DFH-1 satellite was successfully launched on April 24, 1970. It marks the beginning of Chinese Aerospace Technology Industry. From then on, China has developed, manufactured and launched many satellites in scientific and technological test areas.
SJ1 satellite was launched on March 3, 1971. It measured vacuum environment parameters, such as Earth space high altitude magnetic field, X-ray, cosmic-ray, heat flux, and etc. It also tested key technologies of the satellite, such as Si solar battery supporting system and automatic passive thermal controlling system.
SJ-2, SJ-2A and SJ-2B were launched in 1972, they were used for space physics exploration.
SJ-4 was launched in 1994. It was used to detect space environmental parameters and high energetic particle effects.
SJ-5 was launched in 1999. It was the first small scientific test satellite based on common platform in China. It marks that Chinese small satellite development has reached the world leading level, and it constructs a solid foundation for Chinese small satellite development. The satellite achieves an important fruit in space single particle effect and its countermeasure, as well as space fluid scientific test.
The SJ satellites were successfully launched in recent years successively. It achieved a great fruit in scientific exploration and technological test areas.
Space Exploration Satellites
The Double-Satellite project launched by China and Europe is an important part of scientific and technological test satellites in China. The project is launching two satellites detecting the Earth magnetic field. They are respectively delivered into the equatorial orbit and the polar orbit to makeup a "twin stars". They both work in the important area where the Earth space exploration satellites didn't cover at present. The two satellites are used to study the physical mechanism of the solar activity, the interplanetary magnetic layer storm and the catastrophic space weather. TC-1 and TC-2 are together with the ESA magnetic layer exploration project (it has launched four satellites) to build a cooperative science exploration plan. It is the first time that people realize the six-point stereo exploration to Earth space.
TC-1 was delivered into the Earth equatorial orbit by CZ-2C improved version on December 30, 2003. It was aimed to explore the process of near-Earth magnetic storm and the transmission of solar wind from the top of the magnetic layer exposed to the sun to the inside. TC-2 was delivered into Earth polar orbit on July 25, 2004. It was used to detect the process of the energy of solar wind and near-Earth magnetotail transmitting to the polar ionosphere and the upper atmosphere, and the process of ionosphere particles transmitting to the magnetic layers.
TC-1's service life is 18 months and TC-2's is 12 months. With researchers' efforts, the TC-1 didn't retire until October, 2007. TC-2 is still in operation at present. The two satellites have collected large quantities of scientific data.