Cluster (satellite mission)

Cluster II

Artist's concept of four Cluster II satellites in space. Credit: ESA.

Cluster is an ESA (European Space Agency) mission involving four identical satellites – Salsa, Samba, Tango, and Rumba – which fly in formation to study the interaction between the solar wind and Earth's magnetosphere in three dimensions. Each satellite carries a suite of 11 instruments that measure electric and magnetic fields, electrons, protons, and ions, and plasma waves. The Cluster I satellites were lost following the explosion of their Ariane 5 launch vehicle on its maiden flight on 4 June 1996. (Re-use of flight software from Ariane 4 was found to be the cause of the accident – faulty program logic that only took effect on Ariane 5's launch trajectory.) Cluster II is a repeat of the original mission and uses some of its spare parts.


launch dates Jul 16, 2000 (Salsa, Samba);
Aug 9, 2000 (Tango, Rumba)
launch vehicle Soyuz Fregat
launch site Baikonur
orbit 25,000 × 125,000 km × 65°
mass (each) 1,200 kg