Everyone knows that humans can't survive without oxygen, so there's not much mystery surrounding the ultimate fate of an astronaut without a helmet. That being said, we've all wondered what happens before the end. Discovery News lays it all out on paper — and it isn't pretty.

In case anyone was tempted before, I think it's safe to say that after watching this, there won't be any astronauts out there curious enough to be the real-life guinea pig. This is one of those "I'll take your word for it" things. What did you think of the clip? Let us know in the comments below, and be sure to share it with your friends on Facebook!