With the in-depth development of satellite technology in the fields of communications, space stations, and deep space exploration, air-to-ground exchanges are becoming more frequent, and there is an urgent need for large-scale satellite antennas. Mounting a large deployable space antenna on a satellite (or target aircraft) is the only way to achieve this goal.
One of the key materials of the deployable space antenna is a warp-knitted metal mesh with light weight, softness, high strength, stable structure, strong wavelength adaptability, high reflectivity, and strong deployment reliability. Because the wires used to make the metal mesh are extremely thin and the warp knitting is extremely difficult, only developed countries such as the United States, Russia, and Japan have mastered this technology.
The core component of the space antenna
On May 21, 2018, China used the Long March 4C carrier rocket at the Xichang Satellite Launch Center to successfully launch the Lunar Exploration Project Chang'e 4 mission Queqiao relay satellite into the air. The Queqiao relay satellite is the first special relay communication satellite outside the earth orbit in human history.
The Beidou satellite navigation system is a global satellite navigation system independently developed and operated by my country. It is called the world's four major satellite navigation systems together with the United States' global positioning system, Russia's GLONASS, and Europe's Galileo positioning system. On June 23, 2020, China's Beidou-3's last global networking satellite was launched into the sky, marking the complete completion of China's Beidou satellite navigation system. Dozens of navigation satellites in space are like chess pieces, precisely distributed in different orbits of the earth, providing high-quality communication positioning services for users in China and other countries around the world.
Space communication satellites such as the Queqiao relay satellite and Beidou satellite have a common key component-the deployable mesh antenna reflector, which plays the role of long-distance reflection of electromagnetic wave signals. The deployable mesh antenna reflector is the most important structure of large and ultra-large deployable space antennas. It is like an umbrella. It is stowed during launch and will be opened at the right time after entering space.
Among them, the metal mesh is the key component of the space antenna to reflect electromagnetic waves and the basic material of the spaceborne mesh antenna.
Metal mesh antenna woven with ultra-fine gold-plated molybdenum wire fiber
The weight is reduced by more than 90% compared to the previous similar products
In the laboratory of SHDH Engineering Research Center, there is a special "golden yellow metal umbrella": it neither protects from rain nor shades, and the special rib supports a thin layer of yellow metal mesh.
In fact, this special "umbrella" played a vital role in China's Beidou navigation satellites, mobile communication satellites and other series of space satellites. It not only created the history of Chinese satellites using independently developed metal mesh antennas, but also The key products of flexible antennas have played a milestone role in the localization process, laying a solid foundation for the on-orbit application of domestic metal meshes.
In the past, most antennas used traditional metal materials such as aluminum alloy, which had high density and high hardness, and could not be retracted freely in space. So, is there a material that can make the satellite antenna light, strong and stable?
Since 2008, SHDH's R&D team has jointly developed a new material metal mesh antenna with other Chinese research institutes.
In trial and error, the team members found that the gold-plated molybdenum wire material has the characteristics of high strength, low thermal expansion coefficient, high reflectivity, etc., which is an excellent choice for manufacturing the reflective surface of a spatially expandable mesh antenna.
However, it is not simple to make a metal mesh with gold-plated molybdenum wire, because the metal mesh must be strong enough to withstand the external force of launching and fly, and it must be soft and woven so that it can be easily collected and displayed in space. For the team, warp knitting technology is indispensable in order to obtain a "rigid and flexible" metal mesh.
Weaving is usually made of crossed warp and weft threads (the structure of shirt fabric), while warp knitting is like knitting a sweater by bending the yarns into loops and putting them on each other to form a fabric. In the production of mesh fabrics, compared with other production technologies, warp knitting technology is superior: the mesh structure produced is more extensible, more stable and firm, and is more suitable for the folding and unfolding of the reflective surface, and the satellites are in harsh conditions. "Survival" in the space environment.
The team used ultra-fine metal wire stranding and warp knitting technology to achieve a technological breakthrough in the stranding and twisting of ultra-fine gold-plated molybdenum filament fibers (only 1/4 fine hair strands), and designed and manufactured special doubling, warping and warping Edit equipment and design a full set of production processes.
This series of technological and technological breakthroughs not only successfully produced a "rigid and flexible" satellite antenna metal mesh, but also reduced the quality of this "big umbrella" by more than 90%. In the end, the project team broke through the key technology and industrialization of warp knitting production of high-performance satellite large-scale deployable flexible antenna metal mesh materials.
The "satellite antenna metal mesh" has played a vital role in many series of satellites such as China's Beidou navigation satellite and mobile communication satellite. This achievement not only opened the history of Chinese satellites using independently developed metal mesh antennas, but also laid a milestone foundation for the localization of key products of flexible antennas and the smooth application in orbit; it not only greatly improved the communication capabilities of Chinese satellites, but also It also makes my country the second country in the world that can develop a common satellite antenna for transmitting and receiving with a diameter of more than 10 meters after the United States.
In the future, SHDH will continue to devote itself to the research and development of high-performance industrial textiles. While improving and improving the "Tiangong" series of semi-rigid solar substrates, satellite-borne deployable antenna metal mesh and other applications, it will actively develop stratospheric airships and deployable space. Research on key aerospace materials such as cabins and space landing airbags.