Image 1: The paired Cluster satellites were delivered into their preliminary parking orbit by the Fregat upper stage of the Soyuz launcher. Credits: StarsemImage 2: This artist's impression shows electrically charged oxygen, hydrogen and helium atoms (ions) leaking into space from the Earth atmosphere, over the poles. ESA's Cluster mission discovered that this accelerated escape is driven by changes in direction of the Earth own magnetic field. Credits: NASA/ESA