The human body thrives on the welcome confines of Earth, but in space, survival becomes a tense, daily challenge. Micro-gravity's effects on daily human activity, from eating to sleep to sex, are just beginning to be understood. But these are only the start of our problems well also explore how the vacuum of space and its near-zero pressure can kill us within minutes, if not seconds. And the ultimate space executioner may be the ever-present dangers of solar radiation. How will we overcome the odds and survive space.