Introduction

For most atmospheric or exo-atmospheric spacecraft flight scenarios, a well-designed trajectory is usually a key for stable flight and for improved guidance and control of the space vehicle. Among these flight missions, trajectory optimization for reentry vehicles is usually recognized as a challenging problem and it has been widely researched for a couple of decades. One of the current objectives is the development of space maneuver vehicles for a dynamic mission profile. This chapter briefly outlines the background and current development of the reentry trajectory design problem. Typical spacecraft skip entry mission scenarios are also introduced. Following that, the overall aims and objectives of the book will be summarized. Finally, the structure of the entire book, together with some highlights of each chapter, will be given.