Felix Mather was an astronaut who later became the President of the United States.
The Doctor met Mather after his election to the position of President while investigating phony time traveler Baskerville. At this point Mather was the only politician that lifelong spy Jonah Cosgrove really trusted, despite his pro-British stance. Despite this, Mather worked with the Doctor in thwarting Baskerville's prophecies. (PROSE: Father Time, Trading Futures)