Cluster spacecraft F1 and F2 are encapsulated by the Ariane-5 fairing, having already been installed on the Speltra lower-payload cocoon. The complete unit will next be lowered onto Ar-501, which already has spacecraft F3 and F4 attached. These final preparations are taking place in the Batiment d'Assemblage Final (BAF) building at the Kourou, French Guiana launch site.
Following the Ariane 501 launch failure on 4 June 1996, four replacement Cluster satellites are planned for launch in 2000 to study the interaction of the solar wind with Earth's magnetosphere. [Image Date: 1996/05] [97.12.007-001]