Repairability and depreciation are the main problems. A earth data center can be repaired, depreciated, and recycled at EoL recovering some of the costs. SpaceX datacenters are a total write off from the moment they are launched.

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vlovich123 an hour ago | parent | next [-]

The Microsoft design of filling an airtight submersible structure with argon and dropping it to the bottom of the ocean floor is the alternative design - you’re not looking to do repairs but amortize the low cost of failures across the value you extract.

The biggest issue with space is not repairability but heat - when you’re in a vacuum the only way to disperse heat is through black body radiation and that’s horribly slow compared with normal mechanisms. It means you need giant physical structures whose sole job is to accept heat from the processing core and radiate it away and have so much more material that you can radiate it at the speed you generate. It’s a huge unsolved physics problem which is why everyone is skeptical.

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nkrisc 28 minutes ago | parent | next [-]

It’s not an unsolved physics problem. Every satellite in space has to deal with it and even the ISS deals with it by having massive radiator arrays that face perpendicular to the sun.

The problem with data centers in space is one of materials science and engineering: how to make radiators large enough and effective enough to cool it while also being economically feasible, both in terms of construction and getting them up there in the first place.

We can make a space data center right now. It would just be terrible and expensive.

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bakies 29 minutes ago | parent | prev [-]

It's so, so cheap to buy tap water and dump it on the heat exchange.

	▲	munk-a 23 minutes ago \| parent [-]
		With well considered engineering it doesn't even need to be tap water. If you have a closed loop thermal conductor that interacts with the components themselves you can then use really trashy contaminated water that just needs to be clean enough not to actively erode the heat transfer mechanism. We have setups like this all the time that use condensed air via cooling towers or salt water immersed heat sinks to discharge energy - it's more expensive than tap water but it isn't technically complex. So if it ever becomes unpalatable (likely due to politics) to use tap water there are some readily available alternatives. The big win of being in space is just a worse alternative to using an intermediary heat transfer medium.

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jacobgold an hour ago | parent | prev | next [-]

That's actually not a concern I'd have, because hardware that has been sufficiently tested and burned in tends not to fail for a very long time.

I've done builds that ran for 5+ years with virtually no physical attention, just continual degradation as hardware is taken out of service. There's also not much money to recover from 5+ year-old hardware.

I used to run AI inference GPU servers in road vehicles, which is probably an even harsher environment than a single rocket launch, and the vibration problems are real but solvable.

	▲	nijave 18 minutes ago \| parent \| next [-]
		GPUs depreciate super fast. It might last 5-7 years but it's already outdated at 2-3 Also space has more radiation
	▲	asadotzler 12 minutes ago \| parent \| prev \| next [-]
		5 years is a Starlink's typical lifetime. Data center satellite lifetimes will probably be shorter. Demise sooner, replace more often. GPUs get more energy efficient every year and leaving the slower, hungrier chips up there much longer than 3 years seems wasteful given the cheap cost of launch. I think this could be done at an interesting scale even on Falcon 9 alone. If Starship does even 20% of its early design goals, it'll beat Falcon 9 and we could see orbital servers being demised and replaced every 3 years, maybe even 2, for ones with abnormally high failure rates. Now, whether or not this will all make money in the end has a lot to do with what's going on down here on terra firma and how long it takes to get useful capacity into orbit. (It's taken 7 years to get Starlink capacity enough for serving 10M customers. Verizon FiOS did 10M in 5 years. AT&T Fiber took 4-5 years to deploy to 10M. So, space isn't a lot slower than terrestrial.)
	▲	bakies 21 minutes ago \| parent \| prev [-]
		uhh no I dont think the road vehicle is harsher than a rocket launch

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tqi 38 minutes ago | parent | prev [-]

Isn't the problem also that because of radiation, processors in space either need to have larger feature sizes OR additional shielding / redundancy? Seems like a pretty high price to pay for slightly cheaper energy...

	▲	nijave 16 minutes ago \| parent [-]
		Ars had an article that cited some HPE testing on the international space station that said regular hardware is _probably_ fine up to about 5 years Definitely not definitive but it's plausible current hardware could survive with minimal modification