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Artemis II is not safe to fly

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21–30 of 667 posts

Re: Artemis II is not safe to fly

#21
> The trouble is that the heat shield on Orion blows chunks. Not in some figurative, pejorative sense, but in the sense that when NASA flew this exact mission in 2022, large pieces of material blew out of Orion’s heat shield during re-entry, leaving divots. Large bolts embedded in the heat shield also partially eroded and melted through.

Fun wording. This isn't news, concerns have been raised about Artemis II saftey in the past 3+ years since Artemis I and before then as well.

Re: Artemis II is not safe to fly

#22
I am very not brave but I'd volunteer. The trip is far more awesome than anything I have planned for the rest of my life. And if the shield fails on reentry it would only hurt for a few seconds. So if the crew and the backups and their backups read this and have second thoughts, ping me.

Re: Artemis II is not safe to fly

#23
post #17
post #2

Great read and interesting article. Hard to believe that NASA would risk astronauts lives simply to save face, but that appears to be what's going to happen.

They’ve killed dozens during the shuttle program , or did you forget ? Also a number during Gemini, Mercury and Appollo. Terrible safety record , and 5x worse than Soyuz . Shuttle fatality rate was 1/10. Approaching Russian roulette odds

*Freedom Roulette

Re: Artemis II is not safe to fly

#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 a healthy margin remaining of that virgin Avcoat. So it wasn’t like there were large, large chunks.”

Followed by:

> The Avcoat material is not designed to come out in chunks. It is supposed to char and flake off smoothly, maintaining the overall contours of the heat shield.

This is echoes both Shuttle incidents. 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.

There was a similar situation with heat shield damage and Columbia.

In both cases some models were used to justify the decision, with wild extrapolations and fundamentally, a design that wasn't expected to fail in that mode /at all/.

I know the points that astronauts make about the importance of manned space exploration, but I agree with this author that it seems to make sense to run this as an unmanned mission, and probably test the new heat shield which will replace the Artemis II design in an unmanned re-entry as well.

Re: Artemis II is not safe to fly

#26
post #17
post #2

Great read and interesting article. Hard to believe that NASA would risk astronauts lives simply to save face, but that appears to be what's going to happen.

They’ve killed dozens during the shuttle program , or did you forget ? Also a number during Gemini, Mercury and Appollo. Terrible safety record , and 5x worse than Soyuz . Shuttle fatality rate was 1/10. Approaching Russian roulette odds

135 missions, 2 fatal accidents, that’s not 1/10.

Re: Artemis II is not safe to fly

#27

Earlier quoted context omitted.

But that’s exactly what happened with Challenger

And Columbia, too, when they made the decision to reenter without inspection, and reenter instead of waiting for rescue.

A rescue was impractical and potentially riskier no?

Re: Artemis II is not safe to fly

#28

> “Our test facilities can’t reach the combination of heat flux, pressure, shear stresses, etc., that an actual reentering spacecraft does. We’re always having to wait for the flight test to get the final certification that our system is good to go.”—Jeremy VanderKam, deputy manager for Orion’s heat shield, speaking in 2022 This is a strange claim, considering NASA used to have 2 facilities that were capable of this…

The Orion heat shield is sixteen feet across. NASA's test facilities can only test small material samples in these facilities, not capture how the entire heat shield will behave.

Re: Artemis II is not safe to fly

#29
post #17
post #2

Great read and interesting article. Hard to believe that NASA would risk astronauts lives simply to save face, but that appears to be what's going to happen.

They’ve killed dozens during the shuttle program , or did you forget ? Also a number during Gemini, Mercury and Appollo. Terrible safety record , and 5x worse than Soyuz . Shuttle fatality rate was 1/10. Approaching Russian roulette odds

>They’ve killed dozens during the shuttle program

Columbia and Challenger crew totaled 14, who else are you referring to?

Re: Artemis II is not safe to fly

#30
post #7
post #4

Earlier quoted context omitted.

Was there ever a risk-free spaceflight? Pretty sure even with this finding this flight would be safer than any Apollo.

Saturn 5 had a flawless record. The leftover space shuttle parts which SLS is cobbled together from, not so much. SRBs are inherently dangerous, theyre designed to quickly launch nukes from silos, not people. And Orion is just a typical modern Boeing project. So far its fallen at every hurdle right?

Saturn 5 came close to catastrophic failure at least once. It had partial failures. Its sort of perfect record is mostly down to luck and not launching very many times.

Of course, six decades later, we should be able to do a lot better.

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