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Data centers in space makes no sense

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Re: Data centers in space makes no sense

#801

Post by jdhwosnhw »

gpt5 wrote: post #235
lancewiggs wrote: post #177

Earlier quoted context omitted.

It's exiting the 5th best social network and the 10th (or worse) best AI company and selling them to a decent company. It probably increases Elon's share of the combined entity. It delivers on a promise to investors that he will make money for them, even as the underlying businesses are lousy.

I'm confused about the level of conversation here. Can we actually run the math on heat dissipation and feasibility? A Starlink satellite uses about 5K Watts of solar power. It needs to dissipate around that amount (+ the sun power on it) just to operate. There are around 10K starlink satellites already in orbit, which means that the Starlink constellation is already effectively equivalent to a 50 Mega-watt (in a rou…

> A Starlink satellite uses about 5K Watts of solar power. It needs to dissipate around that amount (+ the sun power on it) just to operate.

The “+ solar power” part is the majority of the energy. Solar panel efficiency is only about 25-30% at beginning-of-life whereas typical albedos are effectively 100%. So your estimate is off by at least a factor of three.

Also, I’m not sure where you got 5 kw from. The area of the satellite is ~100 m2, which means they are intercepting over 100 kw of bolometric solar power.

Re: Data centers in space makes no sense

#803

Post by gadders »

This blog post has some sliders you can tweak to see if you can make the numbers make sense: https://andrewmccalip.com/space-datacenters

"So here's what I did. I built a simple model that reduces the debate to one parameter: cost per watt of usable power for compute. The infographic below lets you change the assumptions directly. If you disagree with the inputs, great. Move the sliders. But at least we'll be arguing over numbers that map to reality.

The model is deliberately boring. No secret sauce. Just publicly available numbers and first-principles physics: solar flux, cell efficiency, radiator performance, launch cost, hardware mass, and a terrestrial benchmark that represents the real alternative: a tilt-wall datacenter sitting on top of cheap power. "

"Here's the headline result: it's not obviously stupid, and it's not a sure thing. It's actually more reasonable than my intuition thought! If you run the numbers honestly, the physics doesn't immediately kill it, but the economics are savage. It only gets within striking distance under aggressive assumptions, and the list of organizations positioned to even try that is basically one."

Re: Data centers in space makes no sense

#804

Post by DaedalusII »

rswail wrote: post #685
DaedalusII wrote: post #267

Earlier quoted context omitted.

it could be easier just to build in orbit. its a lot closer, sites can be positioned above various geographic locations as required. i think the moon likely does contain vast mineral deposits though. when europeans first started exploring australia they found mineral anomalies that havent existed in europe since the bronze age. the Pilbara mining region is very cool. it contains something like 25% of the iron ore on…

And Fortescue and others are working on BEV vehicles for those giant Tonka trucks that move the raw ore to the processing areas at the top of the opencut. They were also working on a "zero energy" train that would run "downhill" from the mines to the ports to charge its batteries that would then take the empty train back to the mine. Battery tech wasn't sufficient (yet), but that doesn't mean it can't come back when…

have to take this stuff with a grain of salt. a lot of australian mining companies do this so their stock qualifies as ESG and pension funds can buy it.

turns out pit mining is good for the environment after all

https://www.fortescue.com/en/real-zero/green-metals

Re: Data centers in space makes no sense

#805

Post by garettmd »

prompt: what's the term for financial moves where you keep finding new investors to pay off the previous ones

GPT-4o mini: The term for financial moves where new investors are continually recruited to pay off previous ones is often referred to as a "Ponzi scheme." Another similar term is "pyramid scheme," where returns are paid to earlier investors from the contributions of newer investors, but with a structure that typically requires participants to recruit others to earn returns. Both schemes are unsustainable and illegal.

Re: Data centers in space makes no sense

#806

Post by bunderbunder »

kibwen wrote: post #705
weregiraffe wrote: post #664

Earlier quoted context omitted.

>Specifically: Starship makes no economic sense. Starship can replace Falcon 9 and probably be cheaper, if fully reusable, so more profitable. So at least some economic sense is there already.

No, that's not how any of this works. Try to think for a moment why we still overwhelmingly use non-jumbo jets for aviation in a world where jumbo jets exist.

Not to mention that making the upper stage and payload fairing much bigger and heavier juat so you can recover them is not an automatic win. You can recover it, but you’ve also made it much more expensive in the first place. And the booster needs to be bigger, heavier and more expensive, too.

