Space Elevator

Space Elevator

This term most often refers to a structure that reachs from the surface of the Earth to geosynchronous orbit (and beyond). The concept of a structure reaching to geosynchronous orbit was first conceived by Konstantin Tsiolkovsky, who proposed a compression structure, or "Tsiolkovsky tower." Most recent discussions focus on tensile structures or tether reaching from geosynchrous orbit to the ground. Space elevators have also sometimes been referred to as beanstalks, space bridges, space lifts, space ladders, skyhooks or orbital towers.

The most common proposal is a tether, usually in the form of a cable or ribbon, spanning from the surface near the equator to a point beyond geosynchronous orbit. As the planet rotates, the inertia at the end of the tether counteracts gravity, and also keeps the cable taut. Vehicles can then climb the tether and get in orbit without the use of rocket propulsion. Such a structure could theoretically permit delivery of cargo and people to orbit at a fraction of the cost of launching a payload into orbit, and without the substantial environmental harm caused by some rocket fuels.

Recent proposals for a space elevator are notable in their plans to incorporate carbon nanotubes into the tether design, thus providing a link between space exploration and nanotechnology.

Actual cable-scale technology is currently inadequate to build space elevators, but research is ongoing, and some people believe that technology to do this may soon exist.