CLUSTER 2/FM5 (RUMBA) and CLUSTER 2/FM8 (TANGO) are the second pair of the Cluster quadruplet that were launched by a Soyuz-Fregat rocket from Baikonur at 11:13 UT on 2000 Aug 09. Initial orbital parameters of both were similar: period 3,426 min, apogee 120,500 km, perigee 17,200 km, and inclination 90.7 deg.
This Cluster II spacecraft, FM8 (Tango), was launched together with FM5 (Rumba) by a Soyuz-Fregat rocket from Baikonur. The four similar spacecraft of the Cluster II mission are part of ESA's and NASA's Solar-Terrestrial Science Program (STSP). The current Cluster II mission is a near-replica of the original four-spacecraft mission lost at launch in 1996.
The purpose of the Cluster II mission is to study small-scale structures in three dimensions in the Earth's plasma environment, such as those involved in the interaction between the solar wind and the magnetospheric plasma, in global magnetotail dynamics, in cross-tail currents, and in the formation and dynamics of the neutral line and of plasmoids.
The four Cluster II spacecraft orbit in a tetrahedral formation in near-polar orbits of nominally 4 x 19.6 Earth radii, with period about 57 hours, and inclination about 90.7 degrees. Relative distances between the spacecraft are adjusted in the course of the mission, depending on the spatial scales of the structures to be studied, varying from a few hundred km to a few Earth radii. The tetrahedral formation is essential for making three-dimensional measurements and for determining the curl of vectorial quantities such as the magnetic field.
The orbits of all four spacecraft will be frequently maneuvered so as to achieve the targeted investigations.
Each spacecraft will be spin-stabilized, normally at around 15 rpm, and will be cylindrical in shape, with a 2.9-m diameter and 1.3-m length. It will have two rigid 5-m radial experiment booms, four 50-m experiment wire booms, and two axial telecommunications antenna booms. Telemetry downlink bit rate will be 2 to 262 kbit/s.
Each spacecraft has AC and DC magnetometers, an electric fields and waves sensor, an electron emitter/detector, an electron density sounder, electron and ion plasma analysers, an energetic particle detector, an ion emitter, and a data processing unit.
Facts in Brief
Launch Date: 2000-08-09
Launch Vehicle: Soyuz-Fregat
Launch Site: Tyuratam (Baikonur Cosmodrome), Kazakhstan
Mass: 550.0 kg
Nominal Power: 224.0 W