Professional science is coming.

first part

Early human exploration

The idea of using artificial earth satellites in geosynchronous orbit as relay stations for communication on earth was put forward by British physicist A.C. Clark in his article "Extraterrestrial Relay" published in Radio World magazine in 1945, and it became a reality in the 1960s.

Before the advent of synchronous satellites, various low-orbit satellites were used for scientific experiments and communications. The world's first artificial satellite "Satellite 1" was successfully launched by the Soviet Union in June 5438+0957 and June 5438+00, and it circled the earth. The earth received radio waves from artificial satellites for the first time.

1 In August, 960, the United States launched the balloon satellite "Echo1"with a diameter of 30m and covered with aluminum film into a circular orbit with a height of about 1600km for communication test. This is the first test of so-called passive relay without amplifier in the world.

The United States launched the LEO satellite "relay 1" on June1962+February 13. 1963165438+1On October 23rd, the satellite realized the first television broadcast across the Pacific Ocean between Japan and the United States. This coincided with the assassination of American President Kennedy. News is transmitted to Japan by satellite and broadcast on TV news. The long-distance real-time transmission of satellites has left a deep impression on people and greatly improved the position of artificial satellites in communication.

The first synchronous communication satellite in the world was the "Synchronous II" satellite launched by NASA in July 1963. It has an inclination of 30 with the equatorial plane, and moves in a figure of eight relative to the ground, so it cannot be called a geostationary satellite. It was originally used for communication services in the Atlantic Ocean. SYNC-3 was launched in August 1964. It is the first geostationary satellite in the world, located near the international international date line over the equator of the Pacific Ocean. 1964 10 Menstrual Stars Live the Olympic Games (Tokyo). So far, satellite communication is still in the experimental stage. 1April 6, 965, the first semi-experimental and semi-practical stationary satellite "Early Bird" was launched for commercial satellite communication between Europe and America, and satellite communication entered the practical stage.

the second part

Development history of satellite communication in China

first generation

China launched its first artificial earth satellite, Dongfanghong-1, on April 24th, 1970. It is the fifth country in the world to launch domestic satellites with homemade rockets after the Soviet Union, the United States, France and Japan.

Dongfanghong-1 completed the important experimental task of audio broadcasting, making Dongfanghong's music resound through space. The successful launch of Dongfanghong-1 satellite marks that China has since joined the space club and entered the space age.

second generation

1On April 8, 984, China successfully launched the Dongfanghong-2 communication satellite. China has established an independent satellite communication, radio and television transmission network, which has made historic contributions to the development of communication, radio and television in China.

third generation

Dongfanghong-3 satellite was launched by the Long March 3A carrier rocket developed by China Academy of Launch Vehicle Technology on May 2, 1997, and was successfully fixed on the equator of East longitude 125 on May 20. Dongfanghong-3 satellite is the first generation synchronous satellite with three-axis stabilization technology in China, which is mainly used for TV transmission, telephone, telegraph, fax, broadcasting and data transmission.

The fourth generation

On June 30th, 2008, 10, China successfully developed and launched Venezuelan No.1 communication satellite based on Dongfanghong-4 satellite platform. The public platform of "Dongfanghong-4" large-scale communication satellite is a key civil satellite project in China during the tenth five-year plan period. The platform adopts the design concept of public platform and adheres to the principles of universality, inheritance, expansibility and advancement. The performance of this platform is equivalent to the advanced platform of similar satellites in the world. Design life 15 years, end-of-life output power of 8 10 kW, and payload weight of 600800kg. It is suitable for large-capacity communication broadcasting satellites, large-scale direct broadcasting satellites, mobile communication, distance education and medical care satellites and other stationary satellites. Its successful development has improved the level of communication and broadcasting satellites in China. It laid the foundation for the leap-forward development in the future.

With the continuous development of satellite communication applications, satellite communication has penetrated into all aspects of equipment and will play an increasingly prominent role in the development of the whole national economy, especially in solving the imbalance of regional economic development, the imbalance of information security between developed and remote areas, and emergency communication.

the third part

Tiantong satellite

Tiantong-1 0 1 satellite was successfully launched in xichang satellite launch center on August 6, 20 16, and it is the first satellite in China's satellite mobile communication system.

Tiantong-1 is the first mobile communication satellite system independently developed and applied in China. At present, Tiantong-1 satellites 0 1, 02 and 03 have formed a mobile communication network covering China's territory and surrounding coastal areas, Southeast Asia and parts of the Indian Ocean. It can provide all-weather, all-day, stable and reliable voice, SMS and data services.

China started to operate satellite communication services from 1972. After nearly 50 years of development, it has grown from scratch and begun to take shape.

At present, the satellite communication service represented by Tiantong Satellite provides all-weather, all-day, stable and reliable mobile communication services such as voice, short message and data for users in China and its surrounding areas, the Middle East, Africa and most parts of the Pacific Ocean and Indian Ocean.

Pay attention to China Telecom Satellite Network Office.