 While perhaps not the 'Father' he has been accurately described by Professor John Logsdon as the 'Policy Father of the Space Shuttle'.Mueller held a one-day symposium (held at NASA headquarters) in December 1967 to which 80 people from the Air Force, NASA and industry were invited to discuss low cost space flight and shuttle-like designs.The designs ranged from 'simple' concepts like Martin Marietta's six person reusable craft similar to the Dyna-Soar (launched by a Titan III-M), to partially reusable concepts like Lockheed's Star Clipper or Tip Tank from McDonnell Douglas, to fully reusable two-stage vehicles like the one proposed by General Dynamics.