What boy doesn't dream of becoming an astronaut? However, only a few people around the world can achieve this dream, and only very rich people can go on a private space flight. But in 2050, almost anyone will be able to get into orbit. After all Japan promises to launch the world's first by this time elevator to space.

Among the many efforts to explore outer space, one can separately highlight the initiative of the Japanese construction corporation Obayashi to create an orbital elevator. This vehicle, according to the authors, should appear by 2050. It promises to be the cheapest way to deliver people and cargo into space.

The elevator will move at a speed of 200 kilometers per hour along an ultra-strong and ultra-light cable leading from the earth's surface to a distant orbital station, where not only a scientific laboratory will be located, but also a hotel for space tourists, of whom, with the advent of this type of transport, there will be hundreds or even thousands of times more than exists in our time.

What makes Obayashi's bold promise possible is the development of new materials that can create fibers that are a hundred times stronger than steel. And these technologies are developing with every new year, with every new month.

There are also annual international technical competitions in which participants work on ideas for implementing a space elevator. They are developing new materials and innovative technologies for delivering cargo into orbit. At the same time, every year the ideas become more clear and promising.

The combination of the factors described above is what allows Obayashi Corporation to make stunning claims about the possibility of launching an orbital elevator by 2050.

Today, spacecraft explore the Moon, Sun, planets and asteroids, comets and interplanetary space. But chemically fueled rockets are still an expensive and low-power means of propelling payloads beyond Earth's gravity. Modern rocket technology has practically reached the limit of the capabilities set by the nature of chemical reactions. Has humanity reached a technological dead end? Not at all, if you look at the old idea of ​​a space elevator.

At the origins

The first person to seriously think about how to overcome the planet’s gravity using “pull-up” was one of the developers of jet vehicles, Felix Zander. Unlike the dreamer and inventor Baron Munchausen, Zander proposed a scientifically based option for a space elevator for the Moon. There is a point on the path between the Moon and the Earth at which the gravitational forces of these bodies balance each other. It is located at a distance of 60,000 km from the Moon. Closer to the Moon, lunar gravity will be stronger than Earth's, and further away it will be weaker. So if you connect the Moon with a cable to some asteroid left, say, at a distance of 70,000 km from the Moon, then only the cable will prevent the asteroid from falling to Earth. The cable will be constantly stretched by the force of gravity, and along it it will be possible to rise from the surface of the Moon beyond the limits of lunar gravity. From a scientific point of view, this is a completely correct idea. It did not immediately receive the attention it deserved only because in Zander’s time there were simply no materials from which the cable would not break under its own weight.

“In 1951, Professor Buckminster Fuller developed a free-floating ring bridge around the Earth's equator. All that is needed to make this idea a reality is a space elevator. And when will we have it? I wouldn't like to guess, so I'll adapt an answer that Arthur Kantrowitz gave when someone asked him a question about his laser launch system. The space elevator will be built 50 years after people stop laughing at the idea.”

(“Space elevator: thought experiment or key to the Universe?”, speech at the XXX International Congress on Astronautics, Munich, September 20, 1979.)

First ideas

The very first successes of astronautics again awakened the imagination of enthusiasts. In 1960, a young Soviet engineer Yuri Artsutanov drew attention to an interesting feature of the so-called geostationary satellites (GSS). These satellites are in a circular orbit exactly in the plane of the earth's equator and have an orbital period equal to the length of the earth's day. Therefore, a geostationary satellite constantly hovers over the same point on the equator. Artsutanov proposed connecting the GSS with a cable to a point located below it on the earth's equator. The cable will be motionless relative to the Earth, and along it the idea of ​​launching an elevator cabin into space suggests itself. This bright idea captured many minds. The famous writer Arthur C. Clarke even wrote a science fiction novel, “The Fountains of Paradise,” in which the entire plot is connected with the construction of a space elevator.

Today, the idea of ​​a space elevator on the GSS is already being implemented in the USA and Japan, and even competitions are being organized among the developers of this idea. The main efforts of designers are aimed at finding materials from which it is possible to make a cable 40,000 km long, capable of supporting not only its own weight, but also the weight of other structural parts. It’s great that a suitable substance for the cable has already been invented. These are carbon nanotubes. Their strength is several times higher than what is needed for a space elevator, but we still need to learn how to make a defect-free thread from such tubes tens of thousands of kilometers long. There is no doubt that such a technical problem will be solved sooner or later.

