Double Star TC-1 completes its mission

TC-1, one of the two satellites of the CNSA/ESA Double Star mission, was decommissioned on 14 October as its designed orbit lifetime came to an end. The satellite re-entered Earth's atmosphere and turned to dust during its descent.

Along with its twin TC-2, TC-1 is the first satellite built and operated by the Chinese National Space Administration (CNSA) in cooperation with ESA. Along with its twin and the four Cluster satellites, TC-1 has helped accomplish much during its lifetime.
The four years during which Double Star was operational brought in new perspectives concerning the boundaries of the magnetosphere and the fundamental processes that are playing a role in the transport of mass, momentum and energy into the magnetosphere. Thanks to the measurements of TC-1, there was a chance to observe the evolution of structures and physical processes at small scales with Cluster, and then on large scales with Double Star.

Double Star is CNSA's first scientific mission and also the first in collaboration with ESA. The mission consisted of two spacecraft investigating global physical processes in Earth's magnetic environment and their responses to solar disturbances. The mission has lasted four years, surviving way past its nominal lifetime of one year.

ESA contributed to the development and pre-integration of eight European instruments for the mission. Ground station support was provided with the download of data for four hours each day using the Vilspa-2 ground station near Madrid, Spain. ESA also coordinated the scientific operations for the European instruments, via ESTEC and the European payload operations service at Rutherford Appleton laboratory, UK.

CNSA's contribution included the two spacecraft buses, eight other scientific experiments, and the launches. CNSA was in charge of spacecraft control and operation of the Chinese instruments. After its nominal lifetime of one year, operations of Double Star were extended twice by both agencies until the end of September 2007.

A large number of papers have appeared in the literature since the launch of Double Star. A special issue of Annales Geophysicae on the first Double Star results was published in November 2005.

A special issue of the Journal of Geophysical Research on the latest results of Double Star and Cluster is under review and will be published in the coming months. As of September 2007, the combined list of Cluster and Double Star consists of 691 scientific papers.

Source: European Space Agency
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