Book excerpt: Aimed at engineering students and professionals working in the field of mechanics of space flight, this book examines space tether systems – one of the most forward-thinking directions of modern astronautics. The main advantage of this technology is the simplicity, profitability and ecological compatibility: space tethers allow the execution of various manoeuvers in orbit without costs of jet fuel due to the use of gravitational and electromagnetic fields of the Earth. This book will acquaint the reader with the modern state of the space tether's dynamics, with specific attention on the research projects of the nearest decades. This book presents the most effective mathematical models and the methods used for the analysis and prediction of space tether systems' motion; attention is also given to the influence of the tether on spacecraft's motion, to emergencies and chaotic modes. - Written by highly qualified experts with practical experience in both the fields of mechanics of space flight, and in the teaching - Contains detailed descriptions of mathematical models and methods, and their features, that allow the application of the material of the book to the decision of concrete practical tasks - New approaches to the decision of problems of space flight mechanics are offered, and new problems are posed