The M Two F Two Lifting Body, Bruce Peterson's Near-Fatal Crash at Edwards, and the Wingless Flight Program That Taught the Space Shuttle How to Land

Every Space Shuttle approach and landing - all 133 of them - carried the aerodynamic fingerprints of a series of strange, wingless aircraft flown over the California desert between 1963 and 1975. That program, NASA’s lifting body research effort, is one of the most consequential research initiatives in aviation history, and one of the least studied outside the test pilot community. It began with a hand-built prototype towed behind a Pontiac convertible. It ended with a blueprint for returning from orbit on a concrete runway.

The Problem NASA Was Trying to Solve

In the late 1950s, the core question facing reentry vehicle designers wasn’t how to survive the atmosphere coming back from orbit - it was what to do next. The capsule answer was simple: maximize drag with a blunt body, protect it with an ablative heat shield, and drop into the ocean under parachutes. It worked. But every flight consumed an entire spacecraft, and landing accuracy was measured in miles of open water.

Researchers at NASA’s Ames Research Center and the Flight Research Center at Edwards Air Force Base started asking a different question. Could a vehicle shaped for hypersonic reentry also fly through the lower atmosphere and land on a runway? The answer required solving an aerodynamic problem nobody had cracked at operational scale.

What Is a Lifting Body, and How Does It Fly Without Wings?

A lifting body generates aerodynamic lift from the shape of the fuselage itself, not from a conventional wing. No stub wing, no delta planform - no wing at all. The lift-to-drag ratios this produces are poor compared to any winged aircraft, but they are sufficient for controlled flight. And for a vehicle that has already survived reentry at roughly 17,000 miles per hour, sufficient is remarkable.

The concept demanded physical proof before anyone would fund the next step.

The M2-F1: NASA’s Flying Bathtub

The first test article was the M2-F1 - the designation stood for manned, second design configuration, first variant. It was built by a small California shop from aluminum tubing and fiberglass. The planform was roughly a half-cone: rounded on top, flat on the bottom, with a tail assembly. It had no engine. The engineers and test pilots working with it acknowledged the obvious: it looked like a bathtub.

Initial tests involved towing the M2-F1 across Rogers Dry Lake behind a yellow Pontiac convertible, increasing speed incrementally to validate the low-velocity aerodynamics. When those tests confirmed the concept had merit, the program graduated to tow flights behind a C-47 transport. Test pilot Milt Thompson flew those missions and confirmed what the theory predicted. The M2-F1 flew, it was controllable, and it could be landed with precision. Its glide ratio was approximately 2.8:1 - worse than most hang gliders - but the data was real.

That was enough to justify the next step.

The M2-F2: A Serious Research Aircraft with Dangerous Margins

The M2-F2 was a different class of machine. Northrop Corporation built it, drawing on experience with unconventional aerodynamic geometries. It was heavier and more refined than the M2-F1, carried aloft by an NB-52B - the same modified Stratofortress mothership that launched the X-15 - and released at altitude for unpowered glide tests, with a small rocket motor available for powered climb segments.

Its best glide ratio was approximately 2.5:1. Approach speeds were high, margins were narrow, and roll control was sluggish. The lateral axis feedback wasn’t intuitive. Test pilots described it as an aircraft that rewarded precise technique and punished anything else.

May 10, 1967: Bruce Peterson’s Crash at Edwards

Bruce Peterson was a former Navy pilot with a solid reputation in the Edwards test community. On May 10, 1967, he was on approach in the M2-F2 over Rogers Dry Lake when the accident chain began building. A rescue helicopter positioned nearby as part of the standard safety protocol shifted in a way that caught his attention at a critical moment during the approach. His focus broke. The timing deteriorated. The right main landing gear did not fully extend and lock.

The vehicle touched down. As it rolled out, the partially extended gear caught the lakebed surface. The M2-F2 cartwheeled - five full rotations before coming to rest.

Peterson survived, but barely. His recovery took years. He lost sight in one eye. He eventually flew again.

The Six Million Dollar Man Connection

The crash footage from that morning is among the most-watched aerospace film ever recorded - though most of the people who have seen it don’t know what they’re looking at. The opening title sequence of the 1970s television series The Six Million Dollar Man uses that footage of the tumbling aircraft over the lakebed. Millions of viewers watched a real test pilot, a real experimental aircraft, and a real moment in flight research history, without any of that context.

NASA’s Response: The M2-F3 and the HL-10

NASA did not abandon the concept. They rebuilt it.

The M2-F2 became the M2-F3. Northrop made one targeted structural change: a center vertical fin was added between the two outer fins that the original had lacked. That addition substantially improved lateral stability. The M2-F3 flew successfully and contributed to the expanding data set.

By that point, however, another lifting body had become the centerpiece of the program: the HL-10. The HL designation stood for horizontal lander. Where the M2-F2 family had a rounded upper surface and flat lower surface, the HL-10 had a flatter, more elongated cross-section designed to generate better lift characteristics. The result was a higher lift-to-drag ratio, improved roll control, and handling qualities that test pilots found significantly more manageable.

