The need for this development arises from the increasing congestion in low earth orbits (LEO), which has led to a higher frequency of collision avoidance maneuvers. These maneuvers are critical for maintaining satellite integrity but come with considerable costs in operational efforts and propellant usage. They have a direct impact on reducing the operational lifetime and affecting the nominal mission of satellites. Therefore, satellite operators often delay commanding avoidance maneuvers until absolutely necessary to reassess risks and prevent unwarranted actions.

Traditionally, communicating with satellites in LEO for collision avoidance has been constrained by the limited availability of ground station access, generally only a few times per day. This limitation forces operators to wait until a few hours before a potential collision, utilizing the last available passes of ground stations, to command the avoidance maneuver.

The novel solution proposed by GMV addresses this constraint by providing an alternative pathway for late commanding of maneuvers. This approach allows for triggering the maneuver much closer to the time of conjunction. Consequently, it is expected to lead to a significant reduction in the number of collision maneuvers required, thereby reducing propellant consumption and extending the satellites' operational lifetime.

This innovative solution utilizes the Galileo Signal-in-Space (SiS) and its Return Link Service, offering a continuous alternative communication path. This system enables the relay of collision avoidance maneuver decisions to satellites equipped with onboard Galileo-compatible GNSS receivers. The use of the Galileo system in this manner is not only novel but also potentially synergistic with other space situational awareness (SSA) services like the EU SST, paving the way for a unique, globally available collision avoidance service in the future.

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