Stealth and spy planes

Lockheed engineers are <a href='http://www.cnn.com/2013/11/05/tech/innovation/new-spy-plane/index.html'>developing a hypersonic aircraft</a> that will go twice the speed of the SR-71 Blackbird, which goes three times the speed of sound. That aircraft, seen in this photo illustration, is called the SR-72 or "Son of Blackbird." Take a look through the gallery to see other stealth and spy planes.

Lockheed engineers are developing a hypersonic aircraft that will go twice the speed of the SR-71 Blackbird, which goes three times the speed of sound. That aircraft, seen in this photo illustration, is called the SR-72 or "Son of Blackbird." Take a look through the gallery to see other stealth and spy planes.