If you've ever wondered how NASA prepares equipment, supplies, and astronauts themselves for a journey to space, then this book is for you. If you've ever wondered how astronauts use a toilet in space and how early experiments in space toilets failed, in extreme detail, then this book is definitely for you. Once again Mary Roach takes a subject - how to prepare for a journey to space, and ultimately, a journey to Mars - and digs into every obscure and lesser-examined aspect of the question with her usual thoroughness, attention to detail, and quirky sense of humour.