Chapter 230 Can this also be used to build a space station?
The only countries in the world that have experience in building space stations are America, Russia and China.

Except for China which has built a space station in recent years, the projects of America and Russia to launch space stations were both initiated fifty years ago.

It is too long ago, and the technology back then has undergone tremendous changes compared to today. With the help of new technologies and new materials, we can completely blaze a new trail.

Chen Yuanguang did not deny this, because it was not just new technology, but also the plug-in of future time and space, which was not a difficult thing for him to do.

Four hundred years later, humanity's space mining bases are located in the orbit of Venus.

“In my opinion, we should adopt a highly modular construction model.

Just like building blocks, we launch the most basic modules first. In addition to the structural system, power supply and distribution system, communication system, etc., we can also add two modules to these modules.

3D printing and external robotic arms. "As soon as Chris finished speaking, Chen Yuanguang's eyes lit up. The boss is the boss. The suggestions he put forward are almost exactly the same as the concept of a space station in the future.

“This may sound incredible, but what I mean is not to use 3D printing technology to quickly expand modules like Max Space’s plan.

Wright, have you heard of Max Space's business plan?"

Chen Yuanguang shook his head: "No."

Chris was not surprised. He thought it would be unusual if he had heard of it. After all, the other party was far away from Silicon Valley and it was difficult for him to understand the latest developments in Silicon Valley's commercial aerospace.

After all, the Max Space plan was only proposed in the first half of last year.

"Max Space is a commercial aerospace company in Silicon Valley. They hope to use 3D printing to package the materials on Earth and then transport them to the space station, where the equipment on the space station will be responsible for decompressing them.

Then it will expand from a small module of 1 cubic meter to a large module of 5 cubic meters just like inflating.

They are pinning their hopes on a completely new type of high-density fiber material.”

After listening to this, Chen Yuanguang quickly realized the problem: "This can indeed quickly launch a large number of modules into space in a short period of time.

After all, with the help of large-capacity reusable rockets, the transportation cost has been reduced to a very low level, and the size of the space station module has become a new problem.

But when they do this, how do they constrain the material to expand according to the effect they want?
More importantly, safety is a problem. Since it expands, it means there will be pressure. What if it explodes during transportation? "

Chris nodded: “Yes, this is the technical problem they have to overcome now.

So they demonstrated their technology at the Mars conference hosted by Bezos last year in an attempt to attract investment from Bezos.

When I say Max Space, I don't mean that we should adopt the same strategy as them, but I mean that adding 3D printing equipment to the space station is nothing new, and some people have already tried to do it.

Max Space has even done some testing work on the International Space Station.”

Chen Yuanguang probably knew why Chris said, "Chris, even if no one has done it before, we can do it.

You have to understand that there is no affiliation between me and the China Space Administration. Guangjia Aerospace operates entirely according to my personal will and is not responsible to anyone.

Therefore, we don’t need to do some feasibility research. No matter how radical your idea is and no organization has done it before, I will still discuss the feasibility with you.

As long as it is theoretically feasible and it does have unique advantages, I will find a way no matter how many technical difficulties there are to overcome.

We are a commercial organization and we pursue results, not stability.”

Chen Yuanguang was worried that Chris thought Guangjia Aerospace, like SpaceX, had a very deep relationship with the country's aerospace agency.

As a senior industry insider, Chris is very clear about China Aerospace's operating style, which can be summed up in one word: stable.

Chen Yuanguang thought that the other party was based on this logic, so he had to find some cases first to increase the reliability of the solution he mentioned.

Chris nodded: "I understand, that's right, a company that can catch up with SpaceX in reusable rockets in such a short time should be radical.

Let’s go back to the topic just now. The purpose of the 3D printing module we added is to print the connecting structure between modules.

Didn’t we say before that we want to design highly standardized modules? These modules are like building blocks, connected by some connectors.

These connectors can be produced by 3D printing equipment on the space station.

In the longer term future, the expansion of the space station can be completed directly by the space station itself.

I would also like to mention that asteroid mining is too difficult in a short period of time. We can start with lunar mining. There is not only helium 3 on the moon, but also a large amount of lunar rocks. These rocks can be used as raw materials for concrete.

The structural components of our space station can be built entirely of concrete.”

Chen Yuanguang doubted his ears because he had just told Chris that he could handle any radical plan, and he was embarrassed to say anything more.

