Look here, there are plenty of documentaries where astronauts end up in really bad situations, and they go from bad to worse because they didn't bring a knife. Forget Apollo 13- that was a walk in the park. Imagine landing in a world run by damn, dirty apes who tie you up and put you in a tiger cage! You'd wish you had a knife right then. If there's anything the Duke boys taught us, when counterfeiters tie you to your cousin in an abandoned barn that trusty Buck 110 they missed on your belt comes in reeeeaaal handy-like. Ain't no damn dirty ape gonna keep the Duke boys hostage, no sir! The Duke boys wouldn't go riding no rocket off into space without a knife.