Cluster FM6-FM7

First of two Soyuz-Fregat launches in 2000 that put up the four-spacecraft Cluster II constellation, ESA's mission to map Earth's magnetosphere in three dimensions by flying identical probes in a tetrahedral formation. This flight carried Salsa and Samba; Rumba and Tango followed three weeks later. The quartet was a rebuild of the original Cluster satellites, destroyed when the maiden Ariane 5 failed in 1996.