But general purpose compute no

No? You'd only need one with lots of gpus on the ship at the same time

entirely out of jurisdiction, where it is prohibitively expensive to travel, and impractical for any physical seizure.

you dont need to compute, just store it and P2P amongst satellites.

essentially an orbital NAS.

1) Kessler syndrome is a contingency.

2) This is a logistics issue, not a physical impossibility.

3) Those are different tradeoffs (solar in space). There is not really an argument there.

All in all this is extremely weak reasoning, which is quite the contrast with the definitive title.

I throw this to the "nerds need to feel smarter than Elon" pile of articles. :)

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

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

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

To me it looks like the next Musk’s grift. Remember Mars? Have you heard about it recently? He threw it to the Internet and everyone got excited for a minute. Then nerds did quick math and it didn’t make any sense. And so everyone forgot about Mars. This is the same. Hype everyone up for a week or two to inflate stock before the merger/purchase/IPO/whatever. That is all.

Datacenters in space is ambiguous enough to mean on lunar soil which provides plenty of heat dissipation using geothermal heat pumps.

Similarly mass to orbit is also less problematic if silicon factories (including the refineries) are built on lunar soil as well.

https://pluralistic.net/2024/05/17/fake-it-until-you-dont-ma...

If the nodes are spinning around the earth at orbital velocities, then all the benefits of physical locality are thrown out the window.

It never fails here. Ya'll are soooo determined to assume ulterior motivations. He has always been direct about his motivations, whether it's about politics or business decisions.

To suspect his whole plan for datacenters in space is a ruse or something to drive up some stock price (or whatever), is... just ridiculous. You really think they person who leads SpaceX (more satellites than the rest of the world combined) and Xai (with a competitive frontier model in 2 years starting from scratch), and Tesla (more inference compute than any company on Earth) really knows less than you about the math and physics of this idea??

His immediate focus for Starship has shifted from Mars colonisation to exponential expansion of intelligence, as he thinks it's the best path to extend consciousness. Ridiculous or not, he believes that, and that's the motivation.

Is that possible in our lifetime? I'd be optimistic about that. Can SpaceX pull that off? Space what? ...

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

as always: imho. (!)

we already had this topic before, an example for another good article regarding physical arguments against this idea would be:

"Datacenters in space are a terrible, horrible, no good idea" ~ late 2025

* https://taranis.ie/datacenters-in-space-are-a-terrible-horri...

TL;DR: It's not going to work.

idk ... maybe elon has something else in mind with this merger!?

cheers,

a..z

Just do the basic thermal heat transfer math.

What does "serious" mean

https://spectrum.ieee.org/underground-nuclear-reactor-deep-f...

They make no sense otherwise.

The only other thing I can think of is the whole thing is just a scheme to get investment and they’re never going to actually go through with it.

At this point I kind of think the former is more likely.

then anything that drives money towards your work on that goal is worth pursuing particularly if you think time is short.

But heat radiation rates are proportional to temperature to the 4th power!!!!

That is a magical law. The quality of heat pumps used to concentrate heat, will drive the economics and structure of heat dissipation.

Seldom do we get constraints that favorable to work with.

Besides this, it's concerning how much stuff we're sending to space. One day we'll have to start worrying about satellite parts falling on us.

These companies wanted to merge for financial reasons and the invented reason is nonsensical. We shouldn't even give the nonsensical reason the benefit of trying to make sense of it.

Reusable rockets make no sense.

Autonomous cars make no sense.

Data centers in space make no sense. <--- You are here.

Humanoid robots make no sense.

"Just change the law" ok sure we'll get right on it.

My take-away is - SpaceX is still an extremely good stock to hold. However, the stupid money will buy the stock at IPO on the promise of space datacentres.

When SpaceX inevitably u-turns on this plan and the stock plummets temporarily, THAT will be a good time to buy in.

What they are trying to do is an a very ambitious engineering challenge in several highly integrated domains, from spaceships to robotics, gpu, server design , ai. Typical stakes are high margins are high.

