In the Star Trek universe, Willard Decker (played by Stephen Collins) was briefly captain of the U.S.S. Enterprise after its refit in 2270. It is widely felt in fanon circles that he was the son of Commodore Matt Decker, a friend of Captain James T. Kirk, who commanded the U.S.S. Constellation and was killed by the Doomsday Machine in an episode of the same name in Star Trek: The Original Series. However, this fact has never been established in canon.
Will Decker lost command of the Enterprise to Admiral James T. Kirk in 2271 when V'ger threatened Earth. He had previously had a relationship with the Deltan scientist Lieutenant Ilia, who was assimilated by V'ger so it could interact with humans. Decker chose to represent humanity as V'ger's creator, and merged with it to explore the universe on a higher plane of existence.