One of the U.S. Air Force's Lockheed U-2 Dragon Lady.
Credit: U.S. Air Force

A U-2 spy plane that crashed in northern California earlier this week, killing one of the two pilots, focused attention on a normally clandestine aspect of the U.S. military. The U-2 plane has a long and storied history that stretches back to the late 1950s, but how is the reconnaissance aircraft used today?

U-2 planes have been flown by the United States and other nations for more than 60 years, as both a spy plane and an instrument of science. They key to the aircraft's longevity is its robust and efficient design, said Richard Aboulafia, vice president of analysis at Teal Group Corp., which conducts research and analysis on the aerospace and defense industry. He added that Clarence "Kelly" Johnson, the man who designed the U-2, "got it right."

"Those designers at the Lockheed Skunk Works deserve their legendary status," Aboulafia told Live Science. [Supersonic: The 11 Fastest Military Airplanes]