A suborbital spaceplane is a spaceplane designed specifically for sub-orbital spaceflight. A few projects on civil and military suborbital spaceplanes were launched in Nazi Germany, the United States and the Soviet Union.
History
The first true suborbital spaceplane was the North American X-15, which first flew above the Kármán line in 1963.
The first privately built and privately funded suborbital spaceplane was Scaled Composites SpaceShipOne, which first flew above the Kármán line in 2004.
References
Suborbital spaceplane Wikipedia(Text) CC BY-SA