Jackson was the commander of the R1C on its quest to recover the Minyan race banks from the P7E. He was assisted in the completion of the quest by the Fourth Doctor, Leela and K9. (TV: Underworld)
Behind the scenes
Many of the names and incidents in Underworld were derived from the myth of Jason and the Argonauts. Jackson is an analogue to Jason, a parallel which the Fourth Doctor explicitly acknowledges in the story's final scene.
