Starbase

From The StarCraft 2 Wiki

The Starbase is a flying Starport that was used in Alpha versions of StarCraft II around August-September 2007, as an upgrade from a Starport that could move and produce at the same time. It was removed from current builds in 29th of September 2007, and has not been seen in any versions demonstrated since. The Starport which was supposed to upgrade into the Starbase remains in the game, still functioning as the base of Terrain air unit manufacturing.

Since the unit never made it beyond the Alpha phase, there are no real statistics for the Starbase. It is unclear if Starbases remain valid in terms of Starcraft canon, as they receives no mention in sources other than very early development versions of StarCraft II. Certainly the Terrans have demonstrated flying buildings and space-based construction capabilities, but Starbase facilities that manufacture space vehicles are as of yet unwitnessed.