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The Lunacy of Artemis

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Re: The Lunacy of Artemis

#91

Post by idlewords »

SJC_Hacker wrote: post #84

Loss of crew tolerance is not what it used to be. The Apollo astronauts were given about a 10% chance of not coming back. In Apollo 13 they very narrowly avoided. Which was considered acceptable for the time period. I'd argue that mission failure tolerance is also considerably lower, in todays political environment. Again, Armstrong said their chances of actually landing were maybe 50/50. So if they get there and hav…

According to NASA's own advisory panel, the chance of losing the crew on just the SLS/Orion portion of the mission (so not including the landing, Gateway, or the trip to and from the lunar surface) is 1 in 75. If you make the reasonable assumption that the landing is at least as risky as the trip over, you get a 1 in 30 chance the crew dies.

The Shuttle towards the end of its life had an estimated chance of loss of crew of 1 in 90, and two administrations decided that was untenable. The standard for missions to ISS is 1:250. If a goal of Artemis is to meet modern safety standards, it's falling way short.

Re: The Lunacy of Artemis

#92

Post by Panzer04 »

SJC_Hacker wrote: post #84

Loss of crew tolerance is not what it used to be. The Apollo astronauts were given about a 10% chance of not coming back. In Apollo 13 they very narrowly avoided. Which was considered acceptable for the time period. I'd argue that mission failure tolerance is also considerably lower, in todays political environment. Again, Armstrong said their chances of actually landing were maybe 50/50. So if they get there and hav…

A good part of the article argues that we aren't getting that safety, though. Spending a week around the moon to make up for hardware shortcomings is not encouraging.

It appears by and large that most of the components being used for this will be lucky to have been tested in action more than once before they have to carry astronauts...

Re: The Lunacy of Artemis

#94

Post by oefrha »

codewiz wrote: post #42

Unkind quotes, but hilarious and probably well deserved: "SLS looks like someone started building a Space Shuttle and ran out of legos for the orbiter" "But on top of this monster sits a second stage so anemic that even its name (the Interim Cryogenic Propulsion Stage) is a kind of apology." "the minds behind SLS achieved a first in space flight, creating a rocket that is at the same time more powerful and less capab…

I guess you didn’t reach the end, there are more choice quotes later on:

> Where Apollo was built like a roadster, with a small crew compartment bolted onto an oversized engine, Orion is the Dodge Journey of spacecraft—a chunky, underpowered six-seater that advertises to the world that you're terrible at managing money.

> To hear NASA tell it, NRHO is so full of advantages that it’s a wonder we stay on Earth.

> NASA likes to boast that Orion can stay in space far longer than Apollo, but this is like bragging that you’re in the best shape of your life after the bank repossessed your car.

And I’m only halfway through.

Re: The Lunacy of Artemis

#95

Post by pclmulqdq »

dotnet00 wrote: post #43
GlenTheMachine wrote: post #37

One minor quibble: on-orbit refueling has been demonstrated, during the DARPA Orbital Express mission in 2006. Otherwise, if NASA issued stock, you should consider shorting it.

That was on-orbit refueling of hypergolic propellants, which is already done regularly on the ISS and is conceptually straightforward since you can just use bladder tanks to do the transfer without any special considerations. What hasn't been demonstrated is on-orbit refueling with cryogenic propellants, which involve more considerations regarding thermal and pressure management. Technically the most recent Starship…

"Demonstrated" is a strong word given what we all saw. I'm not sure there has been any document released that they actually proved that they successfully did a propellant transfer.

Re: The Lunacy of Artemis

#96

Post by SJC_Hacker »

hi_hi wrote: post #78

Out of interest, what do people think is going to happen once humans can semi-reliably get to the moon? I don't often see this part talked about. I read lots about the astronomical (thank you!) cost and effort of getting there, often framed in a way that makes the whole endeavour appear pointless and dumb. Will they just potter about for a few days, grab a handful of rocks, take some jaunty selfies, have a cup of tea…

Not much probably. I think it would be at best, be research station.

It will be a bit like Antartica.

The moon isn't going to be mined anytime soon. There's nothing there we can't get on Earth, 10x cheaper.

