Thor: Anatomy of a Weapon System examines the technical aspects of the Thor Intermediate Range Ballistic Missile system as based in the UK during the period 1958 to 1963. Thor has a unique part to play in our Cold War heritage; it was the first operational ballistic missile system deployed in the western world and the only venture by the Royal Air Force into such a weapon system. This book describes the missile, its construction, systems and subsystems and the associated ground support equipment in detail. The guidance system, the "brain" of the missile, and as a result, the most complex of the missile's systems, is conveniently spread across two chapters, separating the airborne elements from the ground based components. The missile guidance description includes an illustrated sub section devoted to the basic principles governing the all - important gyroscopes, vital for controlled flight and navigation. Ballistics and how the properties of the earth affect the missile's flight to its target are also discussed. The ground based guidance chapter describes in detail, with accompanying drawings, the set up and alignment of the guidance system for the required target and the use of the "mysterious" theodolites. Explanations are in "plain English" and any associated mathematics is kept simple and, where possible, avoided altogether. Thor's liquid propellants are subject to inspection with an explanation of how these fuels are produced, stored on site, loaded and their associated ever - present dangers. Chapters are dedicated to the development of the re-entry vehicle (the nose cone), which gave Thor its characteristic blunt profile and to Thor's raison d'etre; the awesome 1.44-megaton warhead; its principles of operation and its terrifying effects. The launch countdown process is comprehensively covered in a series of easy to follow flow diagrams, accompanied by detailed drawings and descriptions of the launch control consoles and equipment. The launch sites are themselves examined, with a description of the surveys required, typical layout, locations, construction and security arrangements. Detailed drawings of the site buildings, made by the author, and believed not to be available elsewhere, complete the book which contains photographs, some from the author's collection, believed to be previously unpublished.