From Earth to low Earth orbit, cargo is delivered by traditional chemical fuel rockets. From there, orbital tugs drop cargo onto the “lower elevator platform,” which is securely anchored by a cable attached to the Moon. An elevator delivers cargo to the Moon. Due to the absence of the need for braking (and the rockets themselves) at the last stage and during ascent from the Moon, significant cost savings are possible. But, unlike the one described in the article, this configuration practically repeats Zander’s idea and does not solve the problem of removing the payload from the Earth, preserving rocket technology for this stage.

The second and also serious task on the way to building a space elevator is to develop an engine for the elevator and a system for its energy supply. After all, the cabin must climb 40,000 km without refueling until the very end of the climb! No one has yet figured out how to achieve this.

Unstable equilibrium

But the biggest, even insurmountable, difficulty for an elevator to a geostationary satellite is associated with the laws of celestial mechanics. The GSS is in its wonderful orbit only due to the balance of gravity and centrifugal force. Any violation of this balance leads to the satellite changing its orbit and moving away from its “standing point.” Even small inhomogeneities in the Earth's gravitational field, the tidal forces of the Sun and Moon, and the pressure of sunlight lead to the fact that satellites in geostationary orbit are constantly drifting. There is not the slightest doubt that, under the weight of the elevator system, the satellite will not be able to remain in geostationary orbit and will fall. There is, however, an illusion that it is possible to extend the tether far beyond geostationary orbit and place a massive counterweight at its far end. At first glance, the centrifugal force acting on the attached counterweight will tighten the cable so that the additional load from the cabin moving along it will not be able to change the position of the counterweight, and the elevator will remain in the working position. This would be true if, instead of a flexible cable, a rigid, unbending rod was used: then the energy of the Earth’s rotation would be transmitted through the rod to the cabin, and its movement would not lead to the appearance of a lateral force that is not compensated by the tension of the cable. And this force will inevitably disrupt the dynamic stability of the near-Earth elevator, and it will collapse!

Heavenly Playground

Fortunately for earthlings, nature has a wonderful solution in store for us - the Moon. Not only is the Moon so massive that no elevators can move it, it is also in an almost circular orbit and at the same time is always facing the Earth with one side! The idea simply suggests itself - to stretch an elevator between the Earth and the Moon, but secure the elevator cable with only one end, on the Moon. The second end of the cable can be lowered almost to the Earth itself, and the force of gravity will pull it like a string along the line connecting the centers of mass of the Earth and the Moon. The free end must not be allowed to reach the surface of the Earth. Our planet rotates around its axis, due to which the end of the cable will have a speed of about 400 m per second relative to the Earth’s surface, that is, move in the atmosphere at a speed greater than the speed of sound. No structure can withstand such air resistance. But if you lower the elevator car to a height of 30-50 km, where the air is quite rarefied, its resistance can be neglected. The cabin speed will remain about 0.4 km/s, and this speed is easily reached by modern high-altitude stratoplanes. By flying up to the elevator cabin and docking with it (this docking technique has long been worked out both in aircraft construction for in-flight refueling and in spacecraft), you can move the cargo from the side of the stratoplane to the cabin or back. After this, the elevator cabin will begin its ascent to the Moon, and the stratoplane will return to Earth. By the way, cargo delivered from the Moon can simply be dropped from the cabin by parachute and picked up safe and sound on the ground or in the ocean.

Avoiding collisions

An elevator connecting the Earth and the Moon must solve another important problem. In near-Earth space there are a large number of working spacecraft and several thousand inactive satellites, their fragments and other space debris. A collision between the elevator and any of them would cause the cable to break. In order to avoid this trouble, it is proposed to make the “lower” part of the cable, 60,000 km long, liftable and remove it from the movement zone of the Earth’s satellites when it is not needed there. Monitoring the positions of bodies in near-Earth space is quite capable of predicting periods when the movement of an elevator car in this area will be safe.

