This book highlights the technological and managerial fundamentals and frontier questions of space science. Space science is a new interdisciplinary and comprehensive subject that takes spacecraft as the main tools to study the planet Earth, the solar-terrestrial space, the solar system, and even the whole universe, to answer significant questions covering the formation and evolution of the solar system and the universe, the origin and evolution of life and the structure of the material. The book introduces major scientific questions in various branches of space science and provides related technological and managerial knowledge. It also discusses the necessity of international cooperation and elaborates on the strategic planning of space science in China. The book can be used as a reference book or textbook for scientists, engineers, college students, and the public participating in space science programs.