China’s Beidou deploys global navigation ＂big chess game＂
At 2:9 on June 25, our country successfully launched the 46th Beidou navigation satellite with the Long March 3B carrier rocket at the Xichang Satellite Launch Center.
The satellite is the 21st networking satellite of the Beidou-3 system and the second satellite in tilted geosynchronous orbit. After a series of in-orbit tests, the satellite will network with the 20 Beidou-3 satellites previously launched to provide timely services and further enhance the coverage and service performance of the Beidou system.
As a resounding calling card of our country’s independent innovation, China’s Beidou is deploying the "big chess game" of global navigation at a leading speed.
In the context of the deployment of constellations with single-orbit satellites by GPS in the United States, Glonass in Russia, and Galileo in Europe, Beidou from China is unique in using three kinds of orbiting satellites to form a hybrid navigation constellation, contributing Chinese wisdom and Chinese solutions to the international satellite navigation technology system. What are the mysteries of Beidou’s "chessboard"? The reporter walked into the five colleges of the Aerospace Science and Technology Group, known as the "base camp of Beidou", to find out.
Three types of "chess pieces" in China’s Beidou chess game
So far, Beidou-3 has successfully launched 21 satellites, including 18 MEO satellites (medium circular orbit satellites), which are called "Mengxing" by netizens because of their small and flexible English abbreviation; 1 GEO satellite (geostationary orbit satellite), which is called "Jixing" by Beidou people; and two IGSO satellites (tilted geostationary orbit satellites), which are called "Aixing" by Beidou people.
Like chess pieces on a criss-crossing chessboard, these three types of satellites hold their posts in different orbits –
"Moe Star" is the main force of the global network, running around the earth tirelessly, making its own under-star trajectory constantly draw wavy lines in order to cover a wider area of the world; "Ji Xing" always moves with the rotation of the earth, in order to always focus on the motherland; "Love Star" is like a hard-working bee, making its under-star trajectory always focus on the Asia-Pacific region and dance the figure of eight.
The 46th Beidou navigation satellite launched this time is the second "love star" of the Beidou-3 system.
These three types of "chess pieces" with outstanding achievements are not the first time they have joined forces in the Beidou No. 3 system. They have jointly displayed "Chinese kung fu" in the Beidou No. 2 system, but their respective job responsibilities have changed.
Based on the national conditions, not blindly seeking success
It is not difficult to see that to undertake the task of global networking, it is enough to have "Moe Star", why should "Love Star" and "Ji Xing" be pulled into the team?
To answer this question, we have to start with the debate about the direction and route at the beginning of Beidou.
What kind of path does China’s navigation satellite take? Is it a step-by-step step to global networking, or a small step and a phased leap? In the fierce collision of ideas, opinions gradually tend to favor the latter.
Academician Fan Benyao, chief designer of the Beidou-1 satellite, who participated in the discussion of the technical route, said: "It took a lot of time and money to build the system so large [global networking] at one time. At that time, the reform and opening up had just begun, and the users were concentrated in the domestic and surrounding areas of our country. Therefore, the technical approach of’regional first, global later ‘is very correct, in line with China’s national conditions and has Chinese characteristics."
China-Asia-Pacific-Global, the three-step route determines the pattern of Beidou. In the first two steps, Beidou needs to lock in China and the Asia-Pacific region to provide services, "Jixing" and "Aixing" obviously have more advantages, while "Moe Star" is not very economical, and many key technologies on "Moe Star" have not yet broken through. But we can’t completely give up "Moe Star", we must verify the technology through actual combat, after all, the final step is still to go global.
Therefore, for the first time, the Beidou people of the Five Academies have built the GEO/IGSO/MEO, that is, the hybrid constellation of "Jixing", "Aixing" and "Moe Xing", and built the Beidou-2 regional satellite navigation system that integrates basic navigation, location reporting and other services with the minimum number of satellites, becoming a model for the construction of regional satellite navigation systems in the world.
This kind of technical system can efficiently build a regional system and expand the global system at the same time. During the construction of the Beidou-2 system, a series of bottlenecks were gradually overcome through the launch and operation of four "Moe Stars" in orbit. Therefore, when Beidou started its global networking journey, the "Moe Star" who jumped into the main force was able to show its power.
However, at this time, the "auspicious star" and "love star" did not withdraw from the stage of history. The Beidou experts of the Five Academies told reporters that the Beidou constellation is a team, and the most emphasis is on complementary advantages and the overall best. The Beidou people fully considered the advantages of "auspicious star" and "love star", and designed a small number of positions for them, but their role is very critical. They not only undertake the "assist" responsibility of cooperating with "Moe Star" and significantly enhancing the overall technical indicators of Beidou No. 3, but also carry a lot of "artifacts" to expand and verify the road of Beidou in the future.
"This Beidou route and constellation design, which is full of the practical wisdom and pragmatism of the Chinese nation, has laid the most solid foundation for the country’s heavy weapons," the expert said.
Check the bottlenecks on the list one by one
In fact, if the intelligent plan design is not implemented in action, it is ultimately a blueprint. From design to completion, the most test of technical strength and perseverance. Since the Beidou No. 1 project was established in 1994, the Beidou people of the Five Courts have embarked on the long road of Beidou.
In order to build the world’s first hybrid constellation regional navigation satellite system, the Beidou-2 satellite system, the scientific research team from the Five Academies has broken through many key technologies such as hybrid navigation constellation design, high-stability signal broadcasting channel, active and passive positioning integration, and high-precision and high-stability thermal control of on-board atomic clocks. For the first time, three services of navigation and positioning, short message communication, and differential enhancement have been integrated. China’s Beidou has thus obtained (meaning the society – reporter’s note) a new skill-
"Jixing" and "Aixing" are a series of key technologies for high-precision navigation; the flexible and efficient spatial data management system of "Aixing" and "Mengxing" has improved the level of satellite information management and autonomous operation.
In the third step of entering the global network, China’s Beidou people have achieved the improvement and leap of our country’s navigation satellite capabilities: our country’s first full-truss satellite platform, bearing efficiency and other indicators have reached the international first-class level; for the first time, a unique new type of navigation signal broadcasting has been realized, which has greatly improved the user’s anti-jamming ability and ranging accuracy; breakthrough in multi-orbit hybrid constellation inter-satellite link technology to achieve "one-stop management" of navigation constellations; breakthrough in satellite independent health management technology, the number of unplanned interruptions of satellite signals has reached the international advanced navigation satellite service level.
As the bottlenecks on the list were ticked off one by one, China’s Beidou firmly grasped the core technology in its own hands and rushed out of Asia to the world.
One link is "twisted", one item after another is "broken".
On the Beidou Long March, the Chinese Beidou pioneered the management model of the aerospace project group, forming a new system exploration, key technology research, achievement transformation, talent training benign mechanism and complete scientific research supporting facilities, which strongly supported the batch production and intensive launch of Beidou satellites, and created the "China Speed" of constellation networking.
The shining constellation was created by China and will serve the world.
China Youth Daily · Zhongqing Online reporter, Qiu Chenhui, correspondent, Pan Chen, source: China Youth Daily