Phoenix and Cluster II—Towards a recovery from the loss of Cluster

Abstract

The four-spacecraft Cluster mission was to aim, for the first time ever, at 3-dimensional measurements of small-scale processes (scale lengths ranging from a few hundred to thousands of kilometres) in the magnetosphere and the solar wind. The four spacecraft were identically equipped with a state-of the-art set of instruments to measure fields, particles and the composition of the plasmas along their highly eccentric, polar orbit. The launch took place on 4 June 1996. Unfortunately, the launcher blew up at an altitude of about 3700 m due to a major malfunction of its guidance system. The spacecraft were lost in this accident. The scientific community is trying to recover from this tragic loss by actively pursuing two alternatives for a replacement mission. As an immediate step towards a recovery, the European Space Agency has already given the go-ahead to industry to assemble the Cluster spare spacecraft and negotiations for a launch vehicle are underway. The scientific community prepares the case for a decision by the relevant funding authorities to either rebuild the Cluster mission or to build for small satellites carrying as many of the original Cluster instruments as possible.