Winch for space elevator

The space elevator to the Moon has a serious problem. The cabins of conventional elevators move at a speed of no more than a few meters per second, and at this speed even an ascent to a height of 100 km (to the lower boundary of space) should take more than a day. Even if you move at the maximum speed of railway trains of 200 km/h, the journey to the Moon will take almost three months. An elevator capable of making only two flights to the Moon per year is unlikely to be in demand.

If you cover the cable with a film of superconductor, then it will be possible to move along the cable on a magnetic cushion without contact with its material. In this case, it will be possible to accelerate half the way and brake the cabin half the way.

A simple calculation shows that with an acceleration of 1 g (equivalent to the usual gravity on Earth), the entire journey to the Moon will take only 3.5 hours, that is, the cabin will be able to make three flights to the Moon every day. Scientists are actively working on the creation of superconductors that operate at room temperature, and their appearance can be expected in the foreseeable future.

To throw out the trash

It is interesting to note that halfway through the journey the cabin speed will reach 60 km/s. If, after acceleration, the payload is unhooked from the cabin, then at such a speed it can be directed to any point in the solar system, to any, even the most distant planet. This means that the elevator to the Moon will be able to provide rocket-free flights from Earth within the Solar System.

And the possibility of throwing harmful waste from the Earth to the Sun using an elevator will be completely exotic. Our native star is a nuclear furnace of such power that any waste, even radioactive, will burn without a trace. So a full-fledged elevator to the Moon can not only become the basis for mankind’s space expansion, but also a means of cleansing our planet from the waste of technical progress.

(GSO) due to centrifugal force. Rising along the cable, carrying payload. When rising, the load will be accelerated due to the rotation of the Earth, which will allow it to be sent beyond the Earth’s gravity at a sufficiently high altitude.

The cable requires an extremely large tensile strength combined with low density. Carbon nanotubes According to theoretical calculations, they seem to be a suitable material. If we assume their suitability for the manufacture of a cable, then the creation of a space elevator is a solvable engineering problem, although it requires the use of advanced developments and. The creation of the elevator is estimated at 7-12 billion US dollars. NASA is already funding relevant developments at the American Institute for Scientific Research, including the development of a lift capable of moving independently along a cable.

Design

There are several design options. Almost all of them include a base (base), cable (cable), lifts and counterweight.

Base

The base of a space elevator is the place on the surface of the planet where the cable is attached and the lifting of the cargo begins. It can be mobile, placed on an ocean-going vessel.

The advantage of a movable base is the ability to perform maneuvers to evade hurricanes and storms. The advantages of a stationary base are cheaper and more accessible energy sources, and the ability to reduce the length of the cable. The difference of a few kilometers of tether is relatively small, but can help reduce the required thickness of its middle part and the length of the part extending beyond geostationary orbit.

Cable

The cable must be made of a material with an extremely high tensile strength to specific gravity ratio. A space elevator will be economically justified if it is possible to produce on an industrial scale at a reasonable price a cable with a density comparable to graphite, and a strength of about 65-120 gigapascals.

In comparison, the strength of most types become- about 1 GPa, and even for its strongest types - no more than 5 GPa, and steel is heavy. Much lighter Kevlar strength is in the range of 2.6-4.1 GPa, and quartz fibers - up to 20 GPa and higher. Theoretical strength diamond there may be few fibers [for how long?] higher.

The technology for weaving such fibers is still in its infancy.

According to some scientists, even carbon nanotubes will never be strong enough to make a space elevator cable.

Experiments by scientists from the University of Technology Sydney made it possible to create graphene paper. Sample tests are encouraging: the density of the material is five to six times lower than that of steel, while the tensile strength is ten times higher than that of carbon steel. At the same time, graphene is a good conductor of electric current, which allows it to be used to transmit power to a lift, as a contact bus.

Thickening of the cable

The space elevator must support at least its own weight, which is considerable due to the length of the cable. Thickening on the one hand increases the strength of the cable, on the other, it adds its weight, and therefore the required strength. The load on it will vary in different places: in some cases, the section of the cable must withstand the weight of the segments located below, in others it must withstand centrifugal force, holding the upper parts of the tether in orbit. To satisfy this condition and to achieve optimality of the cable at each point, its thickness will be variable.

