Tracking Galileo at Earth-2 Perigee Using The Tracking and Data Relay Satellite SystemThe Tracking and Data Relay Satellite System (TDRSS) was successfully used to track the Galileo spacecraft on December 8, 1992, during the Galileo Earth-2 Flyby. This flyby enabled Galileo to obtain a gravity-assisted energy increase as part of the Venus-Earth-Earth trajectory en route to the planet Jupiter.