We’ve all seen it in some form or another in science fiction movies: a character suddenly finds themself exposed, sans protective suit, to the vacuum of space. Maybe it was a crack in their suit or helmet, or they were caught in an open airlock, or they were sucked out of a hole in a spacecraft hull—possibly by their own fault or through the accidental or malicious actions of another. (If there’s one thing science fiction has taught us is that space is full of enemies.) From that point on, what happens to them seems to be up to the imagination of the director. Does their head swell and explode? Do they instantly freeze solid? Does the unfiltered UV light from the Sun fry them alive? Or do they just run out of oxygen and black out?