Proba-3: Challenges and Needs for Sub-Millimetre Autonomous Formation Flying

Proba-3 is the ESA\'s precision formation flying space mission. Encompassing two satellites flying together in a highly elliptic orbit, they focus on creating a \"large virtual rigid structure\", maintaining sub-millimetre and arc second relative position and pointing accuracy. One (the Coronagraph spacecraft) will take pictures of the Sun corona while the other (the Occulter spacecraft) will create an \"artificial eclipse\", allowing observations with an accuracy higher than ever before. The
more » ... ever before. The mission also intends to set the bases and develop the technologies for future \"virtual\" telescopes, capable of achieving focal distances much larger than the ones that can be obtained with rigid structures. The mission is designed to autonomously perform complex sequences of activities every single orbit, which lasts 19.6 hours. Even though the main activities will be performed during the low-disturbances apogee phase, one the main challenges of the mission relies on the amount of activities that have to be performed every revolution, as well as the different needs depending on the mission phase. The spacecraft dynamics forces to execute two point transfer manoeuvre before and after every perigee in order to guarantee that the spacecraft will not collide during the \"non-controlled\" phase of the orbit. Moreover, due the small size of the satellites, the units, metrologies and payload have to be managed specifically depending on the needs, so that the power budget is not exceeded.
doi:10.13009/eucass2019-764 fatcat:p7qx42nr5vestpbj3kcmxhirti