Space is a vacuum. i.e. The lack-of-a-thing that makes a thermos great at keeping your drink hot. A satellite is, if nothing else, a fantastic thermos. A data center in space would necessarily rely completely on cooling by radiation, unlike a terrestrial data center that can make use of convection and conduction. You can't just pipe heat out into the atmosphere or build a heat exchanger. You can't exchange heat with vacuum. You can only radiate heat into it.
Heat is going to limit the compute that can be done in a satellite data centre and radiative cooling solutions are going to massively increase weight. It makes far more sense to build data centers in the arctic.
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.
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.
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.
So your hot thing is radiating directly onto the next hot thing over, the one that also needs to cool down?
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...
Where will they go, nobody knows!
My car doesn't spend too much time driving in vacuum, does yours?
https://en.wikipedia.org/wiki/External_Active_Thermal_Contro...
[1] https://en.wikipedia.org/wiki/External_Active_Thermal_Contro...
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.
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.
[0] https://images-assets.nasa.gov/image/jsc2021e064215_alt/jsc2...
Data centers in space are the same kind of justification imo.
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.
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.
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.
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.
https://www.cbc.ca/news/canada/saskatoon/spacex-cbc-debris-s...
Seems like quite a massive difference to ignore.
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?
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.
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: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.
Once upon a time there was a bonkers "rods from god" mass bomb idea, but that didn't work either.
But when they say, "Win the AI race," they mean, "Build the machine god first." Make of this what you will.
This is just a question. I have no expertise at all with this.
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?)
All in all, the cooling system would likely consume more energy than the compute parts.
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
Presumably they're planning on doing in-orbit propellant transfer to reboost the satellites so that they don't have to let their GPUs crash into the ocean...
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.
It's not physically impossible. Of course not. It's been done thousands of times already. But it doesn't make any economic sense. It's like putting a McDonald's at the top of Everest. Is it possible? Of course. Is it worth the enormous difficulty and expense to put one there? Not even a little.
You might only care about coding models, but text is dominating the market share right now and Grok is the #2 model for that in arena rankings.
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.
Minus one big one: permitting. Every datacentre I know going up right now is spending 90% of their bullshit budget on battlig state and local governments.
Hell, you're going to lose some fraction of chips to entropy every year. What if you could process those into reaction mass?
xAI’s first data center buildout was in the 300MW range and their second is in the Gigawatt range. There are planned buildouts from other companies even bigger than that.
So data center buildouts in the AI era need 1-2 orders of magnitude more power and cooling than your 50MW estimate.
Even a single NVL72 rack, just one rack, needs 120kW.
Same with datacenters in space, not today, but in 1000 years definitely, 100 surely, 10?
As for the economics, it makes about as much sense as running jet engines at full tilt to power them.
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.
> 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...
Yeah, pumps, tubes, and fluids are some of the worst things to add to a satellite. It's probably cheaper to use more radiators.
Maybe it's possible to make something economical with Peltier elements. But it's still not even a budget problem yet, it's not plainly not viable.
> getting quite good here with nanotechnology
Small features and fractal surfaces are useless here.
They have no path to paying for their existence unless they drastically increase usage. There aren't going to be very many big winners in this segment and xAI's expenses are really really big.
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?
putting 1KW of solar on land - $2K, putting it into orbit on Starship (current ground-based heavy solar panels, 40kg for 4m2 of 1KW in space) - anywhere between $400 and $4K. Add to that that the costs on Earth will only be growing, while costs in space will be falling.
Ultimately Starship's costs will come down to the bare cost of fuel + oxidizer, 20kg per 1kg in LEO, i.e. less than $10. And if they manage streamlined operations and high reuse. Yet even with $100/kg, it is still better in space than on the ground.
And for cooling that people so complain about without running it in calculator - >>46878961
>2. The maintenance costs are higher because the lifetime of satellites is pretty low
it will live those 3-5 years of the GPU lifecycle.
Is the plan to have everyone so hopelessly dependent on their product that they grit their teeth and keep on paying?
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.
Peltiers generate a lot of heat to get the job done so even though electricity is pretty much free, probably not a sure bet.
All satellites launched into orbit these days are required to have de-orbiting capabilities to "clean up" after EOL.
I dunno, two years ago I would have said municipal zoning probably ain't as hard to ignore as international treaties, but who the hell knows these days.
Radiative power is really efficient for hot things but not so great when you're trying to keep things down to normal levels. Efficient for shedding heat from a sun but not so much for keeping a cpu from overheating...
- let's say 8x 800W GPUs and neglect the CPU, that's 6400W
- let's further assume the PSU is 100% efficient
- let's also assume that you allow the server hardware to run at 77 degrees C, or 350K, which is already pretty hot for modern datacenter chips.
Your radiator would need to dissipate those 6400W, requiring it to be almost 8 square meters in size. That's a lot of launch mass. Adding 50 degrees will reduce your required area to only about 4.4 square meters with the consequence that chip temps will rise by 50 degrees also, putting them at 127 degrees C.
No CPU I'm aware of can run at those temps for very long and most modern chips will start to self throttle above about 100
Source? I can't immediately find anything like that.
And maintenance and replacing parts and managing flights and ... You're trying to yadda-yadda so much opex here!
> an engineering and physics problem that he will somehow solve
no he won't
1. Assuming 500,000 USD in permitting costs. See 2.
2. Permits and approvals: Building permits, environmental assessments, and utility connection fees add extra expenses. In some jurisdictions, the approval process alone costs hundreds of thousands of dollars. https://www.truelook.com/blog/data-center-construction-costs
3. Assuming a 60MW facility at $10M/MW. See 4.
4. As a general rule, it costs between $600 to $1,100 per gross square foot or $7 million to $12 million per megawatt of commissioned IT load to build a data center. Therefore, if a 700,000-square foot, 60-megawatt data center were to be built in Northern Virginia, the world’s largest data center market, it would cost between $420 million and $770 million to construct the facility, including its powered shell and equipping the building with the appropriate electrical systems and HVAC components. https://dgtlinfra.com/how-much-does-it-cost-to-build-a-data-...
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.
A datacenter costs ~$1000/ft^2. How much equipment per square foot is there? say 100kg (1 ton per rack plus hallway). Which is $1000 to put into orbit on Starship at $100/kg. At sub-$50/kg, you can put into orbit all the equipment plus solar panels and it would still be cheaper than on the ground.
if the current satellite model dissipates 5kW, you can't just add a GPU (+1kW). maybe removing most of the downlink stuff lets you put in 2 GPUs? so if you had 10k of these, you'd have a pretty high-latency cluster of 20k GPUs.
I'm not saying I'd turn down free access to it, but it's also very cracked. you know, sort of Howard Hughesy.
Datacenters already exist. Putting datacenters in space does not offer any new capabilities.
More convenient. But I'm balancing the cost equation. There are regimes where this balances. I don't think we're there yet. But it's irrational to reject it completely.
> Or put it on a boat, which is still 100 times more sensible than outer space
More corrosion. And still, interconnects.
