Gaps
I had long wondered what—if the solution for re-entry was to remove them—was the purpose of the now-famous space shuttle gap fillers. Now I know.
Charles H. Campbell, brother of an MTS employee and a NASA subsystem engineer working on orbiter entry heating, gave a lunch talk at work today. It was technically interesting—mostly he talked about the procedures they have for solving engineering problems, since they often only have hours to make a judgement between when a question arises and when a decision on whether the orbiter can land is needed.
It was also personally interesting. It was obvious that he was personally pained by the destruction of Columbia. I didn’t get too upset when it happened—I am certain that astronauts knowingly take certain risks—but I sympathized with him because the failure was of something to which he was personally attached, even though he was certainly not individually responsible.
The gap-fillers’ actual purpose is to protect the tiles at launch-time, when there are all kinds of vibrations and sonic events (his description) that put up to 15 G of vibration back and forth on the tiles. The gap fillers keep the tiles from chattering against each other and chipping, which it turns out doesn’t happen and so is not terribly important at re-entry.
