 Frank Miller (I) (qv), who plays the mission control voice, was a  member of the US Air Force in real life, and a real mission  controller. He was hired because his voice was the most authentic  the producers could find for the role. Inexperienced and nervous, he  could not keep from tapping his foot during recording sessions, and  the tapping sound repeatedly came through on the audio tracks;  Stanley Kubrick (qv) folded up a towel, put it under Millers  feet, and told him to tap to his hearts content.