on the Double Star equatorial spacecraft
The equatorial spacecraft (TC-1
) has been launched on the 2003-12-29 into an elliptical orbit of
570 x 78 970 kilometres, inclined at 28.5° to the equator. This enables it to investigate the
Earth's magnetic tail, the region where particles are accelerated towards the planet's magnetic
poles by a process known as reconnection. TC-1 operated nominally untill 2007-10-14 when it re-entered the Earth's atmosphere.
The polar satellite (TC-2
) has a 700 x 39 000 kilometre polar orbit. Its instruments
concentrate on the physical processes taking place over the magnetic poles and the development
of auroras. TC-2 was launched in July 2004.
These orbits have been synchronised with those of ESA's four
satellites so that all six spacecraft
are studying the same region of near-Earth space at the same time.
The Double Star payload includes eight European instruments and eight Chinese instruments. Seven
of the eight European instruments, including HIA
, are identical to the ones on Cluster. The Hot Ion Analyser
from the CIS experiment
got some modifications for the DS Program :
- new Flight Interface Board, FPGA, and connectors on the top of the box
- size of the box increased by 4mm on the top, the rear, and the each side (radiation constraints)