| ▲ | hirsin 12 hours ago |
| Simply put no, 50MW is not the typical hyperscaler cloud size. It's not even the typical single datacenter size. A single AI rack consumes 60kW, and there is apparently a single DC that alone consumes 650MW. When Microsoft puts in a DC, the machines are done in units of a "stamp", ie a couple racks together. These aren't scaled by dollar or sqft, but by the MW. And on top of that... That's a bunch of satellites not even trying to crunch data at top speed. No where near the right order of magnitude. |
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| ▲ | mike_hearn 4 hours ago | parent | next [-] |
| But the focus on building giant monolithic datacenters comes from the practicalities of ground based construction. There are huge overheads involved with obtaining permits, grid connections, leveling land, pouring concrete foundations, building roads and increasingly often now, building a power plant on site. So it makes sense to amortize these overheads by building massive facilities, which is why they get so big. That doesn't mean you need a gigawatt of power before achieving anything useful. For training, maybe, but not for inference which scales horizontally. With satellites you need an orbital slot and launch time, and I honestly don't know how hard it is to get those, but space is pretty big and the only reasons for denying them would be safety. Once those are obtained done you can make satellite inferencing cubes in a factory and just keep launching them on a cadence. I also strongly suspect, given some background reading, that radiator tech is very far from optimized. Most stuff we put into space so far just doesn't have big cooling needs, so there wasn't a market for advanced space radiator tech. If now there is, there's probably a lot of low hanging fruit (droplet radiators maybe). |
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| ▲ | leoedin 2 hours ago | parent | next [-] | | But why would you? Space has some huge downsides: * Everything is being irradiated all the time. Things need to be radiation hardened or shielded. * Putting even 1kg into space takes vast amounts of energy. A Falcon 9 burns 260 MJ of fuel per kg into LEO. I imagine the embodied energy in the disposable rocket and liquid oxygen make the total number 2-3x that at least. * Cooling is a nightmare. The side of the satellite in the sun is very hot, while the side facing space is incredibly cold. No fans or heat sinks - all the heat has to be conducted from the electronics and radiated into space. * Orbit keeping requires continuous effort. You need some sort of hypergolic rocket, which has the nasty effect of coating all your stuff in horrible corrosive chemicals * You can't fix anything. Even a tiny failure means writing off the entire system. * Everything has to be able to operate in a vacuum. No electrolytic capacitors for you! So I guess the question is - why bother? The only benefit I can think of is very short "days" and "nights" - so you don't need as much solar or as big a battery to power the thing. But that benefit is surely outweighed by the fact you have to blast it all into space? Why not just overbuild the solar and batteries on earth? | | |
| ▲ | Findeton 2 hours ago | parent | next [-] | | Maybe they should try to build it in the moon. Difficult, but perhaps not as difficult? | | |
| ▲ | nkrisc an hour ago | parent | next [-] | | Sounds more difficult. Not only is the moon further, you also need to use more fuel to land on it and you also have fine, abrasive dust to deal with. There’s no wind of course, but surely material will be stirred up and resettle based on all the landing activity. And it’s still a vacuum with many of the same cooling issues. I suppose one upside is you could use the moon itself as a heat sink (maybe). | |
| ▲ | thephyber 2 hours ago | parent | prev | next [-] | | Almost none of the parent’s bullet points are solved by building on the Moon instead of in Earth orbit. The energy demands of getting to the 240k mile Moon are IMMENSE compared to 100 mile orbit. Ultimately, when comparing the 3 general locations, Earth is still BY FAR the most hospitable and affordable location until some manufacturing innovations drop costs by orders of magnitude. But those manufacturing improvements have to be made in the same jurisdiction that SpaceXAI is trying to avoid building data centers in. This whole things screams a solution in search of a problem. We have to solve the traditional data center issues (power supply, temperature, hazard resilience, etc) wherever the data centers are, whether on the ground or in space. None of these are solved for the theoretical space data centers, but they are all already solved for terrestrial data centers. | | | |
| ▲ | sdenton4 40 minutes ago | parent | prev | next [-] | | The 2.5s round trip communication latency isn't going to be great for chat. (Alongside all the other reasons.) | |
| ▲ | ahoka an hour ago | parent | prev | next [-] | | It has all these problems, plus more. | |
