Skunk Works is an official pseudonym for Lockheed Martin's Advanced Development Programs, formerly called Lockheed Advanced Development Projects. It is responsible for a number of aircraft designs, highly classified research and development programs, and exotic aircraft platforms. Known locations include United States Air Force Plant 42, United States Air Force Plant 4, and Marietta, Georgia. Skunk Works' history started with the P-38 Lightning in 1939 and the P-80 Shooting Star in 1943.