posted 10-12-2025 09:00 AM               

Space Cover 827: B-52 "Balls 8" X-15 Carrier

The X-15's purpose was to fly high and fast, testing the machine and subjecting pilots to conditions that future astronauts would face. It made the first manned flights to the edges of space and was the world’s first piloted aircraft to reach hypersonic speeds - more than five times the speed of sound. The X-15 was an important tool for developing spaceflight in the 1960s, and pilots flying above 50 miles altitude in the X-15 earned astronaut wings.

Like other rocket planes, the X-15 was launched in midair from a B-52 “mothership” at about 45,000 feet. Once its powerful rocket ignited, the X-15 streaked upward to the limits of the atmosphere, then glided unpowered to land on a dry lake bed. Typical flights lasted about 10 minutes.

The carrier aircraft was originally planned to be a Convair B-36 intercontinental bomber but this was soon changed to a Boeing B-52 Stratofortress. Two B-52s were modified to carry the X-15: NB-52A 52-003, "The High and Mighty One," and NB-52B 52-008, "Balls 8."

The X-15 would be under the B-52s for captive flights, glide flights, and powered flights.

Col. Charles C. ‘Charlie’ Bock, Jr. graduated from Purdue University with a Bachelor of Science in Aeronautical Engineering in 1949. His United States Air Force career included being a bomber pilot, fighter pilot, test pilot, and a military astronaut designee. Col. Bock was a B-50 launch pilot for the X-2 and the B-52 launch pilot for the first captive and first powered flights of the X-15. Col. Bock was the pilot for 15 flights and co-pilot on an additional 11 flights.

Thanks to Harry Gordon, there were 6 covers flown by then "Capt. CC Bock" on a local flight at Edwards AFB aboard "Balls 8" on August 24, 1959 where he added as a note, "X-15 CARRIER" in the document cachet. Capt. Bock mailed the covers back to Harry Gordon on August 28th, 4 days after the "Balls 8" flight. Note that the address label to D.P. Thometz was placed on top of the Harry Gordon rubber stamp address.

Though the X-15 rocket plane was not attached to "Balls 8" for this flight, this is a documented piece of X-15 history.

posted 10-12-2025 12:46 PM               

Just an interesting note (at least to me): Mr. Thometz (the addressee on the label) lived about 3-4 miles from where a certain three-year-old future space cover collector was growing up. And Mr. Thometz’ address is not far from the Boeing plant that was in Wichita, so I’d bet he was a Boeing employee.

After the X-15 program, Balls 8 continued to serve as a carrier airplane for a bunch of subsequent research aircraft at Edwards. It was finally retired in 2004 as shown on this cover: