The SR-71 Blackbird is a reconnaissance aircraft that was primarily used for the United States Air Force from 1964 to 1998. The Blackbird was first flown on December 22, 1964, but was introduced much later by Lockheed Martin and Skunk Works division in 1966. The SR-71 Blackbird was known for its impeccable speed, the aircraft could reach speeds of up to mach 3.3 (2301.81mph). Since 1976, the SR-71 Blackbird holds the record for the fastest air breathing aircraft ever recorded. Moreover, the SR-71 Blackbird uses 2 Pratt & Whitney J-58 engines (JT11D-20A) that produces 150kN of thrust (34,000 pounds of thrust) with the afterburners active. In addition, the aircraft has a wingspan of about 16.9m (55 feet and 7 inches), while the length of the aircraft is 32.7 meters long (107 feet and 5 inches). The height on the other hand, is only 5.7 meters tall (18 feet and 6 inches). Furthermore, the aircraft has a fuel capacity of 46,253 liters (12,219 gallons), and has a range of only 3,200 nautical miles. The type of fuel the engines uses is a new jet fuel called, Jet Propellant 7. The propellant was used mainly for the Pratt and Whitney J-58 engines. The fuel is primarily made up of hydrocarbons, which gave the fuel a high flash point and a high thermal stability. Additionally, the SR-71 Blackbird could reach a service ceiling (height) of over 25,908 meters above the sky (85,000 feet). The pilots had to wear $120,000 pressure suits because nitrogen bubbles would make their blood boil if they were to lose cabin pressure at 85,000 feet. Furthermore, the aircraft had a payload capacity of 1,587kg (3,5000lbs). In 1966, the cost per unit of a SR-71 Blackbird was roughly $34 million dollars. A total of 32 SR-71 Blackbirds have been built, but only 12 have been lost in accident related causes. Worth noting, none of the aircrafts were downed by enemies. The SR-71 Blackbird sat two pilots one to fly, the other to operate the surveillance systems. The surveying capabilities of the aircraft were so clear that it was able to capture a picture of a license plate from above 29,908 meters. The aircraft was also very stealthy due to its high altitude capabilities and speed. The SR-71 Blackbird also had a smaller radar cross-section that decreased it’s visibility, as well as using radiation-absorbent material.