Immigrant life on the moon

The company named SOM Architecture Design Office designed the world-famous Burj Khalifa in Dubai, the tallest building in the world. Designing this landmark building has also become one of the characteristics of the company. The work of the architect in the company's new york office is even more amazing-designing drawings for SOM's first alien mission. The company is cooperating with the European Space Agency (ESA) and the Massachusetts Institute of Technology to design the lunar base.

Chief designer Daniel? Inocente showed the principle and effect diagram. In the picture, white pod-like buildings are scattered on the surface of the moon, connected by tubular walkways, surrounded by robots, solar panels and astronauts, all of which are exposed to the blue planet clearly visible in the sky.

Recently, the topic of sending humans back to the moon has become very hot, which is the first time since the end of the Apollo program in the 1970s. In 20 16, the director of the European space agency put forward the concept of "moon village" and deliberately described it very vaguely, encouraging private and public participants to cooperate with each other in robot and human exploration of the moon. In 20 18, eight volunteers from China successfully lived in the simulated lunar base of "Yuegong-1" for one year to test the life support system.

Although the private sector has no plans to send humans to the moon in the near future, the rockets of Space Exploration Technology Company and Blue Origin Company can indeed greatly reduce the cost of relevant government plans. Just a few months ago, US Vice President Mike? Burns promised to send astronauts to the moon again within five years.

Simply put, if human beings want to live on the moon, experts must solve some problems. For example, to cope with the harsh environment, use the moon's own materials to build buildings, master life-supporting technologies, and also need to solve the fatal problem that cannot be solved at present-dust.

As a real estate agent will tell you, the three most important factors in finding a livable place on the moon are location, location and location. SOM thinks the most suitable place is a piece of land on the edge of shackleton crater near the South Pole of the Moon.

There is tangible evidence that the permanent shadow area of the crater contains water left by ancient comets, which can be used for drinking, cooking, bathing and making concrete, and can also be decomposed into oxygen and hydrogen for rocket booster fuel.

However, no matter where they are built, space architects and engineers will be restricted by traditional pioneers. There is almost no air on the moon, so the habitat must be sealed and pressurized. In addition, although most space rocks will burn out in the earth's atmosphere, the surface of the moon will be constantly hit by meteoroids, so the building structure must be able to withstand their attacks.

The gravity on the moon is about 1/6 of that of the earth. In this environment, large-scale buildings can be built, but the number of anchorage points needs to be increased, and the weak gravity makes the excavation work very difficult, because it will bounce back if pushed down. In extreme temperatures, habitats must be equipped with powerful heating and cooling systems, and raw materials must have strong expansion and contraction properties.

Then there is radiation. The sun constantly emits high-speed protons and electrons, which is the solar wind. The earth's magnetic field protects us from the solar wind, but the moon has no magnetic field, so the solar wind will all hit the surface of the moon. Coronal mass ejections are more dangerous. In this process, a large number of protons and electrons with higher energy are ejected into space. When the projectile is strong, it may reach several sieverts on the surface of the moon (sieverts are the measurement unit of radiation exposure), and people may die if they don't return to Earth for bone marrow transplantation. Even if these dangers can be tolerated, astronauts on the moon will have to endure the continuous irradiation of galactic cosmic rays. In this way, astronauts will bear the risk of cancer for life.

Inocente described the company's proposal in SOM's new york office, that is, 3D printing the walls around the pod building in the lunar habitat to protect against deadly radiation. If you live for a long time, you need a protective wall 3 meters thick to resist galactic cosmic rays. It is unrealistic to transport a few tons of concrete from the earth, so astronauts need to "take local materials", that is, use whatever they have.

SOM's idea is to build a wall with lunar soil, but the lunar soil lacks organic matter, so it is more suitable to call it "surface debris". A construction method is 3D printing wall, where the wall is erected, or some bricks can be printed, so that they can be stacked and locked on each other. Some space architects propose to use machine-controlled nozzles to deposit cement with surface chips as the main material layer by layer.

However, what if the liquid used in the cement mixture evaporates or freezes before the wall or brick is formed? European researchers cooperated with Foster+Partners Architectural Design Company to explore adhesives and injection methods, hoping to prevent this from happening. They printed a wall with simulated surface debris, but it also meant that the contractor needed to transport liquid adhesive or special cement powder to the moon.

SOM prefers to use nozzles such as hot melt adhesive to extrude the melted surface drill cuttings. Another method is sintering, that is, heating the surface chips to make them close to the melting point until they are melted. In the RegoLight project of the European Space Agency, researchers focused sunlight into a strong beam, which swept the surface of the surface debris simulator and burned layers of bricks. This process is very slow, and the test brick is very fragile, so many researchers think that the final winning strategy will be microwave sintering, that is, using microwave ovens or light beams to bind dust. SOM is closely following the sintering research.

For relatively low habitats, it may only be necessary to pile surface chips on metal structures (leaving room for maintenance). Another clever way is to set the living area in the lava pipe of the moon, which is a large hollow pipe through which lava once flowed.

Debris on the surface can be used not only to protect buildings, but also to lay launch pads and roads. Brent, Chairman of the Aerospace Building Technical Committee of the American Institute of Aeronautics and Astronautics (AIAA)? Brent Sherwood put forward the idea of firing floor tiles in a microwave oven. If the platform where the plane landed and the road where the vehicle traveled are paved with this kind of brick, less dust will be raised. On this road, the terrain problems faced by robots when walking are also easier to solve. He said: "The idea is basically to transform the surface of the moon into a predictable workplace like an Amazon warehouse."

