In the vast exploration of the universe, there is a team that has forged the brilliance of Chinese space lubrication materials and technology with wisdom and sweat. They are the "Space Lubrication Materials and Technology Research Team," honored with the title of the fifth Science and Technology Master.
Since the establishment of the research institute, the older generation of scientists has been unwaveringly dedicated to the study of friction, wear, and lubrication, laying a solid foundation for China's "two bombs, one satellite" project. Entering the new century, with the rapid development of the national aerospace industry, the demand for high-performance lubrication materials has become increasingly urgent. The Space Lubrication Materials and Technology Research Team emerged, shouldering the heavy responsibility of providing lubrication support for major scientific and technological tasks such as manned spaceflight and lunar exploration projects.
Under the leadership of Academician Liu Weimin, they delved into the mysteries of friction chemistry, friction physics, and material damage protection at the microscopic level, successfully developing high-performance space lubrication and protection materials, as well as friction reduction and wear-resistant technologies. These achievements have not only brought revolutionary changes to high-tech and civil industries but also provided a solid backing for the vigorous development of China's aerospace industry.
Academician Liu Weimin and others discuss special lubricating materials and technologies for future spacecraft. Image provided by Lanzhou Institute of Chemical Physics.
"FY-2" Emergency Call
In 1958, the Lanzhou Institute of Chemical Physics of the Chinese Academy of Sciences was newly established. Under the leadership of senior scientists Chen Shaoli and Dang Hongxin, research on friction, wear, and lubrication began here. After decades of accumulation and sedimentation by several generations, this institute gradually developed its unique research style and profound academic heritage.
With the increasing emphasis on the aerospace industry by the country, especially the glorious achievements of "Two Bombs and One Satellite," the institute's party committee deeply realized that as the "national team" and "national people" of the country, they must take on more responsibilities and missions. Therefore, they set their sights on the international frontier field of space tribology and decided to establish a specialized team for space lubricating materials and technologies research.
Led by Academician of the Chinese Academy of Sciences and Director of the Lanzhou Institute of Chemical Physics Academic Committee, Researcher Liu Weimin, this team brought together 10 leaders such as Wang Qihua, Zhou Feng, Chen Jianmin, as well as nearly a hundred senior, mid-level, and young researchers and engineers. They jointly undertook the important task of providing high-performance lubricating materials for manned spaceflight, lunar exploration projects, and the International Space Station.
Fast forward to a day in June 2003, when Academician Chen Guilin of the Shanghai Institute of Technical Physics of the Chinese Academy of Sciences made a plea to Researcher Liu Weimin, who was then the deputy director of the Lanzhou Institute of Chemical Physics.
"At that time, the FY-2 meteorological satellite, which was in extended service, suddenly encountered a mechanical failure, and the root cause surprisingly pointed to a seemingly minor yet crucial aspect - lubrication failure, leading to partial jamming of the image rotation assembly," said Wang Qihua, secretary of the party committee of the Lanzhou Institute of Chemical Physics, to the "China Science Daily."
The aerospace lubricating oil on which FY-2 relied was the 114 silicone oil developed by the Lanzhou Institute of Chemical Physics since the 1970s. However, with the passage of time and technological advancements, the institute had shifted its main research focus to solid lubrication over the past decade. Faced with the urgent plea from FY-2, the task of restarting the aerospace lubricating oil development project fell on Liu Weimin's shoulders, undoubtedly a daunting challenge.
However, Liu Weimin did not back down. He deeply understood that as a member of a national scientific research institution, their mission was to serve the country's strategic needs. In the face of urgency and difficulty, he simply said, "The development of our lubrication technology has always been based on meeting the country's strategic needs. We will do whatever the country needs."
Liu Weimin made a prompt decision, convening the team overnight to discuss the plan to restart lubricating oil development. He knew that to accomplish this task, they needed to harness the full strength of the institute and, more importantly, the wisdom and experience of the older generation of researchers. Therefore, he personally reached out to retired senior scientists such as Duan Yurong and Pan Guangming, inviting them back to the laboratory to recreate past synthetic techniques and pass them on to the younger researchers.
Subsequently, Liu Weimin and the team members entered a tense research and development phase. They worked day and night, discussing design ideas and experimenting with new lubricant formulations. Despite numerous failures, they were not discouraged but rather strengthened their determination to overcome obstacles. After countless experiments and improvements, they finally succeeded in developing a new lubricant with at least 5 times higher anti-wear performance than the original product.
This success not only resolved the urgent crisis of the FY satellite but also directed the team's research focus towards both solid and liquid space lubrication, leading to the development of solid-liquid composite lubricating material technology. They successively designed more than 10 types of aerospace lubricating greases in 4 series, which not only enhanced the performance and reliability of Chinese spacecraft but also truly placed core technology in the hands of the Chinese people.
