Space elevator



A Space Elevator is the term given to an immense structure constructed by humans which is used to ferry large loads of materials into orbit of a planet. Space elevators generally consist of large structures of carbon nanofiber and metal rings which span straight up from the ground, literally miles high, ending at stations in space. Vehicles using the structure derive power from strands of superconducting material.

Space Elevators were once a common construction by UNSC, both on Earth and her colonies. There were at least two on Earth, the New Mombasa Orbital Elevator in New Mombasa and the Centennial Orbital Elevator in Havana. Before its loss in 2525, Harvest had seven elevators linked to the Tiara, the orbital port of Harvest. However, during the events of the Human-Covenant War, all of these elevators were destroyed during combat operations.

Real World Theory
A space elevator is a theoretical structure designed to transport material from a planet's surface into space. A Space elevator would consist of a cable attached to the surface on the equator and reaching outwards into space. By positioning it so that the total centrifugal force exceeds the total gravity, either by extending the cable or attaching a counterweight, the elevator would stay in place geosynchronously. Once moved far enough, climbers would be accelerated further by the planet's rotation.

The most common proposal is a tether, usually in the form of a cable or ribbon, that spans from the surface to a point beyond geosynchronous orbit. As the planet rotates, the inertia at the end of the tether counteracts gravity and keeps the tether taut. Vehicles can then climb the tether and escape the planet's gravity without the use of rockets. While the engineering of a structure is beyond current knowledge, as it requires an extremely light but extremely strong material (current estimates require a material ~2 g/cm³ in density and a tensile strength of ~70 Gpa). Such a structure could eventually permit delivery of great quantities of cargo and people to orbit, and at costs only a fraction of those associated with current means.

Links

 * Centennial Orbital Elevator
 * New Mombasa Orbital Elevator
 * Tiara
 * socialtext.net article