Late Saturday NASA was still overly optimistic:
NASA believes the damage is minor, but the U.S. agency leaves little to chance since losing the shuttle Columbia crew in 2003 from a similar incident.That changed today with evidence the 3-inch gouge reaches to the shuttle's aluminum skin.[. . .]
"We don't think it (the debris impact) went all the way down to the bottom" of the tile, John Shannon, deputy shuttle program manager and head of the mission management team, told reporters late on Saturday.

The damaged tiles are located near the right main landing gear door, right beneath the aluminum framework for the right wing, which may offer extra protection during reentry.
The space shuttle Columbia was destroyed in 2003 when hot atmospheric gases seeped into a hole in its wing, caused by a similar foam strike, and melted the wing from the inside out.
No decision has been made as to whether to patch the gouge in space.
Otherwise, this shuttle mission has gone well. The successful testing of a new power transfer system that allows Endeavour to draw power from the space station has made it possible to extend the time at the space station to a record 10 days.
Image Credit: NASA
That looks close to me, Time to can the crap and return to the initial foaming agent.
Posted by: Walter E. Wallis | Friday, August 24, 2007 at 01:33 PM