The Lockheed SR-71 Blackbird is a long range, high altitude, Mach 3+ strategic reconnaissance aircraft operated by the United States Air Force (USAF) and NASA. Clarence “Kelly” Johnson, American aerospace engineer, designed the concept of the aircraft. It was initially a black project by Lockheed’s Skunk Works Division during the 1960’s.

To this day, SR-71 still holds the records for the highest altitude and fastest aircraft in the world. During aerial recon missions the plane could be operated at Mach 3.5 and 85.000 feet/25.900 meters high to prevent threats such as Surface-to-Air-Missiles (SAM) and opponents fighter jets.

The category for pilots that flew the Blackbird jets were in between aviators and astronauts. They reached almost to the border of space, they could see the curvature of the Earth due to the very high altitude. No enemy aircraft could intercept this jet let alone shot it down.

The shape of SR-71 was based on the Lockheed A-12, a spy plane designed for Central Intelligence Agency (CIA). The A-12 had a unique aerodynamic design to fly at high speed. Three US organizations were involved during the development : US Air Force, Lockheed and CIA. The CIA monitored all people involved, including their families 24 hours to prevent any leak about the project.

The SR-71 designation was from USAF Chief of Staff General Curtis LeMay. He preferred the SR (Strategic Reconnaissance) designation over RS (Reconnaissance, Strategic), thus the initial RS-71 designation was replaced by SR-71 designation.

The first SR-71 was introduced in January 1966. Originally the Blackbird was built with weapons. But when they realized the plane flew faster than a rifle bullet it was removed from the design, because it would have shot itself down. The production of the SR-71 reach the total of 32 aircraft with 29 SR-71 A, two SR-71B and single SR-71C.

The materials used to build a Blackbird was selected from high quality ones, even for today. While on most aircraft titanium was limited to its high cost, on the SR-71 titanium was used for more than 85% of the structure. The outer windscreen of the cockpit was made of quartz and fused ultrasonically. Also the design was engineered to reduce its radar signature, the radar cross-section (RCS) of the Blackbird is around 110 m2 (110 sq ft).

But despite the incredible ability and power of SR-71 USAF retired its Blackbird fleet on January 26, 1990 due to decreasing defense budget, high cost of operation and maintenance and the growing development of sophisticated spy satellites. Several were shortly reactivated during mid 1990’s and retired again in 1998. The final operator of these Blackbirds was NASA that retiring their planes in 1999.

The successor of SR-71 is the Lockheed Martin SR-72. It is a hypersonic aircraft for intelligence, surveillance and reconnaissance and has the nickname “Son of Blackbird”. Scheduled to fly in 2025, this UAV concept is under development by Lockheed Martin.