Tags Dr. Dana Andrew Chasing The Dream, space shuttle aluminum vs. titanium Boeing SST Program space shuttle Lunar settlement Humans to Mars Air Force vs. NASA Columbia accident X-33 X-37B composites SLS 1983 technology Falcon Heavy XLR 129 Pratt & Whitney rocket motors Rocketdyne SME Space Force non-military space PPP initial shuttle specifications space shuttle cancellation Boeing culture before & after mergers 7373 Max McDonnel Douglas Rockwell X-15 SRBs compared to liquids thermal expansion for the shuttle US budget concerns Elon Musk Jeff Bezos SLS fist stage in orbit use 747 fuselage modified for spaceflight 11/2 stages to orbit Interstellar Travel NASA management space transportation technology advances stage combustion Guest Dr. Dana Andrews Tagline Dr. Andrew's new book, "Chasing The Dream." See his aerospace bio on the website View the discussion thread.