I’m familiar with the story, and actually came across your comment a few days ago.

He didn’t feel right about it, but that’s not the same as hard data. They didn’t actually have data on the performance of the material at those temperatures, which is part of the big discussion with his managers. He essentially said, “we don’t know how it will act in those conditions.”

Granted, on a safety critical system, having no data should be a scenario very, very carefully considered as a harbinger of doubt, but having no data isn’t the same as having a concrete understanding of the risk. The problem with large, complex systems is you will always find someone who thinks management isn’t taking a certain risk seriously. I know aerospace engineers who squawk about the risk being too great, yet that’s a 5 sigma industry.

NASA reliability risk is usually quite rigorously defined. If he had hard data that said the risk was outside the acceptable envelope, it would have been relatively easy for the managers to stand behind him (especially when weather is driving that risk).

Columbia was similar. They had lots of data points that the foam shedding wasn’t a problem is different scenarios, but they didn’t have the same evidence about that specific scenario (the deltaV, flight profile, and where it struck).

Perhaps - but one engineer with a niggle is a problem, and a room full of them is absolutely a justificantion for re-evaluation.