Double Star (satellite)

Double Star, officially known as the Chinese National Space Administration (CNSA) Double Star Exploration Program (DSP), was a joint mission between the CNSA and the European Space Agency (ESA) to investigate the Earth's magnetosphere. The program consisted of two satellites: Tan Ce 1 (TC-1) and Tan Ce 2 (TC-2), meaning "Explorer 1" and "Explorer 2," respectively.

TC-1, also known as the Polar satellite, was launched on December 29, 2003, and operated in a highly elliptical polar orbit. Its primary objective was to study the auroral region and the polar cusp.

TC-2, also known as the Equatorial satellite, was launched on July 25, 2004, and operated in an equatorial orbit. Its main goal was to investigate magnetic storms and substorms in the magnetotail region.

The Double Star mission was designed to complement ESA's Cluster mission, which consisted of four satellites flying in formation. By combining observations from Double Star's TC-1 and TC-2 with those from the Cluster satellites, scientists were able to obtain a more comprehensive understanding of the complex processes occurring within the Earth's magnetosphere in three dimensions. This synergistic approach allowed for a more detailed examination of the interaction between the solar wind and the Earth's magnetic field, as well as the acceleration and transport of plasma within the magnetosphere.

The mission provided valuable data on the Earth's space environment, including the behavior of plasma, magnetic fields, and energetic particles. The Double Star mission significantly contributed to our knowledge of space weather and its impact on Earth. Both satellites successfully completed their planned mission durations and continued to provide data beyond their nominal lifespans. The data collected continues to be analyzed and used in scientific research.