I was scared To say this to NASA (But I said it anyway) – Smarter Every Day • Hacker News Board

Re: I was scared To say this to NASA (But I said it anyway) – Smarter Every Day

#41

Post by jamesTee49 » Sun, Dec 03, 2023, 10:22 PM UTC

dmillar wrote: post #14

My TLDW: He's (not so) indirectly critical of Space X's Starship program and tribal groupthink. He may be "scared" of NASA because he's calling out one of their giant Artemis contracts. Some longer takeaways: - Simplify. We went to the moon 50+ years ago, but we are reinventing the wheel in some significant ways in Artemis. Why? We are supposedly going to the moon in two years, but we have never attempted a cryogenic…

Think about it, we can go to the moon but now can't. None of the superpowercountries like China, Russia, EU, could. I give more credence to we never landed human there but only sent mechanical robots there for deployment to prove we landed there. Look up Neil Armstrong career after coming back from the moon. He was so wasted about his achievement...could have been senator or even some big corporation hotshot. But didnt. Nearly all moonwalkers behave the same. Either they have moon ptsd or as what conspiracy hinted, we never have human landed there.

Re: I was scared To say this to NASA (But I said it anyway) – Smarter Every Day

#42

Post by grecy » Sun, Dec 03, 2023, 10:25 PM UTC

MR4D wrote: post #36

grecy wrote: post #15

Earlier quoted context omitted.

> We went to the moon 50+ years ago, but we are reinventing the wheel in some significant ways in Artemis. Why? Because if we do it the same way we did 50+ years ago, we learn absolutely nothing and the whole thing is a pointless waste of money. In order to progress and learn and improve you must do things you've never done before. You must be ambitious and you must attempt things that are difficult and will probably…

> Because if we do it the same way we did 50+ years ago, we learn absolutely nothing and the whole thing is a pointless waste of money. I would argue that if we did it exactly as we did back then that we would actually learn something because we forgot how to do so much. Literally can’t build an F-1 engine. It would take a ton of work just to recreate it. However, the benefit is that we would then have plans (diagram…

> However, the benefit is that we would then have plans (diagrams, specs, etc) to build it and one built we can iterate.

Hypothetically we've lost the diagrams,designs,knowledge to build a 386.

Is it worth building one today just so we can remember how, and then iterate on it?

No, absolutely not. The F-1 (and the 386) are ancient. Don't start from ancient and work up. Aim higher.

Re: I was scared To say this to NASA (But I said it anyway) – Smarter Every Day

#43

Post by avmich » Sun, Dec 03, 2023, 10:40 PM UTC

dmillar wrote: post #25

carlosdp wrote: post #23

Earlier quoted context omitted.

Idk how you took away that he was criticizing the Starship program at all. SpaceX pivots designs on a swivel, conducts tons of incremental tests, and ends up succeeding at the claimed impossible time and time again. If anything, NASA should be taking a cue from them. He’s being directly critical of Artemis and Orion/SLS, which is not at all built that way, was basically architected by politics, and will probably not…

In-orbit refueling, etc. Those are Starships not SLS being counted: 29:45 Talking about methane, in situ refueling (not just spacex, but they've been the most vocal): 41:25 Complexity/redundancy: 46:28 (looong pause and laughter) Comments on engine design: ~48:00 (you have to be aware of Raptor/SS booster design to get the criticism)

Raptors right now look very nightmarish if used for landing crew on anything - the Earth or the Moon alike. The most advanced liquid fuel engine with tons of feedback loops looks suspiciously like a catastrophe waiting to happen at a worst possible moment.

Landing on the Moon is supposed to use some other engines as well at the time, so that may help. As soon as we'll know more about design, we can say things more confidently.

Re: I was scared To say this to NASA (But I said it anyway) – Smarter Every Day

#44

Post by avmich » Sun, Dec 03, 2023, 10:46 PM UTC

MR4D wrote: post #36

grecy wrote: post #15

Earlier quoted context omitted.

> We went to the moon 50+ years ago, but we are reinventing the wheel in some significant ways in Artemis. Why? Because if we do it the same way we did 50+ years ago, we learn absolutely nothing and the whole thing is a pointless waste of money. In order to progress and learn and improve you must do things you've never done before. You must be ambitious and you must attempt things that are difficult and will probably…

> Because if we do it the same way we did 50+ years ago, we learn absolutely nothing and the whole thing is a pointless waste of money. I would argue that if we did it exactly as we did back then that we would actually learn something because we forgot how to do so much. Literally can’t build an F-1 engine. It would take a ton of work just to recreate it. However, the benefit is that we would then have plans (diagram…

> However, the benefit is that we would then have plans (diagrams, specs, etc) to build it and one built we can iterate.