Project also pushes boundaries of what human can do the same way starlink did. 20 years ago starlink scale was also an "impossible" thing. Is it possible now to push one gpu and serve it from space? Yes, can you do it at scale? Big question.

Obstacles :

Price per kg to orbit. They aim to go from $150 to $10 per kg. Can they deliver? Big question, but having something that demands so many starship, like GPU heavy tasks, will help them achieve this goal. Benefits? No rent, no cooling issues, cheap sun-powered electricity 24 hours a day, unlike anywhere else on Earth.

Jurisdiction. Servers can't be shut down or taken away by police, etc.

Cooling. Yes, it's a vacuum, but with $10 per kg, you can deliver pipes and coolant, and since you don't have space constraints, you can build these pipes with a robot, making that datacenter extremely cheap.

3. Labor. If a robot can do primitive tasks combined with design that is fully remote, you labor costs goes almost to 0.

the output: with $10 per pg, delivering solar panels, coolant + robot for some urgent fixes. Robots even with current technology can swap a harddrive for example, especially if hardware is built to be mantained by robots not human. You don't need large construction, you invest into design, that once assembled , cost you maybe comparable amount of hardware to deliver. After that it runs for free!

The economy if this obviously beating anything exised on earth.

Putting data centers in space keeps them out of reach of humans with crowbars and hammers, which may have been a vulnerability for those robots Tesla is building.

The website insists that you let it record your voice in order to show you the dangers of AI. Is it trolling the visitor? https://civai.org/talk

Does not feel like a vibe.

This is while they try to find a solution to earn money with it.

Where is the tech?

- have very non-deterministic latency

- are located outside of a country that can protect you (ie China could disrupt your space data center)

- have to pay millions of dollars to swap out hardware

Space is cold but has little mass. Either heat can radiated or transfered. To transfer heat, mass which easily absorbs heat is required. The moon might be suitable for that.

We're living in the Age of Distraction… amusing ourselves to death (as usual).

The regulatory framework is getting more and more difficult for data centers.

The options are move to countries with less of an uphill regulatory burden (UAE?), but this comes with other issues.

Space it is.

You do this when the most fragile part in the system fails. Solar panels good for 25 years but the SSDs burn out after 2? Incinerate the lot!

This kind of thinking is late capitalist brain rot. This kind of waste should be a crime.

Anyone planning expenditures as large as a modern data center thinks about all kinds of risks (earthquakes, climate, power, etc), and so perhaps there is a premium for GPUs that are out of the reach of your median angry unemployed guy.

(yes, this is nuts, but I can easily imagine some fever-dream pitch meeting where Musk is talking about it)

This statement is actually completely false. The bottleneck is not cost of building data centers, but the energy accessible on the planet. How much we're willing to pay for increasing that is currently very unclear, but it's far more than the current cost of building a terrestrial data center.

As Jensen Huang famously touted their performance per watt, saying "Our customers won't buy our competitor's chips even if they were free."

Seems like a pretty obvious "no" to me. Loudoun County is a much better choice, just to pick one alternative. Antarctica is an awfully inhospitable place and running a data center there would be a nightmare.

And yet it's way better than space. It's much easier to get to. Cooling is about a thousand times easier. The radiation environment is much more forgiving.

This whole concept is baffling to me.

(Incidentally, a similar thought experiment is useful when talking about colonizing Mars. Think about colonizing the south pole. Mars is a harsher environment in just about every way, so take the difficulties of colonizing the south pole and multiply them.)

1) Water scarcity and energy scarcity here on earth

2) It will drive down launch costs and promotes investment in orbital facilities and launch capabilities.

those two reasons alone are enough.

