A space elevator is a proposed type of space transportation system. The main component is a cable (also called a tether) anchored to the surface of the planetary body and extending into space. The design permits vehicles to travel along the cable, directly into space or orbit, without the use of large rockets. An Earth-based space elevator was first inaugurated in the 22nd Century, and soon others were placed strategically around the equator. At the end of these elevators, in space beyond geostationary orbit (35,800 km altitude) a counterweight station was established, serving as a docking and transfer hub. 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, results in the cable being held up, under tension, and stationary over a single position on the planetary surface. With the tether deployed, climbers repeatedly climb the tether to space by mechanical means, releasing their cargo to orbit. Climbers also descend the tether to return cargo to the surface from orbit.
Space elevators are the preferred method for transfer of goods, obviating the need of most planetary landers. That being said, there are a number of ships that do, but more often than not are used for colonization proceedings, long before the space elevators are up and functional on the planet below.