This book presents a collection of chapters, which address various contexts and challenges of the idea of human enhancement for the purposes of human space missions. The authors discuss pros and cons of mostly biological enhancement of human astronauts operating in hostile space environments, but also ethical and theological aspects are addressed. In contrast to the idea and program of human enhancement on Earth, human enhancement in space is considered a serious and necessary option. This book aims at scholars in the following fields: ethics and philosophy, space policy, public policy, as well as biologists and psychologists.