Space elevator is a very high elevator that connects the ground and the universe, which is often seen in science fiction films or novels. This idea was first put forward by the famous Russian aerospace scientist, Constantine, who is called the father of human space navigation. Tsiolkovsky. When he visited the Eiffel Tower in France 126 years ago, in 1895, he came up with the idea of a cosmic elevator. Constantine is definitely a man of god. This man has never been to school, all his knowledge is taught by himself, and he has lived in a cabin in the suburbs of Russia for most of his life. As a result, the first cosmic speed was calculated in this cabin and the initial rocket model was designed.
Constantine is particularly interested in the universe and strongly advocates space colonization. He has a famous saying: "The earth is the cradle of human beings, but human beings can't live in the cradle all the time." Constantine firmly believes that man will eventually become a God-like being, who can control heaven, earth, time and even everything. He firmly believes that this is an inevitable result.
when Constantine put forward the idea of a space elevator, rockets had not yet come out, so it stayed at such an idea stage. It was not until 196, 65 years later, that a Russian engineer, Yuri? Archutanov, on the other hand, concretized Constantine's theory of cosmic elevator and put forward a possible concrete plan. According to common sense, we usually build elevators that feel like they should be built from the earth, but Yuri? Archutanov said it should be built from space. At a distance of 36, kilometers from the ground, there is a circular orbit-the geostationary orbit. The satellite running in this orbit is stationary relative to the earth's surface, which means that the satellite and the earth rotate at the same speed. After the satellite is launched into the geostationary orbit, a rope is extended from the satellite, and a heavy object is hung on the rope and hung to the earth. Theoretically, as long as the rope is long enough, it will definitely fall to the ground. After hanging to the ground, fix this end on the ground, so that the earth and the satellite are connected by ropes.
But there is a problem. When the weight hangs down, the center of gravity of the satellite and the weight as a whole will move down, leaving the geostationary orbit. In order to keep the satellite in the geostationary orbit all the time, it is necessary to extend a rope from the satellite in the opposite direction to the earth, which is consistent with the length of the rope and the rope hanging to the ground, which is also 36, kilometers. But the length of this 72,-kilometer rope is far from enough, because this rope is in a balanced state vertically on the ground, and it will fall when you pull it. So in order not to let it fall, the rope extending from the satellite to the universe has to be extended by 28, kilometers, that is to say, the rope from the earth to the satellite is 36, kilometers long, and the rope extending from the satellite to the universe is 64, kilometers, with a total length of ***1, kilometers.
Put this rope in place, climb this rope with an elevator, and complete the construction of a cosmic elevator. After the completion of the space elevator, it can theoretically carry 1 tons of goods. This space elevator is relatively simple in theory, so many countries have begun to try to do it. As a result, after 3 years, no country has made any progress. Until 1991, one country made a breakthrough, that is, Japan.
why haven't other countries made any breakthroughs except Japan? This brings up the core problem of building a cosmic elevator-the material of the rope. Ordinary steel can't do it. The density of steel is too high, which leads to its own weight. When it grows to a certain extent, it will break by itself due to its own weight. Just like people, if they grow too high, their legs will be unbearable. But trees can, and trees over 1 meters long are fine. So in theory, it is necessary to find a metal that is lighter than wood but heavier than steel. Thirty years from 196 to 199 were spent looking for such a material, but all in vain. It was not until 1991 that a physicist at NEC Laboratory in Tsukuba, Japan, Iijima Chengnan, discovered nano-carbon fiber tubes in carbon fibers. This nano carbon fiber tube is naturally generated, but it does not conform to the laws of nature, so it is called "supernatural material", which means that nature should not exist, but it just appeared. There are many associations, which may be left here by aliens, or the remains left by a high degree of civilization before.
The characteristics of this material-ultra-light, ultra-hard and flexible, can be made into carbon filaments with fine hair by carbon fiber tube, and one can lift a car, and the strength of several bundles can reach more than twice the strength required by the space elevator. However, this material can't be mass-produced at present, and it belongs to the molecular structure. In theory, it is necessary to connect one molecule with another. With the current technology, the length of 1, kilometers is far away. Japan now seems to feel that this matter is getting more hopeful, and they may have made a very big breakthrough in this technology. In particular, the famous Japanese construction company, Dalin Group, has published on its home page that it will realize the construction of the space elevator in 25. Dalin Formation is a construction company with a history of 13 years. It is especially good at building tall towers, such as the Sky Tower and Roppongi New Town.
on the other hand, why should a thing so difficult to build, the space elevator, be realized? How much benefit will it have after it is done? In fact, the only purpose of realizing the space elevator is to look forward to the rocket. The only way for people or things on earth to leave the earth now is to carry rockets. But there are many problems with rockets. The first is that the launch cost is too high. Today's rockets are much cheaper than before, but they cost hundreds of millions of dollars to launch at a time. Why is it so expensive? Because rockets are disposable, they can't be used after use. Of course, now the rockets launched by Musk's SpaceX company can be recycled and reused. Although the cost has dropped a lot, it will cost hundreds of millions of dollars. So is $1 million expensive? Boeing 787, a $3 million, is more expensive than a rocket. But airplanes can be used tens of thousands of times, and rockets can only be used once.
the second problem with rockets is that they are unsafe. Even now, the failure rate of rocket launch is still quite high. Although the success rate of rocket launch in China is high in recent years, there will still be several failures before. So if rockets are used to carry people, no one wants to take the risk. The Shenzhou-12 manned spacecraft launched in China these two days is equipped with a long March 2F remote launch vehicle with mature technology, but even if it is mature, I will be inexplicably nervous when watching the live broadcast.
the third problem is that rockets are not environmentally friendly. It has been said before that rockets are disposable. After they are lifted into the sky, they are thrown into space to form space garbage. These garbage rotate around the earth at high speed, so it is impossible to guarantee when they will hit satellites or other spacecraft, and these garbage will also collide with each other. Therefore, space junk has become a big topic now.
another is that the efficiency of rockets is too low. Rockets need to consume 2, tons of fuel to send 3 tons of materials to the universe, which is the least efficient means of transportation. To sum up, the rocket is such an unreasonable means of transportation with high cost, insecurity, environmental damage and low efficiency. So people want to find a solution that can replace rockets, and the space elevator is a very good choice.
