Unzervalt is a planet in in the Vela system. Corridor Nine, a special operations division of Star Control, launched an expidition to Vela during the first war. They discovered the earth-like water world of Unzervalt and decided to colonize it. Underneath the planet surface, the expiditionary team discovered a massive Precursor installation. When the installtion was activated, robotic workers buzzed to life and began constructing a starship on the planet surface.
The Captain was born on Unzervalt, and it was he who discovered how to operate the facility and the precursor starship. An expiditionary force was assembled for a voyage back to Earth. Star Control II picks up when The Captain arrives at Sol in his flagship.