A Chinese-European multiscale mission. The double star program

This chapter provides a brief overview of the Double Star Program (DSP) mission. The DSP is a two-satellite space mission designed to investigate physical processes of magnetospheric space storms, establish physical models of magnetospheric space storms, and develop dynamic models and prediction techniques of the near-Earth space environment. It is the first joint endeavor between the Chinese National Space Administration (CNSA) and the European Space Agency (ESA). The first satellite, launched in December 30, 2003, has an eccentric equatorial orbit and the second satellite was launched to an eccentric polar orbit in July 2004. These two satellites will make measurements of the inner magnetosphere, dayside magnetopause, magnetosheath, bow shock, and near-Earth magnetotail. The orbits are synchronized with the four-satellite Cluster mission in local time sampling of magnetospheric regions, making this combination a six-point observing constellation in geospace.