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Artemis II Launch Day Updates

nasa.gov

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Re: Artemis II Launch Day Updates

#551

Post by JumpCrisscross »

NetMageSCW wrote: post #527
JumpCrisscross wrote: post #501

Earlier quoted context omitted.

> is no technological innovation in the Artemis stack Scaling is still engineering. And the environmental control system, laser-optical communication systems and block-construction heat shields are new. For Artemis III, in-obit propellant transfer will be new and transformational.

The block construction heat shield was new on Artemis I. Now we just know that it is an unfixed problem that will be done differently on future missions. And Artemis III has nothing to do with in-orbit propellant transfer, that will be SpaceX and Blue Origin testing independently of Artemis III.

> block construction heat shield was new on Artemis I. Now we just know that it is an unfixed problem

Unfixed problems on a new technology mean it’s still new.

> Artemis III has nothing to do with in-orbit propellant transfer

I may have fucked this up—isn’t the depot supposed to be up for III? Or is that punted to IV?

Re: Artemis II Launch Day Updates

#552

Post by m4rtink »

dingaling wrote: post #482
GaryBluto wrote: post #450

It is very disconcerting to see so many completely disregarding incredible technological innovation because other problems exist, especially on HN. If we were not allowed to progress technology until everybody is 100% free of suffering, we'd never be able to create technological that may potentially lead to the alleviation of suffering. It all feels very crabs in a bucket - "I don't feel happy so nobody else should,…

There is no technological innovation in the Artemis stack. Three of the main engines are refurbished Shuttle engines. The fourth is a clone that cost more than the entire SpaceX Starship stack. The boosters are derived from the Shuttle SRBs. It's a late-60s technology rocket stack with a 2000s-era flight computer. It's such a travesty.

IIRC there are some hydrogen powered APUs on the SLS core stage, replacing the Hydrazine powered ones used on Shuttle (both on orbiter & SRBs). The solar panel control on the Orion also seems coo and useful, not to mention having cameras on the arrays for self-inspections.

I am sure there are more subtle innovations like this that would hopefully be useful on more sensible rockets and space vehicles in the future. :)

Re: Artemis II Launch Day Updates

#553

Post by [deleted] »

layer8 wrote: post #538
lionkor wrote: post #515

Earlier quoted context omitted.

Acceleration is change in speed, so it is, by its very nature, relative just like speed is. If I fall, I might accelerate at G meters per second, relative to the earth, but I don't absolutely accelerate. If the earth decelerates at the same time, I'm now both accelerating an decelerating. It's relative.

It’s absolute in the sense that you can determine your acceleration without any external reference. You feel a certain force (like what you feel in an elevator). That’s your acceleration. You don’t accelerate relative to Earth, or relative to anything else. You accelerate relative to when you wouldn’t be accelerating (your inertial rest frame, a state of free fall). If you are in space accelerating and the Earth woul…

[deleted]

Re: Artemis II Launch Day Updates

#554

Post by techteach00 »

Finally something interesting. I'm familiar with dead Internet theory, the whole Lindy thing where culture died in the early 2010's etc. Economy stinks, global violence everywhere.

Going back to the moon is really acceptable distraction. I mean that seriously. I know it's technically not new but it will be amazing to see modern video and photographic pictures of the moon close up.

Re: Artemis II Launch Day Updates

#555

Post by danem »

dmix wrote: post #535
JumpCrisscross wrote: post #505

Earlier quoted context omitted.

> It's much more popular to be doomer and a critic on the internet Is it more popular? Or is it just easy? Dismissive “reads” are done by the picosecond; there is just much more to choose from than constructive thinking, which takes work.

That's true, most of these comments are just drive by pessimism by people who just skim headlines and don't really care to deeply understand the topics being discussed.

That’s a good 75% of HN these days.

Re: Artemis II Launch Day Updates

#556

Post by fluidcruft »

JumpCrisscross wrote: post #509
mulmen wrote: post #478

Earlier quoted context omitted.

