At present, the mainland is comprehensively advancing the fourth phase of the lunar exploration project, including the Chang'e-6, Chang'e-7 and Chang'e-8 missions. Academician Wu Weiren, chief designer of China's lunar exploration project, once introduced that around 2024, Chang'e-6 will go to the far side of the moon to take samples; around 2026, Chang'e-7 plans to land at the south pole of the moon to find water on the moon; and after that, Chang'e-8 will not only carry out lunar material survey, but also undertake the work of 3D printing to build a house. Eventually, a basic scientific research station will be built at the south pole of the moon. Low gravity, strong radiation, large temperature differences, vacuum, and occasional moonquakes, as well as the complex environment and single materials on the lunar surface, all of these make the construction project on the moon an extremely challenging super project in the future.
Mortise and tenon structures to build interstellar building blocks
There are many options for the construction of lunar bases. For example, the spider robot working on the moon builds a lunar home like building blocks by vacuum-burning bricks, assembling, connecting, etc. In order to make the lunar base more robust, researchers also creatively proposed for the first time in the world to use the mortise and tenon structure of traditional Chinese architecture to build a lunar house. The craftsman wisdom of Chinese architecture has achieved a perfect combination with modern technology. Now, the Moon House is advancing simultaneously from materials to firing technology, to construction plans, and the research and development of robotic equipment. These technological advances will also have an important impact on the development of our geoengineering technology.
Application of mortise and tenon structure
The mortise and tenon structure, condensing the essence of Chinese architectural construction, was born in the Neolithic Age of Hemudu more than 7,000 years ago, and is a national memory earlier than Chinese characters. Its ingenious structure, the result of thousands of years of craftsmanship, is still impressive. The Chinese ancestors who were full of wisdom took the mortise and tenon structure as a starting point to build their homes, live in trees and multiply, and opened a splendid Chinese civilization.
Now, the mortise and tenon structure continues to appear in people's production and life with a new look and rich connotation, showing its enduring and timeless infinite charm. For example, the blades on the aircraft engine are a small improvement of the traditional mortise and tenon structure, and the "fir tree-shaped mortise and tenon structure" makes the aircraft more safe and reliable, and the bendable giant robotic arm outside the core module of the Chinese space station has seven "joints", which are connected by the mortise and tenon structure to achieve the crawling function outside the cabin in a way similar to peristalsis...... In the near future, mortise and tenon structures may also be applied to the moon to build a "moon house".
Let's take a closer look at how to build a "moon house" →
Visit the National Digital Construction Technology Innovation Center
Since 2015, Huazhong University of Science and Technology has taken the lead in starting related research work in China and has entered the frontier together.
At the National Digital Construction Technology Innovation Center at Huazhong University of Science and Technology, a sand table in the lab simulates a scenario for a future lunar base. A building with an arc structure like an eggshell is the prototype of the moon house designed by scientific researchers, and it has a vivid name called Moon Huzun. As a building, there are no load-bearing four beams and eight columns in the moon pot, and the top of the eggshell is a dome structure, and the eggshell body is divided into two layers, inside and outside, and a layer of ribbed structure is mixed in the middle to enhance stability.
Zhou Cheng, professor of Huazhong University of Science and Technology, National Digital Construction Technology Innovation Center: The construction of the lunar surface is mainly limited by the extreme environmental conditions of the local area, such as small gravity environment, vacuum environment, and at the same time, there are moonquakes and drastic temperature conditions, the temperature of the moon exceeds 180 °C during the day, and it reaches -190 °C on the moonlit night. These environments are very demanding and can have a very large impact on the structure, materials, and use of our lunar buildings. According to the team, the eggshell-like shell structure can maintain better stability, and at the same time, the airbag put into the eggshell can be automatically deployed, which has good thermal insulation performance and can form a real living space.
Zhou Cheng, professor at Huazhong University of Science and Technology, National Digital Construction Technology Innovation Center: We hope to use as few materials as possible, so that its weight is lighter, and at the same time, it is necessary to further improve its strength. The relevant results have just been published in a top international journal, which provides us with a good configuration that can adapt to the extreme environment of the lunar surface to do some research work.
