Lin Baojun, Chief Designer of Beidou-3 Satellite System, Revealed the Secret-


　　How the Youth Small Satellite Team Created Miracles

　　The "Beidou-3 Global Satellite Navigation System" entered this year's math papers for the college entrance examination.

Lin Baojun, chief designer of the Beidou-3 satellite system and deputy dean of the Institute of Microsatellite Innovation of the Chinese Academy of Sciences, said in an interview with a reporter from China Youth Daily and China Youth Daily that such a question is conducive to the inheritance of the "national weapon" and can inspire candidates Interest in learning related knowledge.

　　On July 31 last year, my country's self-developed Beidou-3 global satellite navigation system was completed and opened.

"In 2015, when the first Beidou-3 satellite was launched, our design team had a total of 81 people, with an average age of 31." Lin Baojun said that it took about 20 years for the United States to achieve the technological leap from GPS2 to GPS3. The young team only took 3 years and 3 months.

All young people can build small satellites?

　　Among aerospace units with a majority of young people, the youthfulness of the small satellite team is notorious.

　　When Lin Baojun came to Shanghai from Beijing in 2009, the research and development, production, and administrative personnel of the institute totaled less than 150 people.

At that time, team members faced many difficulties in manufacturing, R&D and design.

　　To this end, the institute recruits 100 newcomers every year for 3 consecutive years.

But almost all the young people recruited are graduate students and doctoral students who have just graduated. They feel unfamiliar with the work of developing satellites, and they are even not confident in their own abilities.

　　"The internal combustion engine (major) I studied in my undergraduate course was originally a diesel engine engineer. But I also participated in Shenzhou and Beidou, why can't you?" Although Lin Baojun has a rich resume, including: Bachelor of Internal Combustion Engine, Master of Computer, and Software Control Ph.D., post-doctorate in high-energy astrophysics. He used to be the deputy chief designer of manned space engineering application system. He participated in all the demonstration work from "Shenzhou 1" to "Shenzhou 13", but he doesn't like to put on airs and often uses his own Work experience inspires young colleagues.

　　Without an autonomous satellite navigation system, China is like walking in the dark night-at the critical moment, it is impossible to touch the road. Therefore, the country has high hopes for the Beidou system.

　　The research institute is "not enough", and the overall R&D work of the Beidou system is at a critical stage of transformation: the first challenge is that China's system needs to be adjusted from a regional type of "just the sky above the head" to a global type; the second challenge It is “time-frequency”. The traditional rubidium atomic clock is installed on the satellite, which relies heavily on ground control. The time and position must be calibrated every one or two hours. The third challenge is to achieve “multiple arrows with one stone”. Satellites must be miniaturized and long-lived for rapid networking and launch.

　　At that time, Lin Baojun said to his young colleagues: "When you are my age, you can make a Beidou-3, even if it is not in vain." But to everyone's surprise, this group of young people did it in 2015. Launched the first Beidou-3 satellite, which uses more than 70% of the new technology, and usually a new type of satellite uses no more than 30% of the new technology; in 2018, high-density launch of 8 Beidou-3 satellites; 2020; In 2015, China already had 30 Beidou-3 satellites flying in space.

More than 160 new technologies, all appearances are "unique skills"

　　Lin Baojun can always show a lot of "unique skills". In the final assembly hall, he made gestures casually, "Look at that flat black box, only we (Beidou) have it!"

　　The "flat black box" he referred to is a 150-watt high-power gallium nitride high-efficiency fixed release device, and it is one of the more than 160 innovative technologies of Beidou-3.

　　"The signal transmission capability of the fixed release equipment is stronger, which is better than similar foreign products. In case of failure in space, the traditional traveling wave tube is used for switching, and the performance is the same as that of similar foreign products." Lin Baojun looked at the "baby" in front of him and said. "Others want this thing, but we don't sell it yet!"

　　In addition, Beidou-3 has independently developed a hydrogen atomic clock with better performance than rubidium atomic clocks. "The hydrogen clock is more accurate, and the time can be adjusted once a month or two."

In order to make the small satellite more durable, the R&D team also created its own "Seamless Switching Technology of Hydrogen Clock and Rubidium Clock."

If the hydrogen clock fails in space, it only takes 20 picoseconds to switch to rubidium clock operation.

For users, this can achieve a real "senseless switching".

　　In the field of navigation satellites, the United States’ GPS, Russia’s GLONASS, and the EU’s Galileo system can compete with China’s Beidou on the same platform.

In the satellite family, China's Beidou has taken the lead in achieving the "ton level", while the weight of navigation satellites in other countries and regions is generally 3-4 tons. After all the Beidou-3 satellites are fully assembled, the total weight is only about 1 ton.

　　Although Lin Baojun is a student of engineering, he always composes a poem to celebrate every Beidou launch.

"The two satellites have gone through three zero-returns from development to launch, which is unprecedented." On October 15, 2018, on the day of the launch of the fourth group of MEO satellites of the Beidou-3 of the Chinese Academy of Sciences, he wrote a poem with " "End of the adventure, continue to struggle" is written at the beginning of each verse, "The official is breaking dawn, Zhan Lujian..." Lin Baojun told reporters that the independent construction of the Beidou system is to "serve the world and defend the country", and does not "dominate the martial arts". The meaning of ", I repeatedly considered between "Xuanyuan Jian" and "Zhan Lu Jian", and finally thought that "China's Beidou is also the world's Beidou", and "Zhanlu Jian" is more benevolent.

Let young people "have something to do, have money to spend, and someone loves"

　　In December 2017, Lin Baojun and his team prepared for the launch of the first group of MEO satellites of the Chinese Academy of Sciences Beidou-3 at the Xichang Satellite Launch Center.

Looking at the busy young people in the Satellite Innovation Institute, the person in charge of the launch center said with emotion: "These young people are too hard, don't tire them out."

　　Lin Baojun said, "I'm not tired or tired, just like going home to play cards during the Chinese New Year. If you like it, do it with enthusiasm. I don't feel tired playing cards at home!" But he also feels distressed for these young people," Many of them graduated with a master's degree, and their monthly salary may be less than 10,000 yuan, and the expenses on hand are not generous." He always said to the young people in the research institute: "You should not value those big-name bags, luxury cars, For a mansion, there must be a story to tell the younger generation for the rest of your life."

　　"Many times, we are'accompanying satellites' and we have no time to'accompany our family'." Lin Baojun always encourages young people to "pursue", but when facing the reporter's lens, he also encourages young people to live in reality. Call, "We want these young people to have something to do, to have money to spend, and someone to love."

　　China Youth Daily·China Youth Daily reporter Wang Yejie Source: China Youth Daily