Shulou(Shulou.com)11/24 Report--

On April 24, 1970, China successfully launched its first man-made earth satellite, which is now known as "Dongfanghong 1".

The "Dongfanghong-1" satellite being assembled is of great significance. It makes China the fifth country in the world to independently develop and launch man-made earth satellites after the Soviet Union, the United States, France, and Japan. It also marks that we have officially opened the practice of space exploration.

Dongfanghong-1 is an experimental satellite that has been operating for just 28 days (with a design life of 20 days) and has since lost contact with the ground (but is still flying).

In addition to verifying satellite launch technology and conducting ionospheric and atmospheric density testing experiments, Dongfanghong-1 also had an important communication function at that time-it installed an electronic music generator that could repeatedly broadcast "Dongfanghong" music to the ground through the 20MHz wireless communication band.

After the successful launch of "Dongfanghong 1", the "706 Project" was specially set up in China (started at a meeting in June 1970) to continue to promote the development of the satellite communication system.

The satellite and communication forwarding work of this project is the responsibility of the Seven engine Department. The communication ground station system is the responsibility of the fourth Machine Department.

The starting point of "706 Project" is very high, and it chooses the more advanced digital technology (the international mainstream is still analog). However, because we were in a special historical period at that time, coupled with the lack of our own technical capacity, the progress of the project was slow. There has been no breakthrough in the research of important devices and key technologies.

█ 1972: satellite Communications Cooperation behind the Century handshake at the beginning of 1972, an important historical event took place, that is, Nixon's visit to China.

At that time, in order to achieve better publicity results, the US government proposed to carry out television broadcasts and news reports through satellites, so that the American people could learn about the grand occasion of the president's visit to China for the first time.

The Chinese side agreed to the request put forward by the United States. But here's the problem-China didn't have its own communications satellite at that time.

Under the direction of Premier Zhou, the Chinese side has put forward three demands:

First, ask the US side to be responsible for leasing a communications satellite for the Chinese government; second, during the lease period, the ownership of the satellite belongs to the Chinese Government, and the US side applies to the Chinese side in advance for the right to use it (the time of use and the frequency of use are subject to the approval of the Chinese side. (the United States is not allowed to change it at will), and the Chinese side will agree and collect royalties; third, the leasing fees and royalties should be reasonable.

These three requirements have cleverly safeguarded China's sovereignty and solved the communications needs of the United States, which have been endorsed by the United States.

In this way, from January to March 1972, China's post and telecommunications department leased US satellite communication earth station equipment (from Hughes Company of the United States, HUGHES) and successively set up two temporary satellite communication ground stations at Beijing Capital Airport and Shanghai Hongqiao Airport, opening a satellite communication link between China and the United States.

This is the first time that China has used satellites for communication.

The first satellite communication earth station leased by Beijing long-distance Telecommunications Bureau

During Nixon's visit to China, satellite communications played a great role in the US-made 10-meter antenna mobile satellite communication earth station in Shanghai. The famous pick-up and handshake photo was sent back to the United States by satellite.

After Nixon's visit to China, under the direction of Premier Zhou, we bought the satellite ground station brought by the United States (spent more than 1 million US dollars) and carried out technical research.

Soon after, Beijing completed the construction of satellite ground stations No.1 and No.2. On July 4, 1973, Station 1 began to provide international communications services through international satellites over the Pacific Ocean. On March 25, 1974, the 2nd began to open international communication circuits to Asia, Europe and Africa through international satellites over the Indian Ocean.

All these can be regarded as the early family background of Chinese satellite communications.

█ 1975-1983: the advanced satellite communications technology brought about by Nixon's visit to China, which has had a bumpy fate, has not only greatly shocked Chinese technicians and senior officials, but also strengthened our determination to develop satellite communications.

Soon after, Huang Zhongyu, Lin Keping and Zhong Yixin of the Beijing Institute of posts and Telecommunications (later known as the "three swordsmen of Beijing Post"), after discussion, jointly wrote the "proposal on the Construction of Satellite Communications in China" and reported it to senior leaders.

Their suggestions were approved by the leaders and were called "May 19" instructions.

According to the instructions of the "May 19", the State Planning Commission and the Science and Technology Commission for National Defense jointly put forward a report on the implementation plan. On March 31, 1975, the Central military Commission approved the report on the Development of China's Communication satellites, and subsequently launched the "331 Project."

