16 July

2000: On 16 July 2000, the first pair of the ESA Cluster flotilla blasted off aboard a Russian Soyuz rocket from Baikonur, Kazakhstan.

Cluster is a collection of four spacecraft flying in formation around Earth, relaying the most detailed ever information about how the solar wind affects our planet in three dimensions. The solar wind (the perpetual stream of subatomic particles given out by the Sun) can damage communications satellites and power stations on Earth.

The second pair of Cluster satellites was launched on 19 August 2000, also from Baikonur.