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Artemis II safely splashes down

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Re: Artemis II safely splashes down

#171

Post by pdonis »

roughly wrote: post #163
areoform wrote: post #11

Glad that they're safe and sound. It's worth pointing out that this is the first extremely public, widely acknowledged high risk mission NASA has done in over 50 years. The Shuttle was risky, but it wasn't thought of or acknowledged by NASA as being risky until very late in its lifecycle. According to NASA's OIG, Artemis acceptable crew mortality rate is 1 in 30. Roughly 3x riskier than the shuttle. There genuinely i…

Astronauts are, as a group, extremely risk loving. Every single person who signs up to go into space knows what they’re signing up for - they’ve spent their entire life working for the opportunity to be put in a tin can and shot into orbit atop a million pounds of explosives. There’s a very valid critique that NASA has become far too risk averse - we owe it to the astronauts to give them the best possible chance to c…

My father, who flew combat missions for the Navy in Vietnam and then became a test pilot, told me after the loss of Columbia that if he had had a chance to make that flight and spend 7 days in Earth orbit, even knowing that he'd burn up on reentry, he'd have done it.

Re: Artemis II safely splashes down

#172

Post by alex1138 »

areoform wrote: post #76
irjustin wrote: post #51

Earlier quoted context omitted.

> Artemis acceptable crew mortality rate is 1 in 30. This seems insane to me. That X decades later we accept, with all our advancements in tech, a weaker system than ever before. That if we send 30 people we _accept_ that one is possible to die. That's the starting point? That's what we document as acceptable?

Yes, and the memories of Apollo are made rosy by hagiography. I even wrote an entire thing to explain why, https://1517.substack.com/p/1-in-30-artemis-greatness-and-ri... (yeah, shameless plug, sorry - it's more for the citations than not. You can read the standards and reports I've linked to) But if I'm allowed to repeat myself from elsewhere in the thread and the meat of the above thing, It's physically not possibl…

NASA certainly took many risks back then. People remember Apollo 11 for the landing, but for example on Apollo 8, with a fire roughly 2 years earlier that killed 3 astronauts, they had one manned mission (Apollo 7) and then immediately sent Apollo 8 around the moon with ONE rocket nozzle that had to work (and no LM to escape into, as the Apollo 13 astronauts had to do), basing their faith in trajectory mechanics which hadn't been tested that far out

The ejection seats on Gemini were a joke, and there's an anecdote Gene Kranz tells in his book about Gemini 9 where he thought it was too risky for them to cut away the shroud on the thing they were going to dock with (the Agena having blown up on launch) but NASA was this close to overriding him and doing it anyway (they were saved by the astronauts vetoing it, which was good because the EVA, separately, that Gene Cernan did was incredibly harrowing. he was sweating, way overworked, could barely see)

Re: Artemis II safely splashes down

#173

Post by SoftTalker »

rvz wrote: post #19

Now this is actually for the benefit of humanity.

How? I struggle with this. It all seems like a fearful waste of money and resources. We can't live on the moon. We can't live on Mars. It is a fantasy. We have so many problems here on Earth that are more important to solve than sending a handful of men to the moon (again).

Re: Artemis II safely splashes down

#174

Post by j_bum »

areoform wrote: post #76
irjustin wrote: post #51

Earlier quoted context omitted.

> Artemis acceptable crew mortality rate is 1 in 30. This seems insane to me. That X decades later we accept, with all our advancements in tech, a weaker system than ever before. That if we send 30 people we _accept_ that one is possible to die. That's the starting point? That's what we document as acceptable?

Yes, and the memories of Apollo are made rosy by hagiography. I even wrote an entire thing to explain why, https://1517.substack.com/p/1-in-30-artemis-greatness-and-ri... (yeah, shameless plug, sorry - it's more for the citations than not. You can read the standards and reports I've linked to) But if I'm allowed to repeat myself from elsewhere in the thread and the meat of the above thing, It's physically not possibl…

Thanks for sharing your article - very well written.

