26410, 26411 - CLUSTER II-FM6 (SALSA), CLUSTER II-FM7 (SAMBA)

CLUSTER 2/FM7 and CLUSTER 2/FM6 are the first two of a four-spacecraft European (ESA) mission that were launched by a Soyuz-Fregat rocket from Baikonur at 12:39 UT on 2000 Jul 16. Initial orbital parameters of both were period 620 min, apogee 35,000 km, perigee 247 km, and inclination 65 deg.

Each of the cylindrical (3-m diameter, 1.3-m height), 1,200-kg (with fuel), and 224-W spacecraft carries 11 identical instruments to probe the magnetosphere. All four spacecraft of the CLUSTER 2 mission have an identical design and payload, and were designed to emulate the Clusters that perished during the failed maiden launch of Ariane 5 on 1996 Jun 04.

The instruments/experiments on board are: (1) Fluxgate Magnetometer (FGM) to provide magnetic field components; (2) Electron Drift Instrument (EDI) to enable inference of electric field vector in the vicinity by recapturing the emissions from an electron gun; (3) Active Spacecraft POtential Control experiment (ASPOC) in which positive indium ions are shot in order to neutralize the build-up of positive charges on a spacecraft; (4) Spatio-Temporal Analysis of Field Fluctuation experiment (STAFF) to do in situ analysis of the fluctuations in the magnetic field; (5) Electric Field and Wave experiment (EFW) to measure the electric field and plasma density fluctuations; (6) Digital Wave Processing experiment (DWP) to enable in situ correlations of waves and plasma density; (7) Waves of HIgh frequency and Sounder for Probing Electron density by Relaxation experiment (WHISPER) which excites local plasma oscillations synchronous with the pulsed radio emissions; (8) Wide Band Data instrument (WBD) which monitors the B- and E-fields of natural VLF emissions such as whistlers; (9) Plasma Electron And Current Experiment (PEACE) which enables 3-D distribution function of cold and hot electrons; (10) Cluster Ion Spectroscopy experiment (CIS) to monitor the charge, mass, and distribution function of hot and cold ions; and (11) Research with Adaptive Particle Imaging Detectors (RAPID) to monitor the arrival direction of very-high-energy electrons and ions and their energies.

These spacecraft were frequently maneuvered to enable orbits that provide from time to time the sought-after parameters, mostly with a perigee at around 19,000 km and an apogee at around 119,000 km.

Facts in Brief

Launch Date: 2000-07-16
Launch Vehicle: Soyuz-Fregat
Launch Site: Tyuratam (Baikonur Cosmodrome), Kazakhstan
Mass: 550.0 kg
Nominal Power: 224.0 W