High Quality Content by WIKIPEDIA articles! An orbital propellant depot is a cache of propellant that is placed on an orbit about the Earth or another body to allow spacecraft to be fueled in space. Launching a spacecraft separately from some of its propellant enables missions with more massive payloads. It also facilitates life extension for satellites that have nearly reached end-of-life by consuming nearly all of their orbital maneuvering fuel. The spacecraft would conduct a space rendezvous with the depot, or vice versa, and then transfer propellant to be used for subsequent orbital maneuvers. An in-space fuel depot (alternative name) is not necessarily located near or at a space station.