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, that just power, let's assume that cooling will cost us same per kg, the 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. We're already at $6.3 mil a pop for just hauling it up to orbit, with no cost of solar cells included

I'd imagine comparable hardware for just some solar + batteries on ground is around $200k. I dunno where the repeated 5x cost number comes from. I suspect whoever pushed it was just lying

I mean, I still remember promises of $1000-per-kg for space launches, and how e.g. Gigafactory will produce half of the world battery supply, and other non-scientific fiction peddled by Musk. Remember when SpaceX suggested in 2019 that the US Army could use its Starship rockets to transport troops and supplies across the planet in minutes? I do. By the way, have they finished testing Starship yet, is it ready?

- Data centres need a lot of power = giant vast solar panels

- Data centres need a lot of cooling. That's some almighty heatsinks you're going need

- They will need to be radiation-hardened to avoid memory corruption = even more mass

- The hardware will be redundant in like 2 years tops and will need replacing to stay competitive

- Data centres are about 100x bigger (not including solar panels and heat sinks) than the biggest thing we've ever put in space

Tesla is losing market share (and rank increasingly poorly against alternatives), his robots are gonna fail, this datacentre ambition needs to break the laws of physics, grok/twitter is a fake news pedo-loving cesspit that's gonna be regulated into oblivion. Its only down from here on out.

This is BS, everyone knows that this is BS, but because this is Elon, there are still people who don't call out the BS.

It might be distraction, he might be delusional, he might be asking his investors to stop asking for profit by giving them shares from SpaceX, but this is not him discovering new physics.

How's that full-self driving promised for decades working out?

How's the destruction of USAID working out (oh you wouldn't know a million dead now)

We already have a data-center in space, sort-of, here's how many radiation panels it has to deploy for just the heat produced from the small number of low-power computers

* https://i.sstatic.net/cpIBo.jpg

(ISS, all those white panels are thermal heat radiators)

Adding a global UHVDC grid to even out dips in local PV performance due to cloud cover and the diurnal cycle on spaceship earth seems to be magnitudes cheaper and scaleable than this loony pitch.

The only thing making this hard is requiring supranational collaboration.

What matters is that investors and shareholders love to hear about future space data centers.

Obligatory /s.

You can’t read a 300 word article in 1930 and know that a formula 1 engine could not be built.

Disagree there are bunch of scenarios where Data Centers in space make sense. Like nuclear annihilation and having vaults across the globe to communicate and get back lost information because ground data centers would be wiped out by EMP from blasts.

(If you can't xcancel it yourself your hacker card is revoked.)

As most engineers realize right away, it is not going to be profitable to operate a regular datacenter in space, per the article (and I agree), so something else is going on here. Almost all the discussion is about feasibility, which is not by itself going to explain the situation.

It is clearly somewhat feasible to build Starlink level infrastructure and operate it profitably. I would posit that the narrative is a funding vehicle for a more conservative, incremental objective.

The very fact that the infrastructure is in space places the datacenter on the legal and geopolitical high ground. It's hard to raid servers if they are in orbit. It's hard to disable, audit, or arm-wrestle into submission. It doesn't have to have the scale we've come to expect in 2026 to be useful. And it's for inference, not training, of course. Useful levels of inference is computationally cheap. There are implications with the financial system as well.

In combination with PLTR technology, what I see is another intelligent and strategic move by Musk to enable and be part of hegemony. He is a central player not making decisions in isolation. They are playing a game with different rules, and therefore different unit economics.

Put those three together and maybe it’s possible to push physics to its limits. Faster networking, maybe 4x-5x capacity per unit compared to earth. Servicing is a pain, might be cheaper to just replace the hardware when a node goes bad.

But it mainly makes sense to those who have the capability and can do it cheaply (compared to the rest). There’s only one company that I can think of and that is SpaceX. They are closing in on (or passed) 8,000 satellites. Vertical integration means their cost-base will always be less than any competitor.

This is not true!

    1. Inference
    2. Training

Training is a whole other ballgame. It is parallelisable, sure, but only through heroic efforts involving fantastically expensive network switches with petabits of aggregated bandwidth. It also needs more general-purpose GPUs, access to petabytes of data, etc. The name of the game here is to bring a hundred thousand or more GPUs into close proximity and connect them with a terabit or more per GPU to exchange data. This cannot be put into orbit with any near-future technologies! It would be a giant satellite with square kilometers of solar and cooling panels. It would certainly get hit sooner or later by space debris, not to mention the hazard it poses to other satellites.