Now that I think of it, a big hydro dam would be perfect: power and cooling in one place.
Gemini is practically guaranteed. With the ad model already primed, their financial resources, their traffic to endlessly promote Gemini (ala Chrome), their R&D capabilities around AI, their own chips, crazy access to training data, and so on - they'd have to pull the ultimate goof to mess up here.
Microsoft is toast, short of a miracle. I'd bet against Office and Windows here. As Office goes down, it's going to take Windows down with it. The great Office moat is about to end. The company struggles, the stock struggles, Azure gets spun off (unlock value, institutional pressure), Office + Windows get spun off - the company splits into pieces. The LLMs are an inflection point for Office and Microsoft is super at risk, backwards regarding AI and they're slow. The OpenAI pursuit as it was done, was a gigantic mistake for Microsoft - one of the dumbest strategies in the history of tech, it left them with their pants down. Altman may have killed a king by getting him to be complacent.
Grok is very unlikely to make it (as is). The merger with SpaceX guarantees its death as a competitor to GPT/Gemini/Claude, it's over. Maybe they'll turn Grok into something useful to SpaceX. More likely they'll slip behind and it'll die rapidly like Llama. The merger is because they see the writing on the wall, this is a bailout to the investors (not named Elon) of xAI, as the forced Twitter rollup was a bailout for the investors of Twitter.
Claude is in a weird spot. What they have is not worth $300-$500 billion. Can they figure out how to build a lot more value out of what they have today (and get their finances sustainable), before the clock runs out? Or do they get purchased by Meta, Microsoft, etc.
OpenAI has to rapidly roll out the advertising model and get the burn rate down to meaningless levels, so they're no longer dependent on capital markets for financing (that party is going to end suddenly).
Meta is permanently on the outside looking in. They will never field an in-house competitor to GPT or Gemini that can persistently keep up. Meta doesn't know what it is or why it should be trying to compete with GPT/Gemini/Claude. Their failure (at this) is already guaranteed. They should just acquire GPT 4o and let their aging userbase on FB endlessly talk itself into the grave for the next 30 years while clicking ads.
If Amazon knew what they were doing (they don't right now), they would: immediately split retail + ads and AWS. The ad business ensures that the retail business will continue to thrive and would be highly lucrative. Then have AWS purchase Anthropic when valuations drop, bolt it on to AWS everything. Far less of an anti-trust issue than if what is presently known as Amazon attempted it here and now. Anthropic needs to build a lot on to itself to sustain itself and justify its valuation, AWS already has the answer to that.
If valuations plunge, and OpenAI is not yet sustainable, Microsoft should split itself into pieces and have the Windows-Office division purchase OpenAI as their AI option. It'd be their only path to avoiding anti-trust blocking that acquisition. As is Microsoft would not be allowed to buy OpenAI. Alternatively Microsoft can take a shot at acquiring Anthropic at some point - this seems likely given the internal usage going on at Redmond, the primary question is anti-trust (but in this case, Anthropic is viewed as the #3, so Microsoft would argue it bolsters competition with GPT & Gemini).
That would make your solar panel (40kg) around $60K to put into space.
Even being generous and assuming you could get it to $100 per kg that's still $4000
There's a lot of land in the middle of nowhere that is going to be cheaper than sending shit to space.
Surely given starlinks 5ish year deorbit plan, you could design a platform to hold up for that long... And instead of burning the whole thing up you could just refurbish it when you swap out the actual rack contents, considering that those probably have an even shorter edge lifespan.
This isn't quite true. It's very possible that the majority of that power is going into the antennas/lasers which technically means that the energy is being dissipated, but it never became heat in the first place. Also, 5KW solar power likely only means ~3kw of actual electrical consumption (you will over-provision a bit both for when you're behind the earth and also just for safety margin).
These are all things which add weight, complexity and cost.
Propellant transfer to an orbital Starship hasn't even been done yet and that's completely vital to it's intended missions.
Those flasks don’t have any space age insulating material - mainly just a vacuum…
Technology from 1892…
This adds weight and complexity and likely also forces a much higher orbit.
On the similar lines, why can't one run a refrigerator in space?
I would be. And granted, I know a lot more about launching satellites than building anything. But it would take me longer to get a satellite in the air than the weeks it will take me to fix a broken shelf in my kitchen. And hyperscalers are connecting in months, not weeks.
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.
Yes. These are permitted in weeks for small groups, days for large ones. (In America.)
Permitting is a legitimate variable that weighs in favor of in-space data centers.
I’ve financed two data centers. Most of my time was spent over permitting. If I tracked it minute by minute, it may be 70 to 95%. But broadly speaking, if I had to be told about it before it was solved, it was (a) a real nuisance and (b) not technical.
Think about the stock return over a period - its composed of capital gains and dividends.
Now what happens capital gains disappears and perhaps turns into capital losses? Dividends have to go higher.
What does this mean? Less retained earnings / cashflows that can be re-invested.
Apple is the only one that will come out of this OK. The others will be destroyed for if they dont return cash, the cash balance will be discounted leading to a further reduction in the value of equity. The same thing that happened to Zuckerberg and Meta with the Metaverse fiasco.
Firms in the private sphere will go bust/acquired.
Im not convinced on this TBH in the long-run. Google is seemingly a pure play technology firm that has to make products for the sake of it, else the technology is not accessible/usable. Does that mean they are at their core a product firm? Nah. Thats always been Apple's core thing, along side superior marketing.
One only has to compare Google's marketing of the Pixel phone to Apple - it does not come close. Nobody connects with Google's ads, the way they do with Apple. Google has a mountain to climb and has to compensate the user tremendously for switching.
Apple will watch the developments keenly and figure out where they can take advantage of the investments others have made. Hence the partnerships et al with Google.
Maybe the AI workloads running on it achieve escape velocity? ;)
Downtown Los Angeles: The One Wilshire building, which is the worlds most connected building. There are over twenty floors of data centers. I used Corporate Colo which was a block or two away. That building had at least 10 floors of Data Centers.
Aside from the point others have made that 50 MW is small in the context of hyperscalers, if you want to do things like SOTA LLM training, you can't feasibly do it with large numbers of small devices.
Density is key because of latency - you need the nodes to be in close physical proximity to communicate with each other at very high speeds.
For training an LLM, you're ideally going to want individual satellites with power delivery on the order of at least about 20 MW, and that's just for training previous-generation SOTA models. That's nearly 5,000 times more power than a single current Starlink satellite, and nearly 300 times that of the ISS.
You'd need radiator areas in the range of tens of thousands of square meters to handle that. Is it theoretically technically possible? Sure. But it's a long-term project, the kind of thing that Musk will say takes "5 years" that will actually take many decades. And making it economically viable is another story - the OP article points out other issues with that, such as handling hardware upgrades. Starlink's current model relies on many cheap satellites - the equation changes when each one is going to be very, very expensive, large, and difficult to deploy.
They're losing money now because they're making massive bets on future capacity needs. If those bets are wrong, they're going to be in very big trouble when demand levels off lower than expected. But that's not the same as demand being zero.
