Not that I understand this at all, but did you read
the live thread that leadpenny was running as it happenned, while watching NASA channel?
"The Columbia was making four drastic turns over the western US to dissapate speed. That's the last they heard from it. 41 posted on 02/01/2003 8:21 AM CST by leadpenny [ Post Reply | Private Reply | View Replies | Report Abuse ]"
The turns would be to bleed off speed to bring the shuttle down from 17,000+ mph to roughly 200 mph for landing.