From Jim Oberg:
Remembering the shuttle's start

http://www.msnbc.msn.com/id/12243173/#060412b

James Oberg

April 12, 2006

The very first space shuttle mission, on April 12, 1981, almost ended
soon after it began. Fortunately, the unexpected problem was not observed
when it occurred, so the crew and mission control didn't know how frightened
they should have been.

Nice article. Two key points I would add:

- The reason that the body flap didn't fail was because it had been
designed to the safety margin of the more demanding entry loads. Had
it been designed for ascent only, analysis showed that it would not
have held together.

- The cause of the problem was that the acoustic suppression water
spray had been targeted too low in the blast field. The fix used for
STS-2 and subsequent was to have the water spray initiated much closer
to the nozzle exits.

(Ref: http://www.aiaa-houston.org/cy0506/e...vf-05apr06.pdf)

Another interesting point is that today Bob Crippen mentioned this very
issue, however he stated that the shock had cracked a forward strut. I
found this to be a curious comment since I had never heard of that
before.

Also, when asked what chances he gave himself for surviving that
mission, he said that he felt that it was "Pretty good, 70, 80
percent". Wow.


~ CT