What starship? The fantasy rocket Musk has been promising for 10 years or the real one that has thus far delivered only one banana worth of payload into orbit?
This is not how corporate finance works. Capital gains and losses apply to assets. And only the most disciplined companies boost dividends in the face of decline—most double down and try to spend their way back to greatness.
That is exactly what you do - just like with Starlink - toss out the panels with attached GPUs, laser transmitter and small ion drive.
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.
I don’t remember the difference from my science classes, isn’t This the same thing essentially?
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
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.
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-...
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.
Then you get people paying much more money to use less-tightly-moderated space-based AI rather than heavily moderated AI.
You put the cold side of the phase change on the internal cooling loop, step up the external cooling loop as high temp as you can and then circulate that through the radiators. You might even do this step up more than once.
Imagine the data center like a box, you want it to be cold inside, and there’s a compressor, you use to transfer heat from inside to outside, the outside gets hot, inside cold. You then put a radiator on the back of the box and radiate the heat to the darkness of space.
This is all very dependent on the biggest and cheapest rockets in the world but it’s a tradeoff of convenience and serviceability for unlimited free energy.
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...
At the same time, it'd give the country controlling it so much economic, political and military power that it becomes impossible to challenge.
I find that all to be a bit of a stretch, but I think that's roughly what people talking about "the AI race" have in mind.
0. https://www.arccompute.io/solutions/hardware/gpu-servers/sup...
Just admit it was hyperbole.
The short answer is that ~100m2 of steel plate at 1400C (just below its melting point) will shed 50MW of power in black body radiation.
... if you completely ignore the difficulty of getting them up there. I'd be interested to see a comparison between the amount of energy required to get a solar panel into space, and the amount of energy it produces during its lifetime there. I wouldn't be surprised if it were a net negative; getting mass into orbit requires a tremendous amount of energy, and putting it there with a rocket is not an efficient process.
Note that KSP is a game that fictionalizes a lot of things, and sizes of solar panels and radiators are one of those things.
100 years later: "why does everything taste like cadmium?"
with the GPU costing the same, it would only double the capex.
>Even being generous and assuming you could get it to $100 per kg that's still $4000
noise compare to the main cost - GPUs.
>There's a lot of land in the middle of nowhere that is going to be cheaper than sending shit to space.
Cheapness of location of your major investment - GPUs - may as well happen to be secondary to other considerations - power/cooling capacity stable availability, jurisdiction, etc.
Heat pumps are magic. They're something like 300% efficient. Each watt generates 3 watts of useful heat.
> or the real one that has thus far delivered only one banana worth of payload into orbit?
once it starts delivering real payloads, the time for discussions will be no more, it will be time to rush to book your payload slot.
What is this figure based on?
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."
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.
Imo I would be extremely angry if I owned any spacex equity. At least nvidia might be selling to china in the short term... what's the upside for spacex?
You meet this with "well, once it works, it'll be amazing and you'll be queuing up"? How very very musky!
What a cult.
5kg, 500W panel (don’t exactly know what the ratio is for a panel plus protection and frame for space, might be a few times better than this)
Say it produces about 350kWh per month before losses.
Mass to LEO is something like 10x the weight in fuel alone, so that’s going to be maybe 500kWh. Plus cryogenics etc.
So not actually that bad
I wonder if you were thinking about muh emissions for a chemical rocket launched piece of machinery containing many toxic metals to be burnt up in the air in 3-5 years... It doesn't sound more environmentally friendly.
T^4 is not exponential in T, it’s polynomial. For exponential, T must be in the exponent, e.g. 2^T or so.
Still, pretty effective.
Having said that, agree that Elon is full of it.
Second, are you saying that we basically need to have a radiator as big (approximately) as the solar panels?
That is a lot, but it does sound manageable, in the sense that it approximately doubles what we require anyway for power.
So, not saying that it’s easy or feasible, but saying that cooling then seems “just” as difficult as power, not insurmountably more difficult. (Note that the article lists cooling, radiation, latency, and launch costs as known hard problems, but not power.)
Ionizing radiation disrupts the crystalline structure of the semiconductor and makes performance worse over time.
High energy protons randomly flip bits, can cause latchup, single event gate rupture, destroy hardware immediately, etc.
At the end of the day I don't really care either way. It ain't my money, and their money isn't going to get back into the economy by sitting in a brokerage portfolio. To get them to spend money this is as good a way as any other, I guess. At least it helps fund a little spaceflight and satellite R&D on the way.
The known scammer guy? Like these ideas wouldn't pass the questions at the end of a primary school presentation.
"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.
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).
"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...
I don't know of an instance of this happening successfully.
Every DC I’ve been in (probably around 20 in total) has been multi storey.
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.
(I'm ignoring installation costs etc. because actually creating the satellites is ignored here, too)
Of course that didn't work out with this specific acquisition, but overall it's at least a somewhat reasonable idea.
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.
Yes, only doubling the capex. With the benefits of, hmm, no maintenance access and awful networking?
This is widely believed (especially in the US, where, other than the Leaf, most early electric cars never launched), but honestly pretty dubious. The first real electric cars, with significant production:
2010 - Mitsubishi i-MiEV, Nissan Leaf
2011 - Smart electric, Volvo C30 electric, Ford Focus electric, BYD e6.
2012 - Renault Zoe (Renault launched a couple of other vehicles on the same platform ~2010, but they never saw significant production), Tesla Model S (Tesla had a prior car, the Roadster, but it never saw significant production).
2013 - VW eUP, eGolf (VW occasionally put out an electric Golf historically, going back to 1992, but again those were never produced in large quantities).
The big change ~2010 was around the economics of lithium ion batteries; they finally got cheap enough that everyone started pulling their concept designs and small-scale demonstration models into full production.
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-8054... )
It's still good enough to keep your coffee hot for an entire day.
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
Current satellites get around 150W/kg from solar panels. Cost of launching 1kg to space is ~$2000. So we're at $13.3(3)/Watt. We need to double it because same amount need to be dissipated so let's round it to $27
One NVidia GB200 rack is ~120kW. To just power it, you need to send $3 240 000 worth of payload into space. Then you need to send additional $3 106 000 (rack of them is 1553kg) worth of servers. Plus some extra for piping
Just shoot it into space where it's all inaccessible and will burn out within 5 years, forcing a continuous replacement scheme and steady contracts with Nvidia and the like to deliver the next generation at the exact same scale, forever
The energy demand of these DCs is monstrous, I seriously can't imagine something similar being deployed in orbit...
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.
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).
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.
Because the first company to have a full functioning AGI will most likely be the most valuable in the world. So it is worth all the effort to be the first.
A quick search gave me a lifespan of around 5 years for a starlink satellite.
If you put in orbit a steady stream of new satellites every year maintenance is not an issue, you just stop using worn out or broken ones.
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.
I would assume such a setup involves multiple stages of heat pumps to from GPU to 1400C radiatoe. Obviously that's going to impact efficiency.
