Extraterrestrial settlement

Extraterrestrial settlement can be any type of permanent habitation outside of Earth, beyond its space boundary, such as:
 * Space settlement
 * Orbital space station
 * Cycler
 * Interstellar ark
 * Generation ship
 * Extraterrestrial surface settlement
 * Moonbase
 * Mars base
 * Extraterrestrial underground settlements
 * Extraterrestrial submerged settlements
 * Extraterrestrial floating settlements