The goal of this book is to allow you to begin with a "blank sheet of paper" and design a space mission to meet a set of broad, often poorly defined, objectives. You should be able to define the mission in sufficient detail to identify principal drivers and make a preliminary assessment of overall performance, size, cost, and risk. The emphasis of the book is on low-Earth orbit, unmanned spacecraft. However, we hope that the principles are broad enough to be applicable to other missions as well. We intend the book to be a practical guide, rather than a theoretical treatise. As much as...