The M2-F1 Lifting Body is seen here under tow by an unseen C-47 at the NASA Flight Research Center during a flight on Aug. 28, 1964. The low-cost vehicle was the first piloted lifting body to be test flown. (NASA photo) › View Larger Image
Former NASA Dryden engineer and center director Ken Szalai recalled the legacy of the M2-F1 lifting body championed by the late Dale Reed and flown by the late Milt Thompson (in photos on screen) in his "Taking the Road Less Traveled" historical colloquium on the 50th anniversary of the M2-F1's first flight April 5. (NASA / Ken Ulbrich) › View Larger Image As NASA's Dryden Flight Research Center prepares for Sierra Nevada Corporation's Dream Chaser space-access vehicle to arrive this summer for approach-and-landing flight tests, Dryden employees were recently reminded about the legacy of the craft's shape that was validated through flight research at the NASA field center a half-century ago.
Former Dryden Center Director Ken Szalai recalled the pioneering high-risk, low-cost M2-F1 prototype lifting body project during a colloquium at the center April 5, the 50th anniversary of the first M2-F1 flight. It was on that exact day a half-century ago that a hopped-up Pontiac Catalina convertible towed the M2-F1 lightweight lifting body flown by pilot Milt Thompson into the sky above Rogers Dry Lake for the first time.
Lifting body aircraft are essentially wingless aircraft where the shape of the fuselage provides a small amount of lift in place of a conventional wing – an aeronautical concept known as low lift over drag – and makes it capable of safely landing unpowered.
Szalai explained how that first flight set the stage for research with a series of lifting body designs to study atmospheric flight that contributed to the aerodynamic data used in development of the space shuttle. Szalai brought the flight to life through a video produced in 1997 for an event marking the restoration of the M2-F1 that featured some of the key figures in their own words. Szalai's historical retrospective was also amplified by several retired NASA Dryden researchers who worked on or flew M2-F1, including engineers Bertha Ryan and Wen Painter, pilot Don Mallick and Ross Briegleb, the son of the late M2-F1 builder Gus Briegleb.
Colloquium panelists who recalled their experiences with the M2-F1 lifting body a half-century ago included (from left), Ross Briegleb, son of M2-F1 builder Gus Briegleb; colloquium speaker and former Dryden center director Ken Szalai; retired Dryden research pilot Don Mallick; and retired engineers Bertha Ryan and Wen Painter. (NASA / Ken Ulbrich) › View Larger Image The Dream Chaser embodies the answer to why research from 50 years ago continues to inspire and provide information for current vehicles, Szalai noted. The Dream Chaser's shape is based on the HL-20 lifting body design developed at NASA's Langley Research Center from a Russian design, but never built and flown.
To put the leadership, risk and methodology used to develop the M2-F1 in perspective, Szalai said many of the steps leading to the success of the first lifting body aircraft flights couldn't unfold the same way today because the eras and requirements are so different.
Szalai didn't criticize risk management in today's flight research, rather he focused on how the M2-F1 team's flight research unfolded. He said the partnerships with the Air Force and other NASA centers that are indicative of today's research are just as valuable and should be pursued.
The lifting-body concept was originated by Alfred Eggers and other engineers in the mid-1950s at the National Advisory Committee for Aeronautics' Ames Aeronautical Laboratory at Moffett Field, Calif. However, Dryden researcher R. Dale Reed believed the only way those shapes would be used was to validate them through flight research.
Reed started by flying paper airplanes though the halls at work and decided to fly model aircraft based on lifting body designs, which his wife Donna filmed. With footage in hand, Reed demonstrated to management that the concepts worked and should be further explored with an experimental aircraft.
Reed found a champion for his cause in Thompson, at the time a pilot of the X-15 rocket plane. The two men then convinced Dryden (then Flight Research Center) Director Paul Bikle to fund the low-cost development of the M2-F1. Convinced the idea was solid, Bikle gave the green light for work to begin.
The internal steel structure for the M2-F1 was built at the Flight Research Center. With the external wooden shell built by sailplane builder Gus Briegleb then attached to the framework. Visible in this 1963 photo are the stick, rudder pedals, and ejection seat. (NASA photo) › View Larger Image In all, the M2-F1 was built for only about $30,000 and it has been hypothesized that the cost of such a vehicle from a prime contractor could have easily topped $150,000, Szalai said. Constructed of mahogany and spruce plywood and steel tubing, the ungainly craft was later dubbed the "flying bathtub" by the media for its unique shape. How items for the project were procured was handled carefully. For example, the modified Pontiac convertible needed for towing the aircraft was listed on official records as a "lifting body power plant."
The M2-F1 framework, landing gear and controls were built in-house by specialists in the machine shop, among them Jerry Reedy who attended Szalai's presentation. The framework and the plywood outer shell were attached with just four bolts. The M2-F1 was later fitted with an ejection seat for the air-launched flights, Szalai said. Eggers was instrumental in getting the M2-F1 into a wind tunnel at Ames to gather data prior to the start of research flights, Szalai said.
The decision to fly wasn't unanimous. Szalai recounted Bikle's poll of top managers, one of whom didn't believe it was worth the risk to fly the M2-F1.
"It was a pretty high risk and it could have meant his (Bikle's) career if there was a problem. He trusted Milt and the team and they believed it would work," Szalai said.
Flanked by Ken Szalai and Bertha Ryan, Retired Dryden research pilot Don Mallick recalled how he and Air Force Maj. Chuck Yeager, then commander of the Aerospace Research Pilot School at Edwards, got their first and only checkout flights in the M2-F1. (NASA / Ken Ulbrich) › View Larger Image Bikle also gained confidence from frequent visits to the project and talking with the team as work on the M2-F1 progressed, Szalai explained. There also was an incremental process to flight testing as well as practical and analytical data to review.
A sound byte of former Dryden research pilot Bill Dana in the 1997 video summed up the M2-F1: "It defied imagination."
When the first M2-F1 flight was a success, it "changed the world. We were no longer inexperienced in flying a lifting body aircraft." Szalai said. "The M2-F1 was the key to unlock the door to unpowered lifting body flight."
After more than 100 tows to very low altitudes by the hot-rod Pontiac convertible, the M2-F1 was later towed aloft to higher altitudes for longer flights by a C-47. The more advanced heavyweight lifting bodies that followed the prototype M2-F1 were air launched from NASA's NB-52B to validate high-altitude flight characteristics. Those craft included the M2-F2, the M2-F3, the X-24A, the X-24B and the rocket-powered HL-10, which graces the entrance to Dryden today.
When the Sierra Nevada's Dream Chaser flies at Dryden later this year, it will reinforce the center's legacy with lifting body aircraft, starting with the M2-F1 first flight 50 years ago.