Balls 8

Balls 8 was a NASA Boeing NB-52B mothership. It derives its nickname from its NASA tail number 52-008: leading zeroes plus the number 8. Among USAF personnel it is common practice to refer to aircraft whose tail number is a single number preceded by multiple zeros as "Balls" and the last number of its tail number. It was retired from active service with NASA on December 17, 2004 after almost 50 years flying service. Balls 8 was famous for dropping aerospace research vehicles for 106 flights of the X-15. Like its NB-52A predecessor, a pylon was fitted under the right wing between the fuselage and the inboard engines with a 6 x section removed from the right wing flap in order to accommodate the X-15's tail. It flew a total of 159 captive-carry and launch missions in support of the X-15 program, from June 1959 until October 1968. It also flew missions supporting the X-24, HiMAT, Lifting Body vehicles, X-43, early launches of the OSC Pegasus rocket and numerous others.

Balls 8 was originally an RB-52B that was first flown on June 11, 1955; and entering service with NASA on June 8, 1959. It was the oldest active B-52 still in service at the time of its retirement. It was modified at North American Aviation's Palmdale facility in order to allow it to carry the X-15. The modified bomber first was used to launch the X-15 on its fifth flight, on January 23, 1960. Balls 8 was the last B-52 in service of any type other than the H model. It also had the lowest total air time of any operational B-52. It is on permanent public display near the north gate of Edwards Air Force Base.