals to the ground with a sufficient quality and power to enable a receiver to track them.

Search and Rescue Payload - relays distress and co-ordination messages from COSPAS-SARSAT Search and Rescue service. 

Laser Retroreflector Array - reflects laser light fired at the satellite to support the accurate tracking from the ground of the satellite in its orbit. 

Under the contract, SSTL is responsible for the design, manufacture and test of the navigation payloads using equipment procured mainly from European suppliers. SSTL will also manufacture in-house electronics to interface with the satellite platform integrated by OHB-System and the navigation payload.

The first satellites produced under these contracts will be launched from 2014.



OHB-System AG

ESA - GNSS programme

European Commission - GNSS programme 

Visit SSTL's Media Gallery for downloadable images of the spacecraft being developed for this phase of the  programme. 

This information has been produced under funding of the European Union. The views expressed herein can in no way be taken to reflect the official opinion of the European Union and/or ESA. The OHB/SSTL project is funded by, and part of, an initiative by the European Union (EU) for a satellite-supported European navigation system, and where the European Space Agency (ESA) acts in the name of, and on behalf of, the EU.


SSTL’s pioneering work as prime contractor for the GIOVE-A satellite and in testing the signals will prove invaluable for the execution of this contract. GIOVE-A was the first part of the in-orbit validation phase of the Europe's satellite-supported navigation programme, broadcasting the first signal to successfully secure the critical frequency filing with the International Telecommunications Union (ITU) at 17:25 GMT on the 12th January 2006.

Giove-A panel testing

On the 2nd May 2007 GIOVE-A successfully transmitted the first European navigation message from space, containing the information needed by users' receivers to calculate their position. 



By continuing to use this site, you agree to the use of cookies. You can find out more by following this link Accept & Close ›