21 ms·

I would not assume cooling has been worked out. Space is a vacuum. i.e. The lack-of-a-thing that makes a thermos great at keeping your drink hot. A satellite

• jcgrillo 9mo ago
  A glaring lack of oceans to boil
• atleastoptimal 9mo ago
  Its very simple, xAI needs money to win the AI race, so best option is to attach to Elon’s moneybank (spacex) to get cash without dilution
  • ben_w 9mo ago
    That may be the plan, but this is also a great way for GDPR's maximum fine, based on global revenue, to bite on SpaceX's much higher revenue. And without any real room for argument.
    • deleted 9mo ago
      [deleted]
  • iknowstuff 9mo ago
    Remember how he argued for Tesla’s Solarcity acquisition because solar roofs? Data centers in space are the same kind of justification imo.
    • MobiusHorizons 9mo ago
      Solar roofs are much more practical to be honest.
      • darig 9mo ago
        [dead]
      • undersuit 9mo ago
        Putting solar roofs on a building? For a car company?
        • MobiusHorizons 9mo ago
          In comparison to datacenters in space yes. Solar roofs are already a profitable business, just not likely to be high growth. Datacenters in space are unlikely to ever make financial sense, and even if they did, they are very unlikely to show high growth due to continuing ongoing high capital expenses inherent in the model.
          • ben_w 9mo ago
            I think a better critique of space-based data centres is not that they never become high growth, it's just that when they do it implies the economy is radically different from the one we live in to the degree that all our current ideas about wealth and nations and ownership and morality and crime & punishment seem quaint and out-dated. The "put 500 to 1000 TW/year of AI satellites into deep space" for example, that's as far ahead of the entire planet Earth today as the entire planet Earth today is from specifically just Europe right after the fall of Rome. Multiplicatively, not additively. There's no reason to expect any current business (or nation, or any given asset) to survive that kind of transition intact.
  • Findecanor 9mo ago
    > win the AI race I keep seeing that term, but if it does not mean "AI arms race" or "AI surveillance race", what does it mean? Those are the only explanations that I have found, and neither is any race that I would like to see anyone win.
    • strange_quark 9mo ago
      It’s a framing device to justify the money, the idea being the first company (to what?) will own the market.
    • totetsu 9mo ago
      It’s a graft to keep people distracted and allow for positioning as we fall off the end of the fossil energy boom.
    • ekidd 9mo ago
      A significant number of AI companies and investors are hoping to build a machine god. This is batshit insane, but I suppose it might be possible. Which wouldn't make it any more sane. But when they say, "Win the AI race," they mean, "Build the machine god first." Make of this what you will.
      • FeteCommuniste 9mo ago
        On the edge of my seat waiting to see what hits us first, a massive economic collapse when the hype runs out, or the Torment Nexus.
        • reverius42 9mo ago
          It really seems like the market has locked in on one of those two things being a guaranteed outcome at this point.
    • bigstrat2003 9mo ago
      Big tech businesses are convinced that there must be some profitable business model for AI, and are undeterred by the fact that none has yet been found. They want to be the first to get there, raking in that sweet sweet money (even though there's no evidence yet that there is money to be made here). It's industry-wide FOMO, nothing more.
  • georgemcbay 9mo ago
    > xAI needs money to win the AI race Off on a tangent here but I'd love for anyone to seriously explain how they believe the "AI race" is economically winnable in any meaningful way. Like what is the believed inflection point that changes us from the current situation (where all of the state-of-the-art models are roughly equal if you squint, and the open models are only like one release cycle behind) to one where someone achieves a clear advantage that won't be reproduced by everyone else in the "race" virtually immediately.
    • CamperBob2 9mo ago
      They ultimately want to own everyone's business processes, is my guess. You can only jack up the subscription prices on coding models and chatbots by so much, as everyone has already noted... but if OpenAI runs your "smart" CRM and ERP flows, they can really tighten the screws.
      • adventured 9mo ago
        If you have the greatest coding agent under your thumb, eventually you orient it toward eating everything else instead of letting everybody else use your agent to build software & make money. Go forward ten years, it's highly likely GPT, Gemini, maybe Claude - they'll have consumed a very large amount of the software ecosystem. Why should MS Office exist at all as a separate piece of software? The various pieces of Office will be trivial for the GPT (etc) of ten years out to fully recreate & maintain internally for OpenAI. There's no scenario where they don't do what the platforms always do: eat the ecosystem, anything they can. If a platform can consume a thing that touches it, it will. Office? Dead. Box? Dead. DropBox? Dead. And so on. They'll move on anything that touches users (from productivity software to storage). You're not going to pay $20-$30 for GPT and then pay for DropBox too, OpenAI will just do an Amazon Prime maneuver and stack more onto what you get to try to kill everyone else. Google of course has a huge lead on this move already with their various prominent apps.
        • notahacker 9mo ago
          Dropbox is actually a great example of why this isn't likely to happen. Deeper pocketed competition with tons of cloud storage and the ability to build easy upload workflows (including directly into software with massive install base) exists, and showed an active interest in competing with them. Still doing OK Office's moat is much bigger (and its competition already free). "New vibe coded features every week" isn't an obvious reason for Office users to switch away from the platform their financial models and all their clients rely on to a new upstart software suite
  • danw1979 9mo ago
    I’m not certain spacex is generating much cash right now ? Starship development is consuming billions. F9 & Starlink are probably profitable ? I’d say this is more shifting of the future burden of xAI to one of his companies he knows will be a hit stonk when it goes public, where enthusiasm is unlikely to be dampened by another massive cash drain on the books.
• xupybd 9mo ago
  I think he has rocket company that needs more work. Sufficient hype funds more work for his rocket company. The more work they have the faster they can develop the systems to get to Mars. His pet project. I really think it's that simple.
  • croddin 9mo ago
    Starlink and Falcon 9 have been an excellent pairing, Falcon 9 partially reusable rockets created a lot launch capacity and starlink filled the demand. Starship if it meets its goals will create more launch fully reusable supply by orders of magnitude, but there is not the demand for all that launch capacity. Starlink can take some of it but probably not all so they need to find a customer to fill it in order to build up enough to have the volume to eventually colonize mars.
    • ezst 9mo ago
      > colonize mars Oh, that crap again.
    • belter 9mo ago
      Nobody colonizing Mars. Get real. The most likely outcome, is him landing on a cell when the full Epstein files come out.
      • deepfriedchokes 9mo ago
        The most likely outcome is that no one will be punished for anything in the Epstein files.
    • bunderbunder 9mo ago
      Going to Mars is not a serious goal. We can tell because it’s not being treated as a serious goal. 100% of the focus is on the big vroom vroom part that’s really exciting to kids who get particularly excited by things that go vroom, and approximately 0% of the focus is on developing all the less glamorous but equally essential components of a successful Mars mission, like making sure the crew stays healthy.
• idontwantthis 9mo ago
  One man able to put a data center worth of mass in orbit is one man able to crash a datacenter worth of mass into Earth anywhere he wants.
  • recursive 9mo ago
    Not a given. Re enter the atmosphere. Sure. Avoid vaporization? Much harder problem.
    • debatem1 9mo ago
      There is some evidence to suggest that spacex knows how to reenter an object without burning it up.
      • duskwuff 9mo ago
        Sometimes without even meaning to: https://www.cbc.ca/news/canada/saskatoon/spacex-cbc-debris-space-junk-sask-1.7231571 https://www.cbc.ca/news/canada/saskatoon/spacex-cbc-debris-s...
      • TheOtherHobbes 9mo ago
        The engineering overlap between between a small object designed for reentry and a flying (crashing...) warehouse is not a circle. Once upon a time there was a bonkers "rods from god" mass bomb idea, but that didn't work either.
    • reppap 9mo ago
      I think it's actually the other way around, satellites need to be specifically designed to burn up fast in the atmosphere. See for example the warnings about space debris from Chinese satellites not designed with this in mind.