It can be shown that taking into account the Earth's gravity and centrifugal force (but not taking into account the smaller influence of the Moon and the Sun), the cross-section of the cable depending on the height will be described by the following formula:

Here is the cross-sectional area of ​​the cable as a function of the distance from center Earth.

The formula uses the following constants:

This equation describes a tether whose thickness first increases exponentially, then its growth slows down at an altitude of several Earth radii, and then it becomes constant, eventually reaching geostationary orbit. After this, the thickness begins to decrease again.

Thus, the ratio of the cross-sectional areas of the cable at the base and at the GSO ( r= 42,164 km) is:

Substituting here the density and strength of steel and the diameter of the cable at the ground level of 1 cm, we get a diameter at the GSO level of several hundred kilometers, which means that steel and other materials familiar to us are unsuitable for building an elevator.

It follows that there are four ways to achieve a more reasonable cable thickness at the GSO level:

Another way is to make the base of the elevator movable. Moving even at a speed of 100 m/s will already give a gain in circular speed by 20% and reduce the cable length by 20-25%, which will make it lighter by 50 percent or more. If you “anchor” the cable on a supersonic plane or train, then the gain in cable mass will no longer be measured in percentages, but in dozens of times (but losses due to air resistance are not taken into account).

Counterweight

A counterweight can be created in two ways - by attaching a heavy object (for example, asteroid , space settlement or space dock) beyond the geostationary orbit or the extension of the tether itself to a significant distance beyond the geostationary orbit. The second option has become more popular lately because it is easier to implement, and in addition, it is easier to launch loads to other planets from the end of an elongated cable, since it has a significant speed relative to the Earth.

Angular Momentum, Velocity and Tilt

The horizontal speed of each section of the cable increases with height in proportion to the distance to the center of the Earth, reaching in geostationary orbit escape velocity. Therefore, when lifting a load, he needs to receive additional angular momentum(horizontal speed).

Angular momentum is acquired due to the rotation of the Earth. At first the lift moves a little slower than the cable ( Coriolis effect), thereby “slowing down” the cable and slightly deflecting it to the west. At an ascent speed of 200 km/h, the cable will tilt by 1 degree. The horizontal component of tension in a non-vertical cable pulls the load to the side, accelerating it in an easterly direction (see diagram) - due to this, the elevator acquires additional speed. By Newton's third law the tether slows the Earth down by a small amount.

At the same time, the influence of centrifugal force forces the cable to return to an energetically favorable vertical position, so that it will be in a state of stable equilibrium. If the elevator's center of gravity is always above the geostationary orbit, regardless of the speed of the elevators, it will not fall.

By the time the cargo reaches the GEO, its angular momentum (horizontal velocity) is sufficient to launch the cargo into orbit.

When lowering the load, the reverse process will occur, tilting the cable to the east.

Launch into space

At the end of the cable at a height of 144,000 km, the tangential component of the speed will be 10.93 km/s, which is more than enough to leave Earth's gravitational field and launch ships towards Saturn. If an object is allowed to slide freely along the top of the cable, it will have enough speed to escape solar system. This will happen due to the transition of the total angular momentum of the cable (and the Earth) into the speed of the launched object.

To achieve even greater speeds, you can lengthen the cable or accelerate the load using electromagnetism.

Construction

Construction is carried out from a geostationary station. This is the only place where a spacecraft can land. One end descends to the surface of the Earth, stretched by the force of gravity. The other, for balancing, is in the opposite direction, being pulled by centrifugal force. This means that all materials for construction must be lifted into geostationary orbit in the traditional way, regardless of the cargo's destination. That is, the cost of lifting the entire space elevator into geostationary orbit is the minimum price of the project.

Savings from using a space elevator

Presumably, the space elevator will greatly reduce the cost of sending cargo into space. Space elevators are expensive to build, but their operating costs are low, so they are best used over long periods of time for very large volumes of cargo. Currently, the market for launching loads may not be large enough to justify building an elevator, but the dramatic reduction in price should lead to greater variety of loads. Other transport infrastructure - highways and railways - justifies itself in the same way.

