Another rare piece of early Dyna Soar color art. This one shows the Dyna Soar heading to space atop the centaur upper stage of an Atlas booster. And if you think you are seeing corrugations on the back of the spaceplane, you are correct. At this stage in the design process the Dyna Soar *did* have some fairly massive, un-aerodynamic corrugations, and for the same reason why the SR-71 has corrugations on the wing: to allow for thermal expansion. Why exactly the Boeing Dyna Soar corrugations run crossways to the airflow, I’m a little unclear on. Terrible aerodynamics, but I imagine that’s just the way the structure wanted to flex.
The corrugations rarely appear on the usually simple diagrams you see of early Dyna Soar configurations, but they were there on full-scale mockups.