 The SV-5, the centerpiece of the START (Spacecraft Technology and Advanced Reentry Tests) project, was promoted by Multhopp as superior to NASA's M2 and HL-10 lifting body shapes, having a better lift-to-drag ratio and greater re-entry cross-range capability, along with better aerodynamics and improved design efficiency.Developed into the X-24, Multhopp's design proved successful, and provided valuable flight test information that assisted the design of NASA's Space Shuttle.Multhopp himself, however, faded from public view in the mid- to late-1960s.