The Northrop (later Northrop Grumman) B-2 Spirit, also known as the Stealth Bomber, is an American heavy penetration strategic bomber, featuring low observable stealth technology designed for penetrating dense anti-aircraft defenses; it is a flying wing design with a crew of two. The bomber can deploy both conventional and thermonuclear weapons, such as eighty 500Â lb (230Â kg)-class (Mk 82) JDAM Global Positioning System-guided bombs, or sixteen 2,400Â lb (1,100Â kg) B83 nuclear bombs. The B-2 is the only acknowledged aircraft that can carry large air-to-surface standoff weapons in a stealth configuration.
Development originally started under the "Advanced Technology Bomber" (ATB) project during the Carter administration; its expected performance was one of his reasons for the cancellation of the supersonic B-1A bomber. The ATB project continued during the Reagan administration, but worries about delays in its introduction led to the reinstatement of the B-1 program as well. Program costs rose throughout development. Designed and manufactured by Northrop, later Northrop Grumman, the cost of each aircraft averaged US$737Â million (in 1997 dollars).