This mission is Artemis II. Is Artemis III the one with a lander?

> Is Artemis III the one with a lander? Not anymore. Artemis III is now a LEO systems check [1]. Comparable to Apollo 9. (Side note: when did we switch from Arabic to Roman numerals?) [1] https://en.wikipedia.org/wiki/Artemis_III

I don't know but the rockets and missiles have done that (Saturn V, Minuteman III, etc)

Re: Artemis II Launch Day Updates

#557

Post by JumpCrisscross »

kevin_thibedeau wrote: post #546
JumpCrisscross wrote: post #501

Earlier quoted context omitted.

> is no technological innovation in the Artemis stack Scaling is still engineering. And the environmental control system, laser-optical communication systems and block-construction heat shields are new. For Artemis III, in-obit propellant transfer will be new and transformational.

It isn't moving forward. It's an ill-conceived Apollo 1.5 with the MIC calling all the shots and a lander that is MIA. China is doing Apollo 2.0 which is fine considering this is their first attempt. The US needs a modular launch system with orbital booster tugs that can be mixed in various combinations for different mission profiles. One big booster with all of the risk stacked onto billion dollar launches is not th…

> US needs a modular launch system with orbital booster tugs that can be mixed in various combinations for different mission profiles

This is what the propellant depot is building towards.

Re: Artemis II Launch Day Updates

#558

Post by sarchertech »

NetMageSCW wrote: post #520
kokanee wrote: post #500

Earlier quoted context omitted.

> the agency said it was confident that a change to the re-entry trajectory would be more than adequate to offset any spalling issues. Somewhat confusingly, they also announced their intention to switch to a new heat shield design, starting with Artemis III. It's fine to be concerned, but this kind of take is why public agencies are damned no matter what they do. In the private sector, operating with the suboptimal r…

In the private sector, risking astronaut’s lives when you know a problem exists can result in jail time - what will happen to NASA?

1. The entire mission is “risking astronaut’s lives”.

2. NASA employees don’t have criminal immunity.

Re: Artemis II Launch Day Updates

#559

Post by JumpCrisscross »

Teever wrote: post #537
JumpCrisscross wrote: post #501

Earlier quoted context omitted.

> is no technological innovation in the Artemis stack Scaling is still engineering. And the environmental control system, laser-optical communication systems and block-construction heat shields are new. For Artemis III, in-obit propellant transfer will be new and transformational.

All of this stuff is really great but it's not worth the cost that was spent on it. The thing you have to keep asking yourself is "what could 100 billion dollars of non-pork barrel spending have bought instead of what we ended up with?"

> All of this stuff is really great but it's not worth the cost that was spent on it

It’s building towards a system. If we get Starship and in-orbit propellant depots and a lunar nuclear reactor and then kill the programme, it will probably be judged by history as a success.

> what could 100 billion dollars of non-pork barrel spending have bought instead of what we ended up with?

Rien. This is the system we have, and it’s unclear such a program could have survived sans pork.

Re: Artemis II Launch Day Updates

#560

Post by m4rtink »

feyman_r wrote: post #548
dingaling wrote: post #482

Earlier quoted context omitted.

There is no technological innovation in the Artemis stack. Three of the main engines are refurbished Shuttle engines. The fourth is a clone that cost more than the entire SpaceX Starship stack. The boosters are derived from the Shuttle SRBs. It's a late-60s technology rocket stack with a 2000s-era flight computer. It's such a travesty.

Its true that innovation isn't clearly shown in this mission; we also haven't flown humans out that far in more than 50 years either and while we have memories of it, our ability to even execute something like this must be built again. I'd rather see us doing this and 'pick up from where we were last time', than giving up on it or just using a stack that's not currently set to do this. What Artemis is doing is not im…

Not impending innovation is IMHO debatable - Artemis has definitely potential to motivate a lot of lay population & young people to go do space stuff and tech in general.

On the other hand SLS and Orion have gobbled insane amount of money that could have been invested to other science missions or even more efficient human space flight.

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