Perhaps the most critical part of the Shuttle's flight is the communications blackout phase of reentry, when atmospheric plasma is directly interacting with the vehicle's heat shield. As I understand it, they had to maintain a 40 degree angle of attack during this phase of the flight, and I'm curious how this was actually achieved through the design of the control surfaces.
- Were they hydraulically controlled?
- What were the specifications?
- How did they prevent plasma from entering through the hinges of the control surfaces?
I'm assuming this phase of the flight required some level of active control here, though it's possible that's incorrect. In this video, they mention "closed-loop guidance" during this phase of the flight.