Comment by Analemma_
5 days ago
I wish I could downvote this comment more than once. It's incredibly ghoulish to use the perfectly-sensible argument that modern culture is too risk-averse to handwave away known critical safety problems. Those two things are completely orthogonal. Yes, astronauts should be willing to accept that there are "unknown unknowns" and that they will be facing some amount of unquantifiable risk, and they should be celebrated for this. That does not, not at all, mean that when a mission comes back with heat shield failures we know should not have happened, and multiple Inspector-General reports say the ship is not safe, those concerns should be blown off with rambling about Charles Darwin. That's pure insanity.
Or to put it another way, if you were the manager on the day of the Challenger launch issuing the "go" command over the objections of the Thiokol engineers saying it was unsafe to launch in below-freezing temperatures, would you have done so with paeans to Christopher Columbus? That's the sense I get from your post.
>Camarda is an outlier. The engineers at NASA believe it is safe. The astronauts believe it is safe. Former astronaut Danny Olivas was initially skeptical of the heat shield but came around.
How do you explain so many people believing it is safe?
The problem is risks are far too easy to brainstorm, anyone can come up with endless risks that it takes endless time to mitigate.
If I were the manager for challenger, I would have run the o-ring experiment as soon as it was brought up as a concern. Put the fuel pumps in a freezer, test if they leak. Feynman famously demonstrated it with a glass of icewater. Experiment is what separates made up risks from real risks, I would have definitely told the engineers to take a hike and would have hit launch if they couldn't provide experimental evidence of o-ring failure in cold temps. (Spoiler alert: in that case they easily could have)
No. That famous demonstration only touched on the real failure mode--the rings were covering up other failure and in the cold could not do so.
The real test was creating a full-scale test of ignition, an engine containing mostly inert filler (to occupy the fuel volume) and just enough fuel to reach stable burning.
> How do you explain so many people believing it is safe?
The article itself answers this question: institutional incentives leading to heavy social pressure to agree with the groupthink and declare something is safe when it is not. And we know that the scenario it lays out is highly possible, because it has already destroyed two Space Shuttles. Now that this has happened twice, the burden of proof is on the people saying it's not happening again, especially when the OIG's report directly contradicted what NASA had been saying about the heat shield up to that point (indicating they were lying and had to hastily retcon their story).
>the burden of proof is on the people saying it's not happening again
This specifically I take issue with. You had a bug in your software before so now the burden is on you to formally prove your software is bug-free.
The burden of proof should remain on the naysayers. Take a plasma torch to the heatshield pock marks and see how long it takes to burn through. Do experiments just as Feynman did with the o-rings. Let the outcome of the experiment, not office politics decide.
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