To me the current state looks like as if we

    1) recreated F-1
    2) had plans and diagrams
    3) iterated - first to the level of NK-33, then to the
       level of RD-270, then to the level of Raptors
    4) carefully put those original plans back on the shelf
       and forgot about them.

Yes we can't do F-1 today verbatim. We also can't do many other things, not easily - steam engines, telegraphs, airplanes, cassette players of the time would all require some re-engineering. We however can often do better using very different approach.

Re: I was scared To say this to NASA (But I said it anyway) – Smarter Every Day

#45

Post by avmich » Sun, Dec 03, 2023, 10:56 PM UTC

darksim905 wrote: post #12

ziffusion wrote: post #7

Earlier quoted context omitted.

Hey - you put in the time. Can you please help the rest of us out and post a TLDR?

In the time that it took you to ask several people for the TL;DR, you could've watched the video. I guess I summarize things different than others, but at the 32:00 minute mark, he talks about what he was actually scared about: NASA is essentially, a business (my addition) -- that does not know how to communicate. The left hand very much does not know what the right hand is doing. He brings up a fantastic example of…

> He brings up a fantastic example of how many rockets are required for a particular phase of a mission and showed how multiple people gave different answers without even realizing their launch date is set in stone.

Careful here - multiple Starship refueling launches shown in the video (I've counted 24 tanker launches) are not set in stone and might be not that important for the mission itself, it's just an example of a valid question with added concern that we've yet to have this uncertainty resolved. It may look like an Exhibit A of mismanagement, but could be a very different thing.

I think the most important think he's saying is that NASA is not enough focused on the success of moving forward.

Re: I was scared To say this to NASA (But I said it anyway) – Smarter Every Day

#46

Post by avmich » Sun, Dec 03, 2023, 11:06 PM UTC

marcusverus wrote: post #21

haunter wrote: post #10

Earlier quoted context omitted.

Q: 'How many Starship launches are needed to execute the Artemis III lunar landing?' NASA: 'We don't know but at least 15' Video: 'Oh well that's a huge problem to have a complex project like this and we don't even have an exact answer'

Isn’t this disingenuous? As far as I can tell, Starship can make it to the lunar surface with a significant payload without refueling. The refueling launches are only required if you want to maximize the payload per lunar trip.

BOTE calculations, approximate numbers:

    - delta-V for LEO-to-the-Moon flight - 3100 m/s
    - delta-V to get to low Moon orbit (a-la Apollo) - 1000 m/s
    - delta-V to land on the Moon from low orbit - 1700 m/s
    - extra delta-V during landing like with Apollo LEM for
      emergencies - 700 m/s
    - delta-V to get back to the Moon orbit - 1700 m/s
    - extra delta-V during lift-off like with Apollo - 500 m/s

Total - 3100 + 1000 + 1700 + 700 + 1700 + 500 = 8700 m/s, that's a pretty large delta-V, almost like an Earth SSTO.

Raptor Isp - 3500 m/s, fueled mass - 1320 tons, empty mass - 120 tons, mass ratio - 1320 / 120 = 11. Tsiolkovsky formula:

    exp(8700 / 3500) = m_fueled / m_empty = 12

that is, we need Starship HLS to be somewhat lighter to get to the Moon surface and back to low Moon orbit from LEO than the current numbers for Starship, and that is without any payload.

It's definitely not the final numbers, so the results will change, but

> Starship can make it to the lunar surface with a significant payload without refueling

is questionable at the moment.

If you mean cargo flights with no return to the Moon orbit - rather than crewed flights as agreed with NASA today for Starship HLS - then of course the numbers are better.

Re: I was scared To say this to NASA (But I said it anyway) – Smarter Every Day

#47

Post by avmich » Sun, Dec 03, 2023, 11:10 PM UTC

edmundsauto wrote: post #38

MR4D wrote: post #36

Earlier quoted context omitted.

> Because if we do it the same way we did 50+ years ago, we learn absolutely nothing and the whole thing is a pointless waste of money. I would argue that if we did it exactly as we did back then that we would actually learn something because we forgot how to do so much. Literally can’t build an F-1 engine. It would take a ton of work just to recreate it. However, the benefit is that we would then have plans (diagram…

I agree - there would be tremendous value in taking the 1960s approach, keeping it simple, and optimizing with modern electronics. What they seem to be doing is a code rewrite while adding features.

