[ez]

But the photos of the foam striking the wing during lift-off show the foam striking farther out on the wing. This makes me tend to agree with NASA's decision to keep looking rather than settle for the foam damage explanation.

What if, instead of damaging the wing by smashing it, the foam torqued the wing backwards and caused damage at the front end of the wing-fusilage joint? Seems like the wing would be particularly well-reinforced there, but this WAS the 28th mission.

What if the constant stress on that wing joint weakened it over time?

[Truth29]

Re torquing of wing and constant stress ( 28th mission):

Well, the estimated weight of the insulation is about 2 1/2 pounds and the orbiter was designed for 100 missions. The weight, unless drastically increased by ice, does not seem significant enough to cause torque on the frame and the design parameters for missions are far beyond the actual 28 flights. Of course, the public statements by NASA could be seriously in error, but these variances indicate that the search for another cause will go on.

[Moonman62]

What if, instead of damaging the wing by smashing it, the foam torqued the wing backwards and caused damage at the front end of the wing-fusilage joint? Seems like the wing would be particularly well-reinforced there, but this WAS the 28th mission.

When I look at that video it appears that the entire orbiter flexes away from the rocket stack.