Also I'm not seriously suggesting that 1400C radiators is a reasonable approach to cooling a space data centre. It's just intended to demonstrate how infeasible the idea is.
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.
Or you float them on the ocean circumnavigating the earth?
Or we put the datacenters on giant Zeppelins orbiting above the clouds?
If we are doing fantasy tech solutions to space problems, why not for a million other more sensible options?
Hillary (he features on the NZ Five Dollar note) was one of those guys who does things for no good reason. He also went to both poles. This only tells us that it is indeed possible, but not that it's desirable or will become routine.
Starship launch costs have a $100/kg goal, so we'd be at $40 / kW, or $4800 for a 120kW cluster.
120kW is 1GWh annually, costs you around $130k in Europe per year to operate. ROI 14 days. Even if launch costs aren't that low in the beginning and there's a lot more stuff to send up, your ROI might be a year or so, which is still good.
[1] - https://www.polytechnique-insights.com/en/columns/space/ultr... [2] - https://space.stackexchange.com/questions/12824/lightest-pos...
ISS radiators are huge 13.6x3.1 m. Each radiates 35 kW. So you need 3 of them to have your 100 kW target. They are also filled with gas that needs pumping so not exactly a passive system and as such can break down for a whole lot of reasons.
You also need to collect that power so you need about the same amount of power coming from solar panels. ISS solar array wings are 35x12 m and can generate about 31 kW of power. So we’ll need at least 3 of them. BTW each weighs a ton, a literal metric ton.
It hardly seems feasible. Huge infrastructure costs for small AI server rooms in space.
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.
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.
Also you say meta will never field a competitor to GPT - but they did llama; not as a commercial product, but probably an attempt at it (and failed). Otherwise agreed.
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.
This is the big thing, but Elon's child porn generator in orbit will be subject to US jurisdiction, just as much as if they were in Alaska. I guess he can avoid state law.
If jurisdiction is key, you can float a DC in international waters on a barge flying the flag of Panama or similar flag of convenience which you can pretty much buy at this scale. Pick a tin-pot country, fling a few million to the dictator, and you're set - with far less jurisdiction problems than a US, Russia, France launched satellite.
Everyone is spending crazy amounts of money in the hopes that the competition will tap out because they can't afford it anymore.
Then they can cool down on their spending and increase prices to a sustainable level because they have an effective monopoly.
The physics of consuming bits of old chip in an inefficient plasma thruster probably work, as do the crawling robots and crushers needed for orbital disassembly, but we're a few years away yet. And whilst on orbit chip replacement is much more mass efficient than replacing the whole spacecraft, radiators and all, it's also a nontrivial undertaking
What that does have to do with anything? If you want to solar-power them, you still are subject to terrestrial effects. You can't just shut off a data center at night.
> Or we put the datacenters on giant Zeppelins orbiting above the clouds?
They'd have to fly at 50,000+ ft to be clear of clouds, I doubt you can lift heavy payloads this high using bouyancy given the low air density. High risk to people on the ground in case of failure because no re-entry.
> If we are doing fantasy tech solutions to space problems, why not for a million other more sensible options?
How is this a fantasy? With Starlink operational, this hardly seems a mere 'fantasy'.
Openrouter is a decent proxy for real world use and Grok is currently 8% of the market: https://openrouter.ai/rankings (and is less than 7% of TypeScript programming)
Stop this trope please. We (1) don't really know what their margins are and (2) because of the hard tie-in to GPU costs/maintenance we don't know (yet) what the useful life (and therefore associated OPEX) is of GPUs.
> If they stopped training and building out future capacity they would already be raking in cash.
That's like saying "if car companies stopped researching how to make their cars more efficient, safer, more reliable they'd be more profitable"
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?
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).
However, with Starship SpaceX has both done more and less than putting a banana in orbit. Less, because it's never once been a true orbit; more, because these are learn-by-doing tests, all the reporting seems to be in agreement that it could already deliver useful mass to orbit if they wanted it to.
But without actually solving full reusability for the upper stage, this doesn't really have legs. Starship is cheap enough to build they can waste loads of them for this kind of testing, but not cheap enough for plans such as these to make sense if they're disposable.
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.
A single server in a data center will consume 5-10 kW.
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
Why not?
A capacity problem can be solved by having another data center the other side of the earth.
If it's that the power cycling causes equipment to fail earlier, then that can be addressed far more easily than radiation hardening all equipment so that it can function in space.
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.
Have you done a calculation yourself?
Starship can replace Falcon 9 and probably be cheaper, if fully reusable, so more profitable. So at least some economic sense is there already.
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.
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.
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.
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
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).
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.
Anyway, promising some fantasy and never delivering is definitely a typical Elon endeavor.
If you put a pipe with hot gas inside, in space, it will get colder by convection.
Blow air through the pipe.
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".
Distributing useful work over so many small objects is a very hard problem, and not even shown to be possible at useful scales for many of the things AI datacenters are doing today. And that's with direct cables - using wireless communication means even less bandwidth between nodes, more noise as the number of nodes grows, and significantly higher power use and complexity for the communication in the first place.
Building data centres in the middle of the sahara desert is still much better in pretty much every metric than in space, be it price, performance, maintainance, efficiency, ease of cooling, pollution/"trash" disposal etc. Even things like communication network connectivity would be easier, as at the amounts of money this constellation mesh would cost you could lay new fibre optic cables to build an entire new global network to anywhere on earth and have new trunk connections to every major hub.
There are advantages to being in space - normally around increased visibility for wireless signals, allowing great distances to be covered at (relatively) low bandwidth. But that comes at an extreme cost. Paying that cost for a use case that simply doesn't get much advantages from those benefits is nonsense.
I'm not a space engineer but I'd imagine that smaller satellites can make due with a lot of passive cooling on the exterior of the housing, whereas a shopping-mall sized computer in space would will require a lot of extra plumbing.
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).
(1) There are orbital arrangements that allow satellites to stay close together with minimal orbital corrections. Scott Manley mentioned this in one of his videos.
Is that 5kW of electrical power input at the terminals, or 5kW irradiation onto the panels?
Because that sounds like kind of a lot, for something the size of a fridge.
To use that loophole, the rockets launched by SpaceX would have to be “not owned by a US-company”. Do you think the US government would allow that to happen?
Think of heat like flowing water or charge. Only an altitude or voltage delta creates the flow needed to harvest energy.
You get no useful energy from heat you are already trying to shed because you have no delta to work with. (The entire problem exists because there is no surrounding environment with high heat capacity and lower heat.)
Are Earth-based datacenters actually bound by some bottleneck that space-based datacenters would not be? Grid connections or on-site power plants take time to build, yes. How long does it take to build the rocket fleet required to launch a space “datacenter” in a reasonable time window?
This is not a problem that needs to be solved. Certainly not worth investing billions in, and definitely not when run by the biggest scam artist of the 21st century.
Source: I am out of LEDs and LASERs and now handle aerospace solar for a private company. Guess who almost everyone in the private sector flies on?
