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Artemis II safely splashes down

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Re: Artemis II safely splashes down

#331

Post by tomrod »

irjustin wrote: post #51
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…

> 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?

Turns out riding on top of controlled explosions is a risky engagement.

Re: Artemis II safely splashes down

#332

Post by rustyhancock »

m4rtink wrote: post #329
rustyhancock wrote: post #286

Earlier quoted context omitted.

I'd add a caveat to this. We can do this because of war. We know where it will land accurately because that maths and physics has been sharpened with butt loads of data. Even the reentry blackout has links to war in Plasma Stealth[0]. That data was mostly obtained because we want to know where our ICBM warheads will land. And where the enemies ICBM warheads will land so we can work on the problem of shooting them dow…

IIRC reentry plasma is actually highly radar reflective - so it is not hard to track, just hard to hit due to the speed, as there is limited time to do it.

If that were the case then the mach-10 Kinzhal would be harder to hit than the mach-5 Kh-32.

But the interception rate for the Kh-32 is basically nonexistence (The Kh-22/32 is why mach-5 + maneuverability is the current goal of offensive missile systems.

The plasma has complex interaction with radar, it's not stealth as in entirely invisible just chaotic scattering and reflections. The result is a jamming effect preventing a definite intercept solution.

On the other hand the plasma shows up on satilite based IR tracking systems.

Re: Artemis II safely splashes down

#333

Post by simonebrunozzi »

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…

For context, Jared is NASA Administrator Jared Isaacman. I didn't know, so I think it could be useful for others.

Re: Artemis II safely splashes down

#334

Post by philwelch »

echoangle wrote: post #20

Wild that they manage to fly to the moon but still seem to be having those comms problems. Asking the astronauts if they’re really pressing the PTT button is wild.

This is the same mission where the commander radioed to Houston, “I have two Microsoft Outlooks, and neither one of those are working”.

Re: Artemis II safely splashes down

#335

Post by dboreham »

dgfl wrote: post #151
bombcar wrote: post #115

Earlier quoted context omitted.

Was any shuttle lost to the SRBs?

Yes, challenger. The O-ring failed, creating a gas exhaust that almost instantly destroyed the main propellant tank.

I believe what it destroyed was the strut holding the booster to the tank. When the strut burned through the assembly came apart and aerodynamic forces did the remainder of the destruction.

Re: Artemis II safely splashes down

#337

Post by jkman »

elevatortrim wrote: post #307
rustyhancock wrote: post #286

Earlier quoted context omitted.

I'd add a caveat to this. We can do this because of war. We know where it will land accurately because that maths and physics has been sharpened with butt loads of data. Even the reentry blackout has links to war in Plasma Stealth[0]. That data was mostly obtained because we want to know where our ICBM warheads will land. And where the enemies ICBM warheads will land so we can work on the problem of shooting them dow…

To say “because of war”, you would also have to prove we could not do it without war.

That's an absurd statement. By your logic, you can't just say that we have the smallpox vaccine "because of Edward Jenner". Because you would also "have to prove we could not do it without Edward Jenner". What does that even mean??

Re: Artemis II safely splashes down

#338

Post by andrepd »

simplyluke wrote: post #118
llbbdd wrote: post #85

Earlier quoted context omitted.

I think especially online there's a lot of emphasis on "everything is wrong". A mission like this is hard to ignore and highlights the bias. On the whole, despite setbacks, we continue.

If you want to dispel a bit more of the ever-pervasive online pessimism bias, read up on global rates of hunger the last time we flew to the moon (1972) vs now. The reality is, for all the problems we face today, there's no sane answer other than today to the question "when would you prefer to be born as a random person on earth"

A global view is probably not the right way to look at things, encouraging as it may be. Of course globally hunger rates fell and so did child mortality. If nothing else, by the inexorable progress of science and technology.

But what about comparing the same country/region? After all that's a better sense of how things are progressing locally to you, and when people are asked "are things better or worse" they probably compare the way they live with the way their parents lived.

Would you rather be born in 1980 or 2020 in China? In Poland? No question. Same question but in the USA? In the UK? The West in general? I'm really not so sure.

Re: Artemis II safely splashes down

#339

Post by philwelch »

jiggawatts wrote: post #176
dingaling wrote: post #111

Earlier quoted context omitted.

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 larg…

“Stepping” from one vessel to another in the middle of the ocean is not like getting on your buddy’s sailboat at the marina even if you have your sea legs. Astronauts don’t even have their earth legs when they splash down; when they return from ISS they can’t even walk right away, though Artemis was a shorter duration mission than that.

Re: Artemis II safely splashes down

#340

Post by philwelch »

TheOtherHobbes wrote: post #288
jiggawatts wrote: post #176

Earlier quoted context omitted.

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 larg…

I wondered about that. Winching someone who can barely walk and is wearing a spacesuit into a helicopter over choppy water is safer and quicker than parking them on a motor boat and sailing back to the mothership? What was the real reason? Tradition? Lack of imagination? Photo opportunities? The rest was great tho.

So someone who can barely walk is supposed to safely jump from a space capsule to a boat in the middle of the ocean?
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