Air Force Plant 42, California

A major Air Force aircraft development and construction facility, with over eight million square feet of covered space. Contractors with substantial structures at the site include Northrop-Grumman, Rockwell/Boeing, NASA, and Lockheed-Martin's Skunk Works. Aircraft developed here include the B1-B bomber (Rockwell), B-2A stealth bomber (Northrop), SR-71 surveillance aircraft (Lockheed), all of the NASA Space Shuttles (Rockwell), F-22 Raptor (Lockheed), and currently, several UAV (unmanned aerial vehicle) models. URS Corporation (formerly EG&G), operates a "secret" terminal inside the base, providing air transport to other aerospace R&D centers such as Groom Lake (Area 51).