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Artemis II is not safe to fly

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241–250 of 667 posts

Re: Artemis II is not safe to fly

#241
post #100

Earlier quoted context omitted.

I've often thought world leaders, upon election/selection, should get a free few orbits of the earth, to give them some perspective on the job they're about to undertake. Maybe offer the first one on Artemis II, a deferred one for the current US administration?

James May of Top Gear has flown with a U2 spy plane once [0][1]. When they reached to the edge of space, May said "If everybody could do that once, it would completely change the face of global politics, religion, education, everything". I can't agree more. Another thing I believe needs to be watched periodically is Pale Blue Dot [2]. [0]: https://www.youtube.com/watch?v=w-COlil4tos [1]: https://www.youtube.com/watch…

Yeah, that (and Carl Sagan) was what made me think of the idea.

Re: Artemis II is not safe to fly

#242
post #5

The author seems to have a pretty extensive history of… strong disdain for Artemis II. While has mentioned concerns about the heat shield before it was in the context of a laundry list of complaints, and it was nowhere close to the top. I’m not a rocket scientist, but then neither is the author.

If I recall correctly the Author worked at NASA.

Which somehow is supposed to make him more authoritative than NASA itself?

Re: Artemis II is not safe to fly

#243

Earlier quoted context omitted.

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.

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.

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.

Re: Artemis II is not safe to fly

#244
post #211

Earlier quoted context omitted.

The Artemis program has cost over $100 billion so far. It doesn’t make any sense to spend that much money on something that’s still Russian roulette for the astronauts. If the purpose of the human risk is to let the agency accomplish more, then it needs to be reflected in the cost as a drastic reduction (so you can actually spend the money on doing more). Now Artemis is the worst of both worlds.

If you need expect perfection then we will never have a space mission. Let the astronauts give informed consent. If they mission is to dangerous for NASA then we can only hope, ISRO, CNSA or ROSCOSMOS will go.

The point is that a $100B mission that’s still dangerous and only replicates 1960s achievements is completely pointless.

If they had set out to replicate the Moon landing at much lower cost and a controlled risk, that could have been different. Now they ended up with a very expensive, unsafe, and uninteresting mission - the worst possible combination.

Re: Artemis II is not safe to fly

#245
That we are still using Avcoat is just silly. Pica is so much better. It really shows this design is literally from the 90s. Orian is one of those continual dumbster fire programs that literally only exists to make congress happy. It survived literally years without any reasonable mission at all. NASA had to make up missions for it to do.

Orian is everything erong with US technology development and procurment.

Re: Artemis II is not safe to fly

#246
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…

> test the new heat shield which will replace the Artemis II design in an unmanned re-entry as well.

NASA desperately needs more options. They shouldn't need to expend an SLS to launch an uncrewed Orion with a test heatshield on a trajectory equivalent to a moon return. They should be able to launch that on top of a Falcon Heavy. A Falcon Heavy can launch 63 tons to LEO and a fueled Orion plus service module weights slightly north of 20 tons. An Orion mass simulator with enough attitude control mated with a FH second stage would leave a lot of delta-v to accelerate the capsule back into the atmosphere.

Re: Artemis II is not safe to fly

#248
post #244

Earlier quoted context omitted.

If you need expect perfection then we will never have a space mission. Let the astronauts give informed consent. If they mission is to dangerous for NASA then we can only hope, ISRO, CNSA or ROSCOSMOS will go.

The point is that a $100B mission that’s still dangerous and only replicates 1960s achievements is completely pointless. If they had set out to replicate the Moon landing at much lower cost and a controlled risk, that could have been different. Now they ended up with a very expensive, unsafe, and uninteresting mission - the worst possible combination.

So what's your point? Spend more on a project that is complete but not up to your standard?

Or Extend the mission to something novel? Some how without ballooning the project?

Neither is possible in the slightest.

For what it's worth the Apollo program adjusted for inflation is pushing 200bn USD compared to Artemis 100bn.

The Artemis programme is far safer than the Apollo program in terms of risk, Apollo sampled a much flatter high risk curve just 7 times.

Bottom line let the Astronauts decide what they consider safe enough they're very smart people and deserve to be allowed to give informed consent.

Re: Artemis II is not safe to fly

#249
post #247

I'm nowhere near qualified to say if the design is not safe, but I'm suprised the article doesn't mention that some heat shields are designed to indeed, blow chunks: https://en.wikipedia.org/wiki/Atmospheric_entry#Ablative

This one is an ablative heat shield, but it’s supposed to flake off gracefully, not break off in large chunks.

Re: Artemis II is not safe to fly

#250
mechanical engineering background here. the heat shield honeycomb → block change sounds like a classic cost/complexity tradeoff where you lose structural integrity for easier manufacturing.

reminds me of automotive safety recalls that trace back to "simplified" component designs. sometimes the old complex way was complex for a reason.

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