Cluster was one of the two missions - the other being the Solar and Heliospheric Observatory (SOHO) - constituting the Solar Terrestrial Science Programme (STSP), the first cornerstone' of ESA's Horizon 2000 Programme. After the catastrophic Ariane-5 accident on 4 June 1996 which destroyed the four Cluster spacecraft, the European Space Agency Science Programme Committee gave approval to refurbish the spare Cluster spacecraft and make it ready for flight. This new spacecraft, considered to be the first of a new fleet, is called Phoenix. In the meantime various options to repeat the Cluster...