This week in Edwards history Published Sept. 21, 2017 By 412th Test Wing Public Affairs EDWARDS AIR FORCE BASE, Calif. -- On Sept. 21, 1964, North American Rockwell’s XB-70 Valkyrie experimental aircraft made its first flight from Plant 42 in Palmdale, California, to Edwards. It was flown by North American test pilot Alvin S. White and Col. Joseph F. Cotton. Originally conceived as a strategic bomber with the ability to cruise at Mach 3 speeds, the two XB-70s completed were used as joint Air Force/NASA high-speed research vehicles only.