A theoretical megastructure consisting of a tether from Earth's surface to a counterweight in geostationary orbit, enabling payload transport to space without rockets.
Full Definition
A space elevator is a proposed structure connecting Earth's surface to geostationary orbit (35,786 km) via a long tether anchored at the equator and held taut by centrifugal force from a counterweight beyond GEO. Mechanical or electromagnetic climbers would travel up and down the tether carrying cargo and passengers. First proposed scientifically by Konstantin Tsiolkovsky in 1895 and popularised by Arthur C. Clarke in "The Fountains of Paradise" (1979). The primary engineering challenge is the tether material: required tensile strength far exceeds current materials. Carbon nanotubes and graphene are the leading candidates. Not yet technically feasible.
