[Charles Martel]

2.5 pound debris hits at 1500 mph a surface which is damaged by a human fingernail.

Hey, you'd think NASA would be eager to blame this on the insulation impact at launch. The film of that is as damning as the plume of flame escaping past Challenger's SRB o-ring.

However, the chunk of insulation was not hovering there in the sky for Columbia to hit, it was moving at the same speed and only began to lose velocity (relative to the orbiter) for a second or so before impact. The tiles are fragile, but for NASA to be veering away from the "easy explanation" is at least interesting - and unexpected.

[Zavien Doombringer]

In the video, I did see the foam separate, but not hit the wing. Boundary layer of air around the tank would have caused a vacuum (low-pressure) and "pull" the chunk back towards the tank, which I do see...

[TheDon]

"Hey, you'd think NASA would be eager to blame this on the insulation impact at launch."

I disagree. Anything but that. If that is the cause, heads will roll at NASA as they knew about it and dismissed it.