█ CARYN E. NEUMANN
The SR-71, a black, high-altitude airborne reconnaissance platform that flew at trisonic speed, gave the United States the ability to photograph military sites in hostile countries as well as the opportunity to confirm interpretations of satellite photographs from 1968 until 1990. Photographs taken from SR-71s helped end the siege of Khe Sanh in Vietnam in 1968, preserved the Strategic Arms Limitation Treaty (SALT) with the Soviet Union by monitoring troop movements in Cuba in 1979, and confirmed that Iran had acquired Silk Worm missiles from China for possible use against oil tankers in the Straits of Hormuz in 1987. While of obvious military value, each SR-71 burned enormous amounts of fuel, and required a large amount of staff support. For reasons of economy, the Department of Defense terminated the program and the last SR-71 flew in 1990.
The SR-71, planned in the early 1960s as a weapon in the Cold War, gave the U.S. the ability to survey more than 100,000 square miles of Earth's surface in an hour's time. The 29 aircraft in service flew above 80,000 feet, higher than any other platform, and traveled at Mach 3.17–3.30 covering 30 miles every minute. The SR-71 could survey up to a quarter of a million square miles of territory in one sortie. High-strength lightweight titanium alloy covered 90% of the aircraft with 20% of the skin consisting of radar-transparent plastic. For missions, the platforms were fitted with either a high-resolution horizon-to-horizon optical bar camera or a radar package which generated film of the ground in all weather conditions. The SR-71 contained no armament.
The first operational flight of the SR-71 took place on March 21, 1968, and brought information crucial to the American war effort in Vietnam. Photos taken by the crew revealed the location of heavy artillery emplacements around Khe Sanh, an American garrison in Vietnam under siege by the North Vietnamese. By providing data that had previously eluded sensors on other aircraft, the SR-71 allowed the American command to direct B-52 bombers to the enemy site and helped to end an event which had riveted the attention of the public. In 1979, when a satellite revealed a large Soviet force in Cuba, an SR-71 flew continuing surveillance over the island to monitor the situation and ensure Senate ratification of SALT. A 1987 mission to Iran gathered extensive information about masses of military equipment in the Persian Gulf, including the presence of Silk Worms, land-based anti-ship missiles from China that the Iranians apparently intended to use to threaten merchant tankers in the Straits of Hormuz. The U.S. Navy received warning of the missiles and diplomats brought pressure on Iran to remove them. On 80 occasions in the 1980s when satellites broke down or were unable to see through the atmosphere, SR-71s provided reconnaissance imagery of vital areas in the Middle East.
The SR-71 penetrated hostile territory with comparatively little vulnerability to attack unlike other reconnaissance platforms like the U-2 spy plane. The workhorse U-2, however, operated for considerably less money and generally received reconnaissance assignments while the SR-71s remained in their hangars. The Department of Defense made the decision to terminate the program on November 22, 1989. Secretary of Defense Richard Cheney in June 1990 ordered that three SR-71 aircraft be placed into long-term storage for possible use in a future conflict. The SR-71s did not see service in the Gulf War, however, and most of their aircrews and skilled maintenance force
are now unavailable because of the passage of time. As satellite technology involves less human risk and grows and more precise and cost-effective, it is uncertain that the United States will justify the cost of deploying SR-71 intelligence-gathering machines in the future.
█ FURTHER READING:
Crickmore, Paul F. Lockheed SR-71: The Secret Missions Exposed. London: Osprey, 1988.
Thornborough, Anthony M. Sky Spies: Three Decades of Airborne Reconnaissance. London: Arms and Armour Press, 1993.