Four years ago, space physicists eagerly awaited the launch of Cluster, a quartet of spacecraft designed to fly in tandem to explore the magnetic region that surrounds Earth. On June 4, 1996, minutes after takeoff from the European Space Agency’s launch site in Kourou, French Guiana, the rocket carrying the four craft veered sharply off course and blew up (SN: 7/27/96, p. 59).
Without a hitch this summer, the space agency launched Cluster II, the successor to the failed mission. Launched in pairs from the Baikonur cosmodrome in Kazakhstan on July 16 and Aug. 9, the four craft of Cluster II are now undergoing calibration tests. By early December, the agency says, all 44 instruments on Cluster II will be ready to begin observations.
This will be the first time four identical satellites have ever been operated simultaneously. The quartet will generate the first detailed three-dimensional map of Earth’s magnetosphere, the magnetic region that plays a key role in the aurora borealis and in shielding Earth from solar storms.