There is still no answer to the question whether the space elevator will return the money invested in it or whether it would be better to invest it in the further development of rocket technology.

We should not forget about the limit on the number of relay satellites in geostationary orbit: currently, international agreements allow 360 satellites - one relay per angular degree, in order to avoid interference when broadcasting in the K u -frequency band. For C frequencies the number of satellites is limited to 180.

This circumstance explains the real commercial failure of the project, since the main financial costs of non-governmental organizations are focused on relay satellites occupying either geostationary orbit (television, communications) or lower orbits (global positioning systems, natural resource observation, etc.) .

However, the elevator can be a hybrid project and, in addition to the function of delivering cargo into orbit, remain a base for other research and commercial programs not related to transport.

Achievements

Since 2005, the annual Space Elevator Games competition has been held in the United States, organized by the Spaceward Foundation with the support of NASA. There are two categories in these competitions: “best cable” and “best robot (lift)”.

In the lift competition, the robot must overcome a set distance, climbing a vertical cable at a speed not lower than that established by the rules (in the 2007 competition, the standards were as follows: cable length - 100 m, minimum speed - 2 m/s). The best result of 2007 was covering a distance of 100 m with an average speed of 1.8 m/s.

The total prize fund for the Space Elevator Games competition in 2009 was $4 million.

In the rope strength competition, participants must provide a two-meter ring made of heavy-duty material weighing no more than 2 grams, which a special installation tests for rupture. To win the competition, the strength of the cable must be at least 50% greater in this indicator than the sample already available to NASA. So far, the best result belongs to the cable that withstood a load of up to 0.72 tons.

The competition does not include Liftport Group, which gained notoriety for its claims to launch a space elevator in 2018 (later pushed back to 2031). Liftport conducts its own experiments, for example, in 2006, a robotic lift climbed a strong rope stretched with the help of balloons. Out of one and a half kilometers, the lift managed to cover only 460 meters. In August-September 2012, the company launched a project to raise funds for new experiments with a lift on the site Kickstarter. Depending on the amount collected, it is planned to lift the robot 2 or more kilometers.

At the Space Elevator Games competition from November 4 to 6, 2009, a competition organized by the Spaceward Foundation and NASA took place in Southern California, on the territory of the Dryden Flight Research Center, within the boundaries of the famous Edwards AFB. The test length of the cable was 900 meters, the cable was lifted using a helicopter. The company took the leadership LaserMotive presenting a lift with a speed of 3.95 m/s, which is very close to the required speed. The elevator covered the entire length of the cable in 3 minutes 49 seconds; the elevator carried a payload of 0.4 kg. .

Similar projects

The space elevator is not the only project that uses tethers to launch satellites into orbit. One such project is Orbital Skyhook(orbital hook). Skyhook uses a tether that is not very long compared to a space elevator, which is in low Earth orbit and rotates quickly around its middle part. Due to this, one end of the cable moves relative to the Earth at a relatively low speed, and loads from hypersonic aircraft can be suspended from it. At the same time, the Skyhook design works like a giant flywheel - an accumulator of torque and kinetic energy. The advantage of the Skyhook project is its feasibility using existing technologies. The downside is that Skyhook uses energy from its motion to launch satellites, and this energy will need to be replenished somehow.

