Tag Archives: XLR-99

19 July 1963

Joe Walker with the Number 2 North American Aviation X-15A, 56-6671, on Rogers Dry Lake. (NASA)
Joseph A. Walker, NASA Chief Research Test Pilot
Joseph A. Walker, NASA Chief Research Test Pilot

19 July 1963: Between 1960 and 1963, NASA Chief Research Test Pilot Joseph Albert Walker made 25 flights in the North American Aviation X-15A hypersonic research rocketplanes. His 24th flight was the 21st for the Number 3 X-15, 56-6672, and the 90th of the X-15 program.

At 10:20:05.0 a.m., Walker and the X-15 were airdropped from the Boeing NB-52B Stratofortress, 53-008, Balls 8, over Smith Ranch Dry Lake, Nevada. Walker fired the Reaction Motors XLR99-RM-1 rocket engine and over the next 84.6 seconds the engine’s 60,000 pounds of thrust drove the X-15 upward. The engine’s thrust on this flight was higher than expected, shutdown was 1.6 seconds late, and Walker’s climb angle was 1½° too high, so the X-15 overshot the predicted maximum altitude and its ballistic arc peaked at 347,800 feet (106,010 meters, 65.8 miles). The maximum speed was Mach 5.50 (3,714 miles per hour, 5,977 kilometers per hour).

Walker glided to a touch down at Rogers Dry Lake, Edwards Air Force Base California, after flying 311 miles in 11 minutes, 24.1 seconds of flight. On this flight, Joe Walker became the first American civilian to fly into Space.

North American Aviation X-15A 56-6672 on Rogers Dry Lake after a flight. (NASA)
North American Aviation X-15A 56-6672 on Rogers Dry Lake after a flight. (NASA)

© 2015, Bryan R. Swopes