Machine Man (also known as Aaron Stack, originally known as serial number Z2P45-9-X-51 or X-51 for short) is a fictional character, an android superhero in the Marvel Comics Universe. The character was created by Jack Kirby for 2001: A Space Odyssey #8 (July 1977), a comic written and drawn by Kirby featuring concepts based on the eponymous Stanley Kubrick feature film and Arthur C. Clarke novel. Shortly thereafter, Machine Man spun off into his own Kirby-created series.