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Help me understand why not? I know solar power generation in space, and "beaming" the power back, was a naive idea. But this would actually use the power up the
by charlieflowers 5mo ago
Help me understand why not? I know solar power generation in space, and "beaming" the power back, was a naive idea. But this would actually use the power up there, mostly for training, but also for inference.
That claim seems reasonable. I have zero knowledge of the economics of launching and maintaining satellites though.
- PufPufPuf 5mo agoAs I understand it, the problem is cooling. There isn't any medium to take away the heat, so the only option is to slowly radiate it away.
- Sammi 5mo agoAnyone who has googled just once to ask if datacenters in space make any sense, has found out they don't because they can't get rid of heat. That leaves only two kinds of people left who are still talking excitedly about datacenters in space: The uninformed and the grifters.
- redox99 5mo agoThe area you need in radiators is only half the area you need in solar panels. So it's definitely not a deal breaker. Its still very dumb because of economics, logistics, serviceability and more.
- dzhiurgis 5mo agoScott Manley, I’d say one of the top pop space youtubers say otherwise. If anything it’s easier in space. On earth most complexity in datacenter is cooling. In space you just radiate it away. And SpaceX already proven they can launch sort of datacenters 10k times by launching Starlink (up to 20KW of solar each IIRC). FWIW Musk should support Bernie Sanders more. Putting moratoriums on datacenters would make space based ones far more economical.
- mcmcmc 5mo ago“YouTuber” is an extremely poor qualification for a supposedly trusted source
- kibibu 5mo agoLet's hear what Big Money Salvia has to say about all this
- boredatoms 5mo agoHe's a physicist though, not just a mic jockey
- vel0city 5mo agoHe just mentions and walks through idea of having some amount of compute up there and what the heat rejection calculations roughly look like. He doesn't actually explore the economics of doing such a thing or discuss if it's actually worth doing. It's not that you can't put a server in space, but the costs to do it almost assuredly don't make any sense. Because, if you can do it in space you can do it easier on the ground and save yourself millions in launch cost and extra complexity. Your cooling challenges are way cheaper and simpler in an atmosphere. There's nothing much being in space really gets you, other than it makes it harder for a government to take your computers away. Not impossible, just harder.
- scottyah 5mo agoEspecially with everyone clamoring to have datacenters built in their backyards. There's absolutely no way there can be an advantage to figuring out compute outside Earth's magnetosphere, especially since none of the engineers as SpaceX would ever think of any long-term benefits of that.
- dgfl 5mo agoThe existence of starlink proves that this is false. Look at most current pitches, they don’t talk about GW-class monsters anymore. There’s absolutely nothing stopping a 20-30kW satellite bus the size of starlink (or I guess up to 100kW? once starship is available - it’s all about payload fairing diameter) from hosting ~1 rack of compute and antennas. The economics may or may not make sense, we’ll have to see. There’s very little research work needed to make this happen; it’s all about engineering some satellite buses and having them fly in close formation to get a “data center”. And this group of satellites in sun-synchronous orbit would relay to a comms constellation e.g. starlink itself) and operate as a global scale data center. The heat management and orbital mechanics are all straight forward really.
- dmlittle 5mo agoIt's worth noting that GPUs have a much higher failure rate than traditional CPUs. Over 10x the failure rate due thermal stress. The amount of heat generated is very different. You can't really replace a GPU in a satellite (at least today?) which would place most of these satellites as space debris in a ~5 year horizon.
- lijok 5mo agoWhich is the same lifetime as a starlink sat
- gambiting 5mo agoSo what exactly is the benefit of having that thing in orbit then, where it costs you millions of dollars to put it there?
- Footnote7341 5mo agoThe current bottleneck on compute is power and zoning. Solar panels are 5x more efficient in space, and there is no zoning in space.
- small_model 5mo agoSpaceX have presented on this and it's fairly straightforward and they already do it with starlink satellites, just at a larger scale. Sound like you are the uniformed one (or an EDS victim)
- ceejayoz 5mo agoStarlink satellites don't generate the sort of heat a datacenter full of GPUs does. The ISS has enormous radiators, and it's only in space because it's a space station. Putting datacenters there is just goofy given the amount of available space on the ground.
- lijok 5mo agoWhy are you comparing the output of a datacenter to the output of a single sat? How much power do starlink sats draw and how does it compare to say 8x H200s?
