Sun Zezhou

Sun Zezhou ( Chinese  孫澤洲  /  孙泽洲 , Pinyin Sūn Zézhōu ), * 1970 in Shenyang , Liaoning Province , is a Chinese electrical engineer. He has been the chief designer of the Chinese lunar and Mars probes since April 2016 .

Education

Sun Zezhou's parents both worked at Shenyang Aircraft Corporation , which primarily manufactures fighter planes . That is why he was interested in technology at an early age and in 1988, after graduating from high school, enrolled in the then Faculty of Electrical Engineering (电子 工程系) of the Nanjing Aviation Academy . At the beginning of his studies he had difficulties in finding his way into the learning that suddenly had to be organized independently; especially with the calculus and the theory of electromagnetic fields he could not see any practical use. The test results were correspondingly poor, for which he was seriously criticized by his father during the Spring Festival vacation after the first semester. Friends of his parents then explained to him what use the apparently pointless theory subjects would have in the course of further studies and gave him advice on how to develop the material. Sun Zezhou picked up his feet, and a year later received a scholarship for good performance. He was able to maintain the level, received annual scholarships and graduated in 1992 as an electrical engineer.

Not least because of his achievements, Sun Zezhou was soon promoted to assistant secretary of the Faculty Cell of the Communist Youth Union , where his job was to organize group activities for students. Here he gained experience in leading and motivating people that would be very useful to him in the further course.

Earth observation satellites

Ziyuan 1

Immediately after graduating in 1992, Sun Zezhou joined the Chinese Academy of Space Technology , a subsidiary of the China Aerospace Science and Technology Corporation . After an agreement between China and Brazil on the joint development of earth observation satellites, signed on July 6, 1988 on the occasion of the state visit of President José Sarney , the foreign ministers of the two countries negotiated an agreement between the National Institute for Space Research of Brazil and the Chinese Academy of Space Technology on August 22, 1988 Cooperation agreement signed for the development and construction of two modern long-range reconnaissance satellites , the so-called “ China-Brazil Earth Resources Satellite Program ”. 30% of the total cost of US $ 300 million should be borne by Brazil, 70% by China, and development tasks should be similarly distributed. Sun Zezhou was already involved in the development of the first satellite, called CBERS-1 in Brazil and Ziyuan 1-01 (资源 一号 01 星) in China. The Academy for Space Technology developed its own bus for the satellites of the cooperation project, which are flying in a sun-synchronized orbit , known abroad as the "Phoenix Eye" in China "Fengyan Pingtai" (凤眼 平台). After a few delays, the first satellite was finally launched on October 14, 1999.

During the development of the Phoenix Eye platform, there were five work areas: Housing, attitude control and orbit, temperature control, power supply and telemetry as well as orbit tracking and remote control, plus the payloads of the respective satellite (cameras, data storage, space weather observation). After the successful launch of the first satellite, Sun Zezhou was appointed deputy chief engineer for the identical successor model CBERS-2 and Ziyuan 1-02 at the end of 1999. He was responsible for the orbit tracking and remote control work area as well as for the integration of the payloads. In the latter capacity, he also had to travel to Brazil to take part in the tests of the wide-angle camera developed there . After the satellite was launched from the Taiyuan Cosmodrome on October 21, 2003, he was also responsible for flight path control.

Space-based solar telescope

In the mid-1990s, the Huairou Solar Observatory (since April 2001 part of the National Astronomical Observatories of the Chinese Academy of Sciences ) proposed for the first time that an optical telescope with a 1 m mirror, a high-precision polarizer and a Place two-dimensional real-time spectrographs for the wavelength range from 4000 - 6000 Å in an earth orbit. This project known in China under the name Teles bzw. 望远镜 (Pinyin Kōngjiān Tàiyáng Wàngyuǎnjìng ), known abroad as the Space Solar Telescope or SST , is supported by the National Space Agency because it serves not only basic research but also space weather forecasting . In 2003, Sun Zezhou was appointed deputy chief planner for the technical aspects of the project (背景 型号 副 总设计师) in the group of experts responsible for the preparatory work.

Lunar and Mars probes

While Sun Zezhou worked closely with the Brazilian Institute for Space Research on the development of the Ziyuan 1 earth observation satellite, Ye Peijian developed the purely Chinese reconnaissance satellite Ziyuan 2 in real time on the basis of an expanded phoenix eye platform with two solar modules Could transmit ground station. The first satellite in this series (资源 二号 01 星) was launched on September 1, 2000, the second on October 27, 2002 and the third on November 6, 2004. After the Chinese Academy of Space Technology 2001 under the direction of Ye Peijian an in-house Having initiated a feasibility study for an orbiter to explore the lunar surface, Sun Zezhou was appointed to the group of experts in 2002 because of his experience with the Ziyuan satellites, which performed similar tasks in Earth orbit. There he was again responsible for the tracing and remote control systems on board the probe, when the plans were then concretized, for the precise definition of the tasks and goals of these systems and the design of the interfaces between his systems and the rest of the probe. In 2003 the concept was ready and the company decided to build the probe.

