Good evening and sorry about the delay ...
What likely caused the destruction of the craft - first causal agent, a loss of a component in the exterior Heat Protection System BUT that was only the first in a string of events leading up to the destruction of STS-107 and I'd like to get into that this evening in our continueing lecture series ...
Whether this was on the underside wing or the topside of the wing or the leading edge, we have now have a better idea today, with the release of the STS-107's launch video from NASA and described in this post.
Something, presumed to be insulation foam from the main tank appears to strike the leading of the left wing and then the remains of this object proceeds in what appears to be a shower smaller debris (particles) under the wing and past the shuttle.
This just in via CH 4 Fox locally: A space shuttle tile was discovered on Hyw 67 in Alvarado Tx.
Okay, so we have the causal agent - and that leads to an unclean airfoil/wing on the left side. This forced, upon reentry, the rolling or yawing motion to the left that we discovered today was even more severe than we learned yesterday. In feact, it got so bad the small thrusters began to fire to corect for the yawing and rolling that was taking place. NASA reported to day that it weasn't so much how much yaw and roll had to be corrected for, but rather at what rate these corrections were becoming necessary!
We can then add in the temp msmts coupled with the later loss of various temp msmt points - if I knew where the wiring was run - what conduits and such - this is the smoking gun, so to speak, where hot plasma was literally pouring in and now consuming/melting/varporizing any and all combustibles/materials exposed to that plasma coming via a small (initially) and progressively larger opening first allowed to form because a component of the TPS (heat tile) was damaged ...
To make a long story short - the space craft was ultimately unable to correct for the ever increasing amount of roll and yaw the craft wanted to do - because of an unclean/deformed/consumed by 3000 degree F plasma - exactly the thing that the heat tiles wee supposed to protect the underlying aluminum frame from ever 'seeing' ...
Summarizing:
First Causal agent: loss of tile
Leads to: unstable platform that required ever-increasing amounts of 'stick' to correct the craft attitude
Leading to: a fatal yaw and perhaps roll to the left and exposing the right side of the craft to full effects of Mach 18 flight (along with the high temps it *was* not designed to handle in that attitude)
Ending in: Failure of the right side wall (melts/burns away)
And finally: the hydrazine fuel, oxygen storage tanks explode ... finishing off structure the craft had ...
Loss of tile/damage to tile: 95%
Loss of other system (hydraulics, Elevon): 5%
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Loss/damage to tile on leading wing edge 50%
Loss/damage to tile on bottom: 40%
Loss/damage to tile on top: 10%
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