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SSTL's role in Europe's Galileo navigation system

SSTL has delivered 22 navigation payloads for the deployment phase of Galileo, Europe's satellite navigation system and is under contract to build a further 12 payloads.

In 2010 SSTL was selected with partner OHB System of Bremen, Germany for the provision of the first 14 satellites in the full operational capability phase of the programme.  OHB is the prime contractor and builder of the spacecraft platform and SSTL has full responsibility for the navigation payloads onboard the satellite that will form the heart of the navigation system.

In 2012, the OHB-SSTL pairing was awarded a second contract to supply a further 8 Galileo satellites.

In May 2016, SSTL delivered the 22nd, and final, payload to OHB in Germany under Works Orders 1 and 2.

In June 2017, the OHB-SSTL pairing was awarded a third contract to supply a further 12 Galileo satellites.


SSTL's payload solution is based on European sourced atomic clocks, signal generators, high power TWTAs and antennas. Each payload isformed of a number of subsystems that 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. 


Press Releases

SSTL completes Galileo in-orbit test campaign - 9 September 2008
British company wins key role in Europe's Galileo programme - 7 January 2010
SSTL signs 80m Euros contract with OHB for second batch of Galileo satellites - 11 July 2012
SSTL completes delivery of first four Galileo FOC satellite payloads - 12 June 2013
SSTL delivers 22nd Galileo FOC payload - 13 May 2016
SSTL selected to build third batch of Galileo navigation payloads - 22 June 2017
Lift-off for 4 Galileo satellites as SSTL celebrates navigation payload order - 12 December 2017


OHB-System AG

ESA - GNSS programme

European Commission - GNSS programme 

Visit SSTL's Media Gallery for downloadable images of SSTL's Galileo payload.   

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 has proved 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. 

Find out more about GIOVE-A