What is the living area of the lunar habitat behind the fence made of debris on the lunar surface? The ongoing design of SOM comes from the suggestions of engineers in the past decades, most of which are arch or cylindrical structures, as well as embedded and semi-embedded structures.

Space architects and engineers generally believe that the original lunar habitat will be similar to the cabin of the International Space Station (ISS). Mechanical and aviation engineer at Rutgers University, USA, and author of "The Construction of Lunar Habitat: An Engineering Method for Lunar Settlement" (springer Press, 20 18)? Haym Benaroya said that "the first generation technology may not be so fascinating" compared with the sci-fi renderings. The initial habitat will be some kind of pressure vessel covered with surface debris for radiation protection. In a sense, it will be an underground tin can.

According to Sherwood, who works in Boeing International Space Station, engineers already know how to build, test, launch and maintain this module. He said, "We learned a lot from the space station."

Eventually, we may turn to inflatable chambers with expandable volumes, but before that, we need to know how to integrate them into rigid structures and how to fold them so that they can be unfolded in an appropriate way. Bigelow Aerospace, headquartered in Las Vegas, has authorized NASA to use its patent to manufacture an inflatable module, which was put into the International Space Station for testing in 20 16. At present, the inflatable cabin is only used for storage, but Bigelow has been collecting the response data of the inflatable cabin to temperature change, radiation and space debris impact.

In cooperation with the European Space Agency, SOM chose a structure between tanks and balloons. The living area designed by SOM Architects is approximately cylindrical in shape and 9.5 meters high. The cabin has three floors and a vertical core for passengers to get on and off. The three inflatable parts are as high as the living area, which can increase the living space of all floors. There are three doors on the ground floor, connecting adjacent cabins.

In the process of designing Burj Khalifa, SOM does not need to consider the recycling of urine. The first life support system on the moon may take the form of "open loop", similar to the Apollo program, that is, supplying oxygen, food and water, and treating waste on the spot. A calculation shows that each person needs 5 to 15 tons of consumables every year, mainly air, food and water.

But the first step is likely to be a physical and chemical recovery system like the International Space Station. The space station will collect urine, waste water and condensed water produced by astronauts' sweat and breathing, and then filter them and turn them into drinking water. Use molecular sieve facilities (using silica crystals and alumina) to remove carbon dioxide from the air, and at the same time generate oxygen by electrolyzing water.

Nasa's next-generation life support project is studying some new methods, but the backbone technology expert Murray? Molly Anderson said, "We are not trying to invent a new chemical process." NASA mainly wants to improve the efficiency of the existing system, but also hopes that the hardware can be lighter, more reliable and easier to maintain. In terms of new equipment, the NASA team is testing the following models: space suit oxygen tank oxygen compressor, pyrolysis system that uses heat to decompose solid waste into useful elements, and portable DNA sequencer for monitoring microorganisms on the surface and inside of water bodies.

Anderson said that at least in one respect, life support on the moon is not as difficult as that on the International Space Station, that is, you can shower and flush toilets under gravity.

The next stage of life support on the moon is the biological regeneration system, in which the living things in the habitat can provide food, purify air and water, and decompose waste. MELiSSA of the European Space Agency once conducted an experiment in which three mice lived with some algae plants for six months. Rats convert oxygen into carbon dioxide, and seaweed plants convert carbon dioxide into oxygen.

We can even use living things to build buildings. Luck of the European Space Agency has cultivated bricks from mycelium and plants. Lacker also proved that fungi can withstand weightlessness and radiation similar to those on the moon. This locally grown material may have the potential to replace ground debris as a building material.

We may also need to build a mixed system, some of which comes from the earth. Even if scientists can modify crop genes to produce all the necessary nutrients, astronauts may still need all kinds of food to keep their intestines healthy, and people don't want to eat the same thing every day. Turning plants or algae into food also requires a lot of processing. Anderson said: "The purpose of sending astronauts there is not to let them farm."

Sherwood of the American Academy of Aeronautics and Astronautics agrees with the need for food diversification, especially if the moon is expected to attract space tourists. He said, "You can't run a hotel until you can make martinis and omelets." But we know nothing about cooking methods in low gravity.

In order for human beings to live on the moon, SOM also needs to plan the robot workforce. Sherwood said: "Manpower is not the best choice for survey, surface debris treatment, construction, resource exploitation and simple maintenance." SOM hopes that before humans live in it, robots can build a living cabin, perhaps a food manufacturing cabin, and build a surface debris wall.

In addition, there is a fatal problem for both humans and machines-dust. For billions of years, the impact of meteoroids has crushed the surface of the moon into sharp dust fragments with glass luster, and the surface of the moon lacks air or water to smooth the edges of the fragments. 10% to 20% by weight of lunar surface debris contains particles with a diameter less than 20 microns, similar to fine talcum powder.

The solar wind makes these particles electrostatic, so they will float and stick to anything, and they are so small that people can't see them at all. During the Apollo program, only a few hours after astronauts walked on the surface of the moon, dust began to agglomerate at the bottom of boots, wearing spacesuits, scratching lenses, damaging machinery, blocking air filters, and irritating astronauts' eyes and nose. Inhalation may cause cancer.

It is hard enough to go to the moon, and it is even harder to stay on the moon. But if engineers and architects can overcome these difficulties, we will have a world full of possibilities.

Matthew Hutson