Chen Jianmin, Zhou Huidi, and others conducted simulated experiments on lubricating protective coatings in space environments. Image provided by Lanzhou Institute of Chemical Physics.
Let the Five-Star Red Flag Fly on the Moon
What is "cold welding"?
"In the high vacuum environment of space, the metal surface will lose the gases and other substances it has adsorbed. If the metal surface does not have an oxide film and is just metal atoms, then the two metal pieces will stick together as a whole, which is known as cold welding," said Wang Qihua.
It is reported that this cold welding phenomenon is common in space and may pose a threat to the moving parts of spacecraft, such as causing metal tearing, transfer, and increasing the roughness of the contact surface.
On December 4, 2020, the Chang'e-5 probe landed steadily on the lunar surface. Before the probe took off, a bright Five-Star Red Flag slowly unfolded on the moon. This was not just a display of the national flag, but also the first "independent dynamic display" achieved by China on the lunar surface, symbolizing the brilliant achievements of China's aerospace industry.
Unlike the flags painted on the "Chang'e-3" and "Chang'e-4" probes before, the Chang'e-5 carried a real "fabric version" of the Five-Star Red Flag. And behind this flag lies a technological challenge.
Leading this task was Chen Jianmin's team from Lanzhou Institute of Chemical Physics. Their biggest challenge was how to ensure that the flagpole mechanism would not fail to unfold properly due to cold welding in the extremely low vacuum environment on the moon. If the mechanism failed to unfold successfully, then all efforts would be in vain.
Facing this unprecedented challenge, Chen Jianmin and his team tackled it without hesitation. They continuously experimented, simulated outer space environments, and conducted numerous tests and demonstrations to meet the lightweight, small size, thin wall, high precision, and harsh environmental requirements of the unfolding system.
Chen Jianmin, a researcher at Lanzhou Institute of Chemical Physics, said, "The team modified high-strength resins using multi-functional group active resins. Through repeated experiments and adjustments to material parameters, they continuously optimized the solution. From accepting the task in 2013 to the successful flag unfolding in 2020, they went through 7 years of hard work, conducting more than 30 laboratory tests and 9 ground simulation experiments."
In the end, thanks to the relentless efforts of Chen Jianmin's team, the components of the flag unfolding system were successfully treated with anti-cold welding lubrication, and the Five-Star Red Flag finally unfurled slowly on the lunar surface.
Researcher Zhou Feng and others tested the rheological properties of a new type of ionic liquid. Provided by Lanzhou Institute of Chemical Physics.
"Striving for Technological Heights"
On May 13, 2024, Researcher Zhou Feng was in charge of the 71 items of extravehicular exposure experimental equipment and scientific experimental samples from Lanzhou Institute of Chemical Physics, which successfully landed back on Earth with the return capsule of the Shenzhou-17 manned spacecraft. These materials, including 18 sets of dynamic friction test equipment and 134 pieces of static lubricating material samples, had been in orbit for a year.
Compared to the Shenzhou-7 mission in 2008, this mission not only carried out static lubricating material experiments but also conducted dynamic friction experiments, including ball-on-disc friction experiments and the first bearing experiment. The extravehicular exposure experimental samples included solid lubricating materials and new supramolecular gel lubricating materials. This space station extravehicular flight experiment is also the world's first space friction and wear experiment conducted on liquid lubricating materials.
Partial experimental apparatus and scientific experiment samples. Provided by Lanzhou Institute of Chemical Physics.
Over the past five years, this team has made significant contributions to the development of China's aerospace industry. They have provided key lubricant material technologies for 278 launch missions involving 677 satellites, spacecraft, new types of aircraft, and deep space probes, including the "Ask-Tian" and "Dream-Tian" experimental modules, the "Shenzhou" series manned spacecraft, the "Tianzhou" series cargo spacecraft, and the "Chang Zheng" series carrier rockets. These contributions have effectively ensured the steady progress of China's aerospace industry.
"In the future, the team will delve into the mechanisms of friction and wear, explore the possibility of achieving near-zero friction (super lubrication), and innovate the research paradigm of lubricant materials," said Wang Qihua. The team will also focus on whether lubricant material technology can be made intelligent or adaptive to varying working conditions to cope with increasingly complex industrial environments.
Research Team on Space Lubricants and Technologies. Image provided by Lanzhou Institute of Chemical Physics.
The team aims to break through the technical bottlenecks in the preparation of lubricant base materials and high-end lubricant products, enhancing the performance and quality of lubricants. Simultaneously, they are advancing the development of lubrication technologies for equipment longevity, improving the overall lifespan and performance of machinery. Additionally, the team's future research focus includes multifunctional lubricant grease design and preparation techniques, greening and recycling technologies for lubrication products, as well as biomedical lubricant materials.
Speaking about personal insights, Academician Liu Weimin, the team leader, stated: "We do what the country needs. We are in the best era of technological innovation, and only by carrying a patriotic spirit and working tirelessly can we fulfill the mission of our time."
