ESA satellite program
Select a past or current (on-orbit) ESA satellite program. Discuss the details, including the mission, the orbit, the successes, the failures (if any), and the results. Do not repeat a program that has already been discussed (first come, first serve, incentive to post early).
So far Galileo and Solar Orbiter have been selected. This is a discussion post so formality and strict adherence to APA does not matter.