Re: What was the biggest problem for each of the 2 destroyed US space shuttles?

From: Jay Windley (webmaster_at_clavius.org)
Date: 09/13/04 

Date: Mon, 13 Sep 2004 11:59:28 -0600

"rk" <stellare@nospamplease.comcast.net> wrote in message
news:Xns9562EC38A2C79rk@216.196.97.136...
|
| Here's what Boisjoly said in '87, in part. Others have similar stories of
| being ignored.

And those others are those same engineers who so confidently, and with great
apparent technical justification, had laid out a case for nearly a decade
that the joint was safe to fly even though it was not performing as
designed.

| Why try to change the topic? We are talking about a specific event.

*You* are talking about a specific event. I am trying to broaden the field
of view and interpret that event in terms of what happened in the years that
preceded and followed that event. I believe that context is important to
understanding why people did what they did that night. Not knowing why
people acted the way they did runs the risk of repeating the same mistakes,
only with different people.

As the Columbia accident demonstrated, the problem is not about individuals
or individual wrongdoing, but about a culture that prevents people from
doing the best job they can. This same culture was a problem for
Challenger. Pointing to Boisjoly's disenfranchisement on the eve of the
launch and the alleged management wrongdoing exposes the symptoms of the
problem but does not address the underlying cause.

| If you want to talk about other launches fine but you appear to be
| running away from your position. Fools no one.

I'm not trying to fool anyone. And I will gladly abandon my position if it
is shown to be materially in error. I'm not trying to be right for my own
gratification. I'm trying to be right because I believe us being
(collectively) right helps us have a safer and more productive space
program.

| >| All your words below (and I don't have time right now to go
| >| through all of that as there are a lot of errors) ignores the
| >| fact that the onus is to prove safety, not to prove there is a
| >| problem...
| >
| > I covered that in a previous post.
|
| OK, looks like I'm done responding to you unless you have something
| meaningful to say.

To summarize the post to which I alluded, the culture was less about arguing
against the default not to fly and more about requiring contractors to
provide full technical rationales for their recommendations. That's what
the whole NASA quality system was designed to achieve. The presidential
commission -- and subsequently the public -- misunderstood terms like
"launch constraint" and "waiver" that had precise meanings to NASA and its
contractors. This has given rise to mistaken interpretations of the culture
that prevailed at the time.

It was assumed that the contractors would recommend to fly, but have secret
reservations. Thiokol had for many years provided a detailed rationale for
flying with the SRB joints behaving as they did. This rationale was backed
up by flight experience, by Thiokol's tests, by MSFC's tests, by a
mathematical model, and by reference to the original design rationale (i.e.,
safety in redundancy). That kind of engineering rationale was not only
expected, but also demanded, by those at NASA who supervised Thiokol.

Boisjoly: "It was our feeling at the time that nothing gets presented to
[MSFC director] Dr. [William] Lucas unless the people that are doing the
presenting are absolutely sure that all bases have been covered technically
and that they have all the answers to all the questions that potentially
could be asked, and this was a case [i.e., temperature effect on SRB field
joints] where clearly there were no answers available because it was just a
question of observation as to what we were presenting." (Diane Vaughan, _The
Challenger Launch Decision_, p. 222)

The culture of rigor, like the culture of learning by doing, also works both
ways. If you rigorously support one point of view, and that rigor has come
to be demanded, then changing the point of view requires equal -- nay,
greater -- rigor. You must not only show why your new viewpoint is
technically justified, but also what is wrong with the previous rationale.
It has to be kept clearly in mind that Thiokol's attempt to provide data to
support their recommendation not to launch, backfired. The data they
presented to NASA on the eve of the launch supported a case *against* a
supposed adverse effect of temperature on O-ring performance. All they had
was the general argument -- true though it may be -- that elastomers lose
their elasticity in the cold. But they had no data that the elastomeric
O-rings in the SRB joints (i.e., that a specific elastomer in a specific
context) followed that general rule, and indeed evidence to suggest that it
did not. 

-- 
                                          |
The universe is not required to conform   |  Jay Windley
to the expectations of the ignorant.      |  webmaster @ clavius.org

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