For her audition as Space Girl Mathilda May had to learn her lines phonetically, because she didn't know any English at the time. May learned how to speak English during the six months she spent in England on this movie.
Mathilda May had rubber soles glued to the bottom of her feet in order to avoid cutting them during the scene in which she walks out of the building, after breaking the glass windows.
Tobe Hooper's Director's Cut was two hours and eight minutes, then the movie was cut down to one hour and fifty-six minutes, the cuts being mostly scenes set on the spaceship Churchill. The original unedited European version contains more violent and erotic footage, which Tri-Star Pictures cut from the domestic U.S. version. It also contains the full Henry Mancini score, in place of the occasional Michael Kamen music cues placed at the last minute for U.S. prints. This version is now available on video, and runs one hour and fifty-six minutes.
Tobe Hooper came up with the idea of using Halley's Comet in the screenplay, rather than the asteroid belt, as originally used in the novel, as the comet was going to pass by Earth one year following this movie's release.