 He was the first of the Tracy brothers to be voice-cast.Actor Ray Barrett was so impressed with the marionette, whose face was modeled on singer Adam Faith and actor Charlton Heston, that he immediately advised co-producer Sylvia Anderson that he wanted to play the studious young astronaut with the boyish quiff.The third son of Jeff Tracy (founder and financier of International Rescue), John was named after astronaut John Glenn.