The SR-71 Blackbird was a long-range, high-altitude, high-speed reconnaissance aircraft developed by Lockheed’s Skunk Works and first flown on December 22, 1964. It entered service in 1966 and was retired in 1998. It could fly at more than 2,200 miles per hour at altitudes above 85,000 feet, well beyond the reach of any Soviet interceptor or surface-to-air missile. For more on the U-2 article; the U-2 program is detailed separately.
The SR-71 was the third member of a family of high-altitude reconnaissance aircraft that began with the U-2 and continued with the A-12 OXCART. The A-12, a single-seat predecessor of the SR-71, first flew in 1962 and entered CIA service in 1967. It was smaller and faster than the SR-71 but had a shorter range and a smaller payload. The A-12 was used for the most sensitive photographic missions, including the photography of North Vietnam and the photography of sites in North Korea. It was retired in 1968. The SR-71 was the two-seat Air Force version, designed for operational use by Strategic Air Command and, after 1991, by Air Combat Command.
The design
The SR-71 was designed by the Lockheed Skunk Works team under Clarence “Kelly” Johnson, the same engineer who had designed the U-2. The aircraft was built largely of titanium, which the United States imported from the Soviet Union through third countries in a covert procurement program. The airframe was designed to flex in flight, with the fuselage panels growing visibly looser on the ground and sealing in flight. The engine, the Pratt & Whitney J58, was a hybrid turbojet-ramjet that switched from turbojet to ramjet mode at high speeds. The aircraft’s distinctive black paint, a special formulation of iron-oxide-filled epoxy, was designed to radiate heat from the airframe and to provide some radar absorption.
The SR-71 set numerous speed and altitude records. On July 28, 1976, an SR-71 set the absolute speed record of 2,193.167 miles per hour over a 15/25-kilometer course. The same aircraft, on the same day, set the absolute altitude record of 85,135 feet. The SR-71 was, throughout its career, faster and higher than any operational interceptor or surface-to-air missile. The aircraft was, in operational terms, untouchable.
The operational record
The SR-71 was used for photographic and signals-intelligence reconnaissance in three theaters: over the Soviet Union and its allies (the most sensitive missions), over China and North Korea, and over the Middle East. The aircraft’s most famous mission — the mission that established its operational reputation, was the Operation BLACK SHIELD series of missions over North Vietnam and Laos from 1968 to 1972. The SR-71 flew more than 3,500 sorties during its career, more than 2,800 of them by the Air Force; only one aircraft was lost to enemy action, and that loss was a deliberate shootdown of an SR-71 by a North Korean surface-to-air missile on September 13, 1958. (That aircraft was an A-12, not an SR-71; the only A-12 loss in combat.) The SR-71’s operational loss rate was 1 percent — lower than that of any other American military aircraft in service.
The SR-71’s last operational missions were flown in 1990, before the aircraft was retired by the Air Force in 1998. The retirement was driven by the end of the Cold War and by the cost of operating the aircraft, but the Air Force, after 9/11, briefly returned the aircraft to service in 2001 and 2002 to support operations in Afghanistan. The aircraft was retired again in 2002 and transferred to museums. NASA used a pair of SR-71s for high-speed research until 1999.
Other American reconnaissance aircraft
The U.S. reconnaissance fleet in the late Cold War included, in addition to the U-2 and the SR-71, the TR-1 (a tactical reconnaissance version of the U-2, first flown in 1981 and used by the Air Force and the Air National Guard); the RC-135 Rivet Joint, a signals-intelligence aircraft based on the Boeing 707, in service from 1973 to the present; the EP-3 ARIES, a signals-intelligence aircraft based on the Lockheed P-3, in service from 1969; the RC-12 Guardrail, a tactical signals-intelligence aircraft based on the Beech King Air, in service from 1971; and a range of unmanned aerial vehicles, including the D-21 drone, designed to be launched from the back of the SR-71, and the Lockheed Martin RQ-170 Sentinel, in service from 2007.
The Soviet side
The Soviet Union developed a series of high-speed reconnaissance aircraft of its own. The most capable was the MiG-25R Foxbat-B, a high-altitude reconnaissance version of the MiG-25. The MiG-25R was a remarkable aircraft, with a ceiling of more than 80,000 feet and a top speed above Mach 3, but it was designed for the radar-interception mission and was limited in the photographic-reconnaissance role by the limitations of its cameras and by the operational habits of its pilots. The Soviet Union also developed the M-17/M-55 Mystic, a high-altitude reconnaissance aircraft designed by the Myasishchev design bureau, first flown in 1982. The M-17 was intended as the Soviet response to the U-2; it was used for atmospheric research and, in small numbers, for reconnaissance, but the program was not pursued at scale.
The Russian Federation’s aerial-reconnaissance fleet is, in 2025, much smaller than the Soviet fleet was at the height of the Cold War. The Russian Federation has used the Tu-214R, a signals-intelligence aircraft based on the Tupolev Tu-204, for reconnaissance missions over Ukraine and Syria. The United States and its allies have used a range of unmanned systems, including the RQ-4 Global Hawk and the MQ-9 Reaper, for the equivalent missions.