China Academy of space technology is subordinate to the aerospace science and technology group, also known as the Fifth Academy of Aerospace Science and Technology Group for short. It was founded in 1968 and its first president was Qian Xuesen, a famous scientist. Dongfanghong-1, the first man-made earth satellite launched by China in 1970, came from here.
Academician fan benyao is one of the witnesses of the development of Chinas satellite industry. A detail in the launching process of the last networking satellite of beidou-3 made this senior satellite expert refreshing.
Fan benyao, academician of the Chinese Academy of engineering and chief designer of Beidou No.1, No.5 Academy of Aerospace Science and Technology Group: after the separation of the star and the arrow, we saw the solar wing unfold for the first time, and we couldnt photograph it before.
The first picture that academician fan benyao said was that on June 23, 2020, when China launched the 55th navigation satellite of Beidou system, that is, the last global networking satellite of beidou-3, hundreds of millions of viewers across the country saw the whole process of the solar wing unfolding like two wings of a satellite after the separation of the satellite and the rocket.
Solar wing is one of the main components of the satellite, also known as solar panels, it is the device to collect solar energy on the satellite, that is, the energy source of the satellite. In the past, the solar wings on Beidou satellites were opened more than 30 minutes after the separation of the rocket and the satellite. At that time, the satellite will travel alone in space, and people on the ground will not be able to see the whole process of the expansion of the solar wings.
Since 2006, it began to do research on localization substitution, and it was first used in Beidou in 2014. Now, nearly 40 years have passed. At the 529 plant affiliated to the Fifth Academy of Aerospace Science and technology group, Chinese workers have begun to mass produce domestic satellite solar wings.
Decipher a thrilling breakthrough:
In 2000, with the completion of Beidou-1 satellite navigation system, China solved the problem of domestic regional satellite navigation from scratch with the least satellite and minimum investment. Since then, China began to build its own satellite navigation system, and began to build beidou-2 system covering the Asia Pacific region.
The vast space seems boundless, but due to the limitation of human technology level and development and operation cost, the orbit and frequency resources suitable for satellite navigation are actually limited. In order to regulate space order, countries must apply to ITU for their own frequency band before launching navigation satellites. At this time, in order to build beidou-2, China applied to the International Telecommunication Union for new space frequency resources.
According to ITU, all countries have the right to apply for the right to use frequency resources, but they must launch navigation satellites within the seven-year validity period and successfully receive the transmitted signals, otherwise the right to possess the frequency will automatically become invalid. On April 17, 2000, ITU accepted the application. At 24:00 on April 17, 2007, it was the deadline for launching the first Beidou satellite and sending back signals.
After seven years of countdown to launch, Beidou people are faced with arduous scientific research tasks: for example, the navigation system of the United States covers the whole world because they have established ground base stations all over the world, but China has not been able to solve the problem of building ground base stations in the world for a while; in addition, atomic clock technology, which determines the positioning accuracy of navigation satellites, has not been overcome
In fact, when the construction of the Beidou project began, China was already able to produce atomic clocks. However, it is still uncertain whether it will be able to withstand the tremendous shock of rocket launching and the vacuum in space. Because of this, the atomic clocks on Beidou-1 still rely on imports: when the construction of beidou-2 began, China turned to Europe to buy atomic clocks, but the price, accuracy and stability were not satisfactory. Therefore, it is necessary to accelerate the localization of atomic clock.
On April 8, 2007, with many technical problems including rubidium atomic clock being overcome one by one, the first launch satellite of beidou-2 ushered in the scheduled launch date! But with eight days to go before the launch, the researchers found that there was something wrong with one of the transponders on the satellite during the final joint inspection of the satellite and the rocket.
Cong Fei, chief designer of beidou-3 satellite of the Fifth Academy of China Aerospace Science and technology group, said: it is in the fairing. If it is to be opened, it is very difficult to loosen all eight gongs, and it is also very difficult to open the fairing. In addition, since the satellite is in the third stage of the rocket, after the fairing is opened, the satellites cabin board has to be lifted. The surface of the satellite is covered with many layers, including some thermal control items, which have to be stripped off before the board can be exposed.
There are risks in disassembly and assembly, and the time is very urgent. After three days of careful study and judgment, the transponder was removed from the satellite. After 72 hours of repair and detection, the problem was completely solved. However, the launch of the rocket was postponed to April 14, 2007. At this time, there is only a three-day gap between the expiration date of Chinas space frequency resources.
At the last moment, Chinas Beidou, just like a whistle on the basketball court, narrowly got the ticket to enter the global satellite navigation system club.
Decrypt a rigorous technical screening:
Enlarge 20000 times to find chip defects, strictly control quality and improve localization rate
In the process of continuous improvement of localization, it is particularly important to check the quality of satellite components.
To this end, the Fifth Academy of Aerospace Science and Technology Group established the aerospace material support division in 1984. It has become the earliest professional organization for quality assurance of aerospace components in China. Today, it provides quality assurance for tens of millions of aerospace components every year. Sun Ming, deputy chief commander of aerospace components application verification of the aerospace material support division of the Fifth Academy of Aerospace Science and technology group, showed reporters the nearly rigorous gene screening technology they used for a domestic chip.
Sun Ming, deputy chief commander of aerospace components application verification of aerospace material support division of the Fifth Academy of Aerospace Science and Technology Group: we open the cap of one chip. After opening the cap, we can see the picture with 16 times magnification. Then we zoom in. At 100 times, you can see some obvious defects. These two wires may touch each other, and they will short circuit in our application process.
Further down, enter the search for internal defects, magnify a point that is easy to cause problems by 250 times, and then 750 times, 2200 times and 20000 times. Finally, we can see that there is a hole and a crack. This kind of defect may cause its short circuit after working for a period of time.
The localization rate of beidou-3 core components is 100%. This neck sticking technology is hard to come by
It is understood that in order to enable the beidou-3 satellite navigation system to be put into service as soon as possible, more than 400 units and more than 300000 scientific and technological personnel have successively participated in it. They have successively conquered more than 160 key core technologies, including inter satellite links and high-precision atomic clocks, and achieved breakthroughs in the localization and development of more than 500 kinds of components and important components.
At present, the localization rate of core components of beidou-3 satellite system has reached 100%.
Today, the struggle course of more than 300000 participants in the construction of Beidou has been summed up as the spirit of Beidou in the new era of independent innovation, openness and integration, unity of mind, and pursuit of excellence, and has become the spiritual wealth engraved with the eras Chrome.
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