However, the idea of ​​using concrete as space station components was a bit beyond Chen Yuanguang's understanding.

Because in the past it was believed that the components of the space station should be as light as possible, so aluminum alloy became the only option for both the International Space Station and the Chinese Space Station.

In the future, titanium and some other metal composite materials will become alternatives, and some special structured plastics are also possible. But concrete is somewhat beyond the scope.

"Concrete? I still don't quite understand the specific plan. Please explain it in more detail."

Chris nodded: "I know this plan is very shocking to people who hear it for the first time.

In fact, it is entirely possible.

Concrete is actually a very suitable material.

We use current concrete technology and can easily achieve 6000 psi compressive strength with proper mix design.

If superplasticizers are added, this strength increases to 10,000 psi, and treating superplasticized concrete with silica fume can increase its strength to 17,000 psi.

We can produce concrete on the moon, using lunar rocks as raw materials. The Boston Cement Association has previously conducted tests and found that lunar rocks are a very high-quality raw material.

There are not only lunar rocks on the moon, but also lunar dust, which is a substance similar to volcanic ash, which can be used as raw materials.

We are building a lunar base on the moon to extract lunar oxygen, and the water produced during the oxygen extraction process is used to make concrete.

The hydrogen needed to extract oxygen can be extracted directly from the lunar soil.

Hydrogen is injected into the lunar soil via the solar wind, reaching a concentration of 100 ppm.

If extracting hydrogen is not economically feasible, it can be extracted from the earth.

Previous studies of basalt and highland anorthite brought back by Apollo 17 have shown that it is entirely possible to produce cement with relatively high glass fiber and alumina content on the moon.

The lunar concrete is then sintered in a solar furnace.

Concrete made from this cement is strong but crumbles when it absorbs water. On the dry moon, this cement has advantages without disadvantages.

Due to the moon's low gravity and lack of an atmosphere, transporting construction materials from the lunar surface to Earth orbit could save a lot of energy compared to transporting construction materials from the Earth's surface.

The concrete will be mixed and poured outside the space station, which will provide temperature, pressure and humidity control.”

(Conceptual outer space concrete factory)
Chris asked Chen Yuanguang for a piece of paper, and then drew a simple conceptual blueprint of the outer space factory on the paper.

“You see, two rockets at the end of a tube extending from the module spin the system to provide the required centrifugal force.

Centrifugal force allows conventional mixers to be used in a weightless environment.

Concrete material will be pumped from the storage tank to the mixer through pipes.

Starting from the inlet position, the mixer rotates ninety degrees to an upright position and then rotates on its own axis to agitate the mixture.

By rotating an additional ninety degrees so that the feed opening faces outward, the mixer can discharge fresh concrete into a receiving bucket and the screw mass drive can pump the wet concrete to the pouring location.

After discharge into the formwork, the concrete is consolidated using appropriate vibrators and finished by the operator using a large trowel in a seamless environment.

In land-based construction, poured concrete is usually removed seven days after pouring. In a low-gravity environment, the seven-day requirement can be shortened to one day by reducing the system's rotation speed because less stress is placed on the concrete to cure.

Since it is expensive to create water in space, condensers can be used to capture the water that evaporates during solidification.

Once the concrete has dried sufficiently, the structure can be removed from the modules.

The application of this slip forming technology can help us build cylindrical space station modules of any size.”

External experience is also experience. After listening to it, Chen Yuanguang realized that this plan is completely feasible.

Although there are countless technical difficulties in building a lunar extraction base on the moon and then transporting concrete from the moon to space, it is completely feasible in theory. If you broaden your horizons, you will find that such a strategy will be very low-cost.

Because round trip from the moon to Earth orbit is more economical than between Earth and Earth orbit.

Even electrically powered rocket engines can do it.

In this way, the lunar base will be able to carry out lunar rock collection, solar and nuclear power plants, and round-trip aircraft, so that the expansion of the space station can be completed spontaneously in space.

“So the moon should be our next target after the space station.

In my design, we should design the space station into a long strip, with multiple cubes connected in series, infinitely connected, floating in the earth's orbit like a space train.

In the future, modules will be added around this train using lunar concrete technology.

It's like a tree. What we are building now is its trunk, and the future concrete modules are its branches and leaves." Chris concluded.

(End of this chapter)