Minimizing payload at any point was easily worth a billion dollars. And given how heavy and nessisary the radiators are (look them up), you can bet a decent bit of research was invested in making them lightweight.
Heck, one bit of research that lasted the entire lifetime of the shuttle was improving the radiative heat system [1]. Multiple contractors and agencies invested a huge amount of money to make that system better.
Removing heat is one of the most researched problems of all space programs. They all have to do it, and every gram of reduction means big savings. Simply saying "well a DC will need more of it, therefore there must be low hanging fruit" is naive.
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.
To keep things in orbit ion thrusters work nicely and require just inert gases to keep them functioning. Plus on a low Earth orbit there are suggestions that a ramjet that capture few atoms of atmosphere and accelerates them could work.
Radiative cooling scales by 4th power temperature. So if one can design electronics to run at, say, 100 C, then calling would be much less problematic.
But radiation is the real problem. Dealing with that would require entirely different architecture/design.
Because the permitting process is much easier and there are way, way fewer authorities that can potentially shut you down.
I think this is the entire difference. Space is very, very lightly regulated, especially when it comes to labor, construction and environmental law. You need to be able to launch from somewhere and you need to automate a lot of things. But once you can do this, you escaped all but a few authorities that would hold power over you down on Earth.
No one will be able to complain that your data center is taking their water or making their electricity more expensive, for example.
Someone mentioned in the comments on a similar article that sun synchronous orbits are a thing. This was a new one to me. Apparently there's a trick that takes advantage of the Earth not being a perfect sphere to cause an orbit to precess at the right rate that it matches the Earth's orbit around the sun. So, you can put a satellite into a low-Earth orbit that has continuous sunlight.
https://en.wikipedia.org/wiki/Sun-synchronous_orbit
Is this worth all the cost and complexity of lobbing a bunch of data centers into orbit? I have no idea. If electricity costs are what's dominating the datacenter costs that AI companies are currently paying, then I'm willing to at least concede that it might be plausible.
If I were being asked to invest in this scheme, I would want to hear a convincing argument why just deploying more solar panels and batteries on Earth to get cheap power isn't a better solution. But since it's not my money, then if Elon is convinced that this is a great idea then he's welcome to prove that he (or more importantly, the people who work for him) have actually got this figured out.
Optimization is literally how contractors working for the government got rich. Every hour they spent on research was directly billed to the government. Weight reduction being one of the most important and consistent points of research.
Heck, R&D is how some of the biggest government contractors make all their dough.
SpaceX is built on the billions in research NASA has invested over the decades. It looks like it's more innovative simply because the USG decided to nearly completely defund public spending in favor of spending money on private contractors like SpaceX. That's been happening since the 90s.
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.
It may happen one day, but we are very, very far from that. As of now, big countries watch their space corporations very closely and won't let them do this.
Nevertheless, as an American, you can escape state and regional authorities this way. IIRC The Californian Coastal Commission voted against expansion of SpaceX activities from Vandenberg [1], and even in Texas, which is more SpaceX-friendly, there are still regulations to comply with.
If you launch from international waters, these lower authority tiers do not apply.
[1] https://www.latimes.com/business/story/2025-08-14/california...
This means you need some sort of heat pump. For a practical example you can look at the ISS, which has what they call the "External Active Thermal Control System" (EATCS), it's a complicated system and it provides 70kW of heat rejection. A datacenter in space would need to massively scale up such a system in order to cool itself.
This. Like it would make far more sense to colonize the poles than Mars.
A grift the size of Dogecoin, or the size of "free speech" enthusiast computing, or even the size of the criminal enterprises that run on the dark web, is tiny in comparison to the footer cost and upkeep of a datacenter in space. It'd also need to be funded by investments (since criminal funds and crypto assets are quite famously not available in up-front volumes for a huge enterprise), which implies a market presence in some country's economy, which implies regulators and risk management, and so on.
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...)" ?
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
This is a pump-and-dump bid for investor money. They will line up to give it to him.
There must be many power consumers in the satellite, e.g. radio receivers, lasers, computers and motors, where the consumed energy eventually is converted into heat, but the radio transmitter of a communication satellite must take a big fraction of the average consumed power.
The radio transmitter itself has a great efficiency, much greater than 50%, possibly greater than 90%, so only a small fraction of the electrical power consumed by the transmitter is converted into heat and most is radiated in the microwave signal that goes to Earth's surface.
So there's no regulatory or tax benefit to hosting in space.
Thus the extremities of the foil, which are far from the satellite body, will be much cooler than the body, so they will have negligible contribution to the radiated power.
The ideal heatsink has fins that are thick close to the body and they become thinner towards extremities, but a heatsink made for radiation instead of convection needs a different shape, to avoid a part of it shadowing other parts.
I do not believe that you can make an efficient radiation heatsink with metallic foil. You can increase the radiating surface by not having a flat surface, but one covered with long fins or cones or pyramids, but the more the surface is increased, the greater the thermal resistance between base and tip becomes, and also the tips limit the solid angle through which the bases radiate, so there must be some optimum shape that has only a limited surface increasing factor over the radiation of a flat body.
You'll note that there is still a frame that it gets unfolded with and that you've got the additional mechanical apparatus to do the unfurling (and the human there to fix it if there are problems.
Again, you'll note that there is frame material there.
You don't have a sheet of glass on it, but space doesn't give you the mass savings you think it does.
Those are cutting edge tech (designed to work at Jupiter's distance) and that's about 40 m^2 of space (ten times more than you're describing) and they mass 176 kg ( https://doi.org/10.1007/s11214-025-01190-6 ). If we assume that scales down linearly, the cutting edge technology for solar panels is 20kg for 4m^2 which is more than your estimates. ... And they have problems and can fail to deploy. https://spacenews.com/cygnus-solar-array-fails-to-deploy/ https://spaceflightnow.com/news/n1105/25telstar14r/index.htm... https://www.nasa.gov/history/50-years-ago-skylab-2-astronaut... https://ntrs.nasa.gov/api/citations/20210020397/downloads/Al...
You'll note that the Cygnus used the same design as Lucy, though smaller.
https://en.wikipedia.org/wiki/Cygnus_(spacecraft)
> Starting with the Enhanced variant, the solar panels were also upgraded to the UltraFlex, an accordion fanfold array, and the fuel load was increased to 1,218 kilograms (2,685 lb).
Digging more into Ultra Flex, https://www.eng.auburn.edu/~dbeale/ESMDCourse/Site%20Documen...
> Specific performance with 27% TJ cells: >150 W/kg BOL & > 40 kW/m3 BOL
So there's your number. 150 W/kg of solar panel array. 1 kW is about 7 kg.
They're not cheap.
https://spacenews.com/36576ousted-from-first-orion-flight-ci...
> In 2011, Orbital replaced Dutch Space on the project and gave ATK’s space components division, which was already supplying the substrates for Dutch Space’s Orion solar panels, a $20 million deal to provide UltraFlex arrays for later Cygnus flights.