Space elevator in various works

• In the 1972 USSR film Petka in Space, the main character invents a space elevator.
• One of the famous works Arthur C. Clarke , Fountains of Paradise, is based on the idea of ​​a space elevator. In addition, the space elevator appears in the final part of his famous tetralogy Space Odyssey(3001: The Final Odyssey).
• In the series " Star Trek: Voyager"In episode 3x19 "Rise", a space elevator helps the crew escape from a planet with a dangerous atmosphere.
• In Game Civilization IV there is a space elevator. There he is one of the later “Great Miracles”.
• In a fantasy novel Timothy Zana"Silkworm" (Spinneret, 1985) mentions a planet capable of producing superfiber. One of the races, interested in the planet, wanted to get this fiber specifically for the construction of a space elevator.
• In Frank Schätzing's science fiction novel Limit, a space elevator acts as a central point of political intrigue in the near future.
• In the duology Sergei Lukyanenko « Stars are cool toys“One of the extraterrestrial civilizations, in the process of interstellar trade, delivered to Earth super-strong threads that could be used to build a space elevator. But extraterrestrial civilizations insisted exclusively on using them for their intended purpose - to help during childbirth.
• In a fantasy novel J. Scalzi"Doomed to Victory" ( English Scalzi, John. Old Man's War) space elevator systems are actively used on Earth, numerous terrestrial colonies and some planets of other highly developed intelligent races for communication with the berths of interstellar ships.
• In a fantasy novel Alexandra Gromova“Tomorrow is Eternity” the plot is built around the fact of the existence of a space elevator. There are two devices - a source and a receiver, which, using an “energy beam”, are capable of raising the elevator “cabin” into orbit.
• In a fantasy novel Alastair Reynolds“City of the Abyss” provides a detailed description of the structure and functioning of the space elevator, and describes the process of its destruction (as a result of a terrorist attack).
• In a fantasy novel Terry Pratchett"Strata" is present "Line" - an extra-long artificial molecule used as a space elevator.
• Mentioned in the band's song Sounds of Mu"Elevator to Heaven"
• At the very beginning of the Sonic Colors game, Sonic and Tails can be seen taking the space elevator to get to Dr. Eggman's Park.
• In the book Alexandra Zorich"Somnambulist 2" from the series Ethnogenesis, the main character Matvey Gumilyov (after planting a surrogate personality - Maskim Verkhovtsev, the personal pilot of Alpha's comrade, the head of the Star Fighters) travels in an orbital elevator.
• In the story “Little Snake” by the science fiction writer Alexandra Gromova the heroes use the space elevator “on the way” from the moon to the earth.
• In the series of science fiction novels George Martin"Taf's Travels" on the planet "S"atlem, an orbital elevator leads to a planetoid equipped like a spaceport.

In manga and anime

• In the third episode anime Edo Cyber ​​City with the help of a space elevator it was possible to ascend to the orbital cryogenic bank.
• IN Battle Angel features a cyclopean space elevator, at one end of which is the Sky City of Salem (for citizens) along with the lower city (for non-citizens), and at the other end is the space city of Yeru. A similar structure is located on the other side of the Earth.
• In anime Mobile Suit Gundam 00 There are three space elevators; a ring of solar panels is also attached to them, which allows the space elevator to be used for generating electricity.
• In the anime Z.O.E. Dolores features a space elevator, and also shows what could happen in the event of a terrorist attack.
• The space elevator is mentioned in the anime series Blood of the Trinity, in which the Arc spaceship serves as a counterweight.

see also

• Space Elevator: 2010 (English) Russian

Notes

Literature

• Yuri Artsutanov“To space - on an electric locomotive”, newspaper “ TVNZ" dated July 31, 1960.
• Alexander Bolonkin"Non-Rocket Space Launch and Flight", Elsevier, 2006, 488 pgs.

Despite the crisis and the war of sanctions, there is great interest in astronautics in civilized, economically developed countries. This is facilitated by advances in the development of rocket science and in the study of near-Earth space, the planets of the solar system and its periphery using spacecraft. More and more states are joining the space race. China and India loudly declare their ambitions to explore the Universe. The monopoly of state structures of Russia, the USA and Europe on flights beyond the Earth’s atmosphere is becoming a thing of the past. Businesses are showing increasing interest in transporting people and cargo into space orbit. Companies have appeared that are headed by enthusiasts who are in love with space. They are developing both new launch vehicles and new technologies that will make it possible to make a leap in the exploration of the Universe. Ideas that were considered unfeasible just yesterday are being seriously considered. And what was considered the fruit of the fevered imagination of science fiction writers is now one of the possible projects to be implemented in the near future.

One such project could be a space elevator.

How realistic is this? BBC journalist Nick Fleming tried to answer this question in his article “Elevator in Orbit: Science Fiction or a Matter of Time?”, which is brought to the attention of those interested in space.

Elevator to orbit: science fiction or a matter of time?

