Stealth and spy planes – An SR-71B Blackbird flies over snow-capped mountains in 1995.
Stealth and spy planes – An A-12 reconnaissance aircraft, the predecessor to the SR-71, is seen on display at the Intrepid Sea, Air and Space Museum in New York City in August 2010.
Stealth and spy planes – The EP-3E Aries II aircraft is a reconnaissance aircraft that uses electronic surveillance equipment for its primary mission. One of them was in the news in April 2001 when it collided with a Chinese jet.
Stealth and spy planes – The F-117 Nighthawk is one of the most famous and successful stealth aircraft. It was the first plane to be completely designed around the aspect of stealth, and its development was kept a secret in the early 1980s.
Stealth and spy planes – Lockheed's "Have Blue" prototype was the predecessor of the famed Nighthawk.
Stealth and spy planes – The Northrop YB-49 was not considered stealth aircraft, but its "strategic bomber" design set the foundation for the B-2 Spirit, a future stealth bomber.
Stealth and spy planes – A B-2 Spirit soars over the Pacific Ocean in May 2006.
Stealth and spy planes – The Lockheed YF-12 flies a test mission near Edwards Air Force Base in California.
Eyes in the sky, seen and unseen – The YF-22A fighter, first produced in 1990, used stealth technology and became the first fighter-type aircraft to achieve sustained supersonic flight without employing afterburner.
Stealth and spy planes – The F-22 Raptor interceptor, which uses stealth technology, completed its first successful flight in 1997.
Stealth and spy planes – The MQ-1 Predator is an unmanned aircraft, or drone, that has conducted reconnaissance and surveillance missions.
Stealth and spy planes – In the 1950s, aircraft like these RB-47s conducted surveillance missions over the Soviet Union and other "denied areas," but they became increasingly vulnerable to enemy defenses.
Stealth and spy planes – The Convair RB-36D was the jet-augumented version of the U.S. Air Force's intercontinental strategic bomber. The bomb bay was fitted with 14 cameras, and the No. 2 bay was used to carry 100-pound photo flash bombs for nighttime aerial photography.
Stealth and spy planes – The U-2 high flying spy plane, developed by Lockheed, was considered stealthy because of its ability to fly at extremely high altitudes. But the Soviet Union's defense radar was still able to detect the aircraft.
Stealth and spy planes – CIA pilots stand in pressure suits in front of a U-2 plane. The pilots needed the pressure suits for the extremely high altitudes.