The research article linked above does not claim a better emissivity than Vantablack, but a resistance to higher temperatures, which is useful for high temperature sensors (used with pyrometers), but irrelevant for a satellite that will never be hotter than 100 Celsius degrees, in order to not damage the electronic equipment.
Ah, I see the idea now. It is to get people to talk about robotics and how robots will be able to do all this on the moon or wherever.
Instantly pumps Tesla stock here now on earth!
Solar in space is about 5-10x as effective as solar on the ground.
Nobody describes a satellite by specifying the amount of heat that it produces, but by the amount of electrical energy that it consumes.
In a communication satellite, a large fraction of the consumed electrical energy goes into the radio transmitter. Radio transmitters are very efficient and most of the consumed power is emitted as radio waves and only a very small part is converted into heat, which must be handled by the cooling system.
So in any communication satellite, a significant fraction of the consumed energy does not become heat.
This is with an ideal radiator and perfect pointing so it receives no incident light, so in practice you need a bigger one than this.
However, if you think launching a solar panel that is the size of 10 NYC city blocks is "manageable," then why not throw in a radiator that is about 15 city blocks in size?
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.
And take off again, if reusable spacecraft are meant to be used.
There’s some truly magical thinking behind the idea that government regulations have somehow made it cheaper to launch a rocket than build a building. Rockets are fantastically expensive even with the major leaps SpaceX made and will be even with Starship. Everything about a space launch is expensive, dangerous, and highly regulated. Your datacenter on Earth can’t go boom.
One is based on boring old analysis, hard numbers, and, worst of all, continually updating the analysis as more information (e.g., Raptor’s severe expectations vs reality shortfall) becomes available. People who use this approach don’t seem to have an opinion of Starship that is trending upward.
The other approach seems to be based on vibes, and trusting that Starship will meet its original design goals despite the fact that no rocket project has ever come close to such an achievement. If there’s ever any introspection about why Starship should be the exceptional project that actually does meet its performance goals, the conclusion tends to be something about how Starship is special because it’s being developed by a private company. And I’ve noticed that, if the conversation does get to this point, you can send it in all sorts of unpredictable and fascinating directions by saying words like “OTRAG” and “Conestoga.”
So your huge metal plate would radiate (1673/374)^4 = 400 times less heat, i.e. only 125 kW.
In reality, it would radiate much less than that, even if made of copper or silver covered with Vantablack, because the limited thermal conductivity will reduce the temperature for the parts distant from the body.
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
Moreover, a heat pump would add an equipment with moving parts that can fail, requiring maintenance.
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.
Then it's roughly 10x-15x and still works.
> Invest in reality, not in billionaire's fantasies.
SpaceX has dramatically reduced payload cost already. How is that a fantasy?
Parent said it would make more sense.
I guess in terms of the relative level of stupidity on display, it would be slightly less stupid to build huge reflectors in space than it is to try to build space datacenters, where the electricity can only power specific pieces of equipment that are virtually impossible to maintain (and are typically obsolete within a few years).
From individual POV yes, but already Falcons are not that expensive. In the sense that it is feasible for a relatively unimportant entity to buy their launch services.
"The satellite is built on Earth, so I’m not sure how it dodges any of those regulations practically."
It is easier to shop for jurisdiction when it comes to manufacturing, especially if your design is simple enough - which it has to be in order to run unattended for years. If you outsource the manufacturing to N chosen factories in different locations, you can always respond to local pressure by moving out of that particular country. In effect, you just rent time and services of a factory that can produce tons of other products.
A data center is much more expensive to build and move around. Once you build it in some location, you are committed quite seriously to staying there.
Nobody should doubt that it's possible, since it's been done. It just doesn't make any sense to do it purely for the sake of having computers do things that could be done on the ground.
There's nothing weird about using jet engines to make electricity. The design of a turbine designed to generate thrust isn't necessarily that different from a turbine designed to generate electricity. You can buy a new Avon gas turbine generator today, the same engine used in the Canberra, Comet, Draken, and many others. It makes about a million times more economic sense than putting GPUs in space to run LLMs.
That is clearly not true. How do you power the data center on antarctica? May i remind you it will be in the shadow of earth for half a year.
This may be what they are going for, but there are two effectively religious beliefs with this line of thinking, IMO.
The first is that LLMs lead to AGI.
The second is that even if the first did turn out to be true that they wouldn't all stumble into AGI at the same time, which given how relatively lockstep all of the models have been for the past couple of years seems far more likely to me than any single company having a breakthrough the others don't immediately reproduce.
2 * pi * r^2 * L / (4 * pi * d) * (1 -a) = 4 * pi * r^2 * sigma * T^4
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.
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.
What do you mean we don’t have any plans to avoid that? It is a super well studied topic of satelite management. Full books have been written on the topic.
Here is just one: https://ntrs.nasa.gov/api/citations/20230002470/downloads/CA...
Did you think satelites are kept apart by good luck and providence?
The “+ solar power” part is the majority of the energy. Solar panel efficiency is only about 25-30% at beginning-of-life whereas typical albedos are effectively 100%. So your estimate is off by at least a factor of three.
Also, I’m not sure where you got 5 kw from. The area of the satellite is ~100 m2, which means they are intercepting over 100 kw of bolometric solar power.
This is a Musk escapade, so my guess would be extraterritoriality and absence of jurisdiction.
It’s not an automatic deal breaker, of course. Falcon 9 is obviously a promising success. But Starship is also working with some new challenges that Falcon 9 didn’t have to worry about.
Many of these stem from design compromises that were forced by Starship’s secondary goal of being capable of a trip to Mars. In that respect, it very much resembles another major project to produce a heavy launch vehicle with a reusable combination payload fairing and upper stage that is also capable of carrying a human crew: the Space Shuttle.
- SpaceX launched its first rocket successfully.
- California voted to build high speed rail.
Eighteen years later:
- SpaceX has taken over the space industry with reusable rockets and a global satcom network, which by itself contains more than half of all satellites in orbit.
- Californian HSR has spent over thirteen billion dollars and laid zero miles of track. That's more than 2x the cost of the Starship programme so far.
Building stuff on Earth can be difficult. People live there, they have opinions and power. Their governments can be dysfunctional. Trains are 19th century technology, it should be easier to build a railway than a global satellite network. It may seem truly magical but putting things into orbit can, apparently, be easier.
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.
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.
Space changes this. Laser based optical links offer bandwidth of 100 - 1000 Gbps with much lower power consumption than radio based links. They are more feasible in orbit due to the lack of interference and fogging.
> Building data centres in the middle of the sahara desert is still much better in pretty much every metric
This is not true for the power generation aspect (which is the main motivation for orbital TPUs). Desert solar is a hard problem due to the need for a water supply to keep the panels clear of dust. Also the cooling problem is greatly exacerbated.
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.
The lack of launch costs more than offset the need for extra panels and batteries.
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.
Of course this doesn't solve the myriad problems, but it does put dissipation squarely in the category of "we've solved similar problems". I agree there's still no good reason to actually do this unless there's a use for all that compute out there in orbit, but that too is happening with immense growth and demand expected for increased pharmaceutical research and various manufacturing capabilities that require low/no gravity.
