29 November 1957: The third production Boeing B-52A-1-BO Stratofortress strategic bomber, 52-003, was flown from Boeing’s Seattle plant to the North American Aviation facility at Air Force Plant 42, Palmdale, California, to be modified to carry the new X-15 hypersonic research rocketplane.
Modifications began on 4 February 1958. A pylon was mounted under the bomber’s right wing. A large notch was cut into the trailing edge of the inboard flap for the X-15’s vertical fin. A 1,500 gallon (5,678 liter) liquid oxygen tank was installed in the bomb bay.
A station for a launch operator was installed on the upper deck of the B-52 at the former electronic countermeasures position. A series of control panels allowed the panel operator to monitor the X-15’s systems, provide electrical power, and to keep the rocketplane’s liquid oxygen tank full as the LOX boiled off during the climb to launch altitude. The operator could see the X-15 through a plexiglas dome, and there were two television monitors.
After modifications were completed at Palmdale, 52-003 was flown to Edwards Air Force Base, 14 November 1958.
NB-52A 52-003 is on display at the Pima Air and Space Museum, Tucson, Arizona.
16 September 1999: 44 years, 3 months and 6 days after its very first flight, NASA’s airborne launch aircraft, or “mothership,” Balls 8, completed its 1,000th flight.
Balls 8, so-called because of the double zeros in it U.S. Air Force serial number, 52-008, is a Boeing NB-52, modified as a drop ship from its original configuration as an RB-52B-10-BO Stratofortress reconnaissance bomber assigned to the Strategic Air Command. It made its first flight 11 June 1955 and was reassigned from SAC to Edwards Air Force Base to support NASA flight testing operations, 8 June 1959. Balls 8 served NASA until 17 December 2004, when it was replaced by a newer NB-52H Stratofortress.
52-008 was altered at the North American Aviation facility at Air Force Plant 42, Palmdale, California. A pylon was mounted under the bomber’s right wing. A large notch was cut into the trailing edge of the inboard flap for the X-15’s vertical fin. A 1,500 gallon (5,678 liter) liquid oxygen tank was installed in the bomb bay. A station for a launch operator was installed on the upper deck of the B-52 at the former electronic countermeasures position. A series of control panels allowed the panel operator to monitor the X-15’s systems, provide electrical power, and to keep the rocketplane’s liquid oxygen tank full as the LOX boiled off during the climb to launch altitude. The operator could see the X-15 through a plexiglas dome, and there were two television monitors.
The NB-52B was used during the X-15 Program and carried the three hypersonic research aircraft aloft on 159 of their 199 flights. (NB-52A 52-003, The High and Mighty One, made the other 40 launches.) It has also been used to carry the X-24 and HiMat lifting body research aircraft and to launch Pegasus research rockets.
At the time of its retirement, Balls 8 was the oldest B-52 in service, and also the lowest time B-52. It is on display near the north gate at Edwards Air Force Base.
Of the 744 B-52 Stratofortresses built by Boeing, 50 were B-52Bs and 27 of these were RB-52B reconnaissance bombers.
Early production B-52Bs were powered by eight Pratt & Whitney J57-P-1W turbojet engines, while later aircraft were equipped with J57-P-19W and J57-P-29W or WA turbojets. The engines were grouped in two-engine pods on four under-wing pylons. The J57 was a two-spool, axial-flow engine with a 16-stage compressor section (9 low- and 7-high-pressure stages) and a 3-stage turbine section (1 high- and 2 low-pressure stages). These engines were rated at 10,500 pounds of thrust (46.71 kilonewtons), each, or 12,100 pounds (53.82 kilonewtons) with water injection.
The B-52B/RB-52B had a cruise speed of 523 miles per hour (842 kilometers per hour). The maximum speed varied with altitude: 630 miles per hour (1,014 kilometers per hour) at 19,800 feet (6,035 meters), 598 miles per hour (962 kilometers per hour) at 35,000 feet (10,668 meters) and 571 miles per hour (919 kilometers per hour) at 45,750 feet (13,945 meters). The service ceiling at combat weight was 47,300 feet (14,417 meters).