Titan Base

Titan Base was a large filling station on Titan in the 50th and 51st centuries. It had a crew of four. Three of them worked in shifts, arriving on the base by Titan shuttle and staying until a relief crew arrived. The fourth crew member was the commander, who seemed to have been a permanent inhabitant of the base.

In the year 5000, a relief crew infected by the Swarm took over Titan Base and tried to turn it into a Hive. The Fourth Doctor ignited fuel tanks at the base, which coupled with methane in the atmosphere to create an explosion which destroyed the base. (TV: The Invisible Enemy)

During his seventh incarnation, the Doctor returned to Titan Base in the company of Ace and Hector Thomas in 4920. The TARDIS had been commandeered by Hector, who had fallen under the control of the Swarm. The Swarm sought to ensure its own creation by returning to the Bi-Al Foundation on K4067, where it mutated from the Saturnian plague. (AUDIO: Revenge of the Swarm)