    • idontwantthis 9mo ago
      100 tons of steel will not vaporize before it hits the ground
• aunty_helen 9mo ago
  The equation has a ^4 to the temperature. If you raise the temperature of your radiator by ~50 degrees you double its emission capacity. This is well within the range of specialised phase change compressors, aka fancy air conditioning pumps. Next up in the equation is surface emissivity which we’ve got a lot of experience in the automotive sector. And finally surface area, once again, getting quite good here with nanotechnology. Yes he’s distracting, no it’s not as impossible as many people think.
  • sfink 9mo ago
    > And finally surface area, once again, getting quite good here with nanotechnology. So your hot thing is radiating directly onto the next hot thing over, the one that also needs to cool down?
    • PinkiesBrain 9mo ago
      The inner side of the radiator would be metallized, an anti black body. Together with a bit of vacuum it would thermally be quite far from the PV&GPU. Thermal insulation is easy in space.
      • sfink 9mo ago
        You still can't get more surface area than a sphere without crumpling things up. And given the thermal insulation, you can only lose heat via radiation. Radiating heat from a crumpled boundary means radiating it towards another part of the boundary. If there's an "inner side", then it's a sphere (or some other convex shape, all of which have at most the surface area of a sphere). I don't think you'd want any vacuum at all between the radiator and the heat sources! Thermal insulation is the problem, not the solution. You want the radiator as thermally close to the heat sources as possible, probably via some highly heat conductive metal. Though the optimal approach might be to ditch the vacuum and use a more terrestrial configuration with circulating air or water or mercury to conduct the heat away. Space is a horrible place to do this in all ways except for... well, space. You do have plenty of room up there. (Well, and power. Lots of solar energy to play with. Which in turn causes its own problems with heat and radiation.)
• bagels 9mo ago
  You can reject the heat by shedding hot mass, but only once.
  • denkmoon 9mo ago
    Cooling by mass effect style yeeting hot chunks of metal out the back. Where will they go, nobody knows!
    • strange_quark 9mo ago
      When the radiation burns out a GPU, just dump as much heat into it as possible and yeet it into the atmosphere. Ez.
      • reverius42 9mo ago
        Goodness gracious, great balls of fire! (are raining down on my house)
        • ikekkdcjkfke 9mo ago
          Preferibly directly onto indian electronics salvagers
    • 3eb7988a1663 9mo ago
      Depending on where they land, you can double the service you offer. AI computations coupled with rods from God.
• eek2121 9mo ago
  Not going to read the article, because Data centers in space = DOA is common sense to me, however, did the article really claim cooling wasn't an issue? Do they not understand the laws of thermodynamics, physics, etc? Sure, space is cold. Good luck cooling your gear with a vacuum. Don't even get me started on radiation, or even lack of gravity when it comes to trying to run high powered compute in space. If you think you are just going to plop a 1-4U server up there designed for use on earth, you are going to have some very interesting problems pop up. Anything not hardened for space is going to have a very high error/failure rate, and that includes anything socketed...
  • tzs 9mo ago
    > Not going to read the article, because Data centers in space = DOA is common sense to me, however, did the article really claim cooling wasn't an issue? No. Nearly everyone that talks about data centers in space talks about cooling. The point of this article was to talk about other problems that would remain even if the most commonly talked about problems were solved. It says: > But even if we stipulate that radiation, cooling, latency, and launch costs are all solved, other fundamental issues still make orbital data centers, at least as SpaceX understands them, a complete fantasy. and then talks about some of those other issues.
• stouset 9mo ago
  [flagged]
  • scottyah 9mo ago
    There are several companies working on this, and the first generation tech is already proven, working in space on the ISS. Even Paul G is on board. https://x.com/paulg/status/2009686627506065779?s=20 https://x.com/paulg/status/2009686627506065779?s=20
    • CamperBob2 9mo ago
      https://xcancel.com/paulg/status/2009704615508586811#m https://xcancel.com/paulg/status/2009704615508586811#m for those who don't partake. I liked one comment someone made: if it's just about dodging regulation, then put the data centers on container ships. At any given time, there are thousands of them sailing in international waters, and I'm sure their operators would love to gain that business. That being said, space would be a good place to move heat around with Peltier elements. A lot of the criticisms revolve around the substantial amount of coolant plumbing that will be needed, but that may not necessarily be what SpaceX has in mind.
    • wat10000 9mo ago
      Of course it's working. We've had computers operating in space for decades. There's no doubt it can be done. The question isn't whether it's possible, the question is why you'd do it just for data centers. We put computers in space because they're needed to do things that can only be done from there. Data centers work just fine on the ground. What's so great about data centers in space that makes them worth the immense cost and difficulty. I know a lot of prominent people are talking about this. I do not understand it. pg says "when you look at the tradeoffs" well what exactly is he looking at? Because when I look at the tradeoffs, the whole concept makes no damned sense. Sure, you can put a bunch of GPUs in space. But why would you do that when you can put them in a building for orders of magnitude less money?
      • scottyah 9mo ago
• lofaszvanitt 9mo ago
  It will be the communications, not the compute part.
• TacticalCoder 9mo ago
  Not disagreeing with you at all: that physics fact always come up. My honest question is: if it's a perfect thermos, what does, for example, the ISS do with the heat generated by computers and humans burning calories? The ISS is equipped with a mechanism to radiate excess heat into space? Or is the ISS slowly heating up but it's not a problem?
  • vidarh 9mo ago
    The ISS has giant heat sinks[1]. Those heat sinks are necessary for just the modest heat generated on the ISS, and should give an idea of what a sattelite full of GPU's might require... [1] https://en.wikipedia.org/wiki/External_Active_Thermal_Control_System https://en.wikipedia.org/wiki/External_Active_Thermal_Contro...
  • cluckindan 9mo ago
    Let me google that for you. https://en.wikipedia.org/wiki/External_Active_Thermal_Control_System https://en.wikipedia.org/wiki/External_Active_Thermal_Contro...
  • jamiek88 9mo ago
    The ISS has MASSIVE radiators. Most of its volume is radiator. 900 cubic meters of space 2500 square meters of radiator.
    • deleted 9mo ago
      [deleted]
  • stouset 9mo ago
    The TL;DR is they radiate it into space via large, high surface area arms that stick out of the station.
  • breput 9mo ago
    Massive radiators. In this photo[0], all of the light gray panels are thermal radiators. Note how they are nearly as large as the solar panels, which gives you an idea about the scale needed to radiate away 3-12 people's worth of heat (~1200 watts) + the heat generated by equipment. [0] https://images-assets.nasa.gov/image/jsc2021e064215_alt/jsc2021e064215_alt~large.jpg?w=1920&h=1173 https://images-assets.nasa.gov/image/jsc2021e064215_alt/jsc2...
• lancewiggs 9mo ago
  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.
  • ojbyrne 9mo ago
    Plus government backstop. The federal government (especially the current one) is not going to let SpaceX fail.
    • mullingitover 9mo ago
      Maybe not, but they might force it to sell at fire sale prices to another aerospace company that doesn't have the baggage.
  • gpt5 9mo ago
    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 rough, back of the envelope feasibility way). Isn't 50MW already by itself equivalent to the energy consumption of a typical hyperscaler cloud? Why is starlink possible and other computations are not? Starlink is also already financially viable. Wouldn't it also become significantly cheaper as we improve our orbital launch vehicles?
    • space_fountain 9mo ago
      It's like this. Everything about operating a datacenter in space is more difficult than it is to operate one on earth. 1. The capital costs are higher, you have to expend tons of energy to put it into orbit 2. The maintenance costs are higher because the lifetime of satellites is pretty low 3. Refurbishment is next to impossible 4. Networking is harder, either you are ok with a relatively small datacenter or you have to deal with radio or laser links between satellites For starlink this isn't as important. Starlink provides something that can't really be provided any other way, but even so just the US uses 176 terawatt-hours of power for data centers so starlink is 1/400th of that assuming your estimate is accurate (and I'm not sure it is, does it account for the night cycle?)
