Europe's next generation of Galileo satellites will be able to talk to each other in space, passing messages from satellite to satellite without needing a ground station in sight. The key hardware, intersatellite link antennas, has now passed a battery of grueling ground tests and is ready to be installed on the spacecraft. This means the constellation will no longer rely entirely on being visible from Earth to exchange critical timing and location data.
15 million reorientations in a Swiss lab
Each new Galileo satellite will carry two intersatellite link terminals. Every 40 seconds, a pointing mechanism inside the terminal will swivel the antenna to aim at a different satellite. Over a 15 year lifespan, that adds up to roughly 12 million reorientations. To prove the mechanism could survive that workload without ever being repaired, engineers ran a marathon test at Beyond Gravity's facilities in Switzerland. The mechanism reoriented itself 15 million times in a row, a test that wrapped up in March 2026. It exceeded the expected lifetime demand.
Testing for the vacuum of space
While the Swiss test ran, a second model of the antenna pointing mechanism underwent electromagnetic compatibility checks and micro vibration testing at ESA's technical center in Noordwijk, the Netherlands. Those tests confirmed the hardware can function properly in the harsh space environment. After passing, the mechanisms were delivered to Thales Alenia Space in Spain, where they were integrated onto the intersatellite link panel. The panels then shipped to Rome for final satellite assembly.
Why this matters for navigation
Today, Galileo satellites can only exchange information when a ground station is in direct line of sight. If a satellite is over the ocean or otherwise hidden, contact is impossible until it passes over a station. With intersatellite links, a message can be sent to any visible satellite and then hopped across the constellation to its destination. This makes the entire network more robust and reliable. The second generation satellites, built by Thales Alenia Space and Airbus Defence and Space under contract with ESA, will also feature reconfigurable payloads and support new services. The intersatellite link antennas are one piece of a larger upgrade to Europe's navigation system, now cleared for flight.
