The C-135 series, along with its civilian counterpart, the Boeing 707, emerged on to the drawing boards of technical design teams at the end of the 1940s. Twenty years later, the first C-135 was delivered to the Military Air Transport Service in 1961, five years after the first KC-135 Stratotanker made its first flight for the United States Air Force. Since then, C-135 series aircraft have performed a wide variety of military and civilian tasks. To enable them to be carried out effectively, the majority of aircraft, including the electronic, observation, reconnaissance, and weather-monitoring variants, had extensive modifications carried out both internally and externally. Some were extreme, yet no prefix was assigned, whereas others had the designation amended accordingly. Illustrated with over 150 images, and following on from Seattle Stratotanker Veterans: Boeing KC-135 Variants, this book explores the highly specialist roles that these aircraft and their crews have undertaken in more than 60 years of service.