Fourth son of Jeff Tracy (instigator and financier behind International Rescue), Gordon was named after astronaut Leroy Gordon Cooper jr.. Sources vary in the canon of the Thunderbirds series as to Gordon's age and birth date, although one written source suggests that he was born on February 14 (St. Valentine's Day), 2004. Gordon studied oceanography whilst in the Submarine Service and served in the World Aquanaut Security Patrol (as featured in the preceding TV series Stingray). A high-spirited prankster, often at the expense of his brothers, he also has a healthy respect for the sea and the dangers it poses, having spent a year on the seabed performing scientific research and having also survived a 400 knot hydrofoil crash. Gordon is the pilot of Thunderbird 4, is keen on water-sports and is also a gifted swimmer, cited as being a former Olympic champion in the butterfly stroke. He is also impulsive in his field such as in the episode, "Terror in New York," when TB4 is needed in the city, but the transport plane needed, TB2, is grounded for repairs. Instead, Gordon seriously proposes to pilot his scout craft all the way to the city in a trans-oceanic trip until he is convinced that idea is dangerous and impractical.