Double Star was a joint

satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...

based space mission by the

China National Space Administration The China National Space Administration (CNSA) is a government agency of the People's Republic of China headquartered in Haidian District, Haidian, Beijing, responsible for civil space administration and international space cooperation. These ...

(CNSA) and the

European Space Agency The European Space Agency (ESA) is a 23-member International organization, international organization devoted to space exploration. With its headquarters in Paris and a staff of around 2,547 people globally as of 2023, ESA was founded in 1975 ...

(ESA). It was the first space mission launched by China to investigate

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

magnetosphere In astronomy and planetary science, a magnetosphere is a region of space surrounding an astronomical object in which charged particles are affected by that object's magnetic field. It is created by a celestial body with an active interior Dynamo ...

. It consisted of two satellites: an Equatorial satellite (TC-1) and Polar satellite (TC-2). Double Star followed in the footsteps of ESA's Cluster mission by studying the effects of the Sun on the Earth's environment. After a nominal mission of one year (from the launch of TC-2 in July 2004), the Double Star mission was extended twice by both agencies until the end of September 2007.

Overview

The Double Star mission used two satellites in Earth orbit - each designed, developed, launched, and operated by the

. ESA has agreed to contribute 8 million Euros to the Double Star programme. This funding was used for refurbishment and pre-integration of the European instruments, acquisition of data for four hours per day and co-ordination of scientific operations. This schedule enabled Double Star to operate simultaneously with ESA's Cluster mission. The first equatorial spacecraft (Double Star 1, also known as DoubleStar1, Tan Ce 1, Chinese for Explorer 1, TC-1) was launched by a Long March 2C launch vehicle on December 29, 2003, at 19:06 UTC. Its purpose was to investigate Earth's huge 'magnetotail', the region where particles are accelerated towards the planet's magnetic poles by a process known as 'reconnection'. The second polar spacecraft (Double Star 2, also known as DoubleStar2, Explorer 2, Tan Ce 2, TC-2) was launched July 25, 2004 at 07:05 UTC, also by a Long March 2C. It focuses on physical processes taking place over the magnetic poles and the development of aurorae. The mission formally ended on October 14, 2007, when the TC-1 spacecraft re-entered the Earth's atmosphere after being decommissioned (an unavoidable consequence of its equatorial orbit). The TC-2 spacecraft and payload continued to operate until late 2008, when contact was lost.

Launch and orbits

TC-1 was launched into an equatorial elliptical orbit of 570 x 78 970 km with inclination 28.5° to the equator from the

Xichang Satellite Launch Center The Xichang Satellite Launch Center (XSLC), also known as the Xichang Space Center, is a spaceport in China. It is located in (), Mianning county, approximately northwest of Xichang, Liangshan Yi Autonomous Prefecture in Sichuan. It is op ...

. This apogee of this mission was the deepest into space China had ever sent a spacecraft at that time. The TC-2 spacecraft was launched into a polar elliptical orbit of 700 x 39 000 km, inclination 90° to the equator from Taiyuan Satellite Launch Center.

References

External links

ESA page

ESA Science and Technology page

Imperial College Earth Missions website

{{CNSA space program China National Space Administration Earth observation satellites of the European Space Agency 2003 in China 2004 in China Earth observation satellites of China Twin satellites Geospace monitoring satellites