- ceejayoz 5mo ago> This gives us access to more than 300 megawatts of new capacity (over 220,000 NVIDIA GPUs) within the month. 27,500 satellites need launching - fast! - just for Claude to meet a demand spike?
- lijok 5mo agoThere are over 10k starlink sats in orbit already. They’re obtaining approval for another ~30k. So clearly not a problem for them.
- ericd 5mo agoAll of that has been repeatedly addressed in anything that discusses it, if you care to try to understand. It has ~nothing to do with available space, the US grid can’t handle the current rate of expansion. It’s bad enough that apparently Span, the smart electrical panel company, is pitching a box full of Blackwells that’ll sit outside new construction homes and use all the headroom on residential 200A circuits. Space is starting to look reasonable. Related, US readers should call their reps and ask them to support a successor to EPRA, the Energy Permitting Reform Act, the vast majority of the generation that’s waiting for approval is from clean energy sources. It nearly got over the line before the last Congress ended, and it’s one of the most impactful things we can do to combat climate change, combined with electrifying various carbon intensive activities.
- lijok 5mo agowhat do you mean they can’t get rid of heat? radiators exist
- ceejayoz 5mo agohttps://en.wikipedia.org/wiki/External_Active_Thermal_Control_System https://en.wikipedia.org/wiki/External_Active_Thermal_Contro... All that gets you 70kW of cooling. Radiating to vacuum isn't very efficient.
- scottyah 5mo agoDang, sucks we can never improve any technology. Let's just call it quits, guys.
- ceejayoz 5mo agoTechnology is wonderful. Physics still gets a say.
- cyclopeanutopia 5mo agoMaybe one day we can, but it's definitely not in a category "there is no doubt".
- scottyah 5mo agoOf course not, where's the fun in that category?
- lijok 5mo agoAnd that’s sufficient for roughly 100 unoptimized DC grade H200s. Not efficient, and it doesn’t have to be, because the cooling system has 0 opex cost. And capex clearly can be made to wor
- ceejayoz 5mo agoOK, so you've got a football-sized solar and radiator array to support 100 H200s. Why are we not building it on land again in some abandoned mall's parking lot?
- Gagarin1917 5mo agoWhich is apparently manageable. Scott Manley isn’t an industry veteran, but he does know a lot about space engineering and science. Here’s his breakdown of the feasibility, and heat management is not really a major issue: https://youtu.be/DCto6UkBJoI https://youtu.be/DCto6UkBJoI
- throwaway85825 5mo agoHeat management is not a technical issue but a reliability issue.
- londons_explore 5mo agoThese satellites will be in orbits where they are always illuminated. That means constant temperatures, which means no thermal cycling and no reliability concerns. When people say 'running it hot is bad for reliability', they mean 'running it hot and then brining it back to room temp from time to time will eventually kill it'.
- throwaway85825 5mo agoIt's in space which requires liquid cooling. No rocket is big enough so it has to be assembled on orbit. No liquid cooling terrestrial system is 100% leak free.
- super256 5mo agoIn space you get bit flips fairly quickly when using very small transistors. You would have to run stuff on fairly old hardware, which probably makes the whole thing economically inefficient for serious "computation in space".
- runako 5mo agoCost. The economics don't work unless Starship is doing flights in quantity, and it has met or exceeded its cost targets. Roughly, a single rack plus solar to power it in the $15m+ range just to launch. (This assumes power dissipation is handled via some means that does not require launch to orbit. Also does not include batteries.) Choose your own hardware for the rack, but call it < $5m. SpaceX earning $15m every time someone launches a $5m rack would be a great business for SpaceX. Use your own calculator/LLM, but mine is suggesting that the ~$7B Colossus 1 data center in TFA would be around $50B if launched on Falcon 9 (still ignoring cooling and batteries). (There are obviously a lot of other asterisks. I'm ignoring power storage and heat dissipation. Maintenance probably doesn't matter given 75% of cost is in the launch. Network bandwidth could be a problem considering how DCs are used. Competition - if Company A spends $100B for $25B of actual AI infra, how competitive will they be against Company B who gets $100B for their $100B by spending it in Canada or Mexico, which they can do right now? Etc.) None of this works without Starship, which has not set a date for its first LEO insertion test yet. Yet the whole point of orbital DCs is nothing on the ground can move fast enough, hence the rush to orbit...which can't really move at all right now. No, it doesn't make any sense.