Neil Armstrong is often celebrated as the first man to walk on the Moon, but he was always quick to point out that he was, first and foremost, a pilot and engineer. After all, you have to learn to fly before you can take a bird to the Moon. For Armstrong, he brushed the fringes of space before reaching orbit in the rocket powered X-15 aircraft.
The X-15 was an awesome, tripartite aircraft. Part jet aircraft, part spaceplane, and part glider, it was unique in its design. And tiny, just 51 feet long with a wingspan just 23 feet wide. It was, pilots joked, basically a giant fuel tank. Aside from the cockpit, everything inside the aircraft went to powering its engine.
It was also designed for a unique flight path. The purpose behind the small airplane was to see how spaceplanes would handle the stress of atmospheric reentry and landing under pilot control from space. To do that, it had to fly to near orbital altitudes. Here’s where its three types of flying come into play.
The X-15 was too small to reach near orbital altitudes on its own, even though it was almost all fuel. So it was launched from altitude, it varied on each flight but usually somewhere around 30,000 feet, from underneath the wing of a converted B-52 bomber. After release, the pilot would ignite the engine and scream past the sound barrier towards a peak altitude.
At altitude, the air was too thin for traditional flight – wings need air to push against for control. So the X-15 used reaction controls, tiny gas-fueled rockets in the aircraft’s nose to guide it. That way, once gravity took over from momentum and the aircraft started to descend, the pilot could make sure he was going down nose first.
Then came the tricky gliding landing. Since all the fuel was spent reaching peak altitudes, there was none left for the descent. Landing was an unpowered stage. With a body longer than its wingspan, the X-15 was a lousy glider; it basically fell from the sky. But it did glide enough for the pilot to guide it in a wide circle to slow his speed to a nice, controllable, 230 miles per hour for a safe landing on the dry lakebed at Edwards Air Force Base where the program was based.
When Armstrong arrived at Edwards Air Force Base in 1954, he was thrilled. This was the place he’d been hoping to find himself, it was where history was being made. And would be where he made history; the same year he arrived the National Advisory Committee for Aeronautics took control of the X-15 program and Edwards was its future home.
Almost immediately, Armstrong got to work training in simulators. He was already a talented pilot, a trained naval aviator with experience flying in Korea, but the X-15 demanded he learn a whole new set of flying skill. He trained, and worked on a series of other projects, for six years getting his chance to fly the X-15. By then the NACA had given way to NASA and Armstrong was a civilian pilot flying for the space program.
His first flight came on November 30, 1960. It was a checkout flight, a chance for Armstrong to familiarize himself with the aircraft. It was also a fairly gentle flight. He didn’t go very high or very fast, reaching a top speed of just under Mach 2.
Later flights saw Armstrong set personal records in the X-15. On his sixth flight on April 20, 1962, he reached an altitude of 207,500 feet. That flight he also accidentally set a distance record. At his peak, the X-15 skipped off the planet’s atmosphere and bounced along, taking him fifty miles further from Edwards than he wanted to be. Armstrong did not have any options but to fight to get back to the dry lakebed, a challenge in a rapidly falling aircraft with minimal lift. He managed it but only just. By the time he reached Edwards he was flying so low the trees surrounding the lakebed were at his eye level. His speed record came on his seventh flight on July 26, 1962. Burning all his available fuel, he reached a top speed of 3,989 miles per hour or Mach 5.74. These records weren’t noteworthy for the program as a whole; Joe Walker set an altitude record flying 354,000 feet and Pete Knight managed the top speed of Mach 6.7.
Armstrong only flew seven flights in the X-15. In September 1962, before any of the really high and fast X-15 flight started, Armstrong was offered a position with NASA’s astronaut corps.