The SR-71, also known as the Lockheed SR-71 Blackbird, is a long-range, advanced reconnaissance aircraft developed by the United States in the 1960s. It was designed to fly at high altitudes and speeds, reaching over Mach 3, which is three times the speed of sound. The aircraft was primarily used for intelligence gathering during the Cold War. Equipped with sophisticated cameras and sensors, the SR-71 could capture detailed images and data from enemy territories without being detected. Its unique design, featuring a sleek fuselage and special materials, allowed it to withstand the extreme heat generated by its high-speed flight. The SR-71 was retired in 1998, having set numerous speed and altitude records.