"Charleston" wrote:
IF NASA really understood and appreciated the risks, are you going
to argue we would have lost Challenger and Columbia the way we did?

No, that would be an ignorant position to take. A true and complete
understanding of the flight temperature regime of the SRBs and a true and
complete knowledge of the fragility of the RCC and the damage that can be
caused by ET foam debris would most certainly have been valuable knowledge
prior to both STS-51L and STS-107. Unfortunately, there are people in the
decision-making loop that have made mistakes in the past by discounting said
information and flying anyway.

You said that there have been claims that NASA "kn(e)w the risks and
accept(ed) them", and that those who held that position should "think
again".

I stated that "accepting the risks" in too simplistic a statement. The
good-faith examination of systems that were under observation and accepting
the risks after such an examination are two distinctly different things.
*That* was my point.

Now... having said that, the leading edge RCC panels were *not* thought to
have been as brittle or susceptible to the type of damage seen in the post
STS-107 tests and suspected to be the primary catalyst for the ultimate loss
of Columbia and her crew. Somewhere, in the thought-processes that went
into the post-ascent film review of the foam strike, there were obvious and
ultimately fatal mistakes made. Those mistakes were also compounded by the
lack of approval for imaging and other possible options that may have
pointed out the damage to Columbia's left wing.

There has never been such a cavalier and simplistic "blanket acceptance of
any and all risks" without some thought going into said acceptance. As
pointed out above, there have been errors made in the data-gathering,
analysis, and subsequent actions in the past.

Nope. I think you are just making excuses for NASA.

Incorrect, Daniel... NASA made mistakes.

Correction -- *people* at NASA made mistakes... to the best of my
knowledge, I've never said otherwise.

It was plainly obvious in perfect FORESIGHT that NASA had a management
problem.

Bob? Why are you on Daniel's USENET account?

The goal, of course, is to have a completely risk-free system.

That goal, of course, is hypothetical, as there will *always* be risks
inherent in manned spaceflight.

Correct, however, there is a difference between inherent risks and
acceptable risks.

Again, and to the best of my knowledge, I've never said otherwise.

Columbia would not have flown as it did, or at least
not to where it went in any event.

You can't say that... at least with the certainty of the statement
above.
There was no *real-time* indication of impact or damage... much less
one
that could have led to a *real-time* decision to abort the ascent.

I did say it and I stand by it.

That statement is way too simplistic... especially given 20/20 hindsight.

Please provide some evidence that if NASA had correctly managed the risks
they would have flown STS 107 the way they did.

Again... way too simplistic a statement. To which risks are you referring?
What does "the way they did" mean?

Roger
--
Roger Balettie
former Flight Dynamics Officer
Space Shuttle Mission Control
http://www.balettie.com/