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Artemis II is not safe to fly

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Re: Artemis II is not safe to fly

#41

> “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.

How does SpaceX test it? Have they needed to solve this problem?

Re: Artemis II is not safe to fly

#42
post #38

What I don't get is why the heck are the astronauts willing to risk their lives on something they must know by now is so dangerous? Is it really better to risk death than to risk getting fired?

There aren't many people left who've been that close to the moon. Lots of people would love to be on that list.

[deleted]

Re: Artemis II is not safe to fly

#43

Earlier quoted context omitted.

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.

How does SpaceX test it? Have they needed to solve this problem?

By blowing up unmanned spacecraft and letting the ones that survive catch fire?

Re: Artemis II is not safe to fly

#44
Definitely concerned to hear but I’m hopeful that the core of nasa is intact. They’re some of the kindest and smartest people I’ve had the pleasure of meeting. They don’t joke around with lives on the line. I hope the best for everyone involved. I’ll be watching the launch of Artemis 2 and 3 with excitement and hope.

Re: Artemis II is not safe to fly

#45

Earlier quoted context omitted.

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.

How does SpaceX test it? Have they needed to solve this problem?

SpaceX tests these in prod. Kinda like Artemis I did.

Re: Artemis II is not safe to fly

#46

Earlier quoted context omitted.

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.

How does SpaceX test it? Have they needed to solve this problem?

They do iterative flight testing. Starship is I believe on its twelfth flight test; the first one was in 2023.

Re: Artemis II is not safe to fly

#47

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.

This is an interesting comment -- your life is precious brother, you might have something in store down the road :)

Re: Artemis II is not safe to fly

#48
As someone who is actually (still) a fan of basic research, Artemis looks like a fun time for the 1% with a $100 billion dollar price tag, except that since it's only 4 astronauts and support staff, it's less than 1%. I opposed messing with NASA funding for a long time, but arguments referencing spin-off tech and so on wear thin. Spin-off occurring lately would/could only be captured by existing billionaires anyway, and without much benefit for society in general.

Humans in space are currently still a waste of time/money, largely just a big surrender to PR, space-selfies, the attention economy, and the general emphasis on "seem not be" you see elsewhere. Please just send robots, build a base, and let us know when we can put more than ~10 freaking people up there at one time. If that fails, then at least we'll have results in robotics research that can be applicable elsewhere on Earth right now as well as help us achieve the more grand ambitions later.

House is on fire, has been for a while, fuck business as usual. I honestly think all those smart people ought to be charged with things like using their operations research to improve government generally, or with larger-scale high tech job programs. If you don't want to let NASA big-brains try to fix healthcare, we could at least let them fix the DMV. Hell, let them keep their spin-offs too, so they actually want success, and have some part of their budget that won't disappear. Basic research and fundamental science is (still) something we need, but we need to be far more strategic about it.

Food for thought: The way things are going, we can definitely look forward to a NASA that's completely transformed into an informal, but publicly funded, research/telemetry arm for billionaire asteroid-mining operations, and thus more of the "public risk, private-profits" thing while we pad margins for people who are doing fine without the help. OTOH, if NASA is running asteroid mining businesses at huge profits, then they can do whatever they want with squishy volunteers as a sideshow, and maybe we'll have enough cash left over to fund basic income.

Re: Artemis II is not safe to fly

#49

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.

Dulce et decorum est pro patria mori

Re: Artemis II is not safe to fly

#50

Earlier quoted context omitted.

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.

How does SpaceX test it? Have they needed to solve this problem?

By having a much higher launch cadence and then analyzing the flight hardware afterwards.

Also, they don't have anything human rated going beyond LEO. Coming back from the moon means you're going significantly faster and thus need a better heat shield

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