• strangeloops85 9mo ago
  The energy economics in space are also a bit more complicated than usually thought. I think Starlink has been using Si cells instead of III-V-based ones, but in addition to lower output they also tend to degrade faster under radiation. I guess that's ok if the GPU is going to be toast in a few years anyway so you might as well de-orbit the whole thing. But that same solar cell on Earth will happily be producing for 40+ years. Also the same issue with radiative cooling pops up for space solar cells - they tend to run way hotter than on Earth and that lowers their efficiency relative to what you could get terrestrially.
• s0a 9mo ago
  quantum computers on the sun!
• tbrownaw 9mo ago
  > I would not assume cooling has been worked out. There should be some temperature where incoming radiation (sunlight) balances outgoing radiation (thermal IR). As long as you're ok with whatever that temperature is at our distance from the sun, I'd think the only real issue would be making sure your satellite has enough thermal conductivity.
• bunderbunder 9mo ago
  My guess is it’s just another example of his habit of trying to use one of his companies to manufacture demand for another of his companies’ products. Specifically: Starship makes no economic sense. There simply isn’t any pre-existing demand for the kind of heavy lift capacity and cadence that Starship is designed to deliver. Nor is there anyone who isn’t currently launching heavy payloads to LEO but the only thing holding them back is that they need weekly launches because their use case demands a whole lot of heavy stuff in space on a tight schedule and that’s an all-or-nothing thing for them. So nobody else has a reason to buy 50 Starship launches per year. And the planned Starlink satellites are already mostly in orbit. So what do you do? Just sell Starship to xAI, the same way he fixed Cybertruck’s demand problem by selling heaps of them to SpaceX.
  • drivebyhooting 9mo ago
    There might be a lot of induced demand from starship. I’m sure defense is a big one.
    • bunderbunder 9mo ago
      No, but really, where will it come from? If (as seems to be the case) nobody can identify a specific source of latent demand that is large enough to soak up the two order of magnitude increase in the supply of heavy lift launch capacity that Elon wants to deliver, then that strongly suggests that SpaceX does not actually have a business plan for Starship. Or at least, not a business plan that’s been thought through as clearly as a $5 billion (and counting) investment would warrant. “Defense” is not nearly specific enough to count as an answer. What kind of defense application, specifically, do you have in mind, and why does it need specifically this kind of heavy lift capacity to be viable?
  • weregiraffe 9mo ago
    >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.
• simoncion 9mo ago
  > I would not assume cooling has been worked out. That's wise. However, TFA's purpose in assuming cooling (and other difficulties) have been worked out (even though they most definitely have not) was to talk about other things that make orbital datacenters in space economically dubious. As mentioned: But even if we stipulate that radiation, cooling, latency, and launch costs are all solved, other fundamental issues still make orbital data centers, at least as SpaceX understands them, a complete fantasy. Three in particular come to mind:
• a-dub 9mo ago
  apocalyptic space twitter with satellites shaped like whales that drop from the sky would have been cooler.
• pokot0 9mo ago
  Can’t you heat exchange inside the satellite, and make one part of the satellite incredibly hot so that it radiates a lot and dissipates. This is just a question. I have no expertise at all with this.
  • prpl 9mo ago
    yeah if you want a heat thruster
  • TrainedMonkey 9mo ago
    Good intuition, that is generally how radiators work in space.
  • thinkingkong 9mo ago
    You definitely _can_ the question is, can you do it by enough for a reasonable amount of money. There are a few techniques to this but at the end of the day you need to radiate away, the heat otherwise it will just keep growing. You cannot keep pumping energy into the satellite without distributing the same amount back out again.
  • pas 9mo ago
    Yes, but you need energy to pump heat, and that has an efficiency maximum (thx ~~Obama~~ Carnot), and radiative cooling scales with the ~4th power of the temperature, so it has to be really hot, and so it requires a lot of energy to "cool down" the already relatively cool side and use that "heat" to heat up the other side that's a thousand degree hotter. All in all, the cooling system would likely consume more energy than the compute parts.
  • parl_match 9mo ago
    yes. it is how sats currently handle this. its actually exponentially effective too P = E S A T^4 requires a lot of weight (cooling fluid). requires a lot of materials science (dont want to burn out radiator). requires a lot of moving parts (sun shutters if your orbit ever faces the sun - radiator is going to be both ways). so that sounds all well and good (wow! 4th power efficiency!) but it's still insanely expensive and if your radiator solution fucks up in any way (in famously easy to service environment space) then your entire investment is toast now i havent run the math on cost or what elon thinks the cost is, but my extremely favorable back of hand math suggests he's full of it
• mlindner 9mo ago
  I want to nitpick you here but a thermos is specifically good at insulating because not only does it have a vacuum gap, it's also got two layers of metal (inner and outer) to absorb and reflect thermal radiation. That specific aspect is NOT true in space because there's nothing stopping thermal radiation. Now you're correct that you can't remove heat by conduction or convection in space, but it's not that hard to radiate away energy in space. In fact rocket engine nozzle extensions of rocket upper stages depend on thermal radiation to avoid melting. They glow cherry red and emit a lot of energy. By Stefan–Boltzmann law, thermal radiation goes up with temperature to the 4th power. If you use a coolant that lets your radiator glow you can conduct heat away very efficiently. This is generally problematic to do on Earth because of the danger of such a thing and also because such heat would cause significant chemical reactions of the radiator with our corrosive oxygen atmosphere. Even without making them super hot, there's already significant energy density on SpaceX's satellites. They're at around 75 kW of energy generation that needs to be radiated away. And on your final statement, hyperloop was not used as a "distraction" as he never even funded it. He had been talking about it for years and years until fanboys on twitter finally talked him into releasing that hastily put together white paper. The various hyperloop companies out there never had any investment from him.
  • runarberg 9mo ago
    It is well known that Musk primary reason to push Hyperloop was because he didn’t want them to build a high speed rail for some reason: > Musk admitted to his biographer Ashlee Vance that Hyperloop was all about trying to get legislators to cancel plans for high-speed rail in California—even though he had no plans to build it. https://time.com/6203815/elon-musk-flaws-billionaire-visions/ https://time.com/6203815/elon-musk-flaws-billionaire-visions...
  • kuschku 9mo ago
    > a thermos is specifically good at insulating because not only does it have a vacuum gap, it's also got two layers of metal (inner and outer) to absorb and reflect thermal radiation. Not necessarily. There are many modern thermos "cups" that are just a regular cup, except with two layers of glass and a vacuum. Even the top is open all the time. (e.g. https://www.ikea.com/us/en/p/passerad-double-wall-glass-80540293/ https://www.ikea.com/us/en/p/passerad-double-wall-glass-8054... ) It's still good enough to keep your coffee hot for an entire day.
• JumpCrisscross 9mo ago
  > It could be a legal dodge. It could be a power grab. What it will not be is a useful source of computing power It's a way to get cheap capital to get cool tech. (Personal opinion.) Like dark fibre in the 1990s, there will absolutely–someday–be a need for liquid-droplet radiators [1]. Nobody is funding it today. But if you stick a GPU on one end, maybe they will let you build a space station. [1] https://en.wikipedia.org/wiki/Liquid_droplet_radiator https://en.wikipedia.org/wiki/Liquid_droplet_radiator
• bdangubic 9mo ago
  musk is always up to something but remarkably people still eat this stuff up - remarkable to watch!
• matt-p 9mo ago
  (DTC) Datacentres take electricity and turn it into low grade heat e.g 60c water. Put them anywhere where you've either got excess (cheap) energy or where you can use the heat. Either is fine, both is great, but neither is both bad and current standard practice. It's perfectly possible to put small data centres in city centres and pipe the heat around town, they take up very very little space and if you're consuming the heat, you don't need the noisy cooling towers (Ok maybe a little in summer). Similarly if you stick your datacentre right next to a big nuclear power plant, nobody is even going to notice let alone care.
