This book is all about all the sciences behind support human life in space. Very interesting topics on the problems and inconveniences associated with zero gravity that we take it for granted on earth. For example, drinking, eating, deprecating, sex, recycling of resources, and physical changes in our body from long traveling. Pursuing answers to the those questions requires much brain power and experiments. It takes lots of money – estimated to be $150B to travel from Earth to the Mars. Is it worth it? Probably not but neither is a useless war like Iraq that consumed many lives and the same amount of money. The author did a great job in this book – very enlightening and funny at times in her famous “notes.”