Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The Lunacy of Artemis

idlewords.com

Post reply on HN
Print view View original

391–400 of 539 posts

Re: The Lunacy of Artemis

#391

Post by xondono »

throwawayffffas wrote: post #213

> Conversely, if SpaceX and Blue Origin can’t make cryogenic refueling work, then NASA has no plan B for landing on the moon. If SpaceX and Blue Origin can't. Then Nasa will find someone who can. Cryogenic refueling is the projects real engineering target. Landing on the moon in the twenty twenties just isn't that impressive anymore. The Artemis program is nominally about going to the moon, but it really isn't. It's…

> The Artemis program is nominally about going to the moon, but it really isn't. It's about building and living in habitats beyond low orbit, in orbit refueling, building habitats on the surface of another planetary body, and obviously in the future in situ resource extraction and surface refueling.

Side-goals, fake goals and scope creep are one of the biggest red flags for “projects to avoid”.

Re: The Lunacy of Artemis

#392

Post by Zigurd »

Dalewyn wrote: post #172
fastball wrote: post #154

Earlier quoted context omitted.

My problem with his criticism (and to some extent echoed by Maciej in this article) is that the main takeaway seems to be "we did it once, we can do it again, let's revisit the past instead of re-inventing the wheel". But I don't think anyone actively involved wants to revisit the past. Who wants to go back to the moon just because we can? Nobody. Assuming best intentions: - People at NASA want to go to the moon to b…

>SpaceX doesn't really care about the moon. SpaceX is a business, SpaceX doesn't care about the Moon because there are no customers interested in going to the Moon. If market forces shift and companies start wanting to go to the Moon, you bet SpaceX will care about the Moon because there's money to be made.

SpaceX makes sense as a business in the way a mega-yacht makes sense as a ship. The valuation was set by a vanity investment by the Saudi sovereign wealth fund. 2.7 million subscribers can't keep 4500 satellites in orbit and replaced every 5 years. It is a prestige investment.

Re: The Lunacy of Artemis

#393

Post by chasd00 »

exe34 wrote: post #373
imglorp wrote: post #371

Earlier quoted context omitted.

Yeah, a 9 meter diameter one, which adds mass and volume and complexity and detracts from the payload. Instead what they do is use thrust to accelerate the whole vehicle a little, which presses all the liquid into one end of its tank where it can be pumped out. Instead of carrying special settling thrusters, they originally planned to use ullage gas for this but it's not clear that can work. deeper discussion with ma…

plastic balloon?

pretty much everything, including and especially plastic, becomes a fuel when it comes into contact with liquid oxygen. With liquid oxygen in contact with a fuel you're virtually guaranteed a fire at some point as it takes very little heat to start the combustion. This is why when rockets tip over it's an explosion and not just a broken airframe with fuel/oxidizer leaking out.

Re: The Lunacy of Artemis

#394

Post by xondono »

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…

> the Artemis program was setup at a time when the private space companies were still very new.

This is completely orthogonal. If it weren’t, the lander would be in a better shape, but it’s as much of a clusterfuck as the rest of the mission.

SpaceX has never been outside of LEO, and I’m very unconvinced Starship can do it’s part on Artemis, much less do all the mission by themselves.

Re: The Lunacy of Artemis

#395

Post by anarticle »

imiric wrote: post #176
bayindirh wrote: post #158

Earlier quoted context omitted.

From my understanding, nobody is telling that "We should use Apollo as-is", but "why don't we use the same spirit when we were building these back then?". Everything made/designed in Apollo are no short of marvels. Today we can do much better with lighter, smaller electronics, and should be able to do weight savings or at least cost savings where it matters. Instead Artemis feels like "let's dig the parts pile and pu…

> From my understanding, nobody is telling that "We should use Apollo as-is", but "why don't we use the same spirit when we were building these back then?". The political climate in the 1960s was far more tense than it is today, which fueled the space race in ways that forced both sides to give their absolute best efforts to move space exploration forward. While arguably today there are comparable tensions, countries…

Only difference is when the container is OOMKilled people die!

Re: The Lunacy of Artemis

#396

Post by playingonline »

idlewords wrote: post #255
davedx wrote: post #220

Earlier quoted context omitted.

What do you think is useful for NASA to do? Do you think any form of spaceflight is useful ?

