The PROBA-3 Mission

PROBA-3 is the next ESA mission in the PROBA line of small technology demonstration satellites. PROBA-3, to be launched in 2021, is a mission dedicated to the in-flight demonstration of precise formation flying techniques and technologies. The PROBA-3 mission will place two small satellites in a highly elliptical orbit around the Earth. The two satellites will fly in a precise formation, producing a very long baseline solar coronagraph called ASPIICS (Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun). One spacecraft will carry the optical telescope, and the second spacecraft will carry the external occulter of the coronagraph. The inter-satellite distance of around 150 m will allow observing the inner corona close to the solar limb with very low straylight. The technological challenges and scientific objectives of PROBA-3 will be discussed. A particular emphasis will be put on the perspectives for future missions that could use the formation flying technology.