When the X-15 smashed 350,000ft

It was an aircraft capable of Mach 6.7, and would expand humankind’s reach of the universe by proving that we could fly at unthinkable altitudes. On August 22, 1963, the X-15 reached the unthinkable – and then kept going… 

X-15 in Flight
X-15 in Flight

The North American X-15 was an aircraft unlike any before it. Its aerodynamic design could cut through the sky at speeds that were almost unthinkable. And, flown by an elite team of pilots that included Neil Armstrong, it was able to reach heights never achieved before. To this day, the X-15 remains the fastest manned aircraft ever to grace our skies. And on August 22, 1963 – 57 years ago – the aircraft smashed the ceiling of flight and reached 354,000ft.  

X-15 with test pilot Major Robert M. White, February 7 1961
X-15 with test pilot Major Robert M. White, February 7 1961

That’s 67 miles up. The Kármán Line, considered the official start of space, is at 60 miles.  

X-15A-2 with test pilot Peter Knight, 1965
X-15A-2 with test pilot Peter Knight, 1965

The concept of the X-15 was put together following a request for a proposal that illustrated the desire for a hypersonic research aircraft. North American Aviation was contracted to build the airframe in 1955, whereas Reaction Motors would be the manufacturer of the engines in 1956. Primarily designed to follow on research of the early X-planes, the X-15 was planned to explore the speeds of which aircraft were fully capable. The basic X-15 was a single-seat, mid-wing monoplane designed to explore the areas of high aerodynamic heating rates, stability and control, physiological phenomena, and other problems relating to hypersonic flight. In the early months of 1959, the first X-15 arrived at the NASA High-Speed Flight Station and began a contractor demonstration flight. The aircraft initially flew with two XLR-11 engines and produced a thrust of 16,380lb. Soon after, the Reaction Motors Division of Thiokol Chemical Corp perfected the XLR-99 engine, allowing the X-15 to reach new speeds and produce a remarkable thrust of 57,000lb. 

X-15 cockpit, 1963
X-15 cockpit, 1963

During its research, the X-15 set multiple unofficial world records. The first of these occurred on August 22, 1963. Piloted by NASA pilot Joseph Walker, the X-15 climbed through the sky until it reached an incredible altitude amounting to 354,000ft. This was the highest altitude ever attained for a winged aircraft (other than a space shuttle) at the time, converting to 67 miles high. This achievement would not be surpassed until 2004, when Brian Binnie flew the Scaled Composites SpaceShipOne at 367,487ft. Despite the remarkable achievement of the aircraft, the record was never officially recorded, meaning that it has remained unofficial since it happened. Yet there is little doubt that the X-15 still achieved an incredible breakthrough. 

X-15 simulator, 1961
X-15 simulator, 1961

Part of the reason for the X-15’s record never being made official was that the goal of the programme was to enable research at hypersonic velocities and at the edge of space. The programme yielded data that would eventually be critical in providing the stepping stone into space travel. It allowed major technological advancements and provided a range of new data to demonstrate for the first time that pilots would be able to fly a rocket-powered aircraft in an airless environment. The mind-boggling performance of an experimental aircraft allowed scientists to rewrite the rule book on conventional flight. It spawned an extraordinary legacy through achieving seemingly unattainable records, a legacy which lives on today in every aircraft that takes off and lands. Ultimately, many of the world’s technological advancements involving space travel can be pinpointed to the exact moment that the X-15 broke the invisible ceiling of aviation. 

Dryden pilot Neil Armstrong in the cockpit of the X-15, 1961
Dryden pilot Neil Armstrong in the cockpit of the X-15, 1961

Al images: NASA