The M2-F1 lifting body, dubbed the ''flying bathtub'' by the media, was the precursor of a remarkable series of wingless flying vehicles that contributed data used in the space shuttle and the X-38 Technology Demonstrator for crew return from the International Space Station. The early tow tests were done using the 1963 Pontiac Catalina convertible modified for the purpose. The first flight attempt occurred on 1 March 1963 but was unsuccessful due to control-system problems. It was not until 5 April 1963, after tests in the Ames Research Center wind tunnel, that Milt Thompson made the first M2-F1 tow flight.