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How NASA built Artemis II’s fault-tolerant computer

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

#151
When I was first starting out as a professional developer 25 years ago doing web development, I had a friend who had retired from NASA and had worked on Apollo.

I asked him “how did you deal with bugs”? He chuckled and said “we didn’t have them”.

The average modern AI-prompting, React-using web developer could not fathom making software that killed people if it failed. We’ve normalized things not working well.

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

#152
post #9

How big of a challenge are hardware faults and radiation for orbital data centers? It seems like you’d eat a lot of capacity if you need 4x redundancy for everything

Orbital datacenters is a hypothetical infinite money glitch that could exist between the times:

- after general solution to extra-terrestrial manufacturing bootstrap problem is found, and, - before the economy patches the exploit that a scalable commodity with near-zero cost and non-zero values can exist.

It'll also destroy commercial launch market, because anything of size you want can be made in space, leaving only tiny settler transports and government sovreign launches to be viable, so not sure why commercial space people find it to be a commercially lucrative thing? The time frame within this IMG can exist can also be zero or negative.

The assumption is also like, they'll find a way to rent out some rocks for cash, so anyone with access to rocks will be doing as it becomes viable, and so, I'm not even sure if "space" part of space datacenters even matter. Earth is kinda space too in this context.

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

#153

When I was first starting out as a professional developer 25 years ago doing web development, I had a friend who had retired from NASA and had worked on Apollo. I asked him “how did you deal with bugs”? He chuckled and said “we didn’t have them”. The average modern AI-prompting, React-using web developer could not fathom making software that killed people if it failed. We’ve normalized things not working well.

there's a different level of 'good-enough' in each industry and that's normal. When your highest damage of a bad site is reduced revenue (or even just missed free user), you have lower motivation to do it right compared to a living human coming back in one piece.

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

#155
post #144

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 still affects everyone in his country today, after reassuring people for 2+ years it was never going to happen:

care to explain what exactly he caused and how that still affects everyone in his country? in particular how he managed to jump several years backward in the timeline?

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

#156
post #130

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…

An "autonomous market with enough agents" is carrying a lot of weight there, like "rational actors" and "as sample size goes to infinity'.

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

#157
post #136

Some people are claiming it's the good old RAD750 variant. Is there anything that talks about the actual computer architecture? The linked article is desperately void of technical details.

It's a new (2002) variant of the same RAD750 architecture.

  CPUs:  IBM PowerPC 750FX (Single-core,  900 MHz, 32-bit, radiation hardened) 
  RAM:  256 MB (per processor)
  OS: VxWorks (Real-time OS)
  Network: TTEthernet (Time-Triggered Ethernet) at 1 Gbps
  programming: MISRA C++, flight control laws from Simulink adn MATLAB.

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

#158
post #130

Earlier quoted context omitted.

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…

> optimal Nash equilibrium where both offer and demand are balanced This roughly translates to "optimal utopian society which cannot be criticised in any way" right? Right??

It depends on by what metric you define what is optimal.

For the health system or public transport the nash equilibrium of offer and demand is not what feels optimal to most people.

For manufacturing s.th. like screws, nails or hammers; I really can't see what should be wrong with it.

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

#159

When I was first starting out as a professional developer 25 years ago doing web development, I had a friend who had retired from NASA and had worked on Apollo. I asked him “how did you deal with bugs”? He chuckled and said “we didn’t have them”. The average modern AI-prompting, React-using web developer could not fathom making software that killed people if it failed. We’ve normalized things not working well.

there's a different level of 'good-enough' in each industry and that's normal. When your highest damage of a bad site is reduced revenue (or even just missed free user), you have lower motivation to do it right compared to a living human coming back in one piece.

Yes, of course, but a culture of “good enough” can go too far. One may work in a lower-risk context, but we can still learn a lot from robust architectural thinking. Edge cases, security, and more.

Low quality for a shopping cart feels fine until someone steals all the credit card numbers.

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

#160

[flagged]

> Dissimilar redundancy eliminates that risk. A completely different OS, different codebase, different development team.

Not entirely true. I've heard during my uni years of a case were two independent teams used the same textbook for implementing a feature, which had an error, and thus resulting in the same failure mode.

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