ebook,National Aeronautics and Space Administration (NASA), World Spaceflight News, Wernher von Braun,Wernher von Braun&#39;s 1969 Manned Mars Mission Plans after Apollo and the Boeing 1968 Integrated Manned Interplanetary Nuclear Spacecraft Concept Definition Study,Progressive Management,SCIENCE / Astrophysics & Space Science,TECHNOLOGY & ENGINEERING / Aeronautics & Astronautics" />