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Artemis II is not safe to fly

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Re: Artemis II is not safe to fly

#191

Earlier quoted context omitted.

for human spaceflight we want a lot more than "likely" (>50%). The standard is usually "extremely likely" (~1/100 to 1/1000 chance of failure)

1/100 is absolutely terrible. Shuttle had 1.5% failure rate. Bonkers. [edit] For comparison, commercial aviation has something like 1 in 5.8m or 6x 9's of reliability.

It's not terrible for space flight. Flying a rocket to the moon and commercial aviation are obviously very different things.

Re: Artemis II is not safe to fly

#192

Earlier quoted context omitted.

for human spaceflight we want a lot more than "likely" (>50%). The standard is usually "extremely likely" (~1/100 to 1/1000 chance of failure)

Maybe. What was the probability of Loss of Crew during Apollo? There were 9 crewed missions and 1 almost killed its crew (I will omit Apollo 1 for now). I could argue that Apollo had a 1 in 20 chance of killing a crew. Indeed, that was one reason given for cancelling the program. The first Shuttle launch probably had a 1 in 4 chance of killing its crew. It was the first launch of an extremely complicated system and t…

> There were 9 crewed missions and 1 almost killed its crew (I will omit Apollo 1 for now). I could argue that Apollo had a 1 in 20 chance of killing a crew.

That's not how risk analysis works.

Let's say every Apollo mission had gone flawlessly, and no one even came close to dying. Would you then say that the risk of death for future missions would be zero? No, of course not.

Re: Artemis II is not safe to fly

#194
The heatshield is not quite Avcoat. It is missing the crucial honeycomb that gives it structural integrity. I worked on EFT-1. It's test flight was gorgeous (2014). LM decided to remove the honeycomb. It is like a beehive with no honeycomb.

I changed projects bc it was obvious to that the risk was substantial, long befor Artemis was called Artemis, people said this.

Re: Artemis II is not safe to fly

#195

Earlier quoted context omitted.

could the government rent out monopoly grants for televised football on the moon in exchange for sponsoring manned space exploration?

Is there any research on the effect of apparent gravitational field strength on sports? I’d be willing to bet that rocketry and artillery takes account of 50mm/s2 difference at the equator. While the difference is obviously tiny, the margins in modern sports are also miniscule. Do Fijian rugby games see a 0.5% increase in longest drop goal distance?

I have no idea about the 0.5% increase in drop goal distance, but tongue-in-cheek, I would say only 0.5% as many attempted drop goals - given the Fijian team's emphasis on a ball-in-hand style of play instead of kicking the ball away.

On a slightly related note, I always found the games played in Pretoria in South Africa fascinating. It's 1350 m above sea level, so kicks all go 10% to 15% further (my estimate) which makes quite a difference when there are players kicking penalties from over halfway even at sea level.

Re: Artemis II is not safe to fly

#197

This is a more balanced take, in my opinion: https://arstechnica.com/space/2026/01/nasa-chief-reviews-ori... Camarda is an outlier. The engineers at NASA believe it is safe. The astronauts believe it is safe. Former astronaut Danny Olivas was initially skeptical of the heat shield but came around. And note that the OP believes it is likely (maybe very likely) that the heat shield will work fine. It's hard for me to r…

Camarda isnt an outlier. Lots of people left that project after the Experimental Flight Test, which was done with the honeycomb (making Avcoat truly Avcoat) in 2014. Without Avcoat, spalling was inevitable and breakoff, oh yeah.

The design change by LM, not commentedkn by Textron is like. a beehive with no honeycomb-a crystallized block of honey.

i'll take the structural support of honeycomb any day.

It's a normalization of deviance. That is what Charlie is bringing voice to. Many of us fear reprisals and even when talking to heads of, like with Columbia, we are ignored.

So, Charlie is a voice of many people, not an outlier.

Re: Artemis II is not safe to fly

#198

Someone please answer my obvious question. We sent successful missions to the moon sixty years ago. What heat shield material was used for the Apollo capsules, and why would we need something different now? Are the Artemis mission parameters totally different in a way that requires a new design? Or was Apollo incredibly dangerous and we got lucky they didn’t all fail catastrophically? The article mentions Orion is mu…

The Apollo command module used Avcoat, the same material as Orion. But there are two key differences: 1. The application method is different. Apollo applied it to a metal honeycomb structure with very small cells, while Orion uses blocks of the material. (NASA tried the honeycomb approach for Orion, but it was too labor-intensive). 2. Orion is much bigger and heavier than the Apollo command module. The informal conse…

How reliable is this information?

Just out of curiosity, do we know if the honeycomb method worked before it was deemed too labor intensive? Because I'm told that using this block method results in chunks blowing out.

I'm also having a problem with this set-up: Apollo is at the upper size limit for avcoat; Orion is way bigger; use avcoat.

Reading a real front-fell-off aura from this project. It makes me wonder if spending 6% of GDP to develop and run a crewed lunar program 60 years ago and then immediately destroying the evidence, r&d artifacts, and materials fab capabilities was a good idea.

Re: Artemis II is not safe to fly

#199

Earlier quoted context omitted.

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 ar…

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.

Re: Artemis II is not safe to fly

#200
post #175

Earlier quoted context omitted.

Based on some rough numbers, NASA's budget (around $24B) would be I also looked up the NSF's 2024 budget, which, at $9B, was much lower than I expected.

NASA does both manned and unmanned stuff. Don't conflate those when you are looking at returns. Look at this joke of a list https://www.nasa.gov/missions/station/20-breakthroughs-from-... for an illustration. And those were the 20 best things they could come up with.

There are actually a lot of really interesting discoveries on that list. I haven't thought deeply about whether it represents value for money, but I would say that that is anything but "a joke of a list."
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