Thanks to space elevators capable of delivering people and cargo from the surface of the Earth into orbit, humanity could abandon the use of environmentally harmful rockets. But creating such a device is not easy, as a BBC Future correspondent found out.

When it comes to forecasts regarding the development of new technologies, many consider the authority of millionaire Elon Musk, one of the leaders in the non-governmental research sector, who came up with the idea of ​​​​the Hyperloop - a high-speed pipeline passenger service project between Los Angeles and San Francisco (travel time takes only 35 minutes). But there are projects that even Musk considers practically impossible. For example, the space elevator project.

“This is too technically complex a task. It is unlikely that a space elevator can be created in reality,” Musk said at a conference at the Massachusetts Institute of Technology last fall. In his opinion, it is easier to build a bridge between Los Angeles and Tokyo than to build an elevator into orbit.

The idea of ​​sending people and cargo into space inside capsules sliding upward along a giant cable held in place by the Earth's rotation is not new. Similar descriptions can be found in the works of science fiction writers such as Arthur C. Clarke. However, this concept has not yet been considered feasible in practice. Perhaps the belief that we can solve this extremely complex technical problem is, in fact, just self-deception?

Space elevator enthusiasts believe it is entirely possible to build one. In their opinion, rockets powered by toxic fuel are an outdated, dangerous for humans and nature, and excessively expensive form of space transport. The proposed alternative is essentially a railway line laid into orbit - a super-strong cable, one end of which is fixed to the Earth's surface, and the other to a counterweight located in geosynchronous orbit and therefore constantly hanging above one point on the Earth's surface. Electrical devices moving up and down along a cable would be used as elevator cabins. With space elevators, the cost of sending cargo into space could be reduced to $500 per kilogram - a figure that is now approximately $20,000 per kilogram, according to a recent report by the International Academy of Astronautics (IAA).

Space elevator enthusiasts point out the harmfulness of technologies for launching rockets into orbit

“This technology opens up phenomenal opportunities, it will provide humanity with access to the solar system,” says Peter Swan, president of the International Space Elevator Consortium ISEC and co-author of the IAA report. “I think that the first elevators will operate in automatic mode, and after 10 Within 15 years, we will have six to eight of these devices at our disposal that are safe enough to transport people."

Origins of the idea

The difficulty is that the height of such a structure must be up to 100,000 km - this is more than two earth equators. Accordingly, the structure must be strong enough to support its own weight. There is simply no material on Earth with the necessary strength characteristics.

But some scientists think that this problem can be solved already in the current century. A major Japanese construction company has announced that it plans to build a space elevator by 2050. And American researchers have recently created a new diamond-like material based on nanofilaments of compressed benzene, the strength of which could make a space elevator a reality within many of our lifetimes.

The concept of a space elevator was first considered in 1895 by Konstantin Tsiolkovsky. A Russian scientist, inspired by the recently built Eiffel Tower in Paris, began researching the physics of building a giant tower that could carry spacecraft into orbit without the use of rockets. Later, in 1979, science fiction writer Arthur C. Clarke mentioned this topic in his novel “The Fountains of Paradise” - his main character builds a space elevator, similar in design to the projects now being discussed.

The question is how to bring the idea to life. “I love the audacity of the space elevator concept,” says Kevin Fong, founder of the Center for Altitude, Space and Extreme Medicine at University College London. “I can understand why people find it so attractive: the ability to travel to low Earth orbits inexpensively and safely opens up the entire inner solar system for us.”

Security issues

However, building a space elevator won't be easy. “To begin with, the cable needs to be made of a super-strong but flexible material that has the necessary weight and density characteristics to support the weight of the vehicles moving on it, and at the same time be able to withstand constant lateral forces. This material simply does not exist right now,” says Fong. “In addition, the construction of such an elevator would require the most intensive use of spacecraft and the largest number of spacewalks in the history of mankind.”

According to him, safety issues cannot be ignored: “Even if we manage to overcome the enormous technical difficulties associated with building the elevator, the resulting structure will be a giant stretched string, driving spacecraft out of orbit and constantly being bombarded by space debris.”

Will tourists someday be able to use an elevator to travel into space?

