This book covers all the key concepts, relationships, and ideas behind spaceflight and is the perfect companion for students pursuing courses on, or related to, astronautics. As a crew member of the STS-55 Space Shuttle mission and a full professor of astronautics at the Technical University of Munich, Ulrich Walter is an acknowledged expert in the field. This book is based on his extensive teaching and work with students, and the text is backed up by numerous examples drawn from his own experience. With its end-of-chapter examples and problems, this book is suitable for graduate level or even undergraduate courses in spaceflight, as well as for professionals working in the space industry. This fourth edition includes substantial revisions of many sections to extend their coverage. These include an overview of the different approaches to solving Newton’s gravitational equation of motion, a concise and newly structured coverage of orbital maneuvering, an enlarged and improved sectionabout the sphere of influence, a new section about hierarchical three-body systems, major enlargements in space reference frames and orbit geometry, and a new section about the earth reference ellipsoid.