By converging in orbit, a pair of small satellites will open a new view on the source of the largest structure in the Solar System: the Sun’s ghostly atmosphere, extending millions of kilometres out into space. ESA’s Proba-3 formation flying mission is set for 2019:
http://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions/Proba-3_set_the_controls_for_the_verge_of_the_Sun