Where do "lunar soil bricks" come from and how are they fired?
"It costs $200,000 to transport materials weighing a bottle of mineral water to the moon," is a high cost that people compare to interstellar transportation. This means that the scientific research team can only use lunar materials for in-situ construction as much as possible, that is, using lunar soil as a construction material, so how to fire "lunar soil bricks"?
CCTV reporter Zhang Chunling: If we want to build a house on the moon, a very important step is that we must first have materials. And on the moon is lunar soil, and in what way can lunar soil be sintered into bricks? In the laboratory, we have seen that some researchers are testing how to sinter into lunar soil bricks.
Wang Penglin, a student from the School of Civil and Hydraulic Engineering, Huazhong University of Science and Technology: The electromagnetic induction sintering furnace heats the mold by converting electrical energy into heat energy. In the process of using it, we can evenly heat and heat the lunar soil by placing it in the middle of the crucible.
The lunar soil materials simulated by the researchers in the laboratory are like sand, which are scattered, and they need to be fired at high temperatures, and the electromagnetic induction sintering furnace can heat the temperature to more than 1000 °C, and in about ten minutes, a simulated lunar brick with a length of 18 cm is fired. Another experimental area in the same laboratory is trying another way to prepare fired bricks.
Han Wenbin, Ph.D. student, School of Civil and Hydraulic Engineering, Huazhong University of Science and Technology: We mainly use a vacuum sintering method to sinter the simulated lunar soil. The graphite mold we used had an 18 mm diameter cavity inside. We first fill the powder that simulates lunar soil inside, compact it with a graphite indenter, and then assemble it in its entirety, and then put it into a vacuum sintering furnace together with the graphite mold. The vacuum degree of this sintering furnace can reach 10 minus 2 power pascals, it mainly uses a kind of electric heating, there are 10 heating rods distributed inside, it is silicon molybdenum material, and heat can be generated after being electrified. We place the simulated lunar soil and graphite inside the furnace, and the heat can be vacuumed and the material can be heated by thermal radiation.
According to the researchers, it takes about 24 hours to fire a simulated lunar brick in a vacuum environment, and the reason why the sintering test of this vacuum is also derived from the vacuum environment of the moon for a kind of simulated exploration.
Li Yuan, a student from the School of Civil and Hydraulic Engineering, Huazhong University of Science and Technology: We focus the sunlight on a point through a Fresnel lens, and in the future, the lunar soil will be placed on this point, and the lunar soil will be sintered into bricks through the high temperature of the focal point. On the Moon, a daylight is relatively long, which is very conducive to solar sintering construction on the Moon.
"Super Mason" 3D printing to build "Moon House"
If you have bricks, how can you build a house? Obviously, it cannot be done with manpower. This can only be achieved with automated machines and equipment. The research team found that the use of 3D printing technology is a path that can be explored at the beginning of the research. Now let's see, how these "super masons" built the "moon house".
Chen Quanyao, a student from the School of Civil and Hydraulic Engineering of Huazhong University of Science and Technology: We want to use the in-situ resources of the lunar surface to build the Moon Huzun base, and we have configured materials similar to the properties of lunar soil, and after configuration, we will complete the construction of 3D printing of the lunar base. For the finished product we printed, we should first compare the printed structure with the designed structure, judge its printing accuracy, identify the error, and then adjust it to facilitate the next printing experiment.
Finally, looking up at the starry sky, let's imagine the future of mankind through a map of the lunar base drawn by scientists.
The construction of a scientific research station on the moon is still advancing. There are also plans to use the lunar lava pipeline cave for the construction of a lunar scientific research station to avoid potential safety hazards such as huge temperature differences, high-intensity radiation and meteorite impacts, and to use the lunar lava pipeline to build a lunar farm. What kind of scheme will be used to build a lunar scientific research station in the future is still being further studied and demonstrated. With the continuous progress of science and technology, human beings still have infinite imagination and possibilities about the moon, the exploration of the moon, and even the exploration of deeper space.
(Source: CCTV News)