1960s and 1970s
DFRC (M2-F1), Northrop (M2-F2), Northrop (M2-F3), Northrop (HL-10), Martin (X-24A), Martin (X-24-B). There was one of each lifting body type manufactured. They flew a total of 223 flights between 1963-1975 (not including nearly 400 car tows of the M2-F1). This joint program between the Air Force and NASA demonstrated the ability of pilots to maneuver and safely land a wingless vehicle designed to fly back to Earth from space and be landed like an aircraft at a pre-determined site. The information generated by the lifting body program contributed to the data base that led to development of today's space shuttle program, especially its approach and landing techniques. The rocket-powered lifting bodies (all but the unpowered M2-F1) have also contributed to the upcoming X-33 space technology demonstrator and the X-38.
The construction of the M2-F1 was a joint effort between Dryden Flight Research Center and a local glider manufacturer, the Briegleb Glider Company. Initial testing of the M2-F1, was performed by towing the aircraft across Rogers Dry Lakebed behind a specially modified Pontiac Catalina convertible. Later testing was performed by towing the M2-F1 behind a C-47 aircraft.
The M2-F2 was a joint program between NASA and Northrop Corporation. The aircraft flew 16 times between 1966 and 1967. All flights of the M2-F2 were non-powered glide flights performed by dropping the aircraft from a modified wing pylon of a B-52 aircraft.
The M2-F3 was a joint program between NASA and Northrop Corporation. The aircraft flew 26 times between 1970 and 1972 and achieved its first powered flight on November 25, 1970. During testing, the aircraft reached a top altitude of 71,500 feet and a top speed of 1,064 miles per hour (Mach 1.6). NASA donated the aircraft to the Smithsonian Institute in December of 1973.
The HL-10 was a joint program between NASA and Northrop Corporation. The aircraft flew 37 times between 1966 and 1970. The HL-10 achieved the highest altitude and fastest speed of all the aircraft in the lifting body program. On Feb. 18, 1970, Air Force test pilot Peter Hoag piloted the HL-10 to Mach 1.86 (1,228 mph). Nine days later, NASA pilot Bill Dana flew the vehicle to 90,030 feet setting the altitude record for the lifting body program.
The X-24A was a joint program between NASA, the U. S. Air Force and Martin Aircraft Company. The aircraft flew 28 times between 1969 and 1971. Its unique design further validated the concept that an non-powered Space Shuttle vehicle could be successfully landed. The X-24A shape was later borrowed for the X-38 Crew Return Vehicle (CRV) technology demonstrator designed as an escape vehicle for the International Space Station.
The X-24B was a joint program between NASA, the U. S. Air Force and Martin Aircraft Company. The aircraft flew 36 times between 1973 and 1975. The X-24B was the last of the lifting body aircraft to fly and demonstrated that accurate unpowered reentry vehicle landings were operationally feasible.
North American manufactured two airframes. They flew a total of 129 flights between 1964-1969. The joint program among North American Rockwell, the Air Force, and NASA featured the world's largest experimental aircraft with a delta wing and hinged wing tips that could be folded down to a 65° angle to improve stability at the aircraft's supersonic speeds of up to Mach 3, a speed at which the Valkyrie was designed to ride its own shock wave. The program used the Valkyrie to conduct fundamental flight research at high speeds for use in designing future supersonic aircraft, both military and civilian. The aircraft produced a significant quantity of information on supersonic flight at up to Mach 3 speeds in areas such as noise (including sonic booms), potential flight corridors, validation of wind-tunnel data, flight control, operational problems, and clear-air turbulence.