Northrop’s B-2 Spirit was awarded the U.S. Air Force’s Advanced Technology Bomber contract in 1981 and was designed in extreme secrecy to penetrate the Soviet Union’s integrated air defense system using a flying-wing stealth design with internal weapons carriage and extensive radar-absorbent materials. The Air Force originally planned to procure 132 aircraft, but after the Soviet Union collapsed in 1991, the procurement was cut to 75 and then to…