Bill wrote :

> Christian - I heard someone suggest something today on the
> radio that made
> the most sense. It wasn't the tiles - because they have lost
> tiles before
> without catastrophic consequences. The leading edge of the
> wing has the most
> heat during re-entry (obviously) and had a different material from the
> tiles.

Yeah, I've read that everywhere. They've 27,000-odd tiles on the Shuttle, so
it may not be a problem if they lose half a dozen at lift-off.

> When the foam - or whatever it was - broke off during liftoff
> and hit the
> wing - that's when the damage occurred. And if that was the
> case (who knows
> right now?) then there wouldn't have been a thing anybody
> could have done.
> Columbia was doomed from the liftoff.

Someone else privately wrote me that yes, most likely, the Shuttle was
doomed from lift-off. I've also read that the so-called "foam" becomes hard
as brick when it comes out during lift-off. We may endlessly speculate about
why they did not have spacesuits, why they did not have the ISS docking
assembly, whether they had enough fuel on board to reach the ISS (mandates
both previous points, IMO), what they could have done to rescue crew, why
they did not try and get pics of the Shuttle (can they do that with Hubble
?), etc. The end result is the same - they were most likely doomed from
lift-off, much like the Challenger crew. The difference between both mishaps
is that consequences were faced in very differents timeframes.

> I also heard a couple of other interesting things - (a) some
> think it began
> falling apart over California (400,000 foot altitude - 7:1
> glide ratio)  -

Read that too ... Now let's do the math. Assuming the Shuttle was travelling
at about Mach 20 at that time (it must have been decelerating significantly,
though, probably skewing my own math by a certain factor). That's about
12,400 mph, or 207 mpm (miles per minute). California to East Texas is ...
what ... 2000 miles ? That's about 9,5 minutes. Interestingly enough, I saw
a timeline stretching the chain of events from 8:53 to 9:00 AM CST. In these
7 minutes, the Shuttle may have travelled 1,450 miles or more (depending on
deceleration). I'm not pretending the timeline began when the Shuttle lost
its first piece (it did not), I'm just doing the math based on fact.

> which given the speed they were going - was only minutes
> behind Texas and
> (b) a shuttle has a 1 in 200 chance every liftoff of having something
> catastrophic happen - that's pretty lousy odds if you ask me...

I do not agree with the math. There's been 2 public mishaps, Challenger in
'86 and now Columbia in 2003. That was, IIRC, STS-107. So that's a 1:53.5
probablility something catastrophic happens, which is almost 4 times as
hasardous as your (b) source claims. Of course, this is base on a less that
significant sample (2 occurrences), and it assumes other major failures
(less than catastrophic, though) have not been hidden from the public's
view. But, FWIW, it would now require 293 successful missions to get back to
your (b)-source proposed 1:200 ratio. That would be an amazing safety
record, by any standard. No other space vehicle has EVER experienced such a
ratio in history.

> Bill

Christian Lheureux

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