The B-21 Raider is an American strategic bomber. It is being developed by Northop Grumman for the United States Air Force. It is first 6th generation jet aircraft. The airplane is best known for being very stealthy. It is very hard to see on radar. The plane is intended to replace the B-2 Spirit and B-1 Lancer by 2040. As of February 2022, six B-21s were being built. The B-21 Raider is smaller than the B-2 Spirit, but it has a longer range. The B-21 Raider is named after the Doolittle Raiders, who bombed Tokyo in 1942.