  • MengerSponge 9mo ago
    Resistive heating is a tremendously inefficient way to generate heat. Sometimes it's worth it if you get something useful in exchange (such as full spectrum light in the winter). But it's not all upsides. Heat pumps are magic. They're something like 300% efficient. Each watt generates 3 watts of useful heat.
    • lambertsimnel 9mo ago
      I share your enthusiasm about heat pumps, but I wonder what the efficiency of using waste heat is. Couldn't it be competitive with heat pumps? As it's a waste product, isn't it reasonable to also expect it to be more than 100% efficient?
      • CorrectHorseBat 9mo ago
        Much more than 100% since the only energy you need to put in is for pumping the hot water around.
      • matt-p 9mo ago
        As a rule of thumb (obviously it varies) you spend about 1% pumping water round a heat network. So your CoP is around 99 if you consider heat truly free. It's actually higher as pump energy largely is converted to friction/heat.
      • Nevermark 9mo ago
• jimt1234 9mo ago
  > It makes far more sense to build data centers in the arctic. Please, no!
• phendrenad2 9mo ago
  I think people underestimate how quickly heat radiates to space. A rock in orbit around Earth will experience 250F/125C on the side facing the Sun, and -173C/-280F on the other side. The ability to rotate an insulating shield toward the sun means you're always radiating.
  • pclmulqdq 9mo ago
    I think you may be overestimating how quickly this happens and underestimating how much surface area that rock has. Given no atmosphere, the fact that the rock with 1/4 the radius of Earth has a temperature differential of only 300C between the hot side and the cold side, there's not a lot of radiation happening. In deep space (no incident power) you need roughly 2000 sq meters of surface area per megawatt if you want to keep it at 40C. That would mean your 100 MW deep space datacenter (a small datacenter by AI standards) needs 200000 sq meters of surface area to dissipate your heat. That is a flat panel that has a side length of 300 meters (you radiate on both sides). Unfortunately, you also need to get that power from the sun, and that will take a square with a 500 meter side length. That solar panel is only about 30% efficient, so it needs a heatsink for the 70% of incident power that becomes heat. That heatsink is another radiator. It turns out, we need to radiate a total of ~350 MW of heat to compute with 100 MW, giving a total heatsink side length of a bit under 600 meters. All in, separate from the computers and assuming no losses from there, you need a 500x500 meter solar panel and a 600x600 meter radiator just for power and heat management on a relatively small compute cluster. This sounds small compared to things built on Earth, but it's huge compared to anything that has been sent to space before. The ISS is about 100 meters across and about 30 meters wide for comparison.
    • phendrenad2 9mo ago
      > 2000 sq meters of surface area per megawatt if you want to keep it at 40C What is this figure based on?
    • ralfd 9mo ago
      > it's huge compared to anything that has been sent to space before That is the goal of Starship though. The ISS has a mass of 400 ton, the goal is to need only two cheap launches of Starship v4 for that.
• rpcope1 9mo ago
  I think it's possibly more informative to look at what happened with SolarCity and Tesla and contemplate if there's not a similar dynamic here.
• deleted 9mo ago
  [deleted]
• BobbyTables2 9mo ago
  It’s funny how quickly the general public forgot about the “vacuum thermos”. (Perhaps more popular before StarBucks overran society). Those flasks don’t have any space age insulating material - mainly just a vacuum… Technology from 1892…
  • mytailorisrich 9mo ago
    They are more popular than ever, actually. Pretty much all those fancy cups and bottles (like Stanley, other brands available) sold to keep your coffee hot/drink cold on the go are vaccum ones. It's just updated and more robust design compared to the older thermos flasks.
• bartread 9mo ago
  All of this and more. For example: quite apart from the fact of how much rocket fuel is it going to take to haul all this shit up there at the kind of scale that would make these space data centres even remotely worthwhile. I'm not against space travel or space exploration, or putting useful satellites in orbit, or the advancement of science or anything like that - quite the opposite in fact, I love all this stuff. But it has to be for something that matters. Not for some deranged billionaire's boondoggle that makes no sense. I am so inexpressibly tired of all these guys and their stupid, arrogant, high-handed schemes. Because rocket fuels are extremely toxic and the environmental impact of pointlessly burning a vast quantity of rocket fuel for something as nonsensical as data centres in space will be appalling.
  • energy123 9mo ago
    Does that emit more than Elon's terrestrial data centers powered by natural gas, per unit of compute?
  • ianburrell 9mo ago
    Starship is fueled with methane (natural gas) and liquid oxygen which aren't toxic. It does produce a lot of CO2 which is a problem with lots of flights.
    • afiori 9mo ago
      IIRC the methane is produced at launch site with considerable pollution
• sam 9mo ago
  This is mistaken. In space a radiator can radiate to cold (2.7K) deep space. A thermos on earth cannot. The temperature difference between the inner and outer walls of the thermos is much lower and it’s the temperature difference which determines the rate of cooling.
  • pclmulqdq 9mo ago
    "Radiate" is exactly what you have to do, and that is extremely slow. You need a huge area to dissipate the amount of power you are talking about.
    • fnordpiglet 9mo ago
      Basically you concentrate the heat into a high emissivity high temperature material that’s facing deep space and is shaded. Radiators get dramatically smaller as temperature goes up because radiation scales as T⁴ (Stefan–Boltzmann). There are many cases in space where you need to radiate heat - see Kerbal Space Program
      • pclmulqdq 9mo ago
        "High emissivity, high temperature" sounds good on paper, but to create that temperature gradient within your spacecraft the way you want costs a lot of energy. What you actually do is add a shit load of surface area to your spacecraft, give that whole thing a coating that improves its emissivity, and try your hardest to minimize the thermal gradient from the heat source (the hot part) throughout the radiator. Emissivity isn't going past 1 in that equation, and you're going to have a very hard time getting your radiator to be hotter than your heat source. Note that KSP is a game that fictionalizes a lot of things, and sizes of solar panels and radiators are one of those things.
        • deleted 9mo ago
          [deleted]
        • fnordpiglet 9mo ago
• notepad0x90 9mo ago
  You're thinking of outer space. At any distance away from earth where space is so thin that heat dissipation is impossible, then the speed of light will be prohibitive of any workloads to/from space. there is plenty of altitude above the karman line where there is enough atmosphere to dissipate heat. Furthermore, i don't know if they figured it out, but radiation can dissipate heat, that's how we get heat from the sun. Also, given enough input energy (the sun), active closed-cooling systems might be feasible. https://www.nasa.gov/smallsat-institute/sst-soa/thermal-control/#7.3.4 https://www.nasa.gov/smallsat-institute/sst-soa/thermal-cont... But I really hope posts like this don't discourage whoever is investing in this. The problems are solvable, and someone is trying to solve them, that's all that matters. My only concern is the latency, but starlink seems to manage somehow. Also, a matter of technicality (or so I've heard it said) is that the earth itself doesn't dissipate heat, it transforms or transfers entropy.
  • ericmay 9mo ago
    > At any distance away from earth where space is so thin that heat dissipation is impossible, then the speed of light will be prohibitive of any workloads to/from space. Why would they need to get data back to earth for near real time workloads? What we should be thinking about is how these things will operate in space and communicate with each other and whoever else is in space. The Earth is just ancient history
    • reverius42 9mo ago
      I feel like this is an incredibly fantastic goal-post-moving from the original announcement. SpaceX: "we're going to put datacenters in space" HN comments: "obviously we'll need to move human civilization into space first for this to make sense. checks out."
      • ericmay 9mo ago
        I wasn’t responding to the original announcement, I was responding to someone who presumed that these data centers need to send data back to earth. I was making a snide comment that certain ultra wealthy people don’t need these data centers to send data to earth, because they don’t plan on being here.
