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Artemis II is not safe to fly

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Re: Artemis II is not safe to fly

#651

Post by HeyLaughingBoy »

bookofjoe wrote: post #649
M95D wrote: post #642

Earlier quoted context omitted.

Link?

>Michele Dufault, a 22-year-old physics and astronomy major from Scituate, Massachusetts, was asphyxiated after her hair caught in a lathe in a Sterling Chemistry Laboratory machine shop, where she was working by herself in violation of the existing safety rules. https://yalealumnimagazine.org/articles/3288-after-a-fatal-a...

Hmmm. I was positive that at the time the report came out, they said that she was actually one of the people assigned to monitor machine shop users for safety issues. Maybe that got confused with her taking the advanced safety classes.

In any case, a tragic situation.

Re: Artemis II is not safe to fly

#652

Post by bookofjoe »

HeyLaughingBoy wrote: post #651
bookofjoe wrote: post #649

Earlier quoted context omitted.

>Michele Dufault, a 22-year-old physics and astronomy major from Scituate, Massachusetts, was asphyxiated after her hair caught in a lathe in a Sterling Chemistry Laboratory machine shop, where she was working by herself in violation of the existing safety rules. https://yalealumnimagazine.org/articles/3288-after-a-fatal-a...

Hmmm. I was positive that at the time the report came out, they said that she was actually one of the people assigned to monitor machine shop users for safety issues. Maybe that got confused with her taking the advanced safety classes. In any case, a tragic situation.

To me the wonder is that you remember the details you do, 15 years after the fact!

Re: Artemis II is not safe to fly

#653

Post by pdonis »

anonymars wrote: post #378
Mikhail_K wrote: post #353

Earlier quoted context omitted.

> However NASA also believed the o-rings could still take the abuse, because > although they were moving they were getting shoved deeper into the joint, Why would they be "shoved deeper," when the problem is that the joint opens wider under load?

See here: https://www.researchgate.net/profile/Scott-Post/publication/... What would happen "normally" (i.e. the normalization of deviance) was that the rotation (from the SRB joints bowing--essentially "ballooning") would create a gap, and the O-rings would get blown into that gap and ultimately seal in there With Challenger, it was too cold, so the O-ring rubber was not malleable enough to seal into that space (lik…

> What would happen "normally" (i.e. the normalization of deviance) was that the rotation (from the SRB joints bowing--essentially "ballooning") would create a gap, and the O-rings would get blown into that gap and ultimately seal in there

But data from previous Shuttle flights showed that even that wasn't happening, at temperatures up to 75 F. And the Thiokol engineers had test stand data showing that it wasn't happening even at temperatures up to 100 F. In short, that joint design was unacceptably risky at any temperature.

It is probably true that the design was somewhat more unacceptably risky at 29 F. But that was a relatively minor point. The reason the cold temperature was focused on by the Thiokol engineers (who were overruled by their own managers in the end, as well as NASA managers) in the call the night before the launch was not that they had a good case for increased risk at cold temperature; it was that the cold temperature argument was the only thing they had to fight with--because NASA had already refused to listen to their much better arguments the previous summer for stopping all Shuttle flights until the joint design could be fixed.

Re: Artemis II is not safe to fly

#654

Post by pdonis »

Mikhail_K wrote: post #205
oritron wrote: post #25

I haven't kept up with Artemis development but I've read extensively about Challenger and Columbia. These two parts of the article stood out to me: > Moon-to-Mars Deputy Administrator Amit Kshatriya said: “it was very small localized areas. Interestingly, it would be much easier for us to analyze if we had larger chunks and it was more defined”. A Lockheed Martin representative on the same call added that "there was…

> Challenger: no gasses were supposed to make it past the o-rings no matter what, > but when it became clear that gasses were escaping and the o-rings were being > damaged, there was a push to suggest that it's an acceptable level. Interestingly, the article https://docs.google.com/document/d/1ddi792xdfNXcBwF8qpDUxmZz... > by heat shield expert and Shuttle astronaut Charles Camarda, the former Director of Engineering…

> "it was the O-rings" explanation seems universally believed and sanctified by no lesser authority than the Nobel prize laureate Richard Feynman.