In the report, the approval document clearly stipulates that the entire satellite communications project is the overall responsibility of the Science and Technology Commission for National Defense. Among them, the communication system is the responsibility of the fourth engine Department. Within the fourth Machinery Department, a "331 Project" communication subsystem office has also been set up.

Later, in 1975, after many meetings and discussions, the overall plan of the 331 project communication subsystem was confirmed. According to the plan, a total of 23 sets of ground stations are planned to be trial-produced, which will be installed in the Ministry of posts and Telecommunications, the General staff Department, the Science and Technology Commission for National Defense, the Navy, the Ministry of Electric Power, the Ministry of Communications, the Ministry of four aircraft, and other departments.

At that time, it was Wang Meng, who had just made a comeback, who was responsible for promoting this work. Anyone familiar with the history of Chinese communications knows that Wang Jie is the founder of China Red Communications, the founding lieutenant general, and the then minister of the four Machinery Department.

Wang Meng proposed that adopting imitation to conduct technical research on imported ground stations can improve the research efficiency and reduce the risk. At that time, this plan was snitched by many people as "worshiping foreigners and fawning on foreigners". But Wang Meng argued for reason and finally stuck to it.

Based on this plan, the fourth Machinery Department assigned the relevant research and development tasks to Nanjing, Jiangsu and its surrounding scientific research institutes and factories.

Sure enough, the progress of research and development is faster than expected. In 1975, the 10-meter satellite ground station antenna developed by China was successfully trial-produced in Nanjing, indicating that China has the ability to independently develop satellite ground stations.

By 1978, most of the equipment of the "331 Project" had been developed, including 1-meter, 5-meter, 10-meter and 15-meter ground stations.

Steady progress has been made in the development of the 13-meter satellite antenna ground station hoisted under the ground station under the General staff. Next, let's look at the satellite.

In 1978, German and French "symphony" communication satellites drifted over China's geostationary orbit.

At that time, we did not have a communications satellite developed by ourselves. As a result, China cooperated with Germany and France to carry out satellite communication experiments. These experiments have not only obtained valuable data, but also helped domestic researchers accumulate rich experience and greatly improved the technical level of domestic satellite communications.

However, as China enters the stage of reform and opening up, we have serious differences in the choice of satellite development route.

Many domestic scientific research institutions lack confidence in domestic technology and begin to focus on technology introduction. To be exact, I want to "buy a satellite" instead of "launching a satellite" myself.

Under the influence of this idea, our original plan to launch a domestic communications satellite was shelved in 1980. The whole work came to a standstill.

Later, the plan to import satellites from the United States was not approved (at a cost of US $1.133 billion) because of the country's financial difficulties. At the same time, in May 1980, our country successfully launched an intercontinental ballistic missile into the Pacific Ocean, which verified the launch technology.

As a result, the country decided that the communications satellite should be launched on its own. The 331 project has been restarted.

In November 1981, the revised "Communication Subsystem Scheme for the first Phase of 331 Project" was discussed and approved. According to the plan, the installation and commissioning of ground equipment will be completed in May 1983. At the end of 1983, a satellite was launched.

█ 1984-1992: Dongfanghong 2, making history on January 29, 1984, our country launched Dongfanghong 2 communications satellite (CZ-3 / Y1).

However, it is a pity that the launch mission was not successful. At that time, the rocket engine malfunctioned, resulting in a sudden drop in thrust and the satellite did not enter the geosynchronous transfer orbit.

Despite the failure, aerospace workers were not discouraged and soon launched the launch of the second satellite.

On April 8, 1984, China's first geostationary orbit experimental communication satellite, Dongfanghong 2 experimental satellite (CZ-3 / Y2), was successfully launched and successfully entered orbit.

Dongfanghong-2 experimental satellite is no less significant than Dongfanghong-1 15 years ago. It makes China the fifth country in the world to launch geostationary orbit communication satellites on its own, and also opens the history of China's satellite communications with Chinese satellites.

The satellite, developed by the Chinese Academy of Space Technology, is spin-stabilized, with a cylindrical body, a height of 3.6 meters, a diameter of 2.1 meters, a takeoff weight of 900 kg (payload of 461 kg) and a design life of 4.5 years.

