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The moon space elevator is expected to come out first.
Recently, the elevator port group company founded by NASA’s former engineer Michael Lane stated that since building a space elevator on the moon is easier than building on the earth, the company can use existing technology to build a space elevator on the moon. And that this idea can be realized in 8 years.
At the end of the nineteenth century, he proposed fantasy
The main tool now entering space is the launch vehicle. It uses gravity fuel to escape the gravity of the Earth. Current carrier rockets carry more than 90% of the total weight of rockets, and they cost an average of about $10,000 a day for each kilogram of payload. Although space elevators are expensive, they do not require the use of large amounts of fuel. Therefore, the operating costs after completion are two orders of magnitude lower than that of launch vehicles, and they can operate 24 hours like highways, bringing spacecraft, related cargoes, and tourists with them. Go to space.
With a large sling, one end is fixed on the platform on the earth's equator, and the other end is tightly grasped on a spacecraft that is about 36,000 km from the ground and operates synchronously with the earth. The cargo is traveling along the sling into space... This is the space elevator that some national researchers are trying to design. It seems to be a scientific fantasy, but today, with the rapid development of technology, this dream is likely to become a reality.
The concept of space elevators was first proposed by Russian scientists and father of astronomers Tsiolkovsky in 1895. Since then, Tas Andel, an early Russian space prophet, also proposed to build a space elevator between Earth and the Moon. In 1979, the famous science fiction master Clarke once again proposed the concept of a space elevator in his novel "The Fountain of Paradise", and attracted extensive attention.
At a seminar held in Santa Fe, USA, on September 15, 2003, more than 70 scientists and engineers from Russia and the United States discussed space elevators and finally agreed that it will become a reality in the 21st century. In recent years, this revolutionary project that was once regarded as a science fiction has made great progress in some related technologies and has introduced various solutions.
Space elevators can also play an important role in building space solar stations. With the ever-increasing demand for energy by the Earth’s people, space solar stations may become the most attractive way to obtain energy. However, launching a space-based solar power plant with rockets generates vibrations and requires that the payload must be able to withstand the pressure at the time of launch. Therefore, conventional launching methods are not suitable for putting a large number of fragile solar panels into orbit, and space elevators do not There are these problems.
Space elevator built on the sea (schematic diagram).
Difficulties in the manufacture of high-strength ropes
The principle of a space elevator is not complicated. Basically, a long cable is fixed at one end to the earth, and the other end is fixed on the geosynchronous orbital balancer (such as a large satellite or space station). Under the interaction of gravity and centripetal acceleration, the cable is tightened and the space elevator will use solar energy or laser energy to move up and down the cable.
First of all, it is necessary to build a floating platform in the ocean. The platform should be located in a sea area where there are few storms, lightnings and huge waves. It should also be far away from the route of the aircraft and the orbit of the satellites. The space elevator must be able to prevent lightning, otherwise it will be easily cut off. According to design, the space elevator will weigh up to 20 tons. The whole shape is like a ball with a length of 100,000 kilometers under the ball to serve as the orbit of the space elevator.
The track rails are fixed at both ends of the cable and are driven by power converted from laser light emitted from the ground. It will be built into a tubular passageway that can carry spacecraft, various cargoes, and passengers into space when orbiting back and forth.
In short, launch a satellite or space station with a cable, so that one end of the cable falls back to the ground with a heavy object and eventually connects to the platform on Earth, while the other end deploys on a satellite or space station in outer space. As the Earth rotates, the space elevator's cables generate upward centrifugal force, while the gravity of the earth pulls down the cables so that the cables are balanced.
The human space elevator is a pressurized capsule. If a satellite is to be launched, when the satellite is sent from a space elevator to geostationary orbit, it naturally acquires the required speed of 3.08 km/sec in the geostationary orbit and becomes a geostationary satellite without additional acceleration. When launching a low-orbiting satellite, the satellite can be lifted along a space elevator, leaving the space elevator when it reaches a predetermined altitude. At this time, the satellite has obtained a certain tangential speed, and it will add a certain speed. If we increase the speed of replenishment, we can make the satellite off the earth and fly to the interplanetary space.
At present, Russia, the United States and Japan are all developing space elevators. The biggest obstacle to building space elevators comes from the construction of cables. It must be very light and extremely strong and able to withstand the impact of any object inside or outside the atmosphere that hits it. According to theoretical calculations, the material strength of the cable must be about 180 times that of steel. With the development of nanotechnology, scientists have continuously developed carbon nanotube fiber materials with light weight and high strength. The strength of such existing fiber materials has reached about one-fourth of the required strength, which makes the construction of space elevators gradually becoming may.
Take the space elevator to the sky (Schematic).
Moon gravity is easier to build than a space elevator
American scientist Pearson boldly envisioned a moon elevator program: to build a “lift†between the geostationary moon orbiting the moon and the moon’s surface. The “lift†was held by man-made composite fiber cables. The satellites seemed to fly. Kites in space. Pearson believes that this idea is theoretically feasible, because the lunar gravity is only 1/6th of the earth, and the synthetic fiber ropes that are manufactured on the current state-of-the-art level are sufficient to meet the strength requirements of the transportation work. At the same time, there are no dangers caused by abandoned rocket propellers, satellites, and other space debris around the Moon, which has spared the plan from a worries.
Some people may think that Pearson's idea is too crazy, but NASA's Advanced Concept Research Institute does not think so. This independent agency funded Pearson’s $75,000 in 2004 to design its lunar space elevator.
Now, the United States Elevator Harbor Group has proposed the actual plan for the moon space elevator: to build a lunar space elevator that faces the surface of the moon from 50,000 kilometers above the moon. Because the moon's gravitation is small and there is basically no air on the moon, it can be greatly reduced. With regard to the cable strength requirement, the dream of creating a moon elevator will be realized by using only a high-strength, high-heat-resistant composite fiber called Zylon.
The materials used to make the Moon Space Elevator are much lighter than those used to make Earth Space Elevators. One end of the cable is fixed to one of the lunar surfaces facing the Earth. However, the moon space elevator is small and can only transport 200-250 kg of cargo. However, if it is used to collect and transport lunar ore specimens, it will suffice, which will greatly reduce the cost of the moon's mining and transportation to the earth.
After the completion of the moon space elevator can also be integrated with the Earth space elevator, one day, the human only after a few transfers, you can take the space elevator to reach the moon from the earth.
There are still many engineering problems to overcome
At present, the biggest challenge in the development of space elevators is the ability to produce carbon nanotubes on a large scale at a relatively low cost. Because carbon nanotubes are still only millimeter-sized products, they are far from practical. Theoretically speaking, if carbon nanotubes of this material are used to make carbon nanowires with a diameter of 1 mm, the nanowires can carry a weight of 60 tons; and a 1 meter wide, paper-thin carbon nano cable can be used. Strength is enough to support a space elevator. However, scientists have so far been unable to woven long cables with carbon nanotubes. In addition, the value of carbon nanotubes per gram is 500 US dollars. It is very expensive to make a 100,000 km long carbon nanometer cable.
In addition, it is costly to launch various elevator construction materials into space, and if the space elevator collapses due to a serious accident, the loss is staggering.
Also, when the solar wind exerts pressure on the space elevators, the gravitational effects from the moon and the sun will make the ropes sway. This will likely cause space elevators to sway and create obstacles to space traffic. Space elevators may also collide with artificial satellites or debris from space. Such collisions will result in the breaking of ropes or the failure of space elevators. For this reason, space elevators must build propellers internally to stabilize the deadly swinging vibration of space elevators, but this will increase the difficulty of elevator construction and construction and maintenance costs.
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