Over the past 12 years, three detailed designs for a space elevator have been published around the world. The first is described by Brad Edwards and Eric Westling in the book “Space Elevators,” published in 2003. This elevator is designed to transport 20 tons of cargo using the energy of laser installations located on Earth. The estimated cost of transportation is $150 per kilogram, and the project cost is estimated at $6 billion.

In 2013, the IAA Academy developed this concept in its own project, providing increased protection of elevator cabins from atmospheric phenomena up to an altitude of 40 km, at which point the movement of the cabins into orbit should be powered by solar energy. The cost of transportation is $500 per kilogram, and the cost of building the first two such elevators is $13 billion.

Early space elevator concepts suggested a variety of possible solutions to the problem of a space counterweight to keep the cable taut, including using an asteroid captured and carried into orbit. The IAA report notes that such a solution may someday be implemented, but it is not possible in the near future.

Drogue"

To support a cable weighing 6,300 tons, the counterweight must weigh 1,900 tons. It can be partially formed from spaceships and other auxiliary devices that will be used to build the elevator. It is also possible to use nearby spent satellites by towing them into a new orbit.

They also propose making the “anchor” that attaches the cable to the Earth in the form of a floating platform the size of a large oil tanker or aircraft carrier, and placing it near the equator in order to increase its load-bearing capacity. An area 1000 km west of the Galapagos Islands, which is rarely subject to hurricanes, tornadoes and typhoons, is proposed as the optimal location for the “anchor”.

Space debris could be used as a counterweight at the top end of a space elevator cable

Obayashi Corp., one of Japan's five largest construction firms, last year announced plans to build a more robust space elevator that would carry automated maglev rides. Similar technology is used on high-speed railways. A stronger cable is needed because the Japanese elevator is supposed to be used to transport people. The cost of the project is estimated at $100 billion, while the cost of transporting cargo into orbit can be $50-100 per kilogram.

While there will undoubtedly be many technical challenges in building such an elevator, the only structural element that cannot yet be built is the cable itself, says Swan: “The only technological problem that needs to be solved is finding the right material to make the cable. That's all.” we can build the rest now."

Diamond threads

Currently, the most suitable cable material is carbon nanotubes, created in laboratory conditions in 1991. These cylindrical structures have a tensile strength of 63 gigapascals, that is, they are about 13 times stronger than the strongest steel.

The maximum achievable length of such nanotubes is constantly increasing - in 2013, Chinese scientists managed to increase it to half a meter. The authors of the IAA report predict that the kilometer will be reached by 2022, and by 2030. It will be possible to create nanotubes of suitable length for use in a space elevator.

Meanwhile, last September, a new, ultra-strong material emerged: in a paper published in the materials science journal Nature Materials, a team of scientists led by chemistry professor John Bedding of Pennsylvania State University reported producing super-thin “diamond nanothreads” in the laboratory that could even stronger than carbon nanotubes.

Scientists have compressed liquid benzene under 200,000 times atmospheric pressure. Then the pressure was slowly reduced, and it turned out that the benzene atoms rearranged, creating a highly ordered structure of pyramidal tetrahedra.

As a result, super-thin threads were formed, very similar in structure to diamond. Although their strength cannot be directly measured due to their ultra-small size, theoretical calculations indicate that these threads may be stronger than the strongest synthetic materials available.

Risk reduction

"If we can make diamond nanowires or carbon nanotubes of the right length and quality, we can be pretty sure they'll be strong enough to be used in a space elevator," says Bedding.

However, even if you manage to find a suitable material for the cable, assembling the structure will be very difficult. Most likely, difficulties will arise related to ensuring the safety of the project, the necessary financing and the proper management of competing interests. However, this does not stop Swan.

One way or another, humanity is striving for space and is ready to spend a lot of money on it

“Of course, we will face great difficulties, but problems had to be solved when building the first transcontinental railroad [in the United States] and when laying the Panama and Suez Canals,” he says. “It will take a lot of time and money, but, as in the case With any large project, you just need to solve problems as they arise, while gradually reducing possible risks."

Even Elon Musk is not ready to categorically dismiss the possibility of creating a space elevator. “I don’t think this idea is feasible today, but if someone can prove otherwise, that would be great,” he said at a conference at MIT last year.