Revival of Saturn-V today would likely be very expensive comparing to Starship variants.

Re: I was scared To say this to NASA (But I said it anyway) – Smarter Every Day

#48

Post by imtringued » Mon, Dec 04, 2023, 12:01 AM UTC

carlosdp wrote: post #23

dmillar wrote: post #14

My TLDW: He's (not so) indirectly critical of Space X's Starship program and tribal groupthink. He may be "scared" of NASA because he's calling out one of their giant Artemis contracts. Some longer takeaways: - Simplify. We went to the moon 50+ years ago, but we are reinventing the wheel in some significant ways in Artemis. Why? We are supposedly going to the moon in two years, but we have never attempted a cryogenic…

Idk how you took away that he was criticizing the Starship program at all. SpaceX pivots designs on a swivel, conducts tons of incremental tests, and ends up succeeding at the claimed impossible time and time again. If anything, NASA should be taking a cue from them. He’s being directly critical of Artemis and Orion/SLS, which is not at all built that way, was basically architected by politics, and will probably not…

The Starship program is the big unknown in the whole mission. The SLS is boring and expensive and underperforming but it somewhat works. They should have given it more power to avoid the NRO, which appears to be a source of complexity due to the underperformance of the SLS. It makes things harder than it needs to be, but it isn't a death knell.

He clearly argued against flashy technology demonstrations like orbital refueling, which if you have paid attention, doesn't apply to the SLS but Starship. Orbital refueling adds an insane amount of uncertainty to the entire mission due to the boiling off of cryogenic fuels. He clearly pointed out that despite the plan of sending six Starships to LEO, nobody actually knows how many rocket flights are necessary. Fancy technology has been put on a pedestal, while the actual mission is being neglected. This is a common theme I have seen on HN and Reddit. SpaceX enthusiasts think the moon mission is some irrelevant symbolic political boondoggle to keep NASA facilities open. They all want to go on the promised 100 people trip to mars.

>will probably not end up actually going to the moon unless there’s a major change.

I don't know if you have paid attention lately, but currently Starship is significantly behind schedule. I'm not sure what to call this interpretation except "biased". Maybe this will refresh your memory: The Starship "Propellant Transfer Test" was supposed to happen in 2022 Q4.

EDIT: https://www.reddit.com/r/SpaceXLounge/comments/qujnsi/propos...

Re: I was scared To say this to NASA (But I said it anyway) – Smarter Every Day

#49

Post by imtringued » Mon, Dec 04, 2023, 12:18 AM UTC

avmich wrote: post #39

Good video, many good points. "Focus on the mission" What's the mission? We're "returning to the Moon" - what does it mean? Boots on the regolith? I somehow doubt that. USA did that half a century ago, we're supposed to go farther. What's the mission this time? We're going to the Moon for a more serious, longer exploration this time, right? That's the mission, right? So, we want more people at the same time on the Mo…

Why not just build a smaller Starship to go to the moon? It would probably negate the need for any orbital refueling. The reason of course is that Elon Musk wants NASA to fund his rocket to mars, not to the moon. I.e. technology demonstration is more important than the mission itself. This is how you get neither.

Re: I was scared To say this to NASA (But I said it anyway) – Smarter Every Day

#50

Post by credit_guy » Mon, Dec 04, 2023, 1:02 AM UTC

nabla9 wrote: post #11

ziffusion wrote: post #7

Earlier quoted context omitted.

Hey - you put in the time. Can you please help the rest of us out and post a TLDR?

TL;DR: - Apollo simple, Apollo success. - Artemis very complex, many unknowns. - Stated reasons for doing things are clearly not the real reasons. - Providing honest negative feedback seems to be the the key to success. - Artemis engineers might fear talking honestly. --- Personal comment: The timeline was fubar from the beginning. Remember when VP Mike Pence made a surprise announcement that NASA goes to the Moon 20…

I wonder if he mentioned the reason for Apollo: a muscle-flexing exercise to show the Soviet Union (and the rest of the world) who the boss is. Once the point was made, there was no need for further Moon or outer space exploration, and predictably the program ended.

We don't have that rationale now. Various presidents come with different ideas for space exploration, but the fundamental need is just not there, and without that, the budget and the focus is not there.

The only way for us to get back to the Moon is if we can do it on the cheap. So cheap that it doesn't cost a lot of political capital to do it. And for for that SpaceX seems like the best bet. Maybe not in 2 years, but at some point.