photographic pass or passes, withdrawal to a second aerial refueling in the Thailand area, and return to Kadena. Its turning radius of was such, however, that on some mission profiles it might intrude into Chinese airspace during the turn. Once landed, the camera film was removed from the aircraft, boxed, and sent by special aircraft to the processing facilities. Film from earlier missions was developed at the Eastman Kodak plant in Rochester, New York. Later an Air Force Center in Japan carried out the processing in order to place the photointelligence in the hands of American commanders in Vietnam within 24 hours of completion of a mission. SAM evasion over North Vietnam There were a number of reasons leading to the retirement of the A-12, but one major concern was the growing sophistication of Soviet-supplied surface-to-air missile (SAM) sites that it had to contend with over mission routes. In 1967, the vehicle was tracked with acquisition radar over North Vietnam, but the SAM site was unsuccessful with the Fan Song guidance radar used to home the missile to the target. On 28 October, a North Vietnamese SAM site launched a single, albeit unsuccessful, missile. Photography from this mission documented the event with photographs of missile smoke above the SAM firing site, and with pictures of the missile and of its contrail. Electronic countermeasures equipment appeared to perform well against the missile firing. During a flight on 30 October 1967, pilot Dennis Sullivan detected radar tracking on his first pass over North Vietnam. Two sites prepared to launch missiles but neither did. During the second pass, at least six missiles were fired, each confirmed by missile vapor trails on mission photography. Looking through his rear-view periscope, Sullivan saw six missile contrails climb to about before converging on his aircraft. He noted the approach of four missiles, and although they all detonated behind him, one came within of his aircraft. Post-flight inspection revealed that a piece of metal had penetrated the lower right wing fillet area and lodged against the support structure of the wing tank. The fragment was not a warhead pellet but may have been a part of the debris from one of the missile detonations observed by the pilot. The SA-2 'Guideline' was an early missile design intended to counter lower-flying and slower aircraft such as the B-52 and B-58. In response to faster, higher-flying designs like the B-70,