 The codename of the character "Major Tom" is a reference to the 1969  song "Space Oddity" by David Bowie (I) (qv), which is about an  astronaut called Major Tom. In the game, Major Tom is even asked  "Can you hear me, Major Tom?" This phrase is part of the songs  lyrics. Major Tom explains later in the game that his codename was  taken from the movie The Great Escape. In the movie the prisoners  had three names for the three tunnels they built, Tom, Dick and  Harry. Major Tom explains that he mistakenly identified the tunnel  named Tom as the one the prisoners escaped from. Tom and Dick were  the tunnels that were discovered by the Nazis. Instead of asking  Snake to call him Major Harry, he just shrugs it off and changes his  codename back to Major Zero.