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I've noticed one recurring theme in the comments about the loss of the Columbia: What if... If you go to target="_blank">FreeRepublic.com, you'll find dozens of posts that involve brainstorming about possible was the tragedy could have been avoided. This is, I think, human nature. We want to fix things. The idea that this was simply an unavoidable accident is unpaletable to many people. No one likes that helpless feeling. Granted, it's only been about 48 hours since the accident, but it's looking more and more like damage to the left wing's thermal tiles was to blame. About 24 hours after the launch, reviews of the launch films showed a piece of debris striking the left wing. Worse still, it looks like the exact point of impact may have been the gear well door. This is a weak point in the wing; the worst spot to have a burn-through. href="http://qs240.pair.com/sfnvideo/sts107/030203e212_qt.html" target="_blank" title="QuickTime needed to view clip">A clip of the impact is here. This was about 80 seconds into the flight. If I remember correctly, the shuttle is supersonic at that point. Even a light object will hit with considerable force. The clip shows just such a violent impact. Back to "what if...". Some people have wondered why they just didn't abort the flight. NASA maintains landing sites in Africa and Spain for just such a contingency. The problem, as stated above, is that they didn't spot the problem until the next day. They have a ~4 minute window to bail out of a launch and land at a "TAL" site. "Couldn't they have used the arm to look under the wing?" This mission didn't require the arm. It was removed to save weight. "Couldn't they have spacewalked under the wing?" This brings us to the $64,000 question: Even if they could, what would they have done next? Assuming that they could reach the underside of the wing without causing more damage, the shuttle crew isn't equipped to repair the orbiter's tiles. (Though this leads me to my own personal "What if": What if they had a thermally resistant version of Bondo to trowel into a damaged tile.) Confirming the damage wouldn't have saved the crew. There's currently no way to repair damaged tiles in situ and no way to protect the damaged area during reentry. Rather than surprise at the unexpected loss of the orbiter and crew, we'd have all been treated to the horror of knowing that a crew was about to be lost. style="text-align: left; width: 100%;"> Assuming that this was an accident caused by insulation breaking off of the External Tank, what next? After the Challenger was lost, NASA shut down the shuttle program for over two years. I don't think that such a shut down is necessary this time. When the style="font-style: italic;">Challenger was lost, a "cultural" flaw at NASA was to blame; they were grandstanding. They launched when it was far too cold. NASA's "can-do" attitude had morphed into a "must-do" attitude. That doesn't seem to be the case here. No one could have known that the insulation would break off. And even if we all wince at their estimate of the size of the gash in the tiles, there wasn't anything that could have been done. There wasn't a cultural failure as happened with the Challenger. Thus there isn't a need for a protracted shut down. The bonding method for insulation on the ET needs to be improved. Perhaps a "better-than-nothing" tile repair technique should be designed. But that's about all that needs to be done. NASA could be safely flying by the time the ISS crew needs a ride home. style="text-align: left; width: 100%;"> On a side note: At the time that the Challenger was lost, my wife was working with the same material that went into the boosters' O-rings. She and her co-workers all assumed that the launch would be scrubbed because of the cold. They all knew that the rubber became brittle at cold temperatures. They were shocked to hear that the launch was going ahead.