BackForward Satellite Programme: Cluster 

Programme details
Programme description
  • Formation of 4 satellites flown in two couples, for observation of the magnetosphere.
  • ESA programme with support from NASA as concerns the ground segment.
  • The satellite stabilisation is by spin.
  • The design lifetime is 5 years.
  • The four satellites are flown in tetrahedal formation with relative distance varying from 200 km to 19,000 km.  The measurement gradients are used to re-construct the 3D magnetic field.  Ellistical orbits of perigee 19,000 km, apogee 119,000 km, inclination 90°.
  • For details, see http://sci.esa.int/cluster.
Data circulation
  • Data from the four S/C is synchronized via a highly stable on-board clock. - The Villafranca ground station (Spain) of ESA is the prime station for all TT&C functions. Further support is provided by NASA's Deep Space Network (as well as other ground stations).
  • Data processing is performed at a number of nationally-provided processing centres in Europe and USA, concurring to the Cluster Science Data System (CSDS).
Agencies ESA , NASA
Programme lifetime 2000 - 2026
Associated satellites and instruments

Note: red tag => no longer operational , green tag => operational , blue tag => planned