If you read Feynman's account in the book What Do You Care What Other People Think?, you'll see that he realized afterwards that he was prompted to make the demonstration he made at a NASA press conference--putting a piece of O-ring material in a glass of ice water, clamped with a C-clamp, and then taking it out and releasing the clamp to show that the material did not spring back--to get public attention focused on problems with the joint in a way that could not be ignored. But, as has been pointed out downthread, when the joint was redesigned, the new design did not change the O-rings at all. So the specific issue that was shown in Feynman's demonstration was not the issue that actually needed to be fixed. It was just a convenient way to show the public that there were problems with the joint, with a simple demonstration that everyone could understand. Trying to show the actual problem--that the entire joint design was fundamentally flawed and needed to be changed--would not have worked in a context like that.

Re: Artemis II is not safe to fly

#655

Post by anon291 »

InitialLastName wrote: post #615
doubled112 wrote: post #528

Earlier quoted context omitted.

If I'm simplifying, your argument is that car seats are useless if we'd just stop crashing? Isn't this true for every safety measure? I don't need a guard on my table saw if I don't stick my thumb in it. Don't need a helmet if I don't fall off of my bike.

> Isn't this true for every safety measure? Every safety measure faces a question of whether the resources allocated to it are an efficient means of achieving that reduction in risk. To GP's point, we probably can't prevent people from crashing altogether, but we currently have a road system designed to sacrifice safety on the altar of throughput [0]. How many more or fewer kids (or just people) would die if governme…

Yes simply slowing down, arresting people, revoking licenses, smaller roads, etc would probably do more for road safety

Re: Artemis II is not safe to fly

#656

Post by euroderf »

Findecanor wrote: post #222
euroderf wrote: post #142

Earlier quoted context omitted.

But this mission does not have O.J. Simpson. Does it ?

I was thinking of the risk of the crew capsule burning up on reentry, due to a possibly faulty heat shield — and people in charge knowing about the risk beforehand but going on with it anyway. I had forgotten that O.J Simpson had been in the movie, to be honest.

I was thinking: Capricorn One !

Re: Artemis II is not safe to fly

#657

Post by vannevar »

LorenPechtel wrote: post #569
vannevar wrote: post #368

Earlier quoted context omitted.

All of the controversy over the heat shield is obscuring the much bigger safety issue: Artemis has had only a single unmanned test flight. By contrast, the Saturn launch system had seven successful unmanned tests before being trusted with a crew, including two unmanned flights of the complete Saturn V stack. And even then, three astronauts were lost during ground testing of the crew capsule due to a critical design f…

SpaceX was clear about their policy of flight testing earlier in the development phase. They expected to lose rockets, I do not believe those should count against the launcher.

They do not expect to lose a given vehicle. They are tolerant of losing some vehicles over time, because they understand that every flight may be affected by unknown unknowns. There is certainly no evidence that they expect to lose crewed vehicles, or that they are tolerant of crew loss.

I think the high loss rate for Starship can largely be traced back to the choice of using steel for the vehicle, which drastically reduces margins across the system. You could certainly say that they had a higher expectation of failure because they made that choice. In that sense, I understand your point. But to the best of their ability, they try to fly every vehicle successfully.

Re: Artemis II is not safe to fly

#660

Post by kortilla »

sfn42 wrote: post #605
kortilla wrote: post #597

Earlier quoted context omitted.

Do you think it’s okay for people to indoctrinate their own children with religion and other political views? Far more harm comes from that than tail risk elimination mandating car seats between 8 and 12 years. Would you be willing to make all new parents submit to frequent breathalyzers during pregnancy and after birth? Drinking is a massive factor in infant mortality at birth and SIDS.

I don't see a reasonable way to avoid parents imposing their beliefs on their kids so this point you're trying to make is pretty weak man. You're comparing a problem with a very clear solution vs a problem with no clear solution. You wanna take the kids away from all religious people and all people with differing political views? Good luck with that. Should all parents submit to frequent breathalyzers? Tell me, how m…

>Tell me, how many parents, as a fraction of all parents, drink irresponsibly to the point where it significantly endangers their children?

More than the ones that get harmed between 8 and 12 in cars.

Your whole argument seems to be “it would be okay to take kids from their parents if the enforcement was easy”. It’s clear that you’re in the camp of sacrificing pretty much any liberty in the name of safety.

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