Northrop built the HL-10 as well. It flew from 1966 through 1970, with test pilots including Bill Dana, Jerauld Gentry, and John Manke. In certain configurations, the HL-10 achieved glide ratios approaching 4:1. Still far below any conventional winged aircraft - but the improvement over earlier designs was substantial enough to give pilots genuine energy management flexibility on approach.

The data coming out of the HL-10 program was some of the most important generated by the entire lifting body effort. It didn’t just confirm that the concept was survivable. It defined what the realistic performance envelope of a wingless reentry vehicle actually looked like.

The X-24 Series and the Concrete Runway Milestone

Running somewhat in parallel was the Martin X-24 series. The X-24A had a rounded, near-teardrop cross-section. The X-24B was the most aerodynamically refined lifting body of the entire program - a double-delta planform, still without a conventional wing, but shaped toward what an operational reentry vehicle would eventually need to be.

In August 1975, test pilot John Manke flew the X-24B to a landing on the concrete runway at Edwards Air Force Base.

Not the dry lakebed. Concrete - the kind of hard surface required to operate a fleet of reusable space vehicles at Kennedy Space Center. From a Pontiac-towed prototype in 1963 to a precision concrete runway landing in 1975, the program had spent 12 years answering one fundamental question: can a wingless vehicle shaped for reentry actually fly and land with precision? The answer was now documented in a decade-plus of flight data.

How the Lifting Body Program Shaped the Space Shuttle

The Space Shuttle program was tracking the lifting body results closely throughout the early 1970s, and the research fed directly into the Shuttle’s approach and landing profile.

The Shuttle’s final approach glideslope was approximately 18 to 20 degrees. A standard instrument approach glideslope is 3 degrees. The Shuttle was descending at roughly six to seven times the angle of a conventional approach, at a rate of descent of approximately 9,000 to 10,000 feet per minute. A commercial airliner on a normal approach descends at 500 to 800 feet per minute.

The Shuttle’s glide ratio was approximately 4.5:1. The HL-10 had demonstrated approximately 4:1. That alignment was not coincidental - it was twelve years of empirical data informing the fundamental aerodynamic character of the most complex flying machine ever built.

That glide ratio also meant there was no go-around. No extending the downwind. No second approach. From the moment the vehicle entered the heading alignment cone, the crew had one opportunity at the runway. Energy management from deorbit burn to touchdown had to be executed within narrow margins, every time.

The Shuttle Training Aircraft: Building the Muscle Memory

NASA’s answer to training commanders for this approach was the Shuttle Training Aircraft - a Gulfstream II business jet modified significantly for the purpose. Engineers installed a system that could apply reverse thrust in flight. The landing gear was deployed and locked down. Speed brakes were extended. The combined drag profile was designed to replicate the Shuttle’s steep descent angle and compressed energy management timeline.

Commander candidates flew the Shuttle Training Aircraft hundreds of times - into Kennedy Space Center’s Runway 15, into Edwards, building the instrument scan and physical intuition for an approach that shared almost nothing with anything else in their logbooks. Touchdown speeds in the actual Shuttle were approximately 215 to 220 knots - more than twice the approach speed of a light twin. An early flare meant landing long and potentially running out of pavement. A late flare meant driving the nose gear into the surface with excessive energy. The training aircraft program wasn’t supplementary. It was essential.

The Enterprise Approach and Landing Tests

The first full-system validation came in the fall of 1977. The Enterprise - the first Shuttle orbiter, built for approach and landing tests and never intended for orbital flight - was mated to a modified Boeing 747 Shuttle Carrier Aircraft and carried aloft over the Mojave.

On August 12, 1977, the Enterprise separated from the carrier aircraft at approximately 24,000 feet. The flight crew was Fred Haise - lunar module pilot on Apollo 13 - and Gordon Fullerton. They flew a five-minute unpowered glide to a landing on the dry lakebed at Edwards. Four more free flights followed across two crews. Every one of them a successful deadstick landing.

When Columbia flew the first orbital Shuttle mission in April 1981, commander John Young and pilot Bob Crippen were flying a vehicle whose approach profile had been validated through 14 years of lifting body research, refined through hundreds of Shuttle Training Aircraft sorties, and confirmed by the Enterprise test program.

Key Takeaways

• The NASA lifting body program ran from 1963 to 1975, progressing from a fiberglass prototype towed by a Pontiac to precision landings on concrete at Edwards Air Force Base.
• On May 10, 1967, test pilot Bruce Peterson survived a five-rotation crash in the M2-F2 - footage later used without attribution in the opening titles of The Six Million Dollar Man. Peterson recovered and flew again.
• The HL-10 achieved glide ratios near 4:1, directly informing the Space Shuttle’s 4.5:1 glide ratio and its 18–20 degree approach glideslope.
• The Shuttle’s approach was approximately six to seven times steeper than a standard ILS glideslope, with a descent rate of 9,000–10,000 feet per minute and no go-around option.
• The HL-10 is on display at the Air Force Flight Test Museum at Edwards; the X-24B is at the National Museum of the United States Air Force in Dayton.