Video: Eclipse-making double-satellite Proba-3

Proba-3 is ESA's—and the world's—first precision formation flying mission. A pair of satellites will fly together relative to the sun so that one casts a precisely-controlled shadow onto the other, to create a prolonged solar eclipse in orbit.

In the process, the mission will open up the sun's faint surrounding coronal atmosphere for sustained study. Normally, this corona is rendered invisible by the brilliant face of the sun, like a firefly next to a bonfire.

Due for launch together this autumn, the two Proba-3 satellites will fly 144-m apart for up to six hours at a time to create these eclipses. Beside its scientific interest, this experiment will be a perfect method to demonstrate the precise positioning of the two platforms. It will be enabled using a novel combination of guidance technologies. In this video, the Proba-3 team details the mission concept.