The satellite has two C-band spherical beam antennas, as well as remote control omni-directional antennas and telemetry omni-directional antennas, which can carry out round-the-clock communications, including telephone, television, radio and other communication tests. It adopts geosynchronous orbit, can cover the whole of China and some areas around it, and can greatly enhance the ability of domestic information transmission.

After the successful launch of the satellite, Zhang Aiping, the then defense minister, spoke on the phone with Wang Enmao, first secretary of the Xinjiang Autonomous region, by satellite at the Beijing command post. Soon after, Minister Zhang also wrote an inscription: "all over the world" to praise and encourage the builders of the satellite system.

The famous military parade on the 35th anniversary of National Day in that year was also broadcast through Dongfanghong 2 experimental satellite, which greatly inspired the hearts of the people.

On July 8, 1986, China formally established a domestic satellite communication network. This communication network has greatly promoted the domestic exchange of information and economic development, and created a way for the transmission of national comprehensive television programs.

On March 7, 1988, China made unremitting efforts and successfully launched an improved communications satellite, Dongfanghong 2A. Its performance and communication capacity have been greatly improved compared with before.

After that, Dongfanghong 2 launched many times, some successful and some failed:

Table 1 these satellites are the first generation of independent research and development achievements of Chinese communications satellites. They solve the problem of "from 0 to 1". However, from the technical point of view (the number of transponders, forwarding capacity, service life, etc.), there is still a big gap with the foreign advanced level.

█ 1986-1992: Dongfanghong No. 3, moving forward in frustration

At the end of 1980s, the development of global satellite communication technology entered an explosive period. Many countries launch satellites and broadcast them on television, as well as to meet communication needs. The famous Iridium project was born in that period (1987).

By 1988, nearly 900 communications satellites had been launched around the world. Among them, more than 200 are civil geostationary orbit satellites. Of these satellites, only five belong to China.

To make matters worse, our satellites are not only small in number, but also have a short life span of only a few years.

This means that by the early 1990s, we will be in a situation where there will be no stars available.

In order to ensure domestic communications and television transmission, we have to rent and buy foreign satellites for emergency.

In the mid-1980s, there was still no complete conclusion around "buying stars or making stars" in China. It was not until March 31, 1986 that the high level formally approved the plan of the Ministry of Aerospace for the development of Dongfanghong-3 satellite, which left a glimmer of life for the independent research and launch of domestic satellites.

By the time the Dongfanghong-3 satellite is officially developed and ready for its first launch, it will be 1994 eight years later.

On November 30 of this year, Dongfanghong-3 communications satellite was officially launched from Xichang Satellite launch Base.

After many successful orbit-changing flights, the satellite has entered a geosynchronous orbit of 36000 kilometers. However, it was regrettable that the satellite could not be located successfully and the launch failed because of the fuel leak.

During that period, it was the darkest moment in China's aerospace industry, and there were many major setbacks in the domestic rocket launch mission. In particular, the failure on February 15, 1996 resulted in six deaths and 57 injuries.

The picture of the failure of the launch of the long March 3B learned a painful lesson, and the Chinese aerospace people regained their spirits, found the reasons, improved their work, and continued to explore and try.

On May 12, 1997, we finally successfully launched Dongfanghong-3 satellite.

The satellite is located at 125 °east longitude over the equator and is equipped with 24 C-band transponders with a designed working life of more than 8 years. The satellite adopts advanced technologies such as full three-axis attitude stabilization technology, two-component unified propulsion technology and carbon fiber composite structure, with advanced performance and complex technology, which has reached the advanced level of similar international communication satellites.

Dongfanghong 3 communication and broadcasting satellite is mainly used for television transmission, telephone, telegram, fax, broadcasting and data transmission. Its use greatly alleviated the contradiction of the shortage of transponders in the domestic communication satellite market at that time. Public communications alone can save tens of millions of dollars a year.

Later, Dongfanghong 3 gradually evolved from a communications satellite to a public satellite platform. In other words, the service module part of the satellite is designed to be universal. By carrying different payloads, Dongfanghong 3 can form satellites with various functions for different purposes.

After Dongfanghong became the name of the platform, all Dongfanghong satellites changed their names accordingly. The satellites owned by China Communications and Broadcasting Satellite Co., Ltd. (part of the Ministry of posts and Telecommunications, which will be introduced later) have been renamed "China Star-XX". Dongfanghong 2, which has been launched before, has also been changed (see Table 1 in front).

