The NASA M2-F1 was a lightweight, unpowered prototype aircraft, developed to flight-test the wingless lifting body concept. Its unusual appearance earned it the nickname "flying bathtub" and was designated the M2-F1, the M referring to "manned", and F referring to "flight" version. In 1962, NASA Dryden management approved a program to build a lightweight, unpowered lifting-body prototype. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. Development The lifting-body concept originated in the mid-1950s at the National Advisory Committee for Aeronautics' Ames Aeronautical Laboratory, Mountain View, California. By February 1962, a series of possible shapes had been developed, and R. Dale Reed was working to gain support for a research vehicle. The construction of the M2-F1 was a joint effort by Dryden and a local glider manufacturer, the Briegleb Glider Company. The budget was US$30,000. NASA craftsmen and engineers built the tubular steel interior frame. Its mahogany plywood shell was handmade by Gus Briegleb and company. Ernie Lowder, a NASA craftsman who had worked on Howard Hughes' H-4 Hercules ("Spruce Goose"), was assigned to help Briegleb. Final assembly of the remaining components (including aluminum tail surfaces, pushrod controls, and landing gear from a Cessna 150, later replaced by Cessna 180 landing gear) was done at the NASA facility. The wingless, lifting-body aircraft design was initially conceived as a means of landing a spacecraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of reentry less damaging to the vehicle. Rather than using a ballistic reentry trajectory like a Command Module, very limited in maneuvering range, a lifting-body vehicle had a landing footprint of the size of California. Tow testing The first flight tests of the M2-F1 were at Rogers Dry Lake, at the end of a tow rope attached to a 1963 Pontiac Bonneville convertible. On April 5, 1963 test pilot Milt Thompson lifted the M2-F1's nose off the ground for the first time while being towed. The speed was . The little craft seemed to bounce uncontrollably between the main landing gear wheels, and stopped when he lowered the nose to the ground. He tried again, but each time with the same results. He felt it was a landing gear problem that could have caused the aircraft to roll on its back if he had lifted the main gear off the ground. After looking at