Everyone has taken the elevator, but have you ever taken the elevator that goes straight to the sky or even goes straight to space with one click? If there is such an space elevator , it is no exaggeration to be called the real-life version of the "Tower of Heaven".
Note that this is not a plot that only occurs in the novel. Recently, at the 2022 space technology Peaceful Utilization (Health) International Symposium, Peter Swan, Chairman of the International Space Elevator Alliance and an academician of the International Academy of Aerospace Sciences, confirmed this conjecture. space elevators may no longer be a dream in the future.
Another crystallization of human imagination: space elevator
The most important reason why humans are different from other creatures is that we will think about things other than survival, and to say what is the brightest pearl of everything humans think about is the unparalleled "imagination".
If we do not have imagination and we will only focus on everything in front of us, then all the progress in human history will become empty talk. Take a science fiction novel written by the famous French novelist 19th century Verne , which provides many scientists with inspiration for invention. For example, his book "Twenty Thousand Miles Under the Sea" directly gave birth to modern submersibles, and his book "Sail of Clouds" promoted the birth of modern helicopters.
Verne and Argonaut submarine
Like the modern technology mentioned above, space elevators were originally just a concept by people.
The famous Russian scholar Konstantin Thiorkovs was the first person to propose the concept of a space ladder. He was shocked by the magnificence of the Eiffel Tower , so he imagined a "Sky Castle" built on the top of the giant tower. The height of this castle is far greater than all the buildings currently known to mankind and will be directly built on a stationary orbit tens of thousands of miles away from the earth.
The idea that humans go to space through the "Sky Castle"
Later, many science fiction writers wrote space elevators into their own science fiction novels. At present, the earliest known description of the technical level of space elevators comes from the science fiction master Arthur Clark .
In its 1978 science fiction novel "Foot of Heaven", Arthur Clark directly pointed out the two uses of space elevators: people can not only take the elevator to see the space, but the space elevator itself can also serve as a means of transporting goods.
The ladder designed by NASA
With the development of the times and the advancement of science and technology, more and more scientists have begun to gradually improve the concept of space elevators. In 1999, NASA published an article titled "Ladder: Advanced Infrastructure of Space", which directly marked the beginning of space elevators from fantasy to reality.
At present, in addition to NASA, many space agencies, including the European Space Agency, have publicly claimed that they are developing space elevators, and the International Space Elevator Alliance has been established.
With spacecraft, why do you still need to study space elevators?
So what exactly is a space elevator? What advantages does it have compared with ordinary space facilities that can attract so many space agencies to compete for research and development?
Space elevator connects to near-Earth space station science fiction concept map
Sample-to-size-fits-to-go-to-space elevator. Unlike ordinary elevators, space elevators do not travel between floors, but directly send people and goods to space station , which is far away from thousands of miles away.
Not long ago, my country's Changqi rocket launched the Tianzhou 5 cargo spacecraft mission, which marked another latest progress in the construction mission of the China space station " Tiangong " construction mission. It is understood that my country will complete the construction of space station in orbit by the end of 2022, and by then, the Chinese will have their own space station. All the achievements made by China's aerospace are inseparable from our "Long March" series launch vehicle .
China Space Station
Since the retirement of the space shuttle in 2011, the launch vehicle , which uses liquid or solid fuel as propellant, has become the only vehicle that humans can travel back and forth to space. Although some countries have now successfully developed launch vehicles for recycling, the cost of launching and maintaining launch vehicles remains high. Because of this, the vast space has attracted only a few players, and most countries are simply unable to participate in this space "game".
US Space Shuttle + Launch Vehicle
But the money of these space powers is not blown by strong winds. At present, many space agencies are trying their best to reduce their operating costs of , and space elevators have become one of the better choices.
1. Cost is lower
According to international unified standards, the launch cost of human launch vehicles is calculated in kilograms. Currently, the launch cost per kilogram ranges from about 6,000 to 12,000 US dollars. Although it doesn't sound like a lot, for a launch vehicle with tons of calculation unit , the launch cost can be said to be an astronomical figure, which is really not something that ordinary countries can afford.
Russian heavy launch vehicle
Compared with launch vehicles, the operating cost of space elevators is lower because it is a reusable equipment. According to scientists' calculations, if a space elevator is built, the transportation cost per kilogram of material will be directly reduced to about $500. If the future material transportation is replaced by a launch vehicle to a space elevator, it will save a lot of money. These funds can be used for other space projects such as space station construction, moon exploration, and interstellar travel research.
