The Space Elevator

The Space Elevator

A space elevator is a proposed type of space transportation system. The main component would be a cable (also called a tether) anchored to the surface and extending into space. The cable, ~100 000 km in length the design would permit vehicles to travel along the cable from a planetary surface, such as the Earth’s, directly into space or orbit, without the use of large rockets. An Earth-based space elevator would consist of a cable with one end attached to the surface near the equator and the other end in space beyond geostationary orbit (35,786 km altitude).

The competing forces of gravity, which is stronger at the lower end, and the outward/upward centrifugal force, which is stronger at the upper end, would result in the cable being held up, under tension, and stationary over a single position on Earth. With the tether deployed, climbers could repeatedly climb the tether to space by mechanical means, releasing their cargo to orbit. The mechanics of the cable is also revised and possible damage sources. Climbers could also descend the tether to return cargo to the surface from orbit.

The concept of a space elevator first came from an inventive Russian at the dawn of the space age [ Artsutanov, 1960] but the appearances of the space elevator I enjoy most came in several science fiction books. Arthur C. Clark put together an interesting tale of the construction of the first space elevator in Fountains of Paradise [Clarke, 1978]. Kim Stanley-Robinson had a different and well-thought out take on how the first space elevator might arise in Red Mars [Stanley-Robinson,1993]. These books point out many of the basic aspects and challenges of building a space elevator and keeping it operational. I highly
recommend them for their entertainment value but remember they are fiction and I wouldn’t suggest following their model for building a space elevator in reality, just follow their insights.