B-2, also called Spirit, U.S. long-range stealth bomber that first flew in 1989 and was delivered to the U.S. Air Force starting in 1993. Built and maintained by Northrop Grumman Corporation, the B-2 is a “flying wing,” a configuration consisting essentially of a short but very broad wing with no fuselage and tail. This design gives the B-2 a length (69 feet, or 21 metres) only slightly greater than that of a fighter yet gives it a wingspan (172 feet, or 52.4 metres) approaching that of its gigantic predecessor, the B-52 Stratofortress. The bomber uses stealth materials and shapes to make it effectively immune to detection at normal combat ranges.
Developed in the 1980s as the Advanced Technology Bomber, the B-2 was originally intended to be able to penetrate the sophisticated air defenses of the Soviet Union, deliver nuclear weapons to strategically important targets, and return to bases in the continental United States. In order to direct radar energy in the least revealing directions, the external shape of the bomber incorporates a series of complex, large-radius curved surfaces. Because it has no vertical fin stabilizers, it relies on flaps on the trailing edge of its notched wing to control roll, pitch, and yaw. Sophisticated artificial stabilization and control systems are needed to give the aircraft satisfactory flying characteristics. All ordnance, amounting to some 40,000 pounds (18,000 kg), is carried internally. The bomber is flown by a crew of two, the pilot and the mission commander. Power is provided by four turbofan engines. In order to reduce infrared emissions and extend combat radius, there are no afterburners providing supersonic capability.
The B-2 is the most expensive aircraft in the world, with a price of more than $1 billion per plane. The original plan was to produce 132 of the bombers. However, during the 1990s, with the Cold War at an end, production was reduced to 20 operational bombers and one experimental plane. The chief role of the B-2 was changed to conventional weapons delivery, though the bomber retains a nuclear capability. The operational bombers were assigned to Whiteman Air Force Base in Missouri, though they have also flown from bases overseas—for example, at Guam or Diego Garcia. B-2 bombers struck targets in Serbia in 1999, Afghanistan in 2001, and Iraq in 2003.