Ground Control to Galileo Second Generation

Twelve Galileo Second Generation (G2) satellites will join the current Galileo fleet in the coming years. To make this happen, teams across Europe are working on building components, assembling the satellites and testing the system to ensure the new spacecraft integrate seamlessly with the first-generation constellation to deliver unprecedented positioning, navigation and timing capabilities.

Half of the new satellites are being built by Thales Alenia Space (TAS) and the other half by Airbus Defence and Space (ADS) under contract with ESA, design authority and system development prime for Galileo. In addition to the new G2 satellites, Galileo's ground segment is also being upgraded. Thales Alenia Space, GMV, Thales SIX GTS and their industrial partners are developing the new ground segment to support, monitor and ensure the G2 satellites blend seamlessly into the current Galileo constellation. All these elements need to undergo rigorous testing to show that they work individually and as an integrated system.

A fundamental piece of this effort is the System Compatibility Test Campaign (SCTC), a series of evaluations that ensure that the infrastructure on Earth and the satellites can communicate and operate together as intended. The SCTC is divided into multiple phases, with each test case gradually increasing in complexity.

“In Galileo, the System Compatibility Test Campaigns mark a pivotal moment in the development lifecycle of new generations of satellites and ground segment. It is the moment where requirements, reviews and subsystem development pass the torch to the reality of hardware and software validation across all industrial actors,” says Miguel Manteiga Bautista, Head of ESA's Galileo Programme.

In a first round of compatibility tests last year, a representative model of the satellite was able to connect and communicate with test equipment emulating ground control in a clean room test in Rome. Now, for the first time, the Thales Alenia Space satellite model in the TAS integration facilities in Rome, Italy, has been successfully connected to the operational Galileo Control Centre in Oberpfaffenhofen, Germany, which is managed by Spaceopal's Galileo operational teams.

Together with the Control Centre in Fucino, Italy, these facilities generate the navigation message, keep satellites on time, pinpoint their position and sense possible drifts, process data and monitor the reliability of the constellation.

“The first end-to-end SCTC tests with the TAS satellites, combined with the upcoming tests for the ADS satellites will ensure that Galileo Second Generation risks are mitigated well ahead of their launch, through early identification of inter-compatibility issues that need to be resolved,” notes Daniel Docal Lareu, ESA Galileo System Qualification Manager.

During the test, the control centre activated the payload in the satellite model, which generates the navigation signal, and delivered commands that the satellite was able to acquire, interpret and execute. The satellite model also sent back telemetry data on its operational status.

“We have seen a very successful compatibility test, confirming that the new ground segment will be able to operate the Galileo Second Generation satellites. We are now eager to complete satellite integration and begin testing the first flight models and all their innovative capabilities,” says Dr. Sven Erb, ESA project manager for the Thales Alenia Space satellites.

The equivalent compatibility tests for the Airbus Defence and Space G2 satellites are planned in the coming weeks.

Once Thales Alenia Space and Airbus Defence and Space finalise the flight model integration and the engineering models complete this phase of compatibility testing, the flight models (the satellites that will fly in space) will take centre stage.

In a few months, the first satellites destined for orbit are expected to enter their own series of compatibility tests. These tests will also mark the verification of the reconfigurable payloads, one of the most groundbreaking innovations of Galileo Second Generation.

In parallel to compatibility testing, development activities continue. For the Thales Alenia Space satellite family, the propulsion module is undergoing testing. The atomic clocks are being integrated in the timing sub-system by Thales Alenia Space Spain in Madrid and are expected to arrive in Rome in autumn for installation aboard the satellites.

With fully digital navigation payloads, electric propulsion, a better-performing navigation antenna, inter-satellite link capacity and an advanced atomic clock configuration, G2 satellites will provide more robust and reliable positioning, navigation and timing. Galileo Second Generation satellites will integrate seamlessly with the current fleet to form the largest European satellite constellation and enable a wide array of new applications that will benefit users in Europe and around the world.

About Galileo

Galileo is currently the world’s most precise satellite navigation system, serving billions of users around the globe since entering Open Service in 2016. All smartphones sold in the European Single Market are guaranteed Galileo-enabled. In addition, Galileo is making a difference across the fields of rail, maritime, agriculture, financial timing services and rescue operations.

The Galileo programme is managed and funded by the European Commission under the EU Space programme. ESA leads the design, development and qualification of the space and ground systems. ESA is also entrusted with research and development activities for the future of Galileo within the EU programme Horizon Europe. The EU Agency for the Space Programme (EUSPA) acts as the service provider, bringing the satellites into service and overseeing their operation and the market and application needs.

For more info about Galileo: https://www.usegalileo.eu/EN/