The first advantage of the space elevator is that it is particularly safe. People will go up and down along the rope without much danger, so there will be a higher chance to send people into the universe. The second is low cost. The space elevator does not consume chemical fuel, but is driven by electricity. But electricity is transmitted from the earth to the elevator, and it can't be transmitted by wire, only by wireless. This wireless transmission is also a topic that Dalin Group said to solve. They want to realize 1, kilometers of long-distance power transmission before the construction of the space elevator. The technical difficulty of this remote transmission is not low, not to mention 1 thousand kilometers. If 2 thousand kilometers of remote transmission can be realized, wireless transmission can be carried out anywhere in the world. On the other hand, send electricity to the elevator remotely, and it will climb this rope by itself. At first, electricity was used. As time went by, when the speed became faster and faster, its kinetic energy was continuously converted into potential energy. When it exceeded the stationary orbit (36, kilometers), it could be thrown out by centrifugal force, so almost no electricity was used in the second half. When you return, you need electricity in the first half. When you run, it becomes a free fall. At the end, just slow it down. So the power consumption is not as much as expected.
so how fast can this elevator go? At present, the Dalin Group expects the speed to reach 2 kilometers per hour, but even if the speed is 2 kilometers per hour, it will take 5 hours, that is, 2 days, to run from the ground to the end of 1, kilometers. According to the calculation of Dalin Group, after the space elevator is built, the cost of space travel can be reduced to several hundred dollars, which means it can be cheaper than our general travel. So no matter how you look at it, the space elevator should be the direction of efforts.
Having said that, how much does it cost to build a space elevator? According to the calculation of Japan Space Elevator Association, it is estimated that it will cost 1 billion dollars to build a space elevator, which doesn't seem particularly expensive. Once it is built, it can be returned to the original in a few years. Bill Gates can build ten sets at this price, and it will cost ten times as much to build a full track of maglev trains in Japan, so this price is cost-effective.
The person in charge of Dalin Group said in an interview that they will start the construction of this project in 23. So before 23, three problems should be solved: (1) making 1, km long carbon fiber pipe materials; (2) Testing the strength of this 1,-kilometer-long carbon fiber pipe material; (3) Realize 1, kilometers of long-distance wireless power transmission. If wireless transmission power can really be realized before 23, then our life will be much simpler and more convenient. There are no wires at home, mobile phones don't need to be recharged, and new energy vehicles don't have to worry about battery life.
Why did Dalin Group do such a thing so actively? The reason is that they think the space elevator is very commercial. If it really costs a few hundred dollars, they can take a trip to the universe. I think most people in the world want to go once. And if there is such a building in any city, it will definitely become a landmark building in this city and become a landscape.
The space elevator is also of great significance as a very important infrastructure for space immigrants. In the future, human beings can't rely on rockets to develop the universe, emigrate to Mars, build cosmic cities, robotech, etc., because they need to transport a lot of building materials, which can only be realized by cosmic elevators. In addition, if the space elevator can be realized on the earth, it will be easily transplanted to Mars and the moon, and it will be easier to build on this planet with low gravity, because the requirements for materials will be much lower. If there is a cosmic elevator on these planets, it will be easier for us to get to these planets. At least we don't have to consider the problem of landing. We can fly directly to one end of the elevator and dock with it. It is very convenient for people to take the elevator to the surface of the planet.
another thing worth looking forward to is the convenience of bringing the substances in the universe back to the earth. Now it is necessary to bring the matter in the universe back to earth by spacecraft, such as the Apollo spacecraft in the United States and the Chang 'e-5 probe in China, but the carrying capacity is very small. But if there is a space elevator, you can take it back in chunks. In fact, there are a lot of resources in the space around the earth, all on meteorites. There used to be a lot of resources on our earth, but due to gravity, these things gradually sank into the core. Now they are all light things on the surface, and there are few heavy metals. But meteorites are different. What's on them is what it is, and it won't sink. At present, some asteroids found passing through our earth are all platinum and diamonds. As long as one is intercepted and transported down from the elevator in the universe, it will be developed.
but to whom do things in the universe come back to earth? In 215, the United States passed a bill, the Commercial Universe Development Competition Act, which stipulated that resources developed by individuals or legal persons in the universe were owned by individuals or legal persons. The basis of this law is a lotus principle in the International Law. Lotus Principle-In 1926, a French ship bound for Turkey collided with a Turkish ship near a Turkish port, knocked the latter over and boarded the no one lives. After the French ship docked, the Turkish police boarded the ship and arrested the French. So the international court of justice encountered a difficult problem, whether these French crew members could accept local trials and whether Turkish laws were applicable. Finally, the international court of justice gave an arbitration result, which can be applied. This was later called the Lotus Rule, because the French ship was called the Lotus. In fact, the Lotus Principle is just one sentence. If there is nothing prohibited in international law, each country can exercise jurisdiction according to the scope that its own country can control. The Universal Treaty stipulates that celestial bodies cannot be occupied, and no country can claim to own a planet. But the resources on the planet do not belong to celestial bodies, so resources can be owned by individuals or legal persons.
So the space elevator is such a very dreamy thing.