The Northrop B-2 Spirit, also known as the Stealth Bomber, is an American heavy strategic bomber, featuring low-observable stealth technology designed to penetrate dense anti-aircraft defenses. A subsonic flying wing with a crew of two, the plane was designed by Northrop (later Northrop Grumman) as the prime contractor, with Boeing, Hughes, and Vought as principal subcontractors, and was produced from 1987 to 2000.[1][3] The bomber can drop conventional and thermonuclear weapons,[4] such as up to eighty 500-pound class (230 kg) Mk 82 JDAM GPS-guided bombs, or sixteen 2,400-pound (1,100 kg) B83 nuclear bombs. The B-2 is the only acknowledged in-service aircraft that can carry large air-to-surface standoff weapons in a stealth configuration.

Development began under the Advanced Technology Bomber (ATB) project during the Carter administration, which cancelled the Mach 2-capable B-1A bomber in part because the ATB showed such promise. But development difficulties delayed progress and drove up costs. Ultimately, the program produced 21 B-2s at an average cost of $2.13 billion (~$4.04 billion in 2023), including development, engineering, testing, production, and procurement.[5] Building each aircraft cost an average of US$737 million,[5] while total procurement costs (including production, spare parts, equipment, retrofitting, and software support) averaged $929 million (~$1.11 billion in 2023) per plane.[5] The project's considerable capital and operating costs made it controversial in the U.S. Congress even before the winding down of the Cold War dramatically reduced the desire for a stealth aircraft designed to strike deep in Soviet territory. Consequently, in the late 1980s and 1990s lawmakers shrank the planned purchase of 132 bombers to 21.
The B-2 can perform attack missions at altitudes of up to 50,000 feet (15,000 m); it has an unrefueled range of more than 6,000 nautical miles (6,900 mi; 11,000 km) and can fly more than 10,000 nautical miles (12,000 mi; 19,000 km) with one midair refueling. It entered service in 1997 as the second aircraft designed with advanced stealth technology, after the Lockheed F-117 Nighthawk attack aircraft. Primarily designed as a nuclear bomber, the B-2 was first used in combat to drop conventional, non-nuclear ordnance in the Kosovo War in 1999. It was later used in Iraq, Afghanistan, Libya and Yemen.