• stogot 9mo ago
  > You can't exchange heat with vacuum. You can only radiate heat into it. I don’t remember the difference from my science classes, isn’t This the same thing essentially?
  • FabHK 9mo ago
    The other two methods of heat transfer apart from radiation are conduction (through “touch”, adjacent molecules, eg from the outside of a chicken on the BBQ to the inside) and convection (through movement, eg cold air or water flowing past).
• m463 9mo ago
  I used to really enjoy musk's talks when he was spooling up tesla. He was an engineer and obviously the world is missing what engineers see clearly. But now looking back and accounting for the claims he made there's a pattern. I saw this article: https://www.wired.com/story/theres-a-very-simple-pattern-to-elon-musks-broken-promises/ https://www.wired.com/story/theres-a-very-simple-pattern-to-... that said... he did jumpstart the EV industry. He has put up satellites every week for years. He is still a net benefit to all of us.
  • dsl 9mo ago
    > he did jumpstart the EV industry. He has put up satellites every week for years. He is still a net benefit to all of us. Talk to any former SpaceX or Tesla employee. They will clue you in that both were successful in spite of Elon, not because of him. The Cybertruck was really the first product he saw to completion from his own design. And well...
    • dboreham 9mo ago
      I think you under appreciate him a bit here. No he's not a super genius. He's probably not even a good engineer. But he is a) a total a.hole and b) a tremendous bullshitter. There are circumstances in which you need such a person to succeed (see also Steve Jobs). He yelled at people for 10 years straight and he was crucial in facilitating capital to build these very capital intensive products. A regular smart person would absolutely not have succeeded, for these reasons.
      • someothherguyy 9mo ago
        > bullshitter why is lying at the edge of committing fraud so respected?
        • theshrike79 9mo ago
          It makes the stock go up and people earn crazy amounts of money.
• test6554 9mo ago
  AI sovereignty, not AI efficiency. Redesign AI chips with lower power density and higher thermal tolerances and you get more efficient radiation with some sacrifice in compute power. But you are outside the jurisdiction of every country. Then you get people paying much more money to use less-tightly-moderated space-based AI rather than heavily moderated AI.
• NedF 9mo ago
  [dead]
• energy123 9mo ago
  What in particular is wrong/misleading in the Starcloud whitepaper, then? https://starcloudinc.github.io/wp.pdf https://starcloudinc.github.io/wp.pdf
  • deepfriedchokes 9mo ago
    Probably this bit on page 4, which parent comment addresses: “More efficient cooling architecture taking advantage of higher ΔT in space.”
  • mmoustafa 9mo ago
    They do not at any point outline how cooling will be done, they simply say "it will be more efficient than chillers due to the larger delta T" which is incorrect because it's about dT not delta T
  • beloch 9mo ago
    In Table 1, the cost of cooling of a terrestrial data centre is listed as $7M. The cost of cooling in space is assigned a value of $0 with the claim: "More efficient cooling architecture taking advantage of higher ΔT in space" My bold claim: The cost of cooling will not be $0. The cost of launching that cooling into space will also not be $0. The cost of maintaining that mechanically complex cooling in space will not be $0. They then throw in enough unrealistic calculations later in the "paper" to show that they thought about the actual cost at least a little bit. Apparently just enough to conclude that it's so massive there's no way they're going to list it in the table. Table 1 is pure fantasy.
    • WithinReason 9mo ago
      That row specifically says "chiller energy cost" which is 0
  • trymas 9mo ago
    Previous discussions on HN: - https://news.ycombinator.com/item?id=44390781 https://news.ycombinator.com/item?id=44390781 - https://news.ycombinator.com/item?id=45667458 https://news.ycombinator.com/item?id=45667458 - https://news.ycombinator.com/item?id=43977188 https://news.ycombinator.com/item?id=43977188 I will not re-read them, but from what I recall from those threads is numbers don't make sense. Something like: - radiators the multiple square kilometers in size, in space; - lifting necessary payloads to space is multiples of magnitudes more than we have technology/capacity as the whole world now; - maintanence nightmare. yeah you can have redundancy, but no feasable way to maintain; - compare how much effort/energy/maintenance is required to have ISS or Tiangong space stations - these space datacenters sound ridiculous; NB: I would be happy to be proven wrong. There are many things that are possible if we would invest effort (and money) into it, akin to JFK's "We choose to go to the Moon" talk. Sounded incredible, but it was done from nearly zero to Moon landing in ~7 years. Though as much as I udnerstand - napkin math for such scale of space data centers seem to need efforts that are orders or magnitude more than Apollo mission, i.e. launching Saturn V for years multiple times per day. Even with booster reuse technology this seems literally incredible (not to mention fuel/material costs).
• spoaceman7777 9mo ago
  He goes on about putting a mass driver on the moon for ultra-low-cost space launches. His plan here clearly hinges around using robots to create a fully-automated GPU manufacturing and launch facility on the moon. Not launching any meaningful number from earth. Raises some big questions about whether there are actually sufficient materials for GPU manufacture on the moon... But, whatever the case, the current pitch of earth-launches that the people involved with this "space datacenter" thing are making is a lie. I think it just sounds better than outright saying "we're going to build a self-replicating robot factory on the moon", and we are in the age of lying.
  • bendews 9mo ago
    If any single country tried to create a whole production chain to single-handedly manufacture modern computer equipment it would be on the order of decades to see any result. Doing it on the moon is just not realistic this century, maybe the next one. Although i don't think the economics would ever work out.
    • Findeton 9mo ago
      Do you acknowledge how much change was there in the XX century? How can you probably make such predictions with such confidence?
• uoaei 9mo ago
  The materialist take is that his plan is to eventually over-value and then trade on his company valuations, and also have another merger lined up for future personal financial bailouts.
• ExoticPearTree 9mo ago
  > It makes far more sense to build data centers in the arctic. Unfortunately no. The arctic region is too cold and humid. You need way more energy to manage the cooling of a datacenter there than somewhere hotter.
• ospray 9mo ago
  The only way I see this actually working given the resource requirement is delta-v style with in orbit resource extraction using robots. By transferring heat to asteroids in the shade of the solar panels at L1 or something. https://share.google/uXWQyAp7a8nE03qoi https://share.google/uXWQyAp7a8nE03qoi
• PunchyHamster 9mo ago
  It has been worked out. Just look at how big are ISS radiators and that they dissipate around 100kW then calculate cost of sending all that to space. And by that I mean it would be even more expensive that some of the estimates flying around While personally I think it's another AI cash grab and he just wants to find some more customers for spacex, other thing is "you can't copyright infringe in space" so it might be perfect place to load that terabytes of stolen copyrighted material to train data sets, if some country suddenly decides corporation stealing copyright content is not okay any more
  • CorrectHorseBat 9mo ago
    Maybe you can't copyright infringe in space, but it's still infringement when the result gets back to earth.
    • randyrand 9mo ago
      Keep the result in space, and use large telescopes to look at it!
      • RugnirViking 9mo ago
        the result is the result. If you look at it and use it for something, you have moved the result. Its not a physical object that exists in a place, its an idea. Hence IP. Intellectual property.
        • estearum 9mo ago
          Really depends on how good your lawyers are
    • whycome 9mo ago
      These major AI tools have already been trained on infringing works.
  • pointlessone 9mo ago
• abalone 9mo ago
  > 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 and snow off of the panels (a major concern in deserts which would otherwise seem to be ideal locations). There are so many more considerations that go into terrestrial generation. This is not to deny the criticism of orbital panels, but rather to encourage a real and apolitical engineering discussion.
  • PurpleRamen 9mo ago
    > 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.
    • IsTom 9mo ago
      Sunlight is unevenly distributed in the arctic during the year to say the least.
    • Kuinox 9mo ago
      > Building 3-5x more solar plants in the Arctic, would still be cheaper than travelling to space. Well first you have to make solar panels works in the polar nights, in winter they have a few minutes of sun in the day at most.