The problem with putting inference-only into space is that training still needs to go somewhere, and current AI data centres are pulling double-duty: they're usable for both training and inference, or any mix of the two. The greatest challenge is that a training bleeding edge model needs the biggest possible clusters (approaching a million GPUs!) in one place, and that is the problem -- few places in the world can provide the ~gigawatt of power to light up something that big. Again, the problem here is that training workloads can't be spread out.

Space solves the "wrong" problem! We can distribute inference to thousands of datacentre locations here on Earth, each needs just hundreds of kilowatts. That's no problem.

It's the giaaaant clusters everyone is trying to build that are the problem.

I suspect that Musk wants to build space data centers in order to mitigate political and societal problems, which may yet prove more intractable than cooling in space.

The current expansion of terrestrial data centers has already caused a huge backlash. Their adversaries may well try to regulate them out of existence, at least locally. If an important jurisdiction like California or Germany subjects building of new data centers to regulations similar to building, say, a new nuclear power station, they will achieve a de-facto stop on further development there even without banning them outright.

Space, while not entirely lawless, is much harder to regulate this way. Local authorities have no power over it, nor do governments of nations without space capabilities. Big authorities of big nations (the FAA etc.) do, but they will likely be more friendly to already established launch businesses like SpaceX, not least because of the geopolitical dimensions of having a vibrant space sector.

From Musk's POV, this may be worth the additional cost and technical troubles.

https://www.pbs.org/newshour/world/pentagon-embraces-musks-g...

Data centers in space make absolute sense when you want as close to real time analysis on all sorts of information. Would you rather have it make the round trip, via satellite to the states? Or are you going to build these things on the ground near a battlefield?

Musk is selling a vision for a MASSIVE government contract to provide a service that no one else could hope to achieve. This is one of those projects where he can run up the budget and operating costs like Boeing, Northrup etc, because it has massive military applications.

Is this all an effort to utilize more efficient solar panels? Are solar panels really the limiting factor for data centres?

The self-driving car worked too well. Tesla is promising that for over a decade now, and still can't deliver. They came much closer to the goal, but are still very far away from it. Shareholders don't seem to care.

This might also be a new vehicle to mask any space warfare technology deployments.

BUT the fact that we are even arguing about whether or not we should be putting data centers into space is so incredibly absurd to someone who watched the Challenger explode and assumed that space wouldn't be ventured into again in my lifetime.

People don't realize how much the priors have changed. Take a minute to appreciate that. We are living in a world where people are debating if it makes sense to spend a bazillion dollars to put a hard disk into orbit.

I wonder if the Klingons are good at cyber warfare.

https://climatecosmos.com/sustainability/how-close-are-we-to...

However one flaw in this critique is that is only looks at the cost of ground-based solar panels and not their overall scalability. That is, manufacturing cost is far from the only factor. There is also the need for real estate in areas with good sun exposure that also have sufficient fresh water supply for cleaning.

When we really consider the challenges of deploying orders of magnitude more terrestrial solar, it really requires a more detailed and specific critique of the orbital vision. Positive includes near continuous solar exposure (in certain orbits) and no water requirements.

Much has been said of cooling but remember, there is a lot of literal space between the satellites for radiative cooling fins. It is envisioned they would network via optical links, and each mini satellite would be roughly on the order of a desktop GPU (not a whole data center rack). The vision is predicated on leveraging a ton of space for lots of mini satellites on the order of a Dell desktop tower. The terrestrial areas that are really cold are also not that great for solar exposure.

Personally I don't know how it will play out but the core concern I have about making these kinds of absolutist predictions is they make weak assumptions about the sustainable scalability of terrestrial power. And that is definitely the case here in that it only looks at the manufacturing cost of solar.

