Sorben was the pilot of the Solaros 10 spaceship, which guided by the genius of Professor Parsek, managed to break the barrier and travel faster than the speed of light. It wasn’t a total success as Professor Parsec underwent a mutation when he was caught in an explosion and a mutation field. The Doctor’s timely intervention saw the effects reversed, the ship stabilised and both Sorben and Parsek were saved their mission a success. (DWA: Faster Than Light)