2. More environmentally friendly
In addition to the high launch and operation costs, launch vehicles also have the disadvantage of being extremely easy to produce space garbage.
carrier rocket stage fallout diagram
carrier rocket mainly relies on engine consumption booster forward. After fuel consumption of each stage of rocket will fall off from the rocket body, and then freely falls in the atmosphere . Although most of the falling rockets will burn out in the atmosphere, there will still be many residues surrounding the near-Earth space. Due to the lack of air friction, over time, these residues will become the so-called " space garbage ", causing great trouble to mankind.
space garbage surrounding the earth
space garbage from small space garbage from combustion residues of launch vehicles to large types of spacecraft that are difficult to recover (such as abandoned satellite , abandoned space stations, etc.), they will not only pose a threat to the safety of other spacecraft, but also cause considerable losses if some space garbage falls on the ground.
If the launch vehicle is successfully replaced with a space elevator, it will greatly alleviate the problem of space garbage, because running a space elevator does not require rocket disengagement and other steps, and since contact with the ground is easier to repair, it is unlikely to generate space garbage.
3. Space travel prospects are broad
In 2021, the first commercial space travel mission project of the American commercial space company SpaceX was a complete success. During this period, the "all-civilian human" composed of four non-professional astronauts achieved the goal of three-day travel around the earth.
crew members from left to right: Christopher Senbrouski, Xi'an Proctor, Jared Isaacman and Hayley Arkeno
This is just a small step of exploration of human space travel. With the continuous exploration of companies such as SpaceX, Blue Origin , Virgin Galaxy, etc., commercial space travel will gradually become popular in the future. According to UBS Group's forecast, by 2030, the potential market value of space tourism will reach US$3 billion, and the future prospects will be unlimited.
But it should be noted that due to the complex aerospace technology, the operating costs of launch vehicles remain high. At this stage, commercial space travel is still just the "cake" for a few rich people. For example, all the funds spent on SpaceX's commercial space travel mission were borne by a 38-year-old American billionaire Jared Isaacman, which is far from affordable by ordinary families.
SpaceX "Dragon" spacecraft successfully launched the first commercial manned space mission
It can be foreseen that in addition to the necessary technological progress, if space travel is to truly popularize all mankind in the future, reducing costs is the top priority, and a space elevator with extremely low operating costs is undoubtedly one of the better choices.
It will take time to move from imagination to reality
With the continuous development of modern technology, space elevators are no longer an out of reach dream.
to build a space elevator. Apart from the necessary capital investment, the most important thing is to solve a series of technical problems. Scientists have made a lot of progress in many theories.
1. Design theory is gradually improved
. Since the construction height exceeds any building in human history, in order to successfully build a space elevator, new building materials must be developed so that the overall strength and stretchability of the building can adapt to a height of 10,000 meters. At this stage, scientists have successfully developed carbon nanotube and super-strong graphene, which are believed to be able to basically meet the actual requirements of building space elevators.
Carbon nanotubes and super strong graphene structural diagram
Just having perfect building materials is far from enough, and building space elevators requires scientific and reasonable design solutions. At present, the scientific community has proposed 8 design plans. In theory, they can all successfully build perfect space elevators, and many solutions are already in experiments and are not far from the final implementation.
2. Details still need to be overcome
, but you must know that the final construction of any project, solving macro theoretical problems is always just the first step. In human history, although the theoretical design of many major countries has long been successful, many detailed problems need to be solved in the actual construction process. Often, these details are the biggest troubles that hinder the progress of the project.
According to scientists, before the real construction of a space elevator, a series of detailed problems still need to be solved first:
Space elevators are all details
Space elevators span a height of 10,000 meters, what kind of power device can meet the promotion needs? If rocket propulsion is used, how can there be obvious advantages compared to the current launch vehicle? Therefore, humans need to abandon their original rocket ideas and build brand new high-power engines on the earth to support the operation of space elevators.
Space elevator concept across the earth and moon
Once the speed of high-rise elevators is too fast, it will make people feel uncomfortable. Since you want to use space elevators to achieve space travel, the appropriate round-trip speed is a problem that must be solved. According to the current design plan, the space elevator runs at about 200 kilometers per hour. In theory, since there is no need to worry about fuel loss, its continuous operation time is longer than that of ordinary launch vehicles.
If the space elevator in the future achieves interstellar leap, it is expected to reach the moon in just 14 days, and it will only take about 2 months or 61 days to reach Mars .
Conceptual map of different types of space elevators
Although space elevators can effectively avoid the generation of sky garbage, the space garbage that existed before will still threaten the normal operation of the elevator. If the elevator suddenly encounters space debris impact during operation, what safety measures can protect the safety of passengers and cargo?
has countless detailed problems that need to be solved, but this is not enough to hinder human beings' pace of building space elevators. The progress of human history is difficult to move forward in the struggle against technical problems again and again.
Conclusion
At present, if all technical problems can be solved reasonably, scientists estimate that the space elevator will be put into operation by around 2035 as early as possible. However, as a space project as huge as International Space Station , it actually requires unity and unity among all countries. Only by gathering the power of all mankind can the space elevator truly move from ideas to reality.
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