2001: A Space Odyssey originally had a 20-foot-tall green alien and a 'crap' script

For context, it’s helpful to know that Trumbull was a groundbreaking effects artist whose striking short film, To the Moon and Beyond, shown at the 1964 World’s Fair, caught Kubrick’s attention and led to Trumbull spearheading the effects sequences for 2001. He went on to handle effects for Steven Spielberg’s Close Encounters of the Third Kind and Ridley Scott’s Blade Runner, in addition to directing his own science fiction movies, Silent Running and Brainstorm.