The B-2 Spirit is one of three strategic heavy bombers in U.S. Air Force service. Originally conceived to infiltrate the Soviet air-defense network and attack targets with nuclear weapons, over the decades its mission has grown to include conventional precision attack. The B-2 is the most advanced bomber in U.S. service, and the only one of three types that still carries nuclear gravity bombs.
In the late 1970s, the administration of President Jimmy Carter opposed the high-speed B-1A bomber as a waste of government money. Carter had been briefed on the new field of stealth technology and was responsible for the development of the F-117A stealth fighter. Instead of the B-1A, Carter authorized development of the Advanced Technology Bomber, or Stealth Bomber. Little was known about the bomber at the time except that it would incorporate new radar-evading technologies and possibly a dramatically different shape than previous bombers.