Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The European Space Agency, an international organization uniting 18 member states and around 2200 scientists, is one of the leading space exploration agencies in the world, developing cutting edge missions on its own and in collaboration with other organizations. Learn more about the multinational space agency, its history, and multitude of projects, both still in development and already underway, in this book.