The Lockheed A-12 was a reconnaissance aircraft built for the Central Intelligence Agency (CIA) by Lockheed's famed Skunk Works, based on the designs of Clarence "Kelly" Johnson. The aircraft was designated A-12, the 12th in a series of internal design efforts with the A referring to "Archangel", the internal code name of the aircraft. It competed in the CIA's Oxcart program against the Convair Kingfish proposal in 1959, and won for a variety of reasons.
The A-12's specifications were slightly better than those of the Kingfish, and its projected cost was significantly less. Convair's design had the smaller radar cross section, however, and CIA's representatives initially favored it for that reason. The companies' respective track records proved decisive. Convair's work on the B-58 had been plagued with delays and cost overruns, whereas Lockheed had produced the U-2 on time and under budget. In addition, it had experience running a “black” project.
The A-12 was produced from 1962 to 1964, and was in operation from 1963 until 1968. It was the precursor to the twin-seat U.S. Air Force YF-12 prototype interceptor, M-21 drone launcher, and the famous SR-71 Blackbird reconnaissance aircraft. The A-12's final mission was flown in May 1968, and the program and aircraft retired in June of that year. The program was officially revealed in the mid-1990s.
Over the life of the Oxcart project, the participating US government departments and officials associated the project name "Oxcart" specifically with the A-12. An Agency officer later wrote, "OXCART was selected from a random list of codenames to designate this R&D and all later work on the A-12. The aircraft itself came to be called that as well." The crews named the A-12 the Cygnus which was suggested by the pilot Jack Weeks to follow the Lockheed practice of naming aircraft after celestial bodies, and was the code-name given to the A-12 during testing
When the U-2 became operational in 1956, CIA officials estimated that it would be able to safely overfly the Soviet Union for no more than two years. When the Soviets demonstrated the capability of tracking and attempting to intercept the U-2,Richard Bissell was so concerned about the U-2s vulnerability that he asked DCI Allen Dulles for permission to establish an advisory committee, headed by Edwin H. Land, which became known as the Land Panel, to assist in the selection of a successor aircraft. To prolong the U-2s operational capabilities Lockheed introduced a number of modifications, called "Trapeze", to the U-2. This included the use of wires and paints impregnated with tiny iron ferrite beads. ECM systems were also introduced at this time. U-2s with these enhancements were called "Dirty Birds" and the program was not successful in substantially reducing the radar cross-section (RCS) of the aircraft. A completely new aircraft with stealth characteristics integrated into the design would have to be conceived.
With the failure of the CIA's Project Rainbow to reduce the RCS of the U-2, preliminary work began inside Lockheed in late 1957 to develop a follow-on aircraft to overfly the Soviet Union. Under Project Gusto the designs were nicknamed "Archangel", after the U-2 program, which had been known as "Angel". As the aircraft designs evolved and configuration changes occurred, the internal Lockheed designation changed from Archangel-1 to Archangel-2, and so on. These names for the evolving designs soon simply became known as "A-1", "A-2", etc. The CIA program to develop the follow-on aircraft to the U-2 was code-named Oxcart.
These designs had reached the A-11 stage when the program was reviewed. The A-11 was competing against a Convair proposal called Kingfish, of roughly similar performance. However, the Kingfish included a number of features that greatly reduced its RCS, which was seen as favorable to the board. While Convair prepared for production and struggled with aerodynamic issues, Lockheed pursued its own design efforts on a high-speed, high-altitude reconnaissance platform. Lockheed's own designs evolved from A-4 through A-11. The first three configurations, A-4 through A-6, were smaller, self-launched aircraft with vertical surfaces hidden above the wing. The aircraft employed a variety of propulsion schemes that included turbojets, ramjets, and rockets. None met the required mission radius of 2,000 nautical miles (3,700 kilometres), leading Lockheed to conclude that maximum performance and low radar cross section were mutually exclusive. The A-10 and A-11 configurations were larger aircraft that also focused on performance at the expense of radar cross section. The more refined A-11 was submitted by Lockheed at the next Land Panel review. When the A-11 was rejected by the Land Panel review, Lockheed responded with a simple update of the A-11, adding twin canted fins instead of a single right-angle one, and adding a number of areas of non-metallic materials. This became the A-12 design. On 26 January 1960, the CIA ordered twelve A-12 aircraft.