In Spain, 1kWp of solar can expect to generate about 1800 kWh per year. There's a complication because seasonal difference is quite large - if we assume worst case generation (ie what happens in December), we get more like 65% of that, or 1170 kWh per year.
That means we need to overbuild our solar generation by about 7.5x to get the same amount of generation per year. Or 7.5kWp.
We then need some storage, because that generation shuts off at night. In December in Madrid the shortest day is about 9 hours, so we need 15 hours of storage. Assuming a 1kW load, that means 15kWh.
European wholesale solar panels are about €0.1/W - €100/kW. So our 7.5kWp is €750. A conservative estimate for batteries is €100/kWh. So our 15kWh is €1500. There's obviously other costs - inverters etc. But perhaps the total hardware cost is €3k for 1kW of off-grid solar.
A communications satellite like the Eurostar Neo satellite has a payload power of 22 kW and a launch mass of 4,500 kg. Assuming that's a reasonable assumption, that means about 204kg per kW. Current SpaceX launch costs are circa $1500 per kg - but they're targeting $100/kg or lower. That would give a launch cost of between $300k and $20k per kW of satellite power. That doesn't include the actual cost of the satellite itself - just the launch.
I just don't see how it will make sense for a long time. Even if SpaceX manage to drastically lower launch costs. Battery and solar costs have also been plummeting.
https://www.spaceconnectonline.com.au/manufacturing/4751-air...
https://www.nextbigfuture.com/2025/01/spacex-starship-roadma...
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.
[1] https://www.nlr.gov/news/detail/features/2021/scientists-stu...
No, because of the costs of acquiring land that the railway goes through.
A data center is nowhere near that and requires constant physical interventions. How do they suggest to address this?
It's like his "Mars Colony" junk - and people lap it up, keeping him in the news (in a not explicitly negative light - unlike some recent stories....)
Anywhere on earth is better than space for this application.
- You have to size your cooling towers for your hottest hour. Doing this saves you no capital costs.
- You barely have to run the fans on your cooling towers in the winter because the air is so cold. So often this also won’t save you much operating costs.
- Already there is an essentially unlimited amount of so called “waste heat” from power plants and factories. Building district heating systems is extremely capital intensive, which is why this isn’t done more.
- As a municipality it’s just a horrible idea to make the heating system of your whole city rely on a random company continuing to operate (even worse if said company is in a potential bubble). This is why most district heating systems work with power plants - they already have the government involved in ensuring their continuing operations.
Too bad the fire trucks can't get to you when you catch on fire from that hot GPU.
“The reason I concentrate my research on these urban environments is because the composition of soiling is completely different,” said Toth, a Ph.D. candidate in environmental engineering at the University of Colorado who has worked at NREL since 2017. “We have more fine particles that are these stickier particles that could contribute to much different surface chemistry on the module and different soiling. In the desert, you don’t have as much of the surface chemistry come into play.”
I'd say less than a third.
X failing and can't pay its debts? Welp, better give him a government bailout otherwise no more rockets for you!
I still think a lot about the failed OpenAI coup, and how different things would be now if Microsoft hadn't backed Altman. Would this hype cycle and bubble grown so ridiculous if there were more conscientious people in charge at the front-runner? We will unfortunately never know. I really wish that board had planned out their coup better.
(Space doesn’t help in cooling GPUs in a satellite - space makes cooling worse)
e.g. the lack-of-a-thing that makes a thermos great at keeping your drink cold too
I'm pretty his point is that while cooling is an impossibility, it is not the only one!
> 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.
We use them because they're many orders of magnitude cheaper and simpler for anywhere near the same bandwidth for the distances required.
Is it reasonable to use Neo as a baseline? Modern Starlink satellites can weigh 800kg, or less than 20% of Neo. I see discussions suggesting they generate ~73kw for that mass. I guess because they aren't trying to blanket an entire continent in signal? Or, why are they so much more efficient than Neo?
Interestingly the idea of doing compute in space isn't a new one, it came up a few years ago pre-ChatGPT amongst people discussing the v2 satellite:
https://forum.nasaspaceflight.com/index.php?topic=58374.msg2...
Still, you make good points. Even if you assume much lighter satellites, the GPUs alone are very heavy. 700kg or so for a rack. Just the payload would be as heavy as the entire Starlink satellite.
You cannot put a power station in the middle of a city centre, you can put a datacentre there. The main reason this isn't done more is that it's expensive to build heat network between the 'far out of town industrial area' where they put the heat sources and the city centre where the heat consumers are.
I don't know why a municipality is involved, but regardless you can simply install a backup heat source and/or add a mix of heat suppliers to the network. Backup gas boiler or similar is not that problematic or expensive to add particularly because you don't need to add redundancy as it's just there for a backup scenario.
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.
What radiators look like is foil or sheet covering fluid loops to spread the heat, control the color, and add surface area.
In general, radiators are white because there's no reason for them to absorb visible light, and they're not hot enough to radiate visible light. You want them to be reflective in the visible spectrum (and strongly absorptive/emissive in the infrared).
A white surface pointing at the sun can be quite cool in LEO, < -40C.
They are usually white, because things in a spacecraft are not hot enough to glow in visible light and you'd rather they not get super hot if the sun shines on them.
The practical emittance of both black paint and white paint are very close to the same at any reasonable temperature-- and both are quite good, >90% of this magical material that you cite ;)
Better materials -- with less visible absorption and more infrared emittance -- can make a difference, but you still need to convect or conduct the heat to them, and heat doesn't move very well in thin materials as my sibling comment says.
The graphene radiator you cite is more about active thermal control than being super black. Cheap ways to change how much heat you are dumping are very useful for space missions that use variable amounts of power or have very long eclipse periods, or what move from geospace to deep space, etc. Usually you solve it on bigger satellites with louvers that change what color they're exposing to the outside, but those are mechanical parts and annoying.
I mean why think about anything, you know. Critical thinking is for losers, am I right?
There’s so much overhead you’re hand waving away to make your numbers work.
So the total heat load if 4 MW (of which 1 MW was temporarily electrical energy before it was used by the datacenter or whatever).
Let's assume a single planar radiator, with emissivity ~1 over the thermal infrared range.
Let's assume the target temperature of the radiator is 300 K (~27 deg C).
What size radiator did you need?
4 MW / (5.67 * 10 ^ -8 W / ( m ^2 K ^4 ) * 300 K ^4) = 8710 m ^2 = (94 m) ^2
so basically 100m x 100m. Thats not insanely large.
The solar panels would have to be about 3000 m ^2 = 55m x 55m
The radiator could be aluminum foil, and something amounting to a remote controlled toy car could drive around with a small roll of aluminum wire and locally weld shut small holes due to micrometeorites. the wheels are rubberized but have a magnetic rim, on the outside theres complementary steel spheres so the radiator foil is sandwiched between wheel and steel sphere. Then the wheels have traction. The radiator could easily weigh less than the solar panels, and expand to much larger areas. Better divide the entire radiator up into a few inflatable surfaces, so that you can activate a spare while a sever leak is being solved.