    • abalone 9mo ago
      > 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.
• KaiserPro 9mo ago
  Its not just cooling thats totally not worked out, its internal networking, its power management (what happens when its in darkness?) how do you certify servers for +/-10g vibration (https://www.ralspace.stfc.ac.uk/Pages/Dynamics-and-vibration-testing.aspx https://www.ralspace.stfc.ac.uk/Pages/Dynamics-and-vibration...) What about gamma rays? there is a reason why "space hardened" microcontrollers are MIPS chips from the 90s on massive dies with a huge wedge of metal on it. You can't just take a normal 4micron die and yeet it into space and have done with it. Then there is the downlink. If you want low latency, then you need to be in Low earth orbit. That means that you'll spend >40% of your time in darkness. So not only do you need to have a MAssive heat exchanger and liquid cooling loop, which is space rated, you need to have ?20mwhr of battery as well (also cooled/heated because swinging +/- 140 C every 90 minutes is not going to make them happy) Then there is data consistency, is this inference only? or are we expecting to have a mesh network that can do whole "datacentre" cache coherence? because I have bad news for you if you're going to try that. Its just complete and total bollocks. utter utter bollocks.
  • PinkiesBrain 9mo ago
    You don't put it in a standard orbit, you put it in a polar orbit with near 100% suntime ... obviously. Obviously you use the backside of the massive area of PV you need, for an equally massive area for HOPG radiator films with condensor coils (because obviously you use heatpumps for cooling, not pure liquid). Consider the obvious ways you'd actually do it, not the most naive ways. The GPU pods obviously won't weigh the same as a terrestrial rack. Space based solar arrays obviously don't weigh the same as your hail and storm resistant panels on your roof (see ROSA, but there might be another 10x weight reduction if using flexible solar in tension from rotation). Noone cares about a couple 100 ms extra for first token. Solar wind and drag are in my opinion the biggest issue. Problem : it's a giant surface catching drag and solar wind. Solution : it's a giant solar sail. Controlling the angle of PV for useful thrust, that's never really been done for a satellite.
• owaislone 9mo ago
  or perhaps as simple as saving xAI for himself as he prepares to offload rest of Twitter?
• andix 9mo ago
  I think Musk is backed into a corner financially. Most of his companies don't have that much revenue and their worth is mostly based on hope. They might be closer to collapsing than most people think. It's not unheard of that a billionaires net worth drops to zero over night. I think it's mostly financial reasons why they merged the companies, this space datacenter idea was born to justify the merge of SpaceX and xAI. To give investors hope, not to really do it.
• weinzierl 9mo ago
  "A satellite is, if nothing else, a fantastic thermos." A satellite is quite unlike a thermos in the sense that it is carefully tuned to keep its temperature within a relatively narrow band around room temperature.[1] during all operational phases. This is because, despite intended space usage, devices and parts are usually tested and qualified for temperature limits around room temperature. [1] "Room temperature" is actually a technical term meaning 20°C (exceptions in some fields and industries confirm the rule).
  • throw-qqqqq 9mo ago
    > 1] "Room temperature" is actually a technical term meaning 20°C (exceptions in some fields and industries confirm the rule). Yes 20 and 25°C I believe are the two most popular choices. In many cases it makes little difference with units in Kelvin ¯\_(ツ)_/¯
• latexr 9mo ago
  > Musk is up to something here. This could be another hyperloop (i.e. A distracting promise meant to sabotage competition). It could be a legal dodge. It could be a power grab. It could also just be ignorance and talking out of his ass to look smart. Like when he took over Twitter and began publicly spewing wrong technical details as if he knew what he was talking about and being corrected by the people actually working on the product.
• killerstorm 9mo ago
  People did the calculation: radiative cooling requires smaller surface area than solar panels. So, basically, a solar panel itself can radiate heat. Have you done a calculation yourself?
  • Numerlor 9mo ago
    How can the solar panel itself radiate heat when it's being heated up generating supplying power? Looking at pictures of the ISS there's radiators that look like they're there specifically to cool the solar panels. And even if viable, why would you just not cool using air down on earth? Water is used for cooling because it increases effectiveness significantly, but even a closed loop system with simple dry air heat exchangers is quite a lot more effective than radiative cooling
    • Symmetry 9mo ago
      You take the amount of energy absorbed by the solar panels and subtract the amount they radiate. Most things in physics are linear systems that work like this.
    • killerstorm 9mo ago
      It would be way more productive for you to ask these questions to ChatGPT or similar AI with reasoning. Equations are quite simple. But I'm not going to dump it into a HN comment. You don't have experience of being in space, so your "intuition" about cooling is worth literally nothing without formulas / numbers
  • drtz 9mo ago
    The same radiative (radiant) cooling on Earth works almost just as well, but without the cost of a rocket launch.
    • killerstorm 9mo ago
      It absolutely isn't - on Earth you emission from the environment which is so much warmer than deep space. Why do you just make shit up?
• coliveira 9mo ago
  Jeffrey Epstein's friend Elon Musk is trying to stop a financial disaster in xAi that would expose how irresponsible he is. He's gonna put all that in a company that has real money coming from government and soon will get retail investors money.
• trimethylpurine 9mo ago
  You can't exchange heat with vacuum If you put a pipe with hot gas inside, in space, it will get colder by convection. Blow air through the pipe.
  • valec 9mo ago
    ok. your pipe is full. now what
    • trimethylpurine 9mo ago
      Don't make it full. Pipes are hollow by definition.
      • sfink 9mo ago
        your pipe is full of heat.
        • trimethylpurine 9mo ago
          Yeah, I got the joke, bro. Thanks for the comment.
• wendgeabos 9mo ago
  I have reached the same conclusion -- this is perhaps not a distraction but an attempt to gather funds to pursue the One True Goal...
• TechSquidTV 9mo ago
  I have no idea how it compares to the heat being generated, but one advantage of space would be totally efficient radiative cooling, I believe. Assuming you can pump the heat, and can deploy a large enough surface area (the key question I assume), then you have that at least.
• dev_l1x_be 9mo ago
  The Stefan-Boltzmann Law tells us that radiative power scales to the fourth power of temperature (T^4). While terrestrial cooling is largely linear and dependent on ambient air/water temperature (the "wet-bulb" limit), a radiator in space is dumping heat into a 3-Kelvin sink. That thermal gradient is massive.
  • dr-detroit 9mo ago
    [dead]
  • shadowgovt 9mo ago
    Stefan-Boltzmann is about absolute, not relative temperature. When one does the math on the operating temperatures of regular computing equipment that we use on Earth, how much heat it generates per watt, and how fast it would need to sink that heat to allow for continuous operation, one gets surface areas that are not impossible, but are pretty on the high end of anything we've ever built in space. And then you have to deflect the incoming light from the Sun which will be adding to your temperature (numbers published by private space companies regarding the tolerances of payloads those companies are willing to carry note that those payloads have to be tolerant of temperatures exceeding 100° C, from solar radiation alone). That is doable, you could sunshield the sensitive equipment and possibly decrease some of your thermal input load by putting your craft out near L2 which hangs out in the penumbra of Earth. Still a daunting technical challenge when the alternative is just build it on the planet with the technology and methods we already have.
    • dev_l1x_be 9mo ago
      You’re correct that Stefan-Boltzmann uses absolute temperature (K), but that only reinforces the advantage of moving the "hot side" of the gradient up. If you increase your radiator temp from 300K (standard Earth ambient) to 360K (hot silicon), your radiative efficiency doesn't just go up by 20%—it nearly doubles. The Solar Load is Directional: Unlike a terrestrial atmosphere where heat is omnidirectional, space allows for "shadow engineering." A simple multi-layer insulation (MLI) sunshield can reduce solar flux by orders of magnitude. We do this for the James Webb Space Telescope to keep instruments at 7K while the sun-facing side is at 380K. For a data center, you don't need 7K; you just need to keep the "dark side" radiators in the shade.
