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Artemis II is not safe to fly

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Re: Artemis II is not safe to fly

#461

Post by MoltenMan »

randomNumber7 wrote: post #454
Havoc wrote: post #268

Earlier quoted context omitted.

Suicide ideation and someone willing to take massive risks for something awesome are very different things

> The trip is far more awesome than anything I have planned for the rest of my life. If you would give your live for a single awsome trip (and you would still have multiple years to live), then you are likely suicidal. Even if it is rational because your live sucks so hard, I would still have to classify you as suicidal.

...no? It's the same as when you say you'd 'die for somebody'. I don't want to die, but if I had to die to save my family I would. That's not being suicidal. Similarly, if space is important enough to you to take this risk (which realistically is a pretty low risk!) I wouldn't call that suicidal either. I take the risk of death driving in my car every day; that's the nature of life.

Re: Artemis II is not safe to fly

#462

Post by pavon »

recursivecaveat wrote: post #95
SyzygyRhythm wrote: post #72

Earlier quoted context omitted.

There were 19 successful unmanned Dragon 1 missions before Crew Dragon, and an unmanned Crew Dragon mission before the first crewed one (actually two missions, but one didn't reenter from orbit). The heat shield material and design was essentially the same and so there was a great deal of flight heritage.

In particular I don't think its physically possible to test Orion components in flight very many times. It relies on SLS which chews through 4 space-shuttle engines every time, which even with unlimited money I don't think you could acquire a large supply of very quickly.

SLS is required to get Orion to the moon, but there are other options for LEO tests. Exploration Flight Test-1 was performed on a Delta IV Heavy, and Falcon Heavy is also capable of launching Orion to LEO (and now New Glenn, although that wouldn't have been an option at the time NASA needed to start work on another Orion test).

Re: Artemis II is not safe to fly

#463

Post by wat10000 »

tonymet wrote: post #346
kelnos wrote: post #196

Earlier quoted context omitted.

That... doesn't make any sense.

If the odds were only 1% , how did 14 people die ? You’re not including the lives in your risk assessment . There were 135 events and 14 people died . If you were asked to join mission 136 would you say yes or no? Which risk profile fits: 1% fatality or 10%?

By that logic, the fatality rate in NYC skyscrapers on 9/11 was something like 1500%, since there were It doesn't make any sense. Your numerator and denominator need to use the same units. The rate of fatal accidents was 2/135. The rate of crew fatalities was 14/355. The rate for crew-flight fatalities (separately counting multiple flights by the same person) was 14/852.

If you were evaluating your risk for another flight, the number of crew aboard doesn't affect the risk and it's pretty reasonable to assume that an accident results in either a 0% or 100% fatality rate, so the relevant figure would be the fatal accident rate of 2/135. If your flight follows that profile then that's your probability of dying in an accident.

Re: Artemis II is not safe to fly

#464

Post by colechristensen »

jessewmc wrote: post #355
chadd wrote: post #292

I'm literally guest lecturing at a Harvard class tomorrow on systemic failures in decision making, using the Columbia and Challenger disasters as case studies, and changed my slides last night to include Artemis II because it could literally happen again. This broken safety culture has been around since the beginning of the Shuttle program. In 1980, Gregg Easterbrook published "Goodbye, Columbia" in The Washington Mo…

As an aside, do you have any suggestions for "state of the art" reading on safety culture?

Learn about failures.

Inviting Disaster: Lessons From the Edge of Technology was one of the texts for an aerospace class I didn't take but friends did, but honestly you can just read the book.

There are lots of frameworks for teaching safety and programs for compliance and such but they are far too easy to cargo cult if you don't appreciate safety and the need for safety culture and UNDERSTAND what failures look like.

And when you really understand the need and how significant failures happened... "state of the art" tools and practices take a back seat, they can be useful but they're just tools. What you need is people developing the appropriate vision, and with that the right things tend to follow.

Re: Artemis II is not safe to fly

#465

Post by wolvoleo »

randomNumber7 wrote: post #273
wolvoleo wrote: post #152

Earlier quoted context omitted.

In the space shuttle disasters the hardware had at least been used more than once. A huge lot of this one is only tried and tested on paper. And the idea that 'if we throw this much money at it, it really must be fine' I don't buy either. Look at how that worked out for Boeing. For all my feelings about Musk I would much rather step into a rocket that has exploded in all kinds of imaginable situations before so they…

> For all my feelings about Musk I would much rather step into a rocket Definitely, but we still have to figure out if Musk is such a genious or NASA is full of retards.

Neither is true IMO but musk just picked the right development model.

Big space never did this because the current megaproject cost plus is just what they want, a blank check.

Witn SpaceX Musk was mainly wasting his own money especially in the beginning. So it made sense. It just makes sense, it's not even a 'shortcut'.

Ps yes he did get some grants but not beefy unlimited ones.

Re: Artemis II is not safe to fly

#466

Post by gus_massa »

quasistasis wrote: post #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.

Sorry, I had to google it https://en.wikipedia.org/wiki/Exploration_Flight_Test-1

> [...] previously known as Orion Flight Test 1 [...] Without a crew, it was launched on December 5, 2014 [...]

Re: Artemis II is not safe to fly

#467

Post by jonahx »

rjmunro wrote: post #349
kelnos wrote: post #192

Earlier quoted context omitted.

> 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.

I thought I'd look this up. If you've had 9 successful attempts, assuming nothing has changed between them and no other prior knowledge about success probability, then Laplace’s Rule of Succession says the probability of the next mission being a success is about 83.3%, i.e. there is a 1 in 6 chance of failing next time.

> and no other prior knowledge about success probability

This phrase is misleading, as Laplace's Rule of Succession is equivalent to assuming a uniform Bayesian prior over all values of p. That is, before any experiments, a 50% chance of success. Depending on the situation, this may be roughly accurate or wildly wrong. You cannot appeal to this rule to resolve the situation.

Re: Artemis II is not safe to fly

#469

Post by Cpoll »

pstuart wrote: post #455
MisterTea wrote: post #390

Earlier quoted context omitted.

> This broken safety culture has been around since the beginning of the Shuttle program. It's broken everywhere. I have worked in some dysfunctional shops and the problem I see time and time again is the people who make it into management are often egoists who don't care about anything other than the financial compensation and clout the job titles bestows upon them. That or they think management is the same as being…

A simplistic answer would be to ensure that incentives are aligned with safety and success. Then that leads to the evergreen problem of Goodhart’s Law (when a measure becomes a target, it ceases to be a good measure). Even if it can't ever be truly fixed, at least recognizing the issues and shining daylight on decisions for some form of accountability should be a base-level approach.

> Goodhart’s Law

Useful to be sure, but it's easier to game something like LOC than it is to game "product made money" and "nobody died."

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