The book begins: "To the rocket scientist, you are the problem. You are the most irritating piece of machinery he or she will ever have to deal with. You and your fluctuating metabolism, your puny memory, your frame that comes in a million different configurations. You are unpredictable. You're inconstant. You take weeks to fix."

The remainder of the book is just as good. It deals with the human aspects of spaceflight -- most of them a function of being in a confined space, zero gravity, and outside of you the void. The chapters focus on different issues. One is on going to the bathroom in space, which turns out to be remarkably complicated -- gravity is both how your body knows you need to urinate and also how excrement makes it's way out. Another is one eating in space -- and the problems of crumbs floating around in zero gravity, getting in people's eyes, noses, and fouling up equipment. Other chapters are isolation chambers on earth where people train for space, the Japanese method of psychologically screening potential astronauts (they examine their origami), the careers of famous chimp astronauts, the role of cadavers in crash tests, and training for ultra-high altitude escapes.

The limitation of the book is sometimes it is overly "reported," with extended descriptions of how the author visited such and such facility, who she met, what she found, etc. The author at times seems too taken by her own humor and riffs. Some of the tangents are interesting but there are too many of them for my taste. But these are minor flaws compared to a fascinating book that will forever change the way you see space travel.