Wormholes

Wormholes are quasi-fourth dimensional links between two points in three dimensional space. They need outside stabilization or else they collapse into black holes, destroying anything nearby. Any man-made wormholes are purposely places outside of star clusters to minimize the potential risk to disrupting the stability of nearby interstellar systems. The U.S.S.S. Ursa Major and Ursa Minor were the first stations designed to create and stabilize wormholes for faster than light travel.