The ESA Proba-3 mission is an in-orbit demonstration of precise formation flying. A pair of satellites, the Coronagraph Spacecraft (CSC) and the Occulter Spacecraft (OSC), will autonomously control their relative position to an unprecedented millimeters accuracy. To achieve Proba-3 mission objectives, novel metrology sensors have been developed, especially laser-based optical/RF units and a vision-based Sensor. Testing these units consisted of an engineering challenge in order to comply with the Proba-3 formation scale (150m) and precision (millimeters).
Besides the development and testing on-ground prior to the launch, the Proba-3 mission itself represents an in-orbit test bench to pave the way for future formation flying space missions. The presentation will focus on the achievement of testing the Proba-3 metrology sensors.