Space Station (A World of Difference)

A space station is a spacecraft capable of supporting a crew which is designed to remain in space (most commonly in low Earth orbit) for an extended period of time, and to which other spacecraft can dock. Space stations are distinguished from other spacecraft by the fact that they have no real propulsion system. Currently there are five space stations in Earth orbit (the USSS, RSS, ISS, FSS, and JSS) and two in lunar orbit (the ALS and KLS), with one planned for Mars orbit. Space stations often have rotating crews, as permanent settlement in space (or other very low-gravity locations) would be irreversibly damaging to the human body.