I am stunned to see that LoC risk assessment.

I kept wondering to myself over the past week, “will this be the last USA-supported human space travel if these astronauts don’t survive?”

I’d have a hard time imagining the general public would support any future missions if they hadn’t survived.

These astronauts are some elite humans. My respect for them is even greater now that I’ve seen the risk quantified.

Re: Artemis II safely splashes down

#175

Post by pdonis »

SV_BubbleTime wrote: post #161
gct wrote: post #53

Earlier quoted context omitted.

Orbits do not work that way

Hilarious the the intellectual forum downvoted you for being absolutely right. Artemis II never escaped Earth’s pull. That video that NASA put out where the craft did a sling shop around the moon is extremely deceptive. The pull of the moon had very little effect. If they had missed, they would have eventually crashed back to earth in the worst case, and best case just re-adjusted and returned a little bummed.

> The pull of the moon had very little effect.

No, it had a very significant effect: it's what made possible the free return trajectory while observing the far side of the moon.

Re: Artemis II safely splashes down

#176

Post by jiggawatts »

dingaling wrote: post #111
qrush wrote: post #22

Apparently there's more work than just clicking "Recover Vessel" after splashdown!

1 hour 29 minutes seems excessive to extract the astronauts; if any of them _did_ have a medical issue they'd be in for a long wait. The commentary said that the initial problems with the boats approaching Integrity was due to an unexpected swell. Unexpected, in the Pacific? Edit: all of the Apollo missions, except 8, had their stabilization collars inflated in under 20 minutes. With Integrity today it took nearly an…

I also like how they waffled on about how winching them up to a helicopter was the fastest option, when they obviously could have shaved an hour off the recovery time by simply having them step out onto the waiting boats!

Having worked for various government agencies for a while I've learned to recognise the signs of the "We're following the procedure whether it makes sense or not, dammit!" attitude you get with large bureaucracies.

Re: Artemis II safely splashes down

#177

Post by anon291 »

As I've said before. This is a huge achievement. And also is the most effective political propaganda ever. Bravo to everyone involved .

This is not sarcastic. This is very much meant. I love that America does this. We still get to evoke an awe which previous empires awesome as they may be, could never match. American superlatives are amazing. God bless America

Re: Artemis II safely splashes down

#178

Post by 420official »

dgfl wrote: post #146
420official wrote: post #88

Earlier quoted context omitted.

You seem to intentionally be ignoring the original quote that any error may have caused them to be flung into space. This is patently false unless the one math error is pumping in hundreds of pounds more propellant and burning far longer than the scheduled burns. NASA would need to make a significant series of mistakes beyond orbital math for the "flung out into space" statement to be true. They certainly could've go…

This is underselling the risks. On top of the many trajectories which push them into unrecoverable situations, leaving them stranded in orbit, there can be trajectories where the moon gives a gravity assist strong enough to fling the spacecraft into escape velocity, fulfilling the OP. In fact, the trajectory they chose for this mission exploited the opposite effect to yield a free return without propellant expense. I…

The amount of things that would have to go wrong for the craft to get an accidental gravity boost and be ejected would be significant.

I feel like the original claim paints the whole thing as on a knife edge and barely achieved by virtue of not making a single mistake. In today's age with so many moon landing deniers and worse I feel like we should be specific about where the actual dangers challenges and unknowns there were here. In reality, the orbital mechanics are one of the simplest parts of the entire problem, at least when we're talking about a moon flyby

Re: Artemis II safely splashes down

#179

Post by anon291 »

brianjlogan wrote: post #82

As an American I feel like I've been going through a bit of an identity crisis from what I remember growing up. Probably the rose tinted glasses of being a child but being from Florida I always had a sense of amazement and wonder as I heard the sonic boom of the shuttle returning to earth. Really felt like I was coexisting in this incredible scientific powerhouse of a country full of bright and enabled peoples that k…

The nice thing about a public space program is everyone can share in its success!
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