Makes sense, you know, when the author is insanely smart and pretty much IS an astronaut. You'd think the book would get bogged down in technical drivel (and, well, it is a little bit like that) but its balanced by hilariously sharp wit and humor. And the need to know that the guy is going to be okay.
Funnily enough I was thinking near the end of the book, 'This HAS to be a movie, someone had better make this into a movie because damn and lo, and behold it IS being made into a movie.
Nuff' said. Damned well written book and hilarious to boot. Go read it.