Chang'e-1

When the development group for the now " Chang'e-1 " lunar probe was put together in 2004, Sun Zezhou was appointed deputy chief designer. Now he had to familiarize himself with areas that were previously unfamiliar to him, such as temperature control or the power supply of the probe, and solve the problem of how to accommodate all systems and payloads in a spacecraft that was only allowed to weigh 1150 kg without fuel. In the end, the engineers took the tried and tested DFH-3 bus from the Academy for Space Technology, fitted it with an antenna that could be swiveled all around, etc. for deep-space purposes, and installed instruments from the Ziyuan satellites. In December 2004 the first prototype of the lunar orbiter was ready and has now been subjected to countless tests. More than 100 components and 23 computer programs had to be checked, and problems arose again and again, especially with the software and the interfaces. Despite overtime - Sun Zezhou was regularly at the company until 9 pm, often until midnight - it took until September 2005 for the prototype to function reliably. After the construction of the actual probe was approved at the end of 2005, Sun Zezhou's main task was the quality control of the now 168 components - including the housing and drive. To this end, he introduced the failure mode and influence analysis, which was still new in China at the time, for each work area . This worked. After the start on October 24, 2007, the probe worked flawlessly for almost a year and a half and fulfilled all its tasks until it was deliberately brought down on March 1, 2009.

The lunar orbiter Chang'e-2 , launched on October 1, 2010, had an improved camera, but was otherwise more or less identical to Chang'e-1. Work on the next step of the lunar program had already begun at the Chinese Academy for Space Technology in 2008, and at the age of 38, Sun Zezhou had been appointed chief designer for all systems of the Chang'e-3 lunar probe and its rover Jadehase , both of which were largely new developments . Chang'e-3 had a more sophisticated propulsion system than the orbiters, the probe had to find a suitable place to land on its own, and the shock absorbers in the landing legs had to be constructed. Since the probe was exposed to extreme solar radiation and extreme cold for two weeks at a time on the moon's surface, temperature control was much more difficult to handle than with an orbiter. In addition, the rover had to find a mode of transport that was as dust-free as possible, and autonomous navigation and obstacle avoidance had to be developed. For comparison: with Chang'e-1 about 30% of the probe was newly developed, with Chang'e-3 it was 80%. For the twelve-minute landing process alone, Sun Zezhou and his team carried out 10,000 computer simulations and around 1,000 tests with models. On December 1, 2013, Chang'e-3 took off from the Xichang cosmodrome , on December 14, the soft landing took place in the Mare Imbrium , and even if the rover's locomotion system failed in February 2014, the cameras etc. also failed on August 3, 2016. , the payloads on the probe's lander are still working flawlessly to this day (December 2019).

When the Space Technology Academy officially began development of Chang'e-4 and the Mars probe known today as Tianwen-1 in April 2016 , Sun Zezhou was appointed chief designer for both projects, succeeding Ye Peijian. While Chang'e-3 had landed on the front of the moon, a landing on the back of the moon was to be attempted with Chang'e-4, which made the development of a relay satellite, later called " Elsternbrücke ", necessary, which was in a halo orbit should be stationed around the Lagrange point L ₂ . The landing of the probe was also significantly more demanding than with Chang'e-3: the probe had only 1/8 of the area available as a landing site in the target area on the rugged back of the moon compared to Chang'e-3 and had to be almost vertically Fly into Von Kármán crater . The relay satellite launched on May 20, 2018, the probe followed on December 7, 2018, and on January 3, 2019, the soft landing on the moon took place. The probe and the Rover Jadehase 2 are still working perfectly today (as of July 27, 2020). On June 11, 2020, Sun Zezhou was given the World Space Award by the International Astronautical Federation together with Wu Weiren , the technical director of the lunar program, and his deputy Yu Dengyun for the world's first landing on the back of the moon .

When landing on Mars, the level of difficulty is even higher. Sun Zezhou and his group - the same people who have been working together since Chang'e-3 - were able to take over the autonomous landing system from the lunar probes. Before the engine ignites, however, after entering the Martian atmosphere, the probe first brakes from 4.8 km / h to 460 m / s for 5 minutes with its flow resistance alone , then for 90 seconds with a parachute to 95 m / s. This is the hardest part of the mission, there is only one attempt, and the developers put a great deal of time and care into designing the heat shield and parachute mechanism. To classify: of the 42 Mars missions that various states have carried out since the 1960s, only 52% were successful.