• micromacrofoot 9mo ago
  It's not just Musk, Google is working on it too... very soon to actually launch tests. I have a feeling it's a regulatory dodge of some kind.
• littlestymaar 9mo ago
  > It makes far more sense to build data centers in the arctic This. Like it would make far more sense to colonize the poles than Mars.
• phtrivier 9mo ago
  > Musk is up to something here. This could be another hyperloop (i.e. A distracting promise meant to sabotage competition). It could be a legal dodge. It could be a power grab. What it will not be is a useful source of computing power. Anyone who takes this venture seriously is probably going to be burned. That. Also, am I the only one to remember when SpaceX was supposed to pivot to transporting people from cities to cities, given how cheap and reusable and sure BFF/Starship was going to be ? Or how we were all going to earn money by pooling our full self driving cars in a network of robo taxis ? In all seriousness, what is the number of "unrealized sci-fi pipe dreams" that is acceptable from the owner a company ? Or, to be fair, what is the acceptable ratio of "pipe dreams" / "actually impressive stuff actually delivered (reusable rockets, starlink, decent EVs, etc...)" ?
• vonneumannstan 9mo ago
  Yeah the Space Data Center companies completely gloss over this fact by saying "oh yeah and we'll need radiators 10x the size of our solar panels. NBD."
  • PinkiesBrain 9mo ago
    Because it's not 10x. If you cool the solar panels (which aren't black body absorbers for longer wavelengths) and GPUs to 80C through a heatpump and have the blackbody radiator at 120C it will approximately work out, 1:1.
• Symmetry 9mo ago
  Space is a vacuum and yet here we are on a rock floating in space warmed by the sun and the temperate is actually pretty comfortable. Indeed, without the greenhouse effect it would be positively chilly. An important part of a thermos is that you have to use high albedo materials in the vacuum chamber or else it would lose heat too quickly to radiation. A satellite as a whole will come to thermal equilibrium with space at a fairly reasonable temperature, the problematic part is that the properties of electricity make it easy to concentrate a good part of the incoming energy in a small area where the GPU is. Heat is harder to move than electricity and getting that heat back out to the solar panels or radiators requires either heavy heat pipes or complex coolant pumps.
  • its-summertime 9mo ago
    a data center in space doesn't have a gigantic rock taking up most of its area, a data center in space is 100% data center 0% rock. If it had the same data center to rock ratio as earth, it would just end up being earth in the end, and earth doesn't seem to be wanting to stick to its equilibrium either right now
    • xavortm 9mo ago
      Well, they do have silicon, with some more additives they can make rocks in space! And throw them at earth, that will show em
    • Symmetry 9mo ago
      The rock in this case acts as extra thermal mass that makes it take longer to reach thermal equilibrium, but doesn't change what the ultimate thermal equilibrium is. Only the configuration of the parts of the surface that can absorb or radiate electromagnetic radiation do that. And because rock is a fairly good insulator we only really benefit from the top layer and if the sun went out we would all freeze in a week or so.
      • its-summertime 9mo ago
        it changes the amount of exposed area to release heat back into the universe. if you have a non-negligible amount of compute compared to earth, you are going to be approaching a non-negligible amount of space required to radiate that away, along with all the other costs and maintainability issues
• DiscourseFan 9mo ago
  I don’t believe you’ve considered the possibility of a data center on Pluto… But in all seriousness, if there is a possibility of building industrial centers outside of the Earth’s atmosphere, it is surely not here yet. Lots of areas would need improvement.
• goalieca 9mo ago
  > Musk is up to something here. This is Musk, yet again, pulling themes from sci-fi books. He has that vision of ushering in the "future" which is good for dragging us forward but also he fails a lot. His open letter cited the Kardashev scale and his vision for getting us forward like in the novel accelerando.
• rootnod3 9mo ago
  “Musk is on to something here”? Really? Any high school student with a basic grasp of physics could explain that. But sure, the idiot billionaire nazi “is on to something”. That’s giving him too much credit. Of course it doesn’t fucking make sense to put data centers into space. Even if heating were solved somehow magically, server disks are veeery prone to fail and need replacement. Shoot a rocket up every week to replace failed drives or absolutely burned through GPUs? Yeah, that doesn’t even remotely sound feasible.
  • jvanderbot 9mo ago
    Unless you want cash-rich AI companies to pay a certain company for weekly / daily lifts during the build-out phase. Eventual crash be damned, make hay while the sun shines
    • rootnod3 9mo ago
      And burn even more energy and fuel than DCs on the ground, great idea :D
      • jvanderbot 9mo ago
        Nobody said it was a good idea except his accountant, who doesn't pay the energy bills.
• osigurdson 9mo ago
  I suspect Musk has a workable plan of some sort, realistically. Clearly, the one thing that is available in space is an abundance of square meters. There is no need whatsoever to conserve space at sufficient orbit. It is a little counter intuitive as we are so used to needing to conserve all the things. Power input and heat radiation both scale with area so maybe there is some way to achieve this at scale. For instance, maybe it will not look like a traditional data center or even traditional chips.
  • torginus 9mo ago
    The rumor I heard is that Musk's big issue with SpaceX was that he was only able to employ US citizens with a security clearance, as per the limitations of a rocket company, which he has rallied against multiple times. One of the motivations behind this whole thing could be that he could make a way for foreign talent to work on space projects without the necessary government signoff.
    • osigurdson 9mo ago
      Would that really be that much of an unlock?
      • torginus 9mo ago
        Yes. I don't have an estimate right off the bat, but if you considered all the people employed at top tech companies, what percentage do you think are US nationals eligible for a security clearance? I'd say less than a third.
        • osigurdson 9mo ago
          I had a look at SpaceX career page. There are 128 software related roles available. Perhaps half of those could be filled by big tech type companies, the others are more specialized (like antenna software engineer). I don't think that 64 open positions would move the needle really. And, if it were that easy to get around the security clearance by having another company, he could have created a new / separate company years ago. Wouldn't a simpler explanation be that SpaceX is making a lot of money while xAI is losing a lot. If funds have to flow through Elon personally it is likely complicated and costly. Also, if the "space data center" idea is actually workable (I have no idea if it is) then it does make some logical sense as well. Of course, Twitter just seems like kind of a write off to me at this point.
• bigbuppo 9mo ago
  He's got a trillion dollar compensation package on the line. You can absolutely guarantee he's doing something shady.
• skeptic_ai 9mo ago
  The 4-5nm gpu will break from high energy protons from the sun. Lag for roundtrip: 35ms. But when satelite needs to pass through other satellites as has no ground coverage you add more lag and reduce bandwidth of the whole network. The best part is jurisdiction safety. Very hard to get raided by govs.
• notaustinpowers 9mo ago
  It links his middling AI company and his failing social media company with the only company that can send the United States to space. X failing and can't pay its debts? Welp, better give him a government bailout otherwise no more rockets for you!
  • the_real_cher 9mo ago
    This exactly. His other companies are failing. He links the shitty companies with the only one working.
• catoc 9mo ago
  Exactly - satellites need to be cooled to prevent overheating that wouldn’t happen on earth. (Space doesn’t help in cooling GPUs in a satellite - space makes cooling worse)
• fsckboy 9mo ago
  >i.e. The lack-of-a-thing that makes a thermos great at keeping your drink hot e.g. the lack-of-a-thing that makes a thermos great at keeping your drink cold too
  • catoc 9mo ago
    Yes but in this case the lack-of-a-thing keeps GPUs hot
    • fsckboy 9mo ago
      people who do understand thermodynamics will already understand the problem, but innocent people who don't understand thermodynamics should not be misled by poorly chosen examples presented as proof.
  • fwipsy 9mo ago
    At risk of stating the obvious - computers produce heat. "Keeping them cool" really means dissipating that heat. Insulating them will cause them to get hotter.
