Most modern elevators use pulleys and an electric motor to move the elevator up and down. A pulley is a simple machine, made of a wheel with a cable looped around it. One end of the cable is attached to the elevator box. The other end of the cable is attached to a counterweight that reduces the energy needed to move the elevator. No one knows exactly how to build a space elevator, but the basic design uses a cable that stretches from an anchor on Earth up to a counterweight in space. The elevator box, called a climber, would travel up and down the cable. Some engineers imagine using pulleys and moving cables, just like in a modern elevator. Other engineers think that the cable would stay still and the climber would move up and down the cable.
The tallest structure humans have ever built is the Burj Khalifa in Dubai. This towering building is 829.8 meters (2722 feet) tall! But if you built a space elevator, it would need to reach up 35,400 km (22,000 miles). That’s more than 40,000 times taller than anything humans have ever built!
How far up into space should we go? If you want to build a space elevator, you need to reach Geostationary orbit. This is the point where the speed an object orbiting in space is exactly the same as the speed of Earth spinning below. At this point, the elevator cable will always remain straight up and down, and the destination would not move. If you built a space elevator, you would need to invent new materials. Your space elevator would need to be unbreakable, able to withstand weather in Earth’s atmosphere, radiation from the Sun, and impacts from space rocks.
Finish building the elevator with Cosmo in the episode above!