A
space station, also known as an
orbital station or an
orbital space station, is a
spacecraft capable of supporting a crew, which is designed to remain in
space (most commonly as an
artificial satellite in
low Earth orbit) for an extended period of time and for other spacecraft to dock. A space station is distinguished from other spacecraft used for
human spaceflight by lack of major
propulsion or
landing systems. Instead, other vehicles transport people and cargo to and from the station. two space stations are in orbit: the
International Space Station, which is permanently manned, and China's
Tiangong-1 (which successfully launched on September 29, 2011), which is unmanned most of the time. Previous stations include the
Almaz and
Salyut series,
Skylab and most recently
Mir.