I'm a big fan of space exploration and would love to see a robotic exploration program on the scale of our current human space flight endeavors, sending rovers and landers all over the solar system, along with a major space telescope every 3 years or so (instead of once a decade). I feel like we're squandering an amazing chance to explore space by getting stuck on sending people instead of leveraging the enormous pro…

If we did want to become a spacefaring, world-hopping, intergalactic, etc., species in the long term, we wouldn't be sending humans into space right now, because robots are easier to keep alive and do more science with. That was the overall point I got from this and why not mars, which seems true for now.

But, even though putting humans on the rockets makes them cost more, it also garners more funding. I don't know, maybe we could convince all American schoolchildren to aspire to be robot programmers rather than astronauts. But typing this out, it seems like:

a) you could ask congress to fund robotic exploration, which maybe citizens care about and support, but if they don't then...

b) you could instead set up a giant human space program that wastes tens of billions of dollars to do nothing, then quietly siphon off a few billion here or there for JPL or SpaceX to do valuable unmanned research.

Maybe the former is possible, and you're fighting the good fight, but most voters don't read long blog posts comparing manned vs unmanned space exploration, and really when it comes to space are only excited by people standing on the moon. I do hope you convince more people, but fortunately whatever monstrosity we have now is at least a nice jobs program.

Re: The Lunacy of Artemis

#397

Post by playingonline »

pfdietz wrote: post #386
usrbinbash wrote: post #322

Earlier quoted context omitted.

> So, if it were to be as cheap to go into space as to go to St. Louis Obviously there is a breakpoint at which the cost differential would no longer matter, I agree. It's just as obvious however, that this breakpoint won't be reached in the near future, or even the forseeable future. It would require a radically new propulsion technology, which, and this is the sad truth, we don't have. The way we launch rockets tod…

Why is it obvious? Starship, if it succeeds, could reduce launch costs per mass by two orders of magnitude over Falcon 9. For the cost of one SLS launch, Starship, if it meets its cost targets, could launch the mass of a nuclear supercarrier into low earth orbit. The cost to LEO would become similar to the cost of transport to the South Pole. You will notice we are not using robots at the South Pole.

It could be that for the sort of work we want to do on the south pole a human in a jacket outperforms our current robots, but for the sort of work we want to do on the moon a robot, or our future robot, will outperform a human in a spacesuit.

Re: The Lunacy of Artemis

#398

Post by bryanlarsen »

Zigurd wrote: post #392
Dalewyn wrote: post #172

Earlier quoted context omitted.

>SpaceX doesn't really care about the moon. SpaceX is a business, SpaceX doesn't care about the Moon because there are no customers interested in going to the Moon. If market forces shift and companies start wanting to go to the Moon, you bet SpaceX will care about the Moon because there's money to be made.

SpaceX makes sense as a business in the way a mega-yacht makes sense as a ship. The valuation was set by a vanity investment by the Saudi sovereign wealth fund. 2.7 million subscribers can't keep 4500 satellites in orbit and replaced every 5 years. It is a prestige investment.

SpaceX is cash flow positive despite spending multiple billions each year on Starship and Starlink. The only way this is possible is if Starlink is profitable, and significantly so.

Re: The Lunacy of Artemis

#399

Post by twh270 »

GMoromisato wrote: post #348
cratermoon wrote: post #330

Earlier quoted context omitted.

Counterpoint: all of those incidents, except Apollo 1 are proof that the engineering was great, because nobody died. For example, you mention the computer on the Apollo 11 lunar module crashing. In fact, it was recovering and working properly. The astronauts had left the rendezvous radar on during descent, in case it was needed for abort. That was not a nominal configuration, and the radar kept stealing cycles and ca…

Maybe. But it's hard to tell whether nobody died because the system was robust vs. nobody died because we got lucky. For example, there were several cases of burn-through on the O-rings before Challenger. The engineers thought there was enough margin to not worry about it, so they didn't Similarly, when Columbia was hit by foam-ice on ascent no one worried because it had happened before and nobody had died.

Correction -- at least for Challenger, engineers did not think there was margin, and argued against the launch.

At the technical level, both tragedies were caused by design flaws. Organizationally and culturally, multiple factors contributed, but an attitude of "nothing has happened yet, so this is fine" (normalizing risk) was a major one.

Post reply on HN