| ▲ | kakacik an hour ago | parent | prev [-] | | Yeah, carrying stuff 380k km and still deploying in vacuum (and super dusty ground) doesn't solve anything but adds cost and overhead. One day maybe, but not these next decades nor probably this century. |
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| ▲ | wombatpm an hour ago | parent | prev [-] | | It would make more sense to develop power beaming technology. Use the knowledge from Starlink constellations to beam solar power via microwaves onto the rooftops of data centers | | |
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| ▲ | cogman10 3 hours ago | parent | prev | next [-] | | > I also strongly suspect, given some background reading, that radiator tech is very far from optimized. Most stuff we put into space so far just doesn't have big cooling needs, so there wasn't a market for advanced space radiator tech. If now there is, there's probably a lot of low hanging fruit (droplet radiators maybe). You'd be wrong. There's a huge incentive to optimized radiator tech because of things like the international space station and MIR. It's a huge part of the deployment due to life having pretty narrow thermal bands. The added cost to deploy that tech also incentivizes hyper optimization. Making bigger structures doesn't make that problem easier. Fun fact, heat pipes were invented by NASA in the 60s to help address this very problem. | | |
| ▲ | zero_bias 3 hours ago | parent | next [-] | | ISS and MIR combined are not a "large market". How many radiators they require? Probably a single space dc will demand a whole orders of magnitude more cooling | |
| ▲ | mike_hearn 3 hours ago | parent | prev [-] | | The ISS is a government project that's heading towards EOL, it has no incentive to heavily optimize anything because the people who built it don't get rich by doing so. SpaceX is what optimization looks like, not the ISS. | | |
| ▲ | jeltz 2 hours ago | parent [-] | | By the same token SpaceX has no reason to optimize Starship. That is also largely a government project. | | |
| ▲ | b112 an hour ago | parent [-] | | It's a private company, is profit motivated, and thus has reason to optimize. That was the parent poster's point. Starship isn't largely a government project. It was planned a decade before the government was ever involved, they came along later and said "Hey, this even more incredible launch platform you're building? Maybe we can hire SpaceX to launch some things with it?" Realistically, SpaceX launches far more payload than any government. | | |
| ▲ | habinero 40 minutes ago | parent [-] | | Haha no. SpaceX survives entirely on money from the US government. It's always been that way. |
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| ▲ | thephyber an hour ago | parent | prev [-] | | There is a lot of hand waiving away of the orders of magnitude more manufacturing, more launches, and more satellites that have to navigate around each other. We still don’t have any plan I’ve heard of for avoiding a cascade of space debris when satellites collide and turn into lots of fast moving shrapnel. Yes, space is big, but low Earth orbit is a very tiny subset of all space. The amount of propulsion satellites have before they become unable to maneuver is relatively small and the more satellite traffic there is, the faster each satellite will exhaust their propulsion gasses. | | |
| ▲ | turtlesdown11 31 minutes ago | parent [-] | | >There is a lot of hand waiving away of the orders of magnitude more manufacturing, more launches, and more satellites that have to navigate around each other. This is exactly like the Boring Company plans to "speed up" boring. Lots of hand waving away decades of commercial boring, sure that their "great minds" can do 10x or 100x better than modern commercial applications. Elon probably said "they could just run the machines faster! I'm brilliant". |
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| ▲ | pera 4 hours ago | parent | prev | next [-] |
| New GPU dense racks are going up to 300kW, but I believe the normal at moment for hyperscalers is somewhere around ~150kW, can someone confirm? The energy demand of these DCs is monstrous, I seriously can't imagine something similar being deployed in orbit... |
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| ▲ | synctext an hour ago | parent [-] | | Could this be about bypassing government regulation and taxation? Silkroad only needed a tiny server, not 150kW. The Outer Space Treaty (1967) has a loophole. If you launch from international waters (planned by SpaceX) and the equipment is not owned by a US-company or other legal entity there is significant legal ambiguity. This is Dogecoin with AI. Exploiting this accountability gap and creating a Grok AI plus free-speech platform in space sounds like a typical Elon endeavour. | | |
