For more than 30 years the B-1B Lancer has proven itself as an essential part of America's long-range strategic bomber force. Capable of carrying the largest conventional payload of both guided and unguided weapons in the Air Force, the B-1 can rapidly deliver massive quantities of precision and non-precision weapons against any adversary, anywhere in the world, at any time.
The Air Force's newly acquired B-52 Stratofortress hadn't even taken off for it's first flight before studies for its replacement began. Research started in the realm of a supersonic bomber resulting in the development of the B-58 Hustler and XB-70 Valkyrie in the late 50s. Although cancelled, a joint NASA-U.S. Air Force flight research program continued to use the XB-70 prototypes, which were capable of reaching Mach 3.0, for research purposes into the late 60s.