On February 22, the Long March-8 Yao-3 carrier rocket arrived at the Wenchang Cosmodrome in China, which will be used to launch the Queqiao-2 relay satellite of the fourth phase of the lunar exploration project. At present, the rocket has carried out various first-class tests at the launch site. Previously, in January and early February this year, the Chang'e-6 mission probe and the Queqiao-2 satellite had arrived at the launch site in advance, and they were also undergoing various pre-launch test preparations.
According to the plan, in the first half of this year, China will launch Queqiao-2 and Chang'e-6 successively. Chang'e-6 is to launch a probe to the far side of the moon to collect lunar soil, and then bring it back to Earth for study. So what is the role of Queqiao II? Because there is no direct communication between the far side of the moon and the earth, it is necessary to launch the Queqiao-2 relay satellite first, which can build a "queqiao" for the signal communication between the Chang'e-6 probe and the ground station that will go to the far side of the moon for sampling in the future.
Queqiao "Golden Umbrella" Soft spaceborne antenna metal mesh
Before Queqiao-2, in fact, more than five years ago, there was already a Queqiao relay satellite that provided communication relay services for Chang'e-4's landing and exploration mission on the far side of the moon. The striking feature of the Queqiao is that it has such a "golden umbrella", which is called a spaceborne large deployable antenna. Through this "golden umbrella", communication between the Earth and the far side of the Moon was realized. In the laboratory of Donghua University in Shanghai, there is a scaled sample of the umbrella-shaped antenna of the Queqiao relay satellite, which is actually made of metal.
In the laboratory of the School of Textiles of Donghua University, the reporter saw this "big umbrella", with a thin layer of yellow metal mesh on the umbrella bone. According to experts, the metal mesh is a key component of the spaceborne deployable antenna to reflect electromagnetic waves, which can be deployed in the process of launching into orbit, and the key to its ability to unfold the reflective surface lies in the warp knitting technology.
Chen Nanliang, professor of Donghua University and director of the Industrial Textile Engineering Research Center of the Ministry of Education:When the rocket is launched, it is shrunk inside the rocket. After reaching the orbit, it slowly unfolds the reflective surface of the satellite into a mesh antenna through the deployment mechanism, so we call it a deployable antenna. It's flexible, so it can be unfolded, so we have to weave it through weaving techniques to form such a cloth surface.
The raw material of the metal mesh on the spaceborne deployable antenna is metal molybdenum wire, and in order to increase its performance, experts have done more plating treatment and processing on the ultra-fine molybdenum wire.
Chen Nanliang, professor of Donghua University and director of the Industrial Textile Engineering Research Center of the Ministry of Education:The raw material we use is called gold-plated molybdenum wire, which is gold-plated on the basis of molybdenum wire, because the reflectivity of gold is very good.
Reporter:If the wire is unfolded, it is very thin, is there some special process to weave so evenly?
Chen Nanliang, professor of Donghua University and director of the Industrial Textile Engineering Research Center of the Ministry of Education:These are some of our key technologies. First of all, molybdenum filaments are very thin, about 15 to 30 microns, which is less than a quarter of the diameter of a human hair. Therefore, the drawing itself is very difficult, and there is also gold plating on the surface. After gold plating, to maintain a certain fastness, we doped some organic elements, on the one hand, to improve the toughness of the metal raw material, on the other hand, to make its surface have a better affinity. Therefore, some process improvements make the gold plating of molybdenum wire very strong in the weaving process.
Chen Nanliang, professor of Donghua University and director of the Industrial Textile Engineering Research Center of the Ministry of Education:The weaving process is relatively very delicate and complex, first we have to do the merging. Because it is so thin, we invented a parallel twisting technology, three wires are put together, and the structure is very stable.
Innovative weaving technology makes the satellite antenna metal mesh bigger and lighter
Experts told reporters that metal molybdenum wire is very soft, and single-strand molybdenum wire is not strong enough because it is too thin, so it is usually used to weave metal mesh with three or four molybdenum wires together. However, now, under the trend of large-scale satellites, the reflective surface of antennas is getting larger and larger, which is conducive to communication between heaven and earth. But the larger the area, the heavier the weight. How can you make an antenna big and light? The research team's innovative weaving technology has now made it possible to weave a single strand of molybdenum wire into a larger, lighter metal mesh, the largest of which is almost the size of a basketball court.
Since 2017, the innovation team of industrial textile flexible structural materials of Donghua University has begun to tackle the monofilament warp knitting technology of metal molybdenum wire. After 5 years of hard work, the "micro-tension" warp knitting technology and equipment have been innovatively developed, which greatly reduces the weight of the new antenna reflective surface.
Jiang Jinhua, professor of the School of Textiles, Donghua University:It may be lighter than the original 1 3 or 1 4, the cost may be lower, and the weight will be very lower. So, now the lightest mesh may weigh less than 20 grams per square meter.
