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How NASA built Artemis II’s fault-tolerant computer

cacm.acm.org

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

#21

Post by BitsAndObjects »

jbritton wrote: post #12

I wonder how often problems happen that the redundancy solves. Is radiation actually flipping bits and at what frequency. Can a sun flare cause all the computers to go haywire.

Not a direct answer but probably as good information as you can get: https://static.googleusercontent.com/media/research.google.c...

Basically, yes, radiation does cause bit flips, more often than you might expect (but still a rare event in the grand scheme of things, but enough to matter).

And radiation in space is much “worse” (in quotes because that word is glossing over a huge number of different problems, both just intensity).

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

#22

Post by bluegatty »

geerlingguy wrote: post #19
arduanika wrote: post #18

Earlier quoted context omitted.

Please, this is hacker news. Nothing else is hard outside of our generic software jobs, and we could totally solve any other industry in an afternoon.

I mean I can just replace Dropbox with a shell script.

That's funny because you could! Dropbox started a shell script :)

Funny though I would assume HN people would respect how hard real-time stuff and 'hardened' stuff is.

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

#23

Post by 1970-01-01 »

danhon wrote: post #7
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…

You mean like this? "With limited funds, Google founders Larry Page and Sergey Brin initially deployed this system of inexpensive, interconnected PCs to process many thousands of search requests per second from Google users. This hardware system reflected the Google search algorithm itself, which is based on tolerating multiple computer failures and optimizing around them. This production server was one of about thir…

Google then had complete regret not doing this with ECC RAM: https://news.ycombinator.com/item?id=14206811

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

#24

Post by voodoo_child »

y1n0 wrote: post #16

NASA didn't build this, Lockheed Martin and their subcontractors did. Articles and headlines like this make people think that NASA does a lot more than they actually do. This is like a CEO claiming credit for everything a company does.

Nice “well, actually”. I’m sure Lockheed were building this quad-redundant, radiation-hardened PowerPC that costs millions of dollars and communicates via Time-Triggered Ethernet anyway, whether NASA needed one or not.

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

#25

Post by kersplody »

totetsu wrote: post #10
object-a wrote: 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

They dont go into here.. but I thought that NASA also used like 250nm chips in space for radiation resistance. Are there even any radiation resistance GPUs out there?

NOPE, RAD hardened space parts basically froze on mid 2000s tech: https://www.baesystems.com/en-us/product/radiation-hardened-...

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

#26

Post by ramraj07 »

1970-01-01 wrote: post #23
danhon wrote: post #7

Earlier quoted context omitted.

You mean like this? "With limited funds, Google founders Larry Page and Sergey Brin initially deployed this system of inexpensive, interconnected PCs to process many thousands of search requests per second from Google users. This hardware system reflected the Google search algorithm itself, which is based on tolerating multiple computer failures and optimizing around them. This production server was one of about thir…

Google then had complete regret not doing this with ECC RAM: https://news.ycombinator.com/item?id=14206811

It got them to where they need to be to then worry about ECC. This is like the dudes who deploy their blog on kubernetes just in case it hits front page of new york times or something.

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

#28

Post by bfung »

ramraj07 wrote: post #6
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.

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…

One simply does not [“provision” more hardware|(reboot systems)|(redeploy software)] in space.

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

#29

Post by ramraj07 »

danhon wrote: post #7
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…

You mean like this? "With limited funds, Google founders Larry Page and Sergey Brin initially deployed this system of inexpensive, interconnected PCs to process many thousands of search requests per second from Google users. This hardware system reflected the Google search algorithm itself, which is based on tolerating multiple computer failures and optimizing around them. This production server was one of about thir…

The problem they solved isn't easy. But its not some insane technical breakthrough either. Literally add redundancy, thats the ask. They didnt invent quantum computing to solve the issue did they? Why dunk on sprints?

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

#30

Post by ramraj07 »

bluegatty wrote: post #14
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…

No, space is just hard. Everything is bespoke. You need 10x cost to get every extra '9' in reliability and manned flight needs a lot of nines. People died on the Apollo missions. It just costs that much.

Yep, spend 100 billion on what should have cost 1/50that cost, and send people up to the moon with rockets that we are still keeping our fingers crossed wont kill them tomorrow, and we have to congratulate them for dunking on some irrelevant career?
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