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

How NASA built Artemis II’s fault-tolerant computer

cacm.acm.org

Post reply on HN
Print view View original

161–170 of 257 posts

Re: How NASA built Artemis II’s fault-tolerant computer

#161

Post by randomNumber7 »

arduanika wrote: post #20
dmk wrote: post #3

The quote from the CMU guy about modern Agile and DevOps approaches challenging architectural discipline is a nice way of saying most of us have completely forgotten how to build deterministic systems. Time-triggered Ethernet with strict frame scheduling feels like it's from a parallel universe compared to how we ship software now.

You could even say that part of the value of Artemis is that we're remembering how to do some very hard things, including the software side. This is something that you can't fake. In a world where one of the more plausible threats of AI is the atrophy of real human skills -- the goose that lays the golden eggs that trains the models -- this is a software feat where I'd claim you couldn't rely on vibe code, at least n…

Don’t count your chickens before they hatch.

Re: How NASA built Artemis II’s fault-tolerant computer

#162

Post by randomNumber7 »

nickff wrote: post #57
dyauspitr wrote: post #54

Earlier quoted context omitted.

Agile is not meant to make solid, robust products. It’s so you can make product fragments/iterations quickly, with okay quality and out to the customer asap to maximize profits.

“Agile” doesn’t mean that you release the first iteration, it’s just a methodology that emphasizes short iteration loops. You can definitely develop reliable real-time systems with Agile.

I think people mean so many different things when talking about agile. I'm pretty sure a small team of experts is a good fit for critical systems.

A fixed amount of meetings every day/week/month to appease management and rushing to pile features into buggy software will do more harm than good.

Re: How NASA built Artemis II’s fault-tolerant computer

#163

Post by dgb23 »

weli wrote: post #130
therobots927 wrote: post #74

Earlier quoted context omitted.

Contrary to propaganda from the likes of Ludwig von Mises, the free market is not some kind of optimal solution to all of our problems. And it certainly does not produce excellent software.

Mises never claimed that the free market produced the most optimal solutions at a given moment. In fact Mises explicitly stated many times that the free market does indeed incur in semi-frequent self-corrections, speculations and manipulations by the agents. What Mises proposition was - in essence - is that an autonomous market with enough agents participating in it will reach an optimal Nash equilibrium where both o…

Many intellectuals have this problem. They make interesting, precise statements under specific assumptions, but they get interpreted in all kinds of directions.

When they push back against certain narratives and extrapolations they usually don’t succeed, because the same mechanism applies here as well.

The only thing they can do about it, is throwing around ashtrays.

Re: How NASA built Artemis II’s fault-tolerant computer

#164

Post by randomNumber7 »

therobots927 wrote: post #76
ramraj07 wrote: post #6

Earlier quoted context omitted.

I take the opposite message from that line - out of touch teams working on something so over budget and so overdue, and so bureaucratic, and with such an insanely poor history of success, and they talk as if they have cured cancer. This is the equivalent of Altavista touting how amazing their custom server racks are when Google just starts up on a rack of naked motherboards and eats their lunch and then the world. Le…

Modern software development is a fucking joke. I’m sorry if that offends you. Somehow despite Moore’s law, the industry has figured out how to actually regress on quality.

We have a lot more software developers than 50 years ago and intelligence is still normally distributed.

Re: How NASA built Artemis II’s fault-tolerant computer

#165

Post by dom111 »

I always wondered if the "radiation hardening" approaches of the challenges like this https://codegolf.stackexchange.com/questions/57257/radiation... (see the tag for more https://codegolf.stackexchange.com/questions/tagged/radiatio...) would be of any practical use... I assume not, as the problem is on too many levels, but still, seems at least tangentially relevant!

Re: How NASA built Artemis II’s fault-tolerant computer

#166

Post by randomNumber7 »

ToucanLoucan wrote: post #41
ramraj07 wrote: post #31

Earlier quoted context omitted.

[flagged]

Wild shit to be advising other people to be humble whilst talking directly out of your ass about technology you clearly do not understand and engineers you have no respect for. Perhaps self-reflect.

How do you know that op doesn't know what he is talking about?

I have written code for real time distributed systems in industrial applications. It runs since years 24/7 and there never was a failure in production.

I also think nasa is full of shit.

Re: How NASA built Artemis II’s fault-tolerant computer

#167

Post by randomNumber7 »

georgehm wrote: post #58

>Effectively, eight CPUs run the flight software in parallel. The engineering philosophy hinges on a >“fail-silent” design. The self-checking pairs ensure that if a CPU performs an erroneous calculation >due to a radiation event, the error is detected immediately and the system responds. >“A faulty computer will fail silent, rather than transmit the ‘wrong answer,’” Uitenbroek explained. >This approach simplifies the…

For errors due to radiation the probability is extremely low, since it would need to flip the same bit at the same time in two different places.

Re: How NASA built Artemis II’s fault-tolerant computer

#168

Post by xorcist »

spwa4 wrote: post #144
nairboon wrote: post #125

Earlier quoted context omitted.

Propaganda is quite a strong term to describe the works of an economist. If one wants to debate the ideas of von Mises, it'd be useful to consider the Zeitgeist at that time. Von Mises preferred free markets in contrast to the planned economy of the communists. Partly because the latter has difficulties in proper resource allocation and pricing. Note that this was decades before we had working digital computers and d…

You should read up on Yanis Varoufakis' history and just how bad his solution for Greece went. That will explain the extreme amounts of anger on both his side, the side of Greeks and the side of the EU and worldwide financial community (and the EU itself used to be an industry cartel, so you can guess how much every government institution in the EU aligns with the worldwide financial community). This guy will never b…

> He caused a MAJOR issue for Greece

That link goes to the Greece financial crisis which, according to the Wikipedia page, started in 2009. Varoufakis was elected minister of finance in early 2015 and resigned only half a year later. From the outside, it seems impossible that his half year miniterial tenure could have caused a crisis half a decade earlier. At the time, Greece had already defaulted twice on their loans and were about to do it a third time.

Re: How NASA built Artemis II’s fault-tolerant computer

#169

Post by marmarama »

weli wrote: post #130
therobots927 wrote: post #74

Earlier quoted context omitted.

Contrary to propaganda from the likes of Ludwig von Mises, the free market is not some kind of optimal solution to all of our problems. And it certainly does not produce excellent software.

Mises never claimed that the free market produced the most optimal solutions at a given moment. In fact Mises explicitly stated many times that the free market does indeed incur in semi-frequent self-corrections, speculations and manipulations by the agents. What Mises proposition was - in essence - is that an autonomous market with enough agents participating in it will reach an optimal Nash equilibrium where both o…

The problem with this is that "breaking the Nash equilibrium momentarily" is a spherical cow.

"Momentarily" can mean years or even decades, and millions of people can suffer or die as a result.

Post reply on HN