[pdonis]

> Another NASA screw-up that they're trying to pin on the vendor engineers, just like Challenger.

And, for context, Edward Tufte, whose review of the slides is being referenced in this article, is the same one who misunderstood and misrepresented what the actual issue was during the briefing the night before the Challenger launch, in his paper reviewing the presentation the engineers made then.

Edit: previous HN discussions of Tufte's Challenger review here:

https://news.ycombinator.com/item?id=10989358

https://news.ycombinator.com/item?id=19034783

[dr_orpheus]

Yeah, its very hard to say that Challenger was because of a miscommuncation from the vendor engineers. They wrote out directly [0] "Recommendations: O-ring temperature must be > 53F at launch", and the temperature of the air at launch was 36F and measurements on the solid rocket boosters (where the o-rings are located) got down to 25F and 8F [1].

But their recommendation was challenged by the NASA SRB managers. And after an offline discussion the SRB vendor came back and had changed their opinion that it was safe. And the NASA SRB manager never brought up the o-ring temperature concern to the rest of the management team.

[0] https://history.nasa.gov/rogersrep/v1p90.jpg

[1] https://en.wikipedia.org/wiki/Space_Shuttle_Challenger_disas...

[pdonis]

> their recommendation was challenged by the NASA SRB managers. And after an offline discussion the SRB vendor came back and had changed their opinion that it was safe.

Yes, because the Thiokol managers overrode their engineers and said it was OK to launch.

> And the NASA SRB manager never brought up the o-ring temperature concern to the rest of the management team.

That was probably because NASA had already classified the O-ring issue as a Criticality 1 flight risk, which is supposed to mean that a failure could result in loss of vehicle and loss of life and that the Shuttle can't fly until the issue is resolved--and then waived it. So it wasn't as if the O-ring issue was a new one or that NASA wasn't already aware of its seriousness.

[giantg2]

Wow, I didn't know that. What a poor track record.