If there was a permanent presence there anyway, and in addition, you had something like a mass driver (probably built for other purposes, such as further exploration), then the economics might make sense IF you can find valuable ores, which we don't know where they are. But I think even then its dodgy - you would have to manufacture re-entry grade heat shields on the Moon as well to ship your ores / refined products back.

If they could do local manufacturing, especially for the less complex/bulky items. To support that you probably need a population there of at least 20 or so, with all the supporting equipment and life support. And they couldn't stay there indefinitely, would probably want a rotation of 6 months-1 year (length of navy deployments / ISS stays). We're talking several thousand kg that you would have to move between Earth / Moon a regular basis. Annual program costs would quickly run into the hundreds of billions.

Yeah thats comparable to the US defense budget but one of those things people view as necessary, the other not so much. And no private investor is going to touch it.

Re: The Lunacy of Artemis

#97

Post by zzzeek »

hi_hi wrote: post #78

Out of interest, what do people think is going to happen once humans can semi-reliably get to the moon? I don't often see this part talked about. I read lots about the astronomical (thank you!) cost and effort of getting there, often framed in a way that makes the whole endeavour appear pointless and dumb. Will they just potter about for a few days, grab a handful of rocks, take some jaunty selfies, have a cup of tea…

hm what IS it worth ? There's some kind of valuable minerals there?

Google: "Helium 3". well we do need that

Re: The Lunacy of Artemis

#98

Post by nordsieck »

venusenvy47 wrote: post #47
xt00 wrote: post #15

I think we all can understand the situation here unless people are really dense.. the Artemis program was setup at a time when the private space companies were still very new. SpaceX will soon be quite close to technically doing the entire mission themselves without Artemis at all. SpaceX took the money from NASA to help fund their Starship development and probably for other reasons as well. Net result is that by the…

I don't think there is any plan for a roundtrip Starship lunar mission. I think it is too heavy to get back.

> I don't think there is any plan for a roundtrip Starship lunar mission.

There are currently no official NASA plans to do so. In part because if there were that would be NASA tacitly giving up on SLS and Orion, which Congress would never support.

We'll see what happens if SpaceX ever advertises such a capability.

> I think it is too heavy to get back.

There are a number of architectures that have been proposed that should work. From what I recall, all of the involve using multiple Starship vehicles going to Lunar orbit.

Re: The Lunacy of Artemis

#99

Post by nordsieck »

kemotep wrote: post #58
dotnet00 wrote: post #57

Earlier quoted context omitted.

SLS cannot get from the ground to the moon and back with just the one rocket. Orion is too heavy to land and return from the Moon. That's why the plan, even before Starship's involvement, was to transfer from Orion to the lander in lunar orbit, either directly or via the Lunar Gateway spacestation.

I understand it didn’t land on the moon but it flew to the moon and back (which is what my comment was saying) in 2021. The mission wasn’t perfect but their half of Artemis was demonstrated. Starship has not yet shown to be capable of completing its half. Artemis 2 and 3 should be delayed until NASA can fix their shit.

> The mission wasn’t perfect but their half of Artemis was demonstrated.

Sort of.

The first fully functional Orion will be debuted on Artemis III. As an example of the differences, the Artemis I Orion didn't have functional life support systems. And the Artemis II Orion won't be able to dock with anything.

Re: The Lunacy of Artemis

#100

Post by dotnet00 »

pclmulqdq wrote: post #95
dotnet00 wrote: post #43

Earlier quoted context omitted.

That was on-orbit refueling of hypergolic propellants, which is already done regularly on the ISS and is conceptually straightforward since you can just use bladder tanks to do the transfer without any special considerations. What hasn't been demonstrated is on-orbit refueling with cryogenic propellants, which involve more considerations regarding thermal and pressure management. Technically the most recent Starship…

"Demonstrated" is a strong word given what we all saw. I'm not sure there has been any document released that they actually proved that they successfully did a propellant transfer.

Last month NASA stated at a meeting that SpaceX had successful propellant transfer: https://spacenews.com/spacex-making-progress-on-starship-in-...

"On Flight 3, they did an intertank transfer of cryogens, which was successful by all accounts,"

It has admittedly been a weirdly quiet confirmation though, coming from a NASA official rather than from the usual sources (Elon/Gwynne/SpaceX official X).

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