Details about the U.S. Air Force’s new, secret B-21 Raider stealth bomber have so far been limited, but some have emerged since the service announced that it had picked Northrop Grumman to build the aircraft. As part of the Long Range Strike Bomber program, it is to be an advanced very long-range, large, heavy-payload stealth intercontinental strategic bomber for the United states Air force, able to deliver conventional and thermonuclear weapons.