As the cultural and ideological foundations of imperial Russia were threatened by forces of modernity, an array of Orthodox churchmen, theologians, and lay thinkers turned to asceticism, hoping to ensure the coming Kingdom of God promised to the Russian nation.

Progress in modern radio astronomy led to the discovery of space masers in the microwave range, and it became a powerful tool for studies of interstellar star-forming molecular clouds. Progress in observational astronomy, particularly with ground-based huge telescopes and the space-based Hubble Space Telescope, has led to recent discoveries of space lasers in the optical range. These operate in gas condensations in the vicinity of the mysterious star Eta Carinae (one of the most luminous and massive stars of our Galaxy). Both maser and laser effects, first demonstrated under laboratory conditions, have now been discovered to occur under natural conditions in space too. This book describes consistently the elements of laser science, astrophysical plasmas, modern astronomical observation techniques, and the fundamentals and properties of astrophysical lasers. A book with such an interdisciplinary scope has not been available to date. The book will also be useful for a wider audience interested in modern developments of the natural sciences and technology.

Unmanned aerial vehicles (UAVs) have been widely adopted in the military world over the last decade and the success of these military applications is increasingly driving efforts to establish unmanned aircraft in non-military roles. Introduction to UAV Systems, 4th edition provides a comprehensive introduction to all of the elements of a complete Unmanned Aircraft System (UAS). It addresses the air vehicle, mission planning and control, several types of mission payloads, data links and how they interact with mission performance, and launch and recovery concepts. This book provides enough information to encourage a student to learn more; to provide a specialist with a basic appreciation of the technical issues that drive other parts of the system and interact with their specialty; or to help a program manager understand system-level tradeoffs and know what questions to ask. Key features: Comprehensive overview of all elements of a UAS and of how they interact. Introduces the underlying concepts of key subsystems. Emphasizes system-integration issues and how they relate to subsystem design choices. Practical discussion of issues informed by lessons learned in UAV programs. Introduction to UAV Systems, 4th edition is written both for newcomers to the subject and for experienced members of the UAV community who desire a comprehensive overview at the system level. As well as being a primary text for an introductory course on UAS or a supplementary text in a course that goes into more depth in one of the individual technologies involved in a UAS, this book is a useful overview for practicing engineers, researchers, managers, and consultants interested in UAV systems.