Just FYI, You'll want to look into Starman by by Jamie Doran and Piers Bizony. I was pointed to it by this article on NPR. (I haven't read it yet so I can't comment further)

The two were incredible friends; Vladimir knew the ship was doomed, but went through with it because if he didn't, his friend Yuri would have to go. Knowing a friend did that for you, would have a pretty significant hit on anyone.