Think of the regular elevators you see on Earth. Now imagine the same thing, but a few sizes bigger and instead of travelling between floors on a building, this elevator travels from the surface of our planet into space. That’s the concept of the magical space elevator.
In practice, a space elevator could help transport people and other cargo into space more efficiently than a rocket. It would also be less expensive and safer for its riders. On the inside the theoretical elevator, the trip into space would take a few days to reach its destination and move at about the speed of a train.
The mechanics of a space elevator would rely on a cable tied to Earth with a counterweight on the further end to orbit around the Earth. The cable is an essential part of the elevator, much like earthly elevators, as it is what allows its “climber vehicles” to move up and down quickly. While most blueprints of the elevator use the spinning of planet Earth to keep the cable tight, there are also other variations that move both ends of the cable completely into space. These plans are put into place with the hope of using lower gravity to make transportation easier.
However, one issue of the space elevator occurs in regards to the cable. In the 1960s, the concept of a “Sky-Hook” was presented in attempt to “elongate satellites.” However, the Sky-Hook’s cable was not thick enough, meaning that it could be easily damaged by micro-meteorites.
A special material would have to be used instead. Today, modern space elevators would have to be built with superstrong carbon nanotubes. For context, these pipes are 100 times stronger than steel at 1/6 of the weight.
Along the elevator, the dimensions of the nanotubes would somewhat vary. For example, the ends of the nanotube ribbon would have a greater width than the width between the base and geosynchronous orbit. This makes sense, if you think about other large structures such as Paris’s Eiffel Tower. Its base is much wider than it’s top. On the other hand, on the space elevator, the thickness of the nanotubes would be more constant, averaging at about one micron (1e-4 centimeters) across, adjusting according to tension.