Earth-Saturn probe mission patch
Colonel Shaun Geoffrey Christopher was the son of US Air Force Captain John Christopher.
Colonel Christopher was the commander of the first successful Earth-Saturn probe, a manned mission to Saturn, in the early 21st century. He was accompanied by the astronauts Fontana and O'Herlihy. Christopher was a reason why Captain Kirk had to find a way to return his father to Earth. (TOS: "Tomorrow is Yesterday"; ENT: "First Flight")
Appendices
Background
Shaun Geoffrey Christopher was named after writer John D.F. Black's three sons: Shaun, Geoffrey and Christopher. (Star Trek Encyclopedia)
The exact date of his mission and the space agency is unknown; however, the timeframe seems to indicate that NASA might be the likely host. Christopher was born sometime after 1969, the year his father was captured by the USS Enterprise.
Apocrypha
In the short story "Assignment: One" of Strange New Worlds 8, Gary Seven is assigned to prevent Christopher from boarding one of the airplanes that would be involved in the September 11th terrorist attack.
Christopher also appears in the Star Trek: Myriad Universes story "Seeds Of Dissent" in Infinity's Prism as the captain of the SS Botany Bay.
The novelization of the episode "Relics", gives the name of the shuttle "loaned" to Montgomery Scott as the Chistopher, named for Shaun Geoffrey Christopher, however in the episode, the name Goddard is legible on the hull.