statistics 18-June-2013 07:45:42

Fact Sheet
Cluster is currently investigating the Earth's magnetic environment and its interaction with the solar wind in three dimensions. Science output from Cluster greatly advances our knowledge of space plasma physics, space weather and the Sun-Earth connection and has been key in improving the modeling of the magnetosphere and understanding its various physical processes.

Mission Objectives

Cluster II is part of an international collaboration to investigate the physical connection between the Sun and Earth. Flying in a tetrahedral (triangular pyramid) formation, the four spacecraft collect the most detailed data yet on small-scale changes in near-Earth space and the interaction between the charged particles of the solar wind and Earth's atmosphere. This enables scientists to build a three-dimensional model of the magnetosphere and to better understand the processes taking place inside it.

Mission Name

The name Cluster was chosen because of the way the four spacecraft will fly in a group around the Earth. When studies demonstrated that it would be possible to reuse some parts and to fly four spacecraft which were almost identical to those which were lost, the replacement mission was named Cluster II.

Spacecraft

Diameter:

2.9 m

Height:

1.3 m

Mass:

1200 kg

(of which) Propellant:

650 kg

(of which) Scientific payload:

71 kg

Solar array power:

224 W

Spin rate:

15 rpm

Operational lifetime:

5 years (nominal)

Instruments

Each of the four spacecraft carries an identical set of 11 instruments to investigate charged particles, electrical and magnetic fields. These were built by European and American instrument teams led by Principal Investigators. 

FGM

Fluxgate Magnetometer

EDI 

Electron Drift Instrument

ASPOC

Active Spacecraft Potential Control experiment

STAFF 

Spatio-Temporal Analysis of Field Fluctuation experiment

EFW

Electric Field and Wave experiment

DWP

Digital Wave Processing experiment

WHISPER

Waves of High frequency and Sounder for Probing of Electron density by Relaxation experiment

WBD

Wide Band Data instrument
PEACE  Plasma Electron And Current Experiment
CIS Cluster Ion Spectrometry experiment
RAPID  Research with Adaptive Particle Imaging Detectors

WEC 

Wave Experiment Consortium (DWP, EFW, STAFF, WBD, and WHISPER)

 
 

Orbit

Elliptical polar orbit, 19 000 to 119 000 km, 57 hour period.

Operations Centre

  • Spacecraft operations centre: European Space Operations Centre (ESOC), Germany.
  • Ground station: Villafranca and Maspalomas, Spain.
  • Science operations centre: Joint Science Operations Centre at Rutherford Appleton Laboratory, Didcot, UK.

Last Update: 21 December 2012

For further information please contact: SciTech.editorial@esa.int