Apollo 10 on the crawler, courtesy Retro Space Images
FDL-5 space plane.
NASA studied this Lockheed Martin concept for a partially reusable space transportation system during the Shuttle research effort in 1969-1971.Model, Space Shuttle, Lockheed Starclipper LS200-8 Stage-and-a-Half Concept,1:96
1972 NASA concept art shows an early space shuttle concept on the launch pad. This was the fully reusable design, including a very large winged manned booster which would carry a smaller winged manned orbiter. Both craft could fly again.