A rescue was not on the table because the accident (sabotage in my opinion) was not anticipated. every single shuttle launch has damaged and sometimes even few missing bricks during launch or even from flying debris in space. If a piece of a rocket cone (on Atlantis) did not cause enough damage, polyurethane foam at a relatively slow speed, I doubt much more than a speeding car, maybe twice as much, should not have caused major damage. If indeed it was missing tiles, heating should have been observed as soon as they hit the atmosphere over the pacific, not when they already slowed down to around 60% of initial orbiting speed. What happened there must have been sudden and catastrophic, and probably from within the left landing wheel well.
Zeev