The US Air Force on Friday will unveil its new B-21 Raider, a high-tech stealth bomber that can carry nuclear and conventional weapons and is designed to be able to fly without a crew on board.
The B-21 -- which is on track to cost nearly $700 million per plane and is the first new US bomber in decades -- will gradually replace the B-1 and B-2 aircraft, which first flew during the Cold War.