Later, a number of communications satellites, such as China Star 22 and China Star 20, as well as three "Beidou" navigation and positioning satellites, were launched through the Dongfanghong 3 platform.

Please pay special attention to the industrialization of █ satellite communications. The 1990s is a critical period for China's reform and development. During that period, the wave of domestic reform was surging, and many state-owned enterprises were restructuring to promote market-oriented operation. At that time, a large number of emerging joint-stock companies were set up to participate in the market competition.

Satellite communications have also experienced the baptism of the wave of reform. Great changes have taken place in the satellite communications industry.

In previous satellite communications, because of the high technical threshold and the large occupation of funds, only large state-owned enterprises could participate and adopted the national system.

On October 12, 1984, the year of the successful launch of Dongfanghong 2, China Communications and Broadcasting Satellite Co., Ltd. (ChinaSat) was established, which was under the Ministry of Post and Telecommunications. It was the first state-owned enterprise in China to operate satellite communications and broadcasting business, and it was also the only one at that time.

In the late 1980s, with the wave of international satellite television business, two special satellite operation and service companies were set up in Hong Kong, namely AsiaSat and Asia-Pacific Satellite (the names are a bit similar, please pay attention to the distinction).

AsiaSat, whose full name is AsiaSat, was founded in 1988 and headquartered in Hong Kong. It is the first regional commercial satellite operation organization in Asia. Its background is the familiar Citic Group. Citic Group began to build AsiaSat in 1986.

AsiaSat is the pioneer of satellite communications in the entire Asian region. On April 7, 1990, they successfully launched Asia's first commercial communications satellite, Asia-1.

It is particularly worth mentioning that it was China's "long March 3" carrier rocket that carried out the launch mission at that time. This is the first time that China has successfully used its own carrier rocket to launch a commercial satellite, which caused a national sensation at that time.

Later, AsiaSat launched a number of satellites one after another, and based on these satellites, it provided satellite communications and radio and television services to more than 50 countries and regions and 2/3 people in the world.

And look at the Asia-Pacific satellite.

Asia-Pacific Satellite, whose full name is Asia-Pacific Satellite Holdings Limited, was born later than AsiaSat and was established in 1992. Its controlling shareholder is China Aerospace Science and Technology Corporation.

In the mid-1990s, the mainland also set up new satellite companies. For example, SinoSat Communications Co., Ltd. (Sinosat), which was established in May 1994, and China Oriental Communication Satellite Co., Ltd., which was established in April 1995.

Xinnuo is headquartered in Beijing. It is a state-owned joint-stock company jointly initiated and established by the China Aerospace Science and Technology Corporation, the people's Bank of China, the Shanghai Municipal people's Government and the China Development Bank, mainly serving the markets of China and the Asia-Pacific region.

In July 1998, Sinovel successfully launched Xinnuo-1. The satellite, which is made in Europe and supervised by China, has a large communication capacity and has an advanced level in the world in the 1990s.

In 1998, a lot of great things happened on Xinuo No.1. This year, the Ministry of posts and Telecommunications with a long history was split. On the basis of the former Ministry of Electronic Industry and the Ministry of posts and Telecommunications, the Ministry of Information Industry was established. This also sounded the clarion call for the first restructuring of the communications industry.

Soon after, the paging, satellite and mobile services of China's General Administration of Telecommunications were spun off. Among them, the satellite business became the later China Satcom (established in December 2001).

To be continued.

References:

1. "Historical Review of the Development of Satellite Communication system in China", Wei Xuexing

2. "70 years 70 people" Communication | Min Shiquan: a star in the sky, decades on earth ", Min Shiquan

3. "White Paper on the Development of China's Satellite Communications Industry", Sadie think tank

4. "Satellite Communications bear witness to the normalization of diplomatic relations between China and the United States", people's Post and Telecommunications

5. History of the Development of China's Satellite Industry, Chen Yunli

6. "the opening of a New era of Satellite Communications in China", Wang Chunting

7. "the Development of Chinese Communication Satellite", bilibili, Wen Yao Xinghe

8. "the great journey of the development of China's satellite communications industry in the past 45 years", Guo Haoran, Zhang Yuwei, Guo Xinzhe and Yin Shuming

This article comes from the official account of Wechat: fresh Jujube classroom (ID:xzclasscom), author: Xiaozaojun

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