The swept-wing Rockwell B-1 Lancer (called “Bone”) is the United States’ largest payload strategic bomber and its only supersonic bomber (the B-1 Lancer has a top speed of Mach 1.2). It was built to replace (or partially replace) the United States Air Force’s B-52 Stratofortress, but it will be the first strategic bomber to be retired as the B-21 Raider starts to enter service. Still, the Lancer and more life in it yet and has continued to receive upgrades with the new BEAST program keeping it lethal until the 2040s.