[idlewords]

If you play a single round of Russian roulette with a revolver, it is likely you will not die, but it is also not safe to do that. The same idea applies here.

The foam shedding/impact problem was heavily analyzed throughout the Shuttle program, and recognized as a significant risk. Read the CAIB report for a good history.

That report also describes the groupthink dynamic at NASA that made skeptical engineers "come around" for the good of the program in the past. Calling Camarda an outlier is just a different way of stating this problem.

[arppacket]

It looks like they did some worst case testing that was reassuring, so that it isn't Russian roulette? Any comments on that? I suppose their composite testing and temperature projections could also be wrong, and their trajectory changes might not be mitigating enough for the heat shield chunking, but that's a few different things all simultaneously being wrong for a catastrophic failure to occur.

The NASA engineers wanted to understand what would happen if large chunks of the heat shield were stripped away entirely from the composite base of Orion. So they subjected this base material to high energies for periods of 10 seconds up to 10 minutes, which is longer than the period of heating Artemis II will experience during reentry.

What they found is that, in the event of such a failure, the structure of Orion would remain solid, the crew would be safe within, and the vehicle could still land in a water-tight manner in the Pacific Ocean.

[palata]

I think the point of the article is that there is no particular need to send humans in Artemis II.

Sure, they made tests. But it's not the same as trying in real conditions. The argument is that if they were able to predict everything with tests before the real flight, then Artemis I wouldn't have had those issues. But we know what happened.

[IshKebab]

But then no spacecraft is safe to fly. We're obviously willing to accept a much higher level of risk sending humans to the moon than in other situations. I think I read somewhere at a 1 in 30 chance of them all dying was acceptable. Not too far off from Russian roulette!

[LorenPechtel]

I don't see it so much as no spacecraft is safe to fly, but rather no spacecraft should have a crew on it so long as there are major safety questions.

This is not the Shuttle that couldn't be flown without a crew.

[tclancy]

Pro tip: you’re supposed to use a revolver.

[IshKebab]

Who says I'm not?

https://www.rockislandauction.com/detail/62/1323/rare-and-un...

[mikkupikku]

Juggle five guns after loading one.

[mastermage]

> If you play a single round of Russian roulette with a revolver, it is likely you will not die, but it is also not safe to do that. The same idea applies here.

Fundamentally space travel is not save, it cannot be (atleast at our Technological level) Space is unimaginably hostile to life. We cannot reduce this danger to zero.

[wavemode]

This is (no offense) intellectually dishonest. Nobody wants the risk to be zero. What we want is that, if there is a specific KNOWN flaw in a life-critical system, that the flaw is addressed and the shuttle re-tested before humans are placed in it.

There's no good reason not to do this, except as a lazy cost-cutting measure (and, presumably, under time pressure to perform the eventual moon landing mission within the timeframe of Trump's presidency).

[Grimburger]

Have you bothered to ask the astronauts on board if they want to risk it?

You're getting clicks, they're going to the moon and there's a lot of people on Earth who would happily take any tradeoff for that.

[tclancy]

Hang on, without a dog in this fight, have I asked the people who trained their whole lives to drive cool cars if this particular cool car, which they were not involved in designing or building, is safe to drive? Is that what you are asking?

[ethmarks]

They asked if the astronauts "want to risk it", not if it was actually safe. Those are very different questions. The astronauts are, in fact, the world's leading experts on whether or not they personally want to risk it, so it's not entirely unreasonable to think that they could answer that question.

It just depends on whether you think that the fact that they accept the risks is reason enough to let them fly a potentially-dangerous spacecraft.

[palata]

I know we all have a lot of respect for astronauts, but the fact is that they blindly trust whoever tells them "it's safe enough" that it is, actually, safe enough.

Artemis II doesn't need astronauts to do its flights. Astronauts are trained to survive in a spaceship that does not need them to do anything at all. That it is their dream to survive in such a spaceship does not say at all that they have any valid idea of how much risk they are taking.

We can say "maybe the astronauts would accept to fly knowing that they have a probability of 1/30 of dying" all we want, but that doesn't answer the question here, which is: what is the probability that they die?

The article says "we don't really know: the first test flight was very concerning, and we used the exact same methods to prepare the second flight, so we won't really know how unsafe it is until we try it".

Sure, they have made tests on the ground. But the first flight proves that those tests are not enough, otherwise Artemis I wouldn't have had those issues in the first place.

[trothamel]

This is a perfect way to put it.

Artemis II is not safe, at least by the standards we apply to things. It's the third flight of a capsule, on the second flight of the rocket, and the first flight of things like the life support system.

At the end of the day, one of the reasons astronauts are respected is they understand those risks, and go into space anyway. That doesn't mean we shouldn't try to minimize risks - but at some point the risk becomes acceptable, and the cost of reducing it too great.

To paraphrase a quote from Star Trek - risk is their business.

[falcor84]

Taking a related quote from Dollhouse: "That is their business, but that is not their purpose."

[InsideOutSanta]

> there's a lot of people on Earth who would happily take any tradeoff for that

That's not reassuring, though. And it isn't just about them.

[quasistasis]

The astronauts are cool with it. They are basically brainwashed to rationalize exceptional trust in all of the people and components so that they are able to focus on the task at hand.

[mikkupikku]

I wouldn't say brainwashed, but they're definitely aware of the political angles related to succeeding with a career at NASA and almost always agree to play ball without causing trouble for the org.

[quasistasis]

That's a fair way to put it. Though I know people who honestly believe the mantraof trust, to the exclusion of data.

[kbelder]

Yeah, the astronauts aren't nearly as rational and clear-thinking as HN posters.

[dminik]

Have you bothered to ask the gambler if they want to risk it?

No offense to the astronauts of course, but asking people that have dreamed of this opportunity their whole life doesn't actually tell you all that much about the actual safety of the mission as a whole.