Mark Max Q - 29/8/2006 7:15 PM
This may be a stupid question, but are huge mechanical areas of the orbiter, such as the MPS, affected by the vibrations of a rollout, then rollback, brakes on, rollback out? Whole lotta shaking going on?
Yes, there are areas of the Orbiter and SSMEs that are effected by rollout induced vibrations. It does subtract from the fatigue life of the systems. Vibes aren't as much as launch like Jim stated, but fatigue damage is cumulative. I've got a video of the SSMEs and other parts of the orbiter during rollout that really shows the parts shaking. More than you would think. I've been trying to get the video to Chris but its too big.
Each track of the crawler, I don't know how much they weigh but its alot, slaps down on the ground in a steady rythm. This excites the structure just as if it were a modal survey test. You can tune the vibrations by changing the speed of the crawler, but not by much.