Thales and Airbus test intersatellite communication for Galileo Gen2

Thales Alenia Space and Airbus Defence and Space are currently conducting tests on intersatellite communication technology intended for use in the second generation of Europe's Galileo satellite navigation system. This innovation aims to enable satellites within the Galileo constellation to communicate directly with one another in orbit, exchanging data related to time and position. According to the European Space Agency (ESA), this capability is being tested extensively by both companies to ensure its reliability over the operational lifespan of the satellites.

Currently, Galileo satellites rely on ground stations for communication. A satellite sends data to a ground station, which then relays the information to the receiving satellite. This method requires both satellites to have a clear line of sight to a ground station. The new intersatellite communication system will eliminate this requirement. If two satellites cannot establish direct contact, other satellites can act as relay points, ensuring continuous connectivity even when direct links are unavailable.

The second-generation Galileo satellites are equipped with two terminals, each featuring its own antenna. These antennas are designed to realign themselves every 40 seconds to point toward a different satellite. Over the expected 15-year operational life of a satellite, this would result in approximately 12 million antenna adjustments. The ESA emphasized the importance of testing these mechanisms thoroughly, as they must function reliably throughout the entire service period of the satellites.

Testing has been ongoing for several months, involving millions of alignment operations to verify their functionality. Thales Alenia Space completed its final tests earlier this year, while Airbus concluded its testing at the end of last year. Airbus has already delivered the first antenna alignment systems to its subsidiary, Tesat-Spacecom, where they will be integrated into the satellites.

The development of the second-generation Galileo satellites is progressing rapidly, according to the ESA. This includes advancements in the ground infrastructure necessary to integrate the new satellites seamlessly into the existing Galileo constellation. Despite the introduction of intersatellite connections, the ground segment remains crucial. It continues to monitor the satellites, issue correction messages, and serve as the central control unit for the constellation. The intersatellite links enhance the system’s robustness, enabling additional time synchronization and distance measurements, thereby improving the overall performance of Galileo.

The Galileo satellite navigation system became available in December 2016 after numerous disputes and delays. The last four satellites of the first generation are scheduled to be launched in pairs during this year and the next. The first two pairs of second-generation satellites are expected to be launched as early as 2027. Each launch will be carried out using the current European heavy-lift rocket, Ariane 6.

The integration of intersatellite communication into the Galileo system represents a significant technological advancement. By allowing satellites to communicate directly with one another, the system becomes more resilient and efficient. This reduces dependency on ground stations and ensures continuous operation even under challenging conditions. The ability to perform precise time synchronization and distance measurements enhances the accuracy and reliability of the navigation system, making it more competitive with global counterparts such as GPS and GLONASS.

The successful implementation of this technology depends heavily on the collaboration between multiple organizations, including the ESA, Thales Alenia Space, Airbus Defence and Space, and Tesat-Spacecom. Each entity plays a critical role in developing, testing, and integrating the necessary components. As the project advances, further testing and validation will be required to confirm the long-term viability of the intersatellite communication system. The ultimate goal is to ensure that the second-generation Galileo satellites provide enhanced capabilities and maintain the system's reputation as a reliable and high-performance navigation solution.