A fleet of lifting bodies flown at the NASA Flight Research Center (FRC), Edwards, Calif., from 1963 to 1975 demonstrated the ability of pilots to maneuver (in the atmosphere) and safely land a wingless vehicle. These unique research vehicles, with their unconventional aerodynamic shapes, were the M2-F1, M2-F2, M2-F3, HL-10, X-24A, and the X-24B. The information the lifting body program generated contributed to the data base that led to development of today's space shuttle program.
The original idea of lifting bodies was conceived about 1957 by Dr. Alfred J. Eggers Jr., then the assistant director for Research and Development Analysis and Planning at what later became the NASA Ames Research Center, Moffett Field, Calif.(then called the Ames Aeronautical Laboratory).Eggers found that by slightly modifying a symmetrical nose cone shape, aerodynamic lift could be produced. This lift would enable the modified shape to fly back from space rather than plunge to Earth in a ballistic trajectory.
In 1962, FRC Director Paul Bikle approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. Construction was completed in 1963. The first flight tests were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. These initial tests produced enough flight data about the M2-F1 to proceed with flights behind a NASA R4D tow plane at greater speeds.
The success of the M2-F1 program led to NASA's development and construction of two heavyweight lifting bodies based on studies at NASA's Ames and Langley research centers--the M2-F2 and the HL-10, both built by the Northrop Corporation. The "M" refers to "manned" and "F" refers to "flight" version. "HL" comes from "horizontal landing" and "10" is for the tenth lifting body model to be investigated by Langley. The Air Force later became interested in lifting body research and had a third design concept, the X-24A, built by the Martin Company. It was later modified into the X-24B and both configurations were flown in the joint NASA-Air Force lifting body program.