Engineering is always a question of tradeoffs.

Launch costs are dropping, and we’re still using inefficient rockets. Space elevators & space trains, among others, can drop this much more, the launch costs are still dropping, even using rockets, maybe we’ll never get to elevators & trains the costs will drop so low!

Radiation shielding is not required for VLEO or LEO, and phenomenally more capable aerospace processors are near - hi Microchip Inc! There are many other radiation solutions coming, no doubt with nuclear power.

Satellites can be upgraded at scale, though for many things, it does not make $ sense to upgrade them, but fuel , reaction wheels, solar panels, among other things do make $ sense to replace.

Latency was technically solved in 1995 & 2001 with the first laser comms missions NASDA’s ETS-VI kiku-6 and ESA’s Artemis , and Laser crossbars for comms are common. A full laser TDRS no RF is not yet extant but soon. Earth to deepspace was just demonstrated by ESA.

Cooling can be significantly improved due to lower launch costs, heat piping, RTGs, TEGs, and thermoradiative cells, not to mention sunside solar and darkside inline radiators

Furthermore, it is very likely that as neuromorphics with superior SWaP emerge, we could see very different models of space based computation.

Economic tradeoffs should drive many of these decisions as I’m not discussing the other applications of datacenter in space

If you're looking at this and saying "Lol, no, we don't need data centers in space just to power more GPT sycophancy and some health insurance company's RAG workflows." Then you're right, so just move on from that usage and consider the things we'd like to do in space, and especially the things we're already doing but want to do more of.

I know, my gut was telling me this is ridiculous, premature at best even through the lens of expanding space industry. But then with respect to the need for data centers-- had I even thought about it a year ago, my gut would have laughed if someone had said "Buy Wester Digital, HDD's are a growth stock".

* They assume 1 satalite = 1 GPU. This is quite funny, actually. A single H200 floating in space with a solar panel and an antenna. In reality, a satellite would pack as many chips as the heat/power allows. A Starlink-sized satellite should be able to hold 40 or so chips. There's no reason why a larger satellitte couldn't hold, say, 1024. * They mention training, but sampling is what makes sense here. Training is a different beast, and requires high reliability, high bandwidth, low latency, and a lot of IO. Space would not be ideal for this. I'd expect training to remain terrestrial and just do sampling in space. (FWIW, sampling will be most of the compute allocation). * Also, no one upgrades GPUs in datacenters, they just add new nodes and leave the old ones there. Google still has their P100 nodes running. Not being able to fix them, though, is a significant concern.

Yeah, space is cold, but also you don't have access to large thermal masses with which to exchange heat, so the fact that space is cold does not help much.

In space the only option for cooling is large radiators. If you had a data center in space you'd need enormous radiators -- much larger than the data center itself.

(On Earth we can exchange heat with the environment, and the environment includes convection and the water cycle and ultimately can expel excess heat via high altitude condensation of water vapor where most of the heat released escapes to space. As well clouds can both block insolation as well as keep heat below trapped, but altogether between high altitude condensation and blocking insolation this is the mechanism by which Earth keeps its temperature as a random walk around the average that we enjoy.)

If you assume that these people aren't completely stupid, then there is some reason why they want this workload running at great physical distance from all the people down on Earth. It's probably not to protect people on Earth. After all they'll happily deorbit satellites and other junk from orbit and let it rain down on us. And they will happily destroy the environment with all those rocket launches too. Therefore it must be to protect the workload from us.

What is a workload that is something that people would probably want to destroy, and which would also provide enough value to offset the expense to launch and run in space? The only thing that might make sense is a military AI platform. Think something that observes Earth, launches missiles, and controls terrestrial drone armies remotely, with relatively low latency.

It gets built and launched thanks to endless military budget, and once it is up there, running such an AI from space means that effectively the only people who can take it out are nation state level foes who can launch rockets into low earth orbit. And this thing is a satellite, probably part of a network that is watching the Earth all the time. Start building something that looks like a rