This is not an economics book. It is a book about the application of economic principles and concepts in decision making related to space activities. The book is primarily tutorial and elaborates upon concepts and methodology and their applications. Emphasis is placed upon applications with typical results of performed analyses presented to demonstrate concepts and methods. The use of mathematical and simulation models serves as the underpinning for much of the presented materials. A number of models are described with numerous applications presented. The specific models considered have been selected to demonstrate the role that a structured thought process can play in the decision process. Since most decisions relating to technology development, product design, capital expenditures, and investments involve uncertainty and risk, a number of the selected models, developed methodologies, and presented examples explicitly and quantitatively consider uncertainty and risk. The objective of this book is to put economic analysis into perspective with respect to real-world decision making in the space industry. It will expand the perspective of the reader with respect to the type of tools and analyses that might be brought to bear on complex business and government problems.