This book sketches key design, development, and engineering issues. To think up an airbreathing hypersonic aircraft is one thing; to design, develop, and produce it is another one. Airframe-propulsion integration plays a central role, with six integration types identified. Most demanding is that of a large aircraft with both lift and propulsion located at its lower side-an approach exemplified early by the US National Aerospace Plane. Topics treated are the flight environment, design sensitivities, fuel considerations, aerothermodynamics, scramjet propulsion, airframe-propulsion integration, structural and materials issues, and aerothermoelasticity. Persistent challenges include laminar-turbulent transition and joint modelling. Capabilities and shortcomings of experimental, computational, and in-flight simulation are considered. The second wave of mathematization-culminating in the concept of the virtual product-has fundamentally transformed flight vehicle design, enabling integrated, high-fidelity simulation across disciplines. In this book, students, design engineers, and technical managers will find ample insight and practical knowledge regarding hypersonic airbreather design.