• EGreg 9mo ago
  The ideal would be to park the data centers at the lagrange point behind the Earth in its umbra, so they don't need to dissipate direct solar heat.
  • sfink 9mo ago
    Then they also don't get the only advantage of being in space, namely free solar energy. You'd need to have solar collectors in a sunny spot, beaming energy to the shady spot, or something. (Beaming because they don't get to be in the lagrange point, so cables aren't going to work.) But then you're just inefficiently moving sunlight around (and shifting/narrowing its frequencies, but still).
    • EGreg 9mo ago
      That’s not true, solar energy still reaches the lagrange point, these tiny machines don’t need that much of it solar energy reaches the Earth-Sun Lagrange point 2 (\(L_{2}\)), even though it is located behind the Earth, because it sits slightly beyond the reach of Earth's full shadow (umbra). Here is a breakdown of how this works: Location of \(L_{2}\): The \(L_{2}\) point is located approximately 1.5 million kilometers away from Earth on the side opposite the Sun.Earth's Umbra Length: The tip of Earth's main, total shadow (the umbra) ends before it reaches the \(L_{2}\) point, usually around 92% of the distance to \(L_{2}\).Solar Exposure: Because \(L_{2}\) is outside the full umbra, a satellite at this location (like the James Webb Space Telescope) is never in total darkness.Halo Orbits: Spacecraft at \(L_{2}\) usually do not sit exactly at the point but in a "halo" orbit, which keeps them in constant, direct sunlight to power their solar panels.Penumbra: While the Earth may block some sunlight, the region is technically in a partial shadow (penumbra) or outside of it entirely, allowing for consistent solar energy harvesting. In summary, \(L_{2}\) is not in permanent darkness, and solar power is fully functional there.*
• jmalicki 9mo ago
  "But even if we stipulate that radiation, cooling, latency, and launch costs are all solved, other fundamental issues still make orbital data centers, at least as SpaceX understands them, a complete fantasy. " I'm pretty his point is that while cooling is an impossibility, it is not the only one!
• dfabulich 9mo ago
  In 2024, Starcloud posted their plans to "solve" the cooling problem. https://starcloudinc.github.io/wp.pdf https://starcloudinc.github.io/wp.pdf > As conduction and convection to the environment are not available in space, this means the data center will require radiators capable of radiatively dissipating gigawatts of thermal load. To achieve this, Starcloud is developing a lightweight deployable radiator design with a very large area - by far the largest radiators deployed in space - radiating primarily towards deep space... They claim they can radiate "633.08 W / m^2". At that rate, they're looking at square kilometers of radiators to dissipate gigawatts of thermal load, perhaps hectares of radiators. They also claim that they can "dramatically increase" heat dissipation with heat pumps. So, there you have it: "all you have to do" is deploy a few hectares of radiators in space, combined with heat pumps that can dissipate gigawatts of thermal load with no maintenance at all over a lifetime of decades. This seems like the sort of "not technically impossible" problem that can attract a large amount of VC funding, as VCs buy lottery tickets that the problem can be solved.
  • estimator7292 9mo ago
    Yes, on the face of it, the plan is workable. Heat radiation scales linearly with area and exponentially (IIRC) with temperature. It really is as simple as just adding kilometers of radiatiors. That is, if you ignore the incredible cost of transporting all that mass to orbit and assembly in space. Because there is quite simply no way to fold up kilometer-scale thermal arrays and launch in a single vehicle. There will be assembly required in space. All in all, if you ignore all practical reality, yes, you can put a datacenter in space! Once you engage a single brain cell, it becomes obvious that it is actually so impractical as to be literally impossible.
    • Andrex 9mo ago
      I kind of want to play it out though... if someone did do this (for whatever reasons), what would the real benefits even be? Something terrestrial operations wouldn't be able to catch up to in 5-10 years?
• slashdev 9mo ago
  As an engineer of the software variety, logically heat dissipation would seem like a difficult problem. But SpaceX has lots of real engineers who are very smart. I’m certain they ran the math on it. Which is more than you or I have done. If they say it can be done, I’m inclined to believe them.
  • therein 9mo ago
    [flagged]
    • paulryanrogers 9mo ago
      I think it's more an appeal to (expert) authority
• foobiekr 9mo ago
  Musk lies with ease and routinely. This and Optimus are both just more examples of that.
• tim333 9mo ago
  >I would not assume cooling has been worked out On the other hand Starlink has several thousand satellites up there using solar power to run processors and cooling them with radiators so it's not totally new technology. Here's a Musk tweet linking some analysis https://x.com/elonmusk/status/2013676764099199156 https://x.com/elonmusk/status/2013676764099199156
• DoctorOetker 9mo ago
  > Space is a vacuum. i.e. The lack-of-a-thing that makes a thermos great at keeping your drink hot. 1) The heat can be transported by a heat carrier conducting heat standing still. 2) The heat can be transported by a heat carrier in motion. 3) The heat can be transported by thermal radiation. The first 2 require massive particles, the latter are spontaneous photons. A thermos bottle does not simply work by eliminating the motile mass particles. Lets consider room temperature as the outer thermos temperature and boiling hot water as the inner temperature, that is roughly 300 K and 400 K. Thermal radiation is proportional to the fourth power of temperature and proportional to emissivity (which is between 0 and 1). Lets pretend you are correct and thus thermally blackened glass (emissivity 1) inside the vacuum flask would be fine according to you. That would mean that the radiation from your tea to the room temperature side would be proportional to 400^4 while the thermal radiation from room temperature to the tea would be proportional to 300^4. Since (400/300) ^ 4 = 3.16 that means the heat transport from hot tea to room temperature is about 3 times higher. If on the other hand the glass was aluminized before being pulled vacuum the heat transports are proportional to 0 * 400 K ^ 4 and 0 * 300 K ^ 4 . So the heat transport in either direction would be 0 and no net heat transport remains. If you believe the shiny inside of your thermos flask is an aesthetic gimmick, think again. You are making a non-comparison. Imagine comparing a diesel engine car to an electric car, but first removing the electric motor. Does that make a fair comparison???
  • estimator7292 9mo ago
    Nobody made any of the claims you're "refuting". You've imagined an argument so you can dunk on it to appear superior. In addition, thermoses aren't made of glass. It is far more common to make them out of steel or aluminum.
    • DoctorOetker 9mo ago
      I literally quote a person attributing the thermal insulation capabilities of vacuum flasks mono-causally to the lack of gas. I didn't imagine this, its right there to verify. Reminding people of laws of nature that have been known for 150 years and have withstood the test of time of investigation by physicists isn't "dunking on" anything, just reminding people of how the universe works. The original vacuum flasks were made of glass, and a lot of laboratory grade vacuum flasks and Dewars are still made of glass. The consumer level Thermoses eventually switched to stainless steel.
• timmit 9mo ago
  This is my 2 cents, I have an engineer background, not space science background. At earth or above sea, we use cooling to maintain the temperature below 60 degrees, or 80 or 100 or something. Shadow of space is -157 degrees, the cooling design will be different.
• nurumaik 9mo ago
  > makes a thermos great at keeping your drink hot Thermos has 2 parts responsible for thermal isolation: vacuum and some coating that reflects heat radiation Also in earth conditions, most of thermal radiation goes to surrounding air, heating it. This is not the case with vacuum, so thermal radiation will be even more efficient
• DustinBrett 9mo ago
  What about this articles points? https://research.33fg.com/analysis/debunking-the-cooling-constraint-in-space-data-centers https://research.33fg.com/analysis/debunking-the-cooling-con...
• MarceliusK 9mo ago
  Radiative cooling scales with surface area, compute scales with volume and density. That mismatch is brutal for high-density workloads like AI training
• hpdigidrifter 9mo ago
  Radiative cooling in space is not some unsolved problem. The problem is whether it's worth the launch costs for it.