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.
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.
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.