Chinese Satellite Communications Systems
The development of China's communications satellites started at the beginning of the 1970s. China's first experimental geostationary orbit communications satellite was launched successfully in 1984, which indicated that China had completely grasped technologies for the design, development, manufacture, test and TT&C operation of geostationary orbit communications satellites, and laid preliminary foundation for the development of communications satellite technology. In March and December 1988, China successfully launched two DFH-2A operational communications satellites respectively, which had 8 C-band transponders. On May 11, 1997, the DFH-3 satellite was launched successfully, of which the general power is 1.7kW, the designed life span is 8 year. And it has 24 C-band transponders and medium communications capacity, which marked that China has reached the new level in the development of the communications satellite.
By 1994 China had opened 8100 post and telecommunications satellite communications lines, 11 television satellite lines and 30 broadcasting lines. These communications satellites perform the transmission of TV, broadcasting and education TV programs of the central committee, provinces and cities, and carry out the public communications between China and other countries, and special communications for such state agencies as finance, water and electricity, energy, transportation and public security, etc.. The successfully launched communications broadcasting satellites have opened many application items, such as digital and simulation telephone, TV and broadcast items transmission, facsimile, data report form transmission and TV education communications.
By 2000 China had established more than 30,000 satellite TV receiving stations. The coverage of TV programs has reached 80%. The application of communications satellites has directly promoted the rapid development of TV, broadcast, education, post and telecommunications, etc..
The communications satellite is the most important and commercialized field, which has made the widest use of aerospace technology. Since the cost of the development and use of satellite communications is 43% of that of microwave communications, the services of the satellite communications system increased by 15%-20% yearly in recent 20 years and has formed a broad market. For instance, Inner Mongolia Autonomous Region planned to spend more than one billion yuan to erect microwave relay trunk line within 5-8 years to solve the problem of TV reception. But after using satellite TV receiving stations, the region only spent 3-4 million yuan and covered the whole region within about 2 years. The total investment is only 10 million yuan, including cost of the satellite.
