The space elevator was proposed more than 100 years ago
There is such a story in “Bible Genesis”-the ground and the sky are connected by a “ladder”, through which people can travel between heaven and earth. In his dream, Jacob obtained the “sacred fire” along the ladder to the sky. Later generations called this dream ladder “Jacob’s Ladder”.
The concept of the space elevator was first proposed in 1895. At that time, Russian rocket expert Tsiolkovsky got inspiration from the Eiffel Tower in Paris and boldly proposed to build an “independent tower” from the surface of the earth to the height of its stationary orbit, and through a cable and an elevator cabin, The “tower” is connected to the ground so that the spacecraft can enter orbit without launching a rocket. However, this seemed like a fantasy at the time, and some people even mocked him as “it is better to switch to writing science fiction”.
However, since the concept of the space elevator was proposed, it has indeed become a common creative element in science fiction. In 1978, Arthur Clark, known as one of the three giants of modern science fiction, wrote this idea into his sci-fi masterpiece “The Fountain of Heaven.” This novel depicts that on a tropical island, people can travel to space for sightseeing or transport goods by taking a ladder that falls on the equator.
Liu Cixin, the winner of the “Hugo Award”, the world’s highest award for science fiction in 2015, also mentioned the space elevator many times in his science fiction book “Three Body”. There is a description:
”All space elevators have only one primary guide rail. Compared with the four guide rails in the design, the carrying capacity is much smaller, but it is no longer in the same way as the chemical rocket era. If you do not consider the construction of the ladder cost, the cost of access to space has now significantly lower than the civil aircraft
not only in the literary world, in reality, a space elevator also piqued the interest of researchers.
”I love this whimsical idea,” University of London School of height, space and extreme Kevin Fang, the founder of the Environmental Medicine Center, said in an interview with BBC TV News, “I can understand why people are attracted to the concept of space elevators. If we can enter space in a cheap and safe way, the entire solar system will become What’s in our bag. ”
Finding manufacturing materials is one of the biggest challenges
According to the imagination of scientists, the main body of the space elevator consists of five parts: ground base, cable, elevator cabin, space station and weight balancer.
Its mode of operation is roughly as follows: a cable is “thrown” from a geostationary satellite 36,000 kilometers away from the ground and sags to the ground base station. Under the interaction of gravity and centripetal acceleration, the cable is tightened; People and things are transported by cables; in addition, in order to maintain balance, a cable track of tens of thousands of kilometers must be erected on the other side of the space station away from the earth, and a weight balancer is connected to the end of the cable. The length of the entire cable is about 100,000 kilometers, roughly equivalent to 1/4 of the distance from the earth to the moon.
So what are the challenges in building a space elevator in reality?
From Gothic cathedrals to skyscrapers to space elevators, when constructing any high-rise building, firmness and balance of gravity are the two keys. But until now, the materials that can be used to make the ropes required for space elevators are still very few.
An ordinary steel wire hanging down from an altitude of 9 kilometers will be broken by its own weight. Fortunately, the discovery of carbon nanotubes has rekindled hope. In September 2014, American scientist and professor of chemistry at Penn State University John Barding published an article in Natural Materials, saying that they have developed ultra-fine and ultra-strong nanowires, which are stronger than previously discovered carbon nanotubes. And reliable. “Our nanowire is like a miniature necklace made up of the smallest diamonds. One of the craziest ideas is to make super strong light ropes, making the dream of building a space elevator a reality.” Budding said.
At present, the space elevator is no longer regarded as an “advanced proposition.” This project is gradually accepted by research institutions such as NASA and the European Space Agency. With the development of new material science, the space elevator has begun to move from fantasy to reality, and is no longer so remote.