Projects managed as chief designer

• Chang'e-4
• Tianwen-1

Web links

• Works by Sun Zezhou in the Chinese National Library (Chinese)

Individual evidence

1. ↑ The student protests, which had spread across the country from Hefei via Nanjing , Shanghai and Beijing in December 1986 , had already come to an end in January 1987. Stephen Uhalley Jr .: A History of the Chinese Communist Party. Hoover Institution Press, Stanford 1988, p. 227f and Joachim Glaubitz: China under increasing domestic political pressure. In: Wolfgang Wagner et al. (Ed.): Die Internationale Politik 1987–1988. R. Oldenbourg Verlag , Munich 1991, p. 323.
2. ↑ Compare the completely opposite experiences of Zhang Bainan , today chief designer of the manned spaceships of China, at the University of Science and Technology of National Defense .
3. ↑ 钱 钰: “嫦娥” 总 师 孙泽洲 受聘 母校 南航 大. In: news.carnoc.com. March 6, 2014, accessed December 8, 2019 (Chinese). 
4. ↑ story. In: cbers.inpe.br. February 5, 2018, accessed December 9, 2019 . 
5. ↑ Phoenix Eye in the Encyclopedia Astronautica , accessed December 9, 2019.
6. ↑ Gunter Dirk Krebs: CBERS 1, 2, 2B / ZY-1 01, 02, 02B. In: space.skyrocket.de. Retrieved December 9, 2019 . 
7. ↑ 凤眼 平台. In: cast.cn. July 31, 2015, accessed December 9, 2019 (Chinese). 
8. ↑ ZY in the Encyclopedia Astronautica , accessed on December 9, 2019.
9. ↑ 钱 钰: “嫦娥” 总 师 孙泽洲 受聘 母校 南航 大. In: news.carnoc.com. March 6, 2014, accessed December 8, 2019 (Chinese). 
10. ↑ 孙泽洲. In: ceie.nuaa.edu.cn. September 20, 2017, Retrieved May 6, 2019 (Chinese). 
11. ↑ China Exclusive: Scientists looking for site for giant solar telescope. In: spacedaily.com. August 29, 2012, accessed December 9, 2019 . 
12. ↑ 孙家栋 et al .: “十一 五” 空间 科学 发展 规划.国防 科 工委, 北京 2007.
13. ↑ 孙泽洲. In: ceie.nuaa.edu.cn. September 20, 2017, Retrieved May 6, 2019 (Chinese). 
14. ↑ 叶培 建 : 科学院 院士 叶培 建. In: cast.cn. August 3, 2015, accessed December 9, 2019 (Chinese). 
15. ↑ 资源 二号 卫星 ZY-2. In: cast.cn. August 3, 2015, accessed December 9, 2019 (Chinese). 
16. ↑ 2002 年 10 月 27 日 “中国 资源 二号” 卫星 成功 发射. In: people.com.cn. August 1, 2003, accessed December 9, 2019 (Chinese). 
17. ↑ 凤眼 平台. In: cast.cn. July 31, 2015, accessed December 9, 2019 (Chinese). 
18. ↑ Gunter Dirk Krebs: ZY-2 01, 02, 03 (JB-3 1, 2, 3). In: space.skyrocket.de. Retrieved December 9, 2019 . 
19. ↑ 孙泽洲 从 “探 月” 到 “探 火” 一步 一个 脚印. In: cast.cn. October 26, 2016, Retrieved December 12, 2019 (Chinese). 
20. ↑ 徐 超 、 黄治茂: “嫦娥 一号” 副 总设计师 孙泽洲. In: news.163.com. November 8, 2007, Retrieved May 6, 2019 (Chinese). 
21. ↑ 德 先生: 孙泽洲 ： 嫦娥 四号 传 回 月球 近景 图 离不开 他 13 年 的 付出 ， 月 背 软着陆 为 中国 实现 载人 登月 打下 契机. In: zhuanlan.zhihu.com. January 8, 2019, accessed December 11, 2019 (Chinese). 
22. ^ Lunar-based Ultraviolet Telescope (LUT). In: nao.cas.cn. Retrieved December 12, 2019 . 
23. ↑ “嫦娥” “玉兔” 再 入梦乡 ， “天 问 一号” 正在 征途. In: spaceflightfans.cn. July 27, 2020, accessed July 27, 2020 (Chinese). 
24. ↑ 嫦娥 四号 任务 团队 优秀 代表 首 获 国际 宇航 联合会 世界 航天 最高 奖. In: tech.sina.com.cn. June 11, 2020, accessed August 10, 2020 (Chinese). 
25. ↑ 2020 IAF Award Recipients. In: iafastro.org. Accessed August 10, 2020 (English). 
26. ↑ 孙泽洲 从 “探 月” 到 “探 火” 一步 一个 脚印. In: cast.cn. October 26, 2016, Retrieved December 12, 2019 (Chinese). 

Note: This article places the family name before the person's first name. This is the usual order in Chinese. Sun is the family name here, Zezhou is the first name.