[js1138]

Isn't there still the option to abort the flight after launch before the shuttle leaves the earths atmosphere? I know that time is short in that margin but it seems there would be some sort of contingency or emergency procedures that would apply.

They have a few minutes after liftoff, before they're committed to orbit. However, the "debris" had been seen many times before. There was nothing in the first few minutes that looked unusual.

[john316]

The Return To Launch Site (RTLS) abort maneuver is very risky, and given the payload and engineering changes since Challenger I wouldn't think it would even be a viable option anymore.