It’s not an automatic deal breaker, of course. Falcon 9 is obviously a promising success. But Starship is also working with some new challenges that Falcon 9 didn’t have to worry about.

Many of these stem from design compromises that were forced by Starship’s secondary goal of being capable of a trip to Mars. In that respect, it very much resembles another major project to produce a heavy launch vehicle with a reusable combination payload fairing and upper stage that is also capable of carrying a human crew: the Space Shuttle.

Re: Data centers in space makes no sense

#807

Post by abalone »

PurpleRamen wrote: post #593
abalone wrote: post #566

Earlier quoted context omitted.

> It makes far more sense to build data centers in the arctic. What (literally) on earth makes you say this? The arctic has excellent cooling and extremely poor sun exposure. Where would the energy come from? A satellite in sun-synchronous orbit would have approximately 3-5X more energy generation than a terrestrial solar panel in the arctic. Additionally anything terrestrial needs maintenance for e.g. clearing dust…

> A satellite in sun-synchronous orbit would have approximately 3-5X more energy generation than a terrestrial solar panel in the arctic. Building 3-5x more solar plants in the Arctic, would still be cheaper than travelling to space. And that's ignoring that there are other, more efficient plants possible. Even just building a long powerline around the globe to fetch it from warmer regions would be cheaper.

> Even just building a long powerline around the globe to fetch it from warmer regions would be cheaper.

Deserts have good sun exposure and land availability but extremely poor water resources, which is necessary for washing the sand off the panels. There are many challenges with scaling both terrestrial and orbital solar.

Re: Data centers in space makes no sense

#808

Post by shagie »

turtlesdown11 wrote: post #797
shagie wrote: post #393

Earlier quoted context omitted.

He is very influenced by The Culture of Iain Banks. They're really good sci-fi... and describe a hedonistic world where machines do the hard thinking and bidding of the biologicals. https://recommentions.com/elon-musk/books/culture-by-iain-ba... https://www.vox.com/culture/413502/iain-banks-culture-series... https://fortune.com/2025/12/15/billionaire-elon-musk-say-tha... > Musk pointed to The Culture series by Iain M…

If Musk was in the Culture universe, he'd be Veppers

https://x.com/elonmusk/status/1008121639337320454

> [I recommend] all of them, especially Surface Detail

Re: Data centers in space makes no sense

#809

Post by benl »

audunw wrote: post #505
benl wrote: post #379

Data centers in space may or may not make sense (personally I'm quite skeptical) but the objections in the article certainly don't make sense. 1. The only reason there are 15,000 satellites in space is because SpaceX launched about 9,500 of them (Starlink is 65% of all satellites) on their semi-reusable Falcon 9. If fully-reusable Starship pans out, they will be launching satellites at 10x the rate of Falcon 9 at the…

3. The falling costs won’t benefit space as much. The cost of sending mass to space will still be a big factor in the space solar panel costs. Much of the reason why solar is getting cheaper is not the panels themselves, but due to innovations that reduce installation costs. Those don’t apply to space (outside of the already assumed reductions in sending mass to space to make this viable)

Yes, launch cost is the crux of the matter. My skepticism is based on whether they’ll be able to get launch cost low enough and launch cadence high enough. SpaceX has shown the ability to get launch costs dramatically lower and cadence dramatically higher, but it’s not a slam dunk that those curves will continue to the levels needed for this idea to work.

Re: Data centers in space makes no sense

#810

Post by clysm »

mike_hearn wrote: post #582
elamje wrote: post #353

I was talking to someone about this the other day. I was part of a team at NASA that developed a cooling system for the ISS and this whole premise makes no sense to me. 1. Getting things to space is incredibly expensive 2. Ingress/egress are almost always a major bottleneck - how is bandwidth cheaper in space? 3. Chips must be “Rad-hard” - that is do more error correcting from ionizing radiation - there were entire t…

It sounds hard but it shouldn't not make sense. 1. Solving cost of launching mass has been the entire premise of SpaceX since day one and they have the track record. 2. Ingress/egress aren't at all bottlenecks for inferencing. The bytes you get before you max out a context window are trivial, especially after compression. If you're thinking about latency, chat latencies are already quite high and there's going to be…

3. There are WAY more things to get corrupted on a computer system than tokens. And non-determinism does NOT mean it’s tolerant to faults. Random values are intentionally introduced at the right moment for LLMs.
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