NASA pilot Neil Armstrong is seen here in the cockpit of the X-15 after high speed research flight…

NASA research pilot Neil Armstrong is seen here in the cockpit of the X-15 ship #1 (56-6670) after a…

 X-15 (56-6672) research aircraft is secured by ground crew after landing on Rogers Dry Lakebed. Th…

 Both the HL-10 and X-15 shown here parked beside one another on the NASA ramp in 1966, underwent m…

 Both the HL-10 and X-15 shown here parked beside one another on the NASA ramp in 1966, underwent m…

 X-15 aircraft in flight over the desert  December 20, 1961. Ship #3 made 65 flights during the pr…

One of the major advances in aircraft development, pilot training, mission planning, and research fl…

 This photo shows the X-15 cockpit and was unique for many reasons, including the fact that it had …

 Hangar 4802 at the NASA Flight Research Center in 1966. Aircraft on left include (left to right): …

 This photo shows one of the four attempts NASA made launching two X-15 aircraft in one day. This a…

 X-15 rocket powered aircraft was taken aloft under the wing of a B-52. Because of the large fuel c…

The X-15 ship #3 (56-6672) is seen here on the lakebed at the Edwards Air Force Base, Edwards, Calif…

The X-15 (56-6670), seen here on the lakebed at Edwards Air Force Base, Edwards, California. This X-…

The X-15-3 (56-6672), seen here on the lakebed at Edwards Air Force Base, Edwards, California, was a…

The X-15 aircraft, ship #1 (56-6670), sits on the lakebed early in its illustrious career of high sp…

The X-15 rocket-powered aircraft was taken aloft under the wing of a B-52. Because of the large fuel…

 X-15 rocket-powered research aircraft being carried aloft under the wing of its B-52 mothership. T…

 High-altitude contrails frame the B-52 mothership as it carries the X-15 aloft for a research flig…

The X-15-1(56-6670) rocket powered research aircraft as it was rolled out in 1958. At this time, the…

 After receiving a full scale ablative coating to protect the craft from the high temperatures asso…

In June 1967, the X-15A-2 rocket powered research aircraft received a full-scale ablative coating to…

In June 1967, the X-15A-2 rocket powered research aircraft received a full-scale ablative coating to…

In June 1967, the X-15A-2 rocket-powered research aircraft received a full-scale ablative coating to…

 A view of some of the mission markings, painted on the side of NASA's B-52 mothership, that tell t…