The program was canceled in 1977, after the B-1A prototypes had been built. The combination of the high cost of the aircraft, the introduction of the AGM-86 cruise missile that flew the same basic speed and distance, and early work on the B-2 stealth bomber reduced the need for the B-1. This version had a top speed of Mach 2.2 at high altitude and the ability to fly for long distances at Mach 0.85 at very low altitudes. After a long series of studies, Rockwell International (now part of Boeing) won the design contest for what emerged as the B-1A. The B-1 was first envisioned in the 1960s as a platform that would combine the Mach 2 speed of the B-58 Hustler with the range and payload of the B-52, and was meant to ultimately replace both bombers.
Air Force fleet along with the B-2 Spirit and the B-52 Stratofortress as of 2023. It is one of three strategic bombers serving in the U.S. It has been nicknamed the 'Bone' (from 'B-One'). The Rockwell B-1 Lancer is a supersonic variable-sweep wing, heavy bomber used by the United States Air Force. North American Rockwell/Rockwell International
