[mostlyundecided]

mission control knew that some signals, like tire pressure and hold temperature were lost well before the shuttle reached Texas; either the sensors were destroyed or the wires connecting them to the transponder. Either way, these events spelled serious trouble because those things are internal to the craft.

What is in the hold? Could something have caught fire inside and that been the cause of fire and not re-entry heat? It has happened on aircraft.

[coloradan]

I think this was the compartment that held the tires. I don't know what else is there, but you make a good point, perhaps the fire started there and not from a hole to the outside. Could something bad have been slipped in intentionally? Possibly, though I think loss of a few tiles from the launch impact is more likely, followed by burn-through upon re-entry. I'm sort of thinking that even if the shuttle didn't break up as it did, it would still have been short some tires and such and the landing would have been very, very rough.