The Land-Sound-4-01 antenna is close to the size of a basketball court
The reflective surface of the Land-based Exploration No. 4 01 satellite, which was launched in August 2023, is woven with ultra-fine metal molybdenum filament, and its large annular antenna deployment area is close to the area of a basketball court, which greatly improves the reflective surface area and communication capability of the deployable antenna of high-orbit satellites.
Jiang Jinhua, professor of the School of Textiles, Donghua University:Because the antenna may become larger and larger in the future, it may reach the level of 100 meters or kilometers, and the grid structure of monofilament is required to meet the application of ultra-large satellite antennas. Nowadays, communication is becoming more and more frequent, and the data throughput is increasing. If the caliber is too small, it will not be able to meet the frequent high-throughput data transmission. Now we are not only making molybdenum wire, we are also making other raw materials, and we are also doing some trial applications.
The "wings" of the heavenly boat are woven into the "tennis racket".
On January 17, the Tianzhou-7 cargo spacecraft sent a batch of daily necessities and experimental equipment to the space station. It turns out that the solar wing substrate of the Tianzhou cargo spacecraft is also braided, and its fiberglass mesh structure looks like a tennis racket.
Fiberglass mesh structure Lightweight and oxidation-resistant
According to reports, the Tianzhou cargo spacecraft uses semi-rigid solar wings, the frame of which is carbon fiber, and the middle is a mesh composed of fiberglass nets, similar to a tennis racket, and the solar cells are hooked on the fiberglass net. This fiberglass mesh structure has the characteristics of light weight, and has stronger protection against atomic oxygen and plasma in the low-orbit space environment.
Chen Nanliang, professor of Donghua University and director of the Industrial Textile Engineering Research Center of the Ministry of Education:There is a large amount of atomic oxygen in the space, and the oxidation capacity is very strong, so the general organic polymer materials are oxidized very strongly, so to choose a material with a very high oxidation resistance, we chose the inorganic material glass fiber.
Glass fiber has the advantages of anti-oxidation and light weight. However, it is very difficult to weave a net out of fiberglass.
Chen Nanliang, professor of Donghua University and director of the Industrial Textile Engineering Research Center of the Ministry of Education:Fiberglass also has a very big weakness, its weaving properties are very poor, because it is very brittle. Textile materials are closely related to the fineness of the fiber, and the finer the fiber, the stronger the softness. After twisting in strands, it becomes a very coarse raw material that can be woven to achieve such a goal.
Chen Nanliang, professor of Donghua University and director of the Industrial Textile Engineering Research Center of the Ministry of Education:It also has the benefit of being lightweight, all mesh, hooking the solar cell to it.
Glass fiber coated with resin is more resistant to space environment
After the fiberglass is woven into the substrate of the solar sail panel, it is also coated with resin to enhance its performance.
Jiang Jinhua, professor of the School of Textiles, Donghua University:The main purpose of coating resin is to make the surface smoother, and it can also play a protective role. Because resins like silicones are more resistant to space environments, and their stability and wear resistance can also be improved, and the overall performance can be greatly improved.
You don't know that you can do this with "textile".
The use of new materials and new weaving processes make the word textile more than just the concept of clothing. Like the "spaceborne antenna metal mesh" just mentioned, it has been applied to a variety of satellites such as Queqiao relay satellite, Beidou navigation satellite, and mobile communication satellite. Textiles are not only widely used in the aerospace field, but also in large aircraft manufacturing and even in biological applications.
Chen Nanliang, professor of Donghua University and director of the Industrial Textile Engineering Research Center of the Ministry of Education:Textile is a material, possibly a special material, such as aerospace. In the aerospace field, for example, deployable antennas, it needs to be larger. Steel is a hard material, and it can't be carried so big, and it can't be carried. So you need something soft to fold up, and then when it comes to the scene of use, only textiles can make this kind of soft thing.
Barrier-free communication Mobile phone with satellite
Chen Nanliang, professor of Donghua University and director of the Industrial Textile Engineering Research Center of the Ministry of Education:The large deployable antenna is mainly used to enhance the exchange of high-performance satellites and ground data, and is mainly used in some communication satellites and navigation satellites, and is also useful in Beidou. In the communication, there is a Tiantong satellite, which also uses a reflective surface antenna. Satellites and our mobile phones can communicate, and this antenna plays a very decisive role.
Biological application of vascular patches of organs
Chen Nanliang, professor of Donghua University and director of the Industrial Textile Engineering Research Center of the Ministry of Education:There are many application areas of textiles that can be expanded, such as the biomedical field. The organs, blood vessels, and patches of the human body are closely related to textile technology and textile products.
Carbon fiber fabrics make large airplanes
Chen Nanliang, professor of Donghua University and director of the Industrial Textile Engineering Research Center of the Ministry of Education:Now that C919 has used our country's carbon fiber fabric, the amount of C929 will be even greater. There are also many in the aerospace field, and this rigid material made of carbon fiber material has become very common. The application of flexible textile materials has just begun, so we talk about textile technology also has a very big prospect.
*: CCTV News Client Editor-in-charge: Yang Xue.