I'll suggest deletion as well but before the thread goes away, I'll say this.
The shuttle itself does NOT have a self-destruct device onboard. On lift off, the SRB's and main fuel tank DO have explosives designed to destroy the vehicle if it goes outside a predetermined zone. The controllers @ Cape Canaveral are the ones who would send the order for auto-destruct, not the crew. The plan, at least on paper, is for the shuttle to have already separated from the rockets and land back in Florida or @ the emergency landing zones throughout the Atlantic and in Spain. However, NASA has said that if necessary, they would destroy the shuttle, crew and all, if the liftoff went off course and was going to come down in a populated area. However, I do not believe that the shuttle was destroyed by anything other than a tragic accident. It was not a UFO, not a terrorist, and not some non-existent self-destruct device.
I feel that while the astronauts knew they had a problem, they probably did not know how serious it was until the very end. Not being able to visually see parts of the shuttle breaking off meant all they could rely on were their instrument readings, which didn't tell them much. They probably realized just seconds before the end as the auto pilot lost its fight to keep the shuttle flying that the shuttle was out of control. Breakup and death would have been only seconds later and thank God, very quick and painless.
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