| ▲ | 9dev 32 minutes ago | parent | next [-] | | Untrue. Responsible for any spacefaring vessel is in all cases the state the entity operating the vessel is registered in. If it's not SpaceX directly but a shell company in Ecuador carrying out the launch, Ecuador will be completely responsible for anything happening with and around the vessel, period. There are no loopholes in this system. | |
| ▲ | habinero an hour ago | parent | prev | next [-] | | No. There is no "one weird trick" when it comes to regulation. The company is based in the US, therefore you just go after that. Anyway, promising some fantasy and never delivering is definitely a typical Elon endeavor. | |
| ▲ | jacquesm 43 minutes ago | parent | prev [-] | | You misspelled 'hate speech'. |
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| ▲ | tensor 9 hours ago | parent | prev | next [-] |
| How much of that power is radiated as the radio waves it sends? |
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| ▲ | hirsin 7 hours ago | parent | next [-] | | Good point - the comms satellites are not even "keeping" some of the energy, while a DC would. I _am_ now curious about the connection between bandwidth and wattage, but I'm willing to bet that less than 1% of the total energy dissipation on one of these DC satellites would be in the form of satellite-to-earth broadcast (keeping in mind that s2s broadcast would presumably be something of a wash). | |
| ▲ | nosianu 2 hours ago | parent | prev | next [-] | | The radio receiver and transmitter are additional hardware and energy consumption. They add to the heat, not subtract from it. | | |
| ▲ | jeltz an hour ago | parent [-] | | I think you missed the point. If you have a 100 MW communicstion satellite and a 100 MW compute satellite those are very different beasts. The first might send 50% of the energy away as radio communication making it effectively a 50 MW satellitefor cooling purposes. | | |
| ▲ | habinero 34 minutes ago | parent [-] | | No, they didn't. You can't "send away" thermal energy via radio waves. At the temperatures we're talking about, thermal energy is in the infrared. That's blackbody radiation. |
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| ▲ | mlyle 6 hours ago | parent | prev | next [-] | | I doubt half the power is to the transmitter, and radio efficiency is poor -- 20% might be a good starting point. | | |
| ▲ | synctext 5 hours ago | parent | next [-] | | Is the SpaceX thin-foil cooling based on graphene real? Can experts check this out? "SmartIR’s graphene-based radiator launches on SpaceX Falcon 9" [1]. This could be the magic behind this bet on heat radiation through exotic material. Lot of blog posts say impossible, expensive, stock pump, etc. Could this be the underlying technology breakthrough? Along with avoiding complex self-assembly in space through decentralization (1 million AI constellation, laser-grid comms). [1] https://www.graphene-info.com/smartir-s-graphene-based-radia... | | |
| ▲ | ajnin 3 hours ago | parent [-] | | This coating looks like it can selectively make parts of the satellite radiators or insulators, as to regulate temperature. But I don't think it can change the fundamental physics of radiating unwanted heat and that you can't do better than black body radiation. | | |
| ▲ | synctext 2 hours ago | parent [-] | | Indeed, graphene seems capable of .99 of black body radiation limit. Quote: "emissivity higher than 0.99 over a wide range of wavelengths". Article title "Perfect blackbody radiation from a graphene nanostructure" [1]. So several rolls of 10 x 50 meters graphene-coated aluminium foil could have significant cooling capability. No science-fiction needed anymore (see the 4km x 4km NVIDIA fantasy) [1] https://opg.optica.org/oe/fulltext.cfm?uri=oe-21-25-30964 | | |
| ▲ | habinero 27 minutes ago | parent [-] | | It's not as exciting as you think it is. "emissivity higher than 0.99 over a wide range of wavelengths" is basically code for "it's, like, super black" The limiting factor isn't the emissivity, it's that you're having to rely on radiation as your only cooling mechanism. It's super slow and inefficient and it limits how much heat you can dissipate. Like the other person said, you can't do any better than blackbody radiation (emissivity=1). |
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| ▲ | PunchyHamster 5 hours ago | parent | prev [-] | | Entirely depends on band, at 10GHz more like 40%, at lower frequencies more, for example FM band can even go to 70% |
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| ▲ | adgjlsfhk1 8 hours ago | parent | prev [-] | | the majority is likely in radio waves and the inter satellite laser communication | | |
| ▲ | hdgvhicv 6 hours ago | parent [-] | | Inter sat comms cancels out - every kw sent by one sat is received by another. | | |
| ▲ | mlyle 6 hours ago | parent [-] | | It doesn't, because the beams are not so tight that they all fall on the target satellite, and not all of that is absorbed :P |
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| ▲ | lloeki 4 hours ago | parent | prev [-] |
| For another reference, the Nvidia-OpenAI deal is reportedly 10GW worth of DC. |