It may be more elegant to have rovers on both inside and outside of the radiator: the inner one can drop a heat resistant silicone rubber disc / sheet over the hole, while the outside rover could do the welding of the hole without obstruction of the hole by a stopgap measure.
Also I'm astounded how important AI data centers are when we are running out of freshwater, to mention a thing we could easily solve with focusing our efforts on it instead of this. But yeah, surely the Space AI Data Centers (aka. "SkyNet") is the most important we must build...
Also this is just about Elon jumping the shark...
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
Computers aren't humans. High-performance silicon can comfortably operate at a junction temperature of 80C to 90C (approx. 360K). Because of that T^4 relationship, a radiator at 85C rejects nearly double the heat per square meter than a radiator at 20C, unless I miss something.
So this makes it a bit more nuanced.
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.
As I've pointed it out to you elsewhere -- how do you couple the 4MW of heat to the aluminum foil? You need to spread the power somewhat evenly over this massive surface area.
Low pressure gas doesn't convect heat well and heat doesn't conduct down the foil well.
It's just like how on Earth we can't cool datacenters by hoping that free convection will transfer heat to the outer walls.
Nowadays such microwave power amplifiers should be made with gallium nitride transistors, which should allow better efficiencies than the ancient amplifiers using LDMOS or travelling-wave tubes, and even those had efficiencies over 50%.
For beamformers, there have been research papers in recent years claiming a great reduction in losses, but presumably the Starlink satellites are still using some mature technology, with greater losses.
Lets assume you truly believe the difficulty is the heat transport to the radiator, how is it solved on earth?
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.
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???
It's both. You have to spread a lot of heat very evenly over a very large surface area. This makes a big, high-mass structure.
> how is it solved on earth?
We pump fluids (including air) around to move large amounts of heat both on Earth and in space. The problem is, in space, you need to pump them much further and cover larger areas, because they only way the heat leaves the system is radiation. As a result, you end up proposing a system that is larger than the cooling tower for many nuclear power plants on Earth to move 1/5th of the energy.
The problem is, pumping fluids in space around has 3 ways it sucks compared to Earth:
1. Managing fluids in space is a pain.
2. We have to pump fluids much longer distances to cover the large area of radiators. So the systems tend to get orders of magnitude physically larger. In practice, this means we need to pump a lot more fluid, too, to keep a larger thing close to isothermal.
3. The mass of fluids and all their hardware matters more in space. Even if launch gets cheaper, this will still be true compared to Earth.
I explained this all to you 15 hours ago:
> If this wasn't a concern, you could fly a big inflated-and-then-rigidized structure and getting lots of area wouldn't be scary. But since you need to think about circulating fluids and actively conducting heat this is much less pleasant.
You may notice that the areas, etc, we come up with here to reject 70kW are similar to those of the ISS's EATCS, which rejects 70kW using white-colored radiators and ammonia loops. Despite the use of a lot of exotic and expensive techniques to reduce mass, the radiators mass about 10 tonnes-- and this doesn't count all the hardware to drive heat to them on the other end.
So, to reject 105W on Earth, I spend about 500g of mass; if I'm as efficient as EATCS, it would be about 15000g of mass.
Using higher heat to raise lower heat is just the most simple case.
But purpose isn't relevant to this constraint, it is a physics constraint. Regardless of purpose, you can't extract useful energy from heat without a heat difference to work with. (And without a heat difference, even "heating" with heat doesn't do anything.)
And it still doesn’t solve the problem of a cascade causing shrapnel density to increase in an orbit shell which then causes satellites to use some of their scarce maneuver budget to avoid collision. But as soon as a satellite exhausts that budget, it becomes fodder for the shrapnel cascade.
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.
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.
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)_/¯
None of the big-box stores have created a monopoly.
Amazon unseated behemoth Walmart with a mere $300,000 startup capital.
Musk founded his empire with $28,000.
But I don't really see how that is relevant to the question of using waste energy to heat homes. We don't have ideal Carnot machines so there's always energy wasted, which most of the time is still good enough for residential heating.
For example - richard stallman is pedantically correct about many things regarding licenses or privacy or any number of related subjects. But nobody can wholeheartedly accept and adopt his viewpoint and behave as he does (no phone, doesn't use non-free software, etc)
Musk is similar in his promises and predictions. Nobody can wholeheartedly accept his views.
But the reason these folks are valuable are - they move the goalposts. Moving the goalposts moves the thoughts and behavior of people close to their viewpoints, and can eventually unseat the complacent middle.
imho :)
EDIT: I think nobody is immune to this. Lots of people will understand the bullshit is deep when someone comes up to them and relentlessly over-the-top flatters them. But they are likely to listen to and accept the person, logic be damned.
And you still haven’t provided a source for your claim.
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.
Well acttshually, it's 100% efficient. If you put 1W in, you will get exactly one watt out, steady state. The resulting steady state temperature would be close to watts * steady state thermal resistance of the system. ;)
I don't think you could use "efficiency" here? The math would be based on thermal resistance. How do you get a percentage from that? If you have a maximum operating temperature, you end up with a maximum operating wattage. Using actual operating wattage/desired operating wattage doesn't seem right for "efficiency".
The conversation was about harnessing energy, from heat, in orbit.
Heat pumps take energy to move energy. But you can't power the heat pump from the heat it is already pushing against the heat gradient.
Waste heat can be used, if there is a difference in heat to work across, but not if there isn't. A datacenter in Antarctica could recover energy from waste heat, against the freezing outdoor temperatures.
In orbital systems, the problem is getting rid of heat, so there isn't some cold place to use to create a heat gradient and harvest energy. Space is cold, but particles are so diffuse they have little heat energy capacity, so essentially a heat insulator, and not useful to create a gradient. Thus the use of radiators.
To be clear I’m not advocating KSP as a reality simulator, or that data centers in space isn’t totally bonkers. However the reality is the hotter the radiator the smaller the surface area for pure radiance dissipation of heat.
Why not do the obvious comparison with terrestrial data centers?
Imagine a liquid which can be electrically charged, and has a low boiling point.
(Ask 3M/DuPont/BASF/Bayer... - context 'immersion cooling')
Attach heat-pipes with that stuff to the chips as is common now, or go the direct route via substrate-embedded microfluidics, as is thought of at the moment.
Radiate the shit out of it by spraying it into the vacuum, dispersing into the finest mist with highest possible surface, funnel the frozen mist back in after some distance, by electrostatic and/or electromagnetic means. Repeat. Flow as you go.
Wouldn't even need to be that 'autonomous', since the installation is fixed.
More like the things simulating fireworks with their LEDs in preprogrammed formation flight over a designated area.
The article itself said the maximum was 50% and it was significantly less of a problem in the desert. Even 50% still beats space by miles, that only increases per kWh cost by ~2c the need for batteries is still far more expensive.
So sure I could bring up other sources but I don’t want to get into a debate about the relative validity of sources etc because it just isn’t needed when the comparison point is solar on satellites.