An orbital supply station was a supply station located in orbit of a planet at the end of an orbital tether. The orbital tethers were traveled by a mag-lev carriage, which lifted cargo from the surface to the station.
The Nezu colony planet visited by USS Voyager in 2373 had multiple orbital tethers that were used to transport raw materials to orbital supply stations overhead. These stations were located in low orbit, well outside the ionosphere, over three hundred kilometers from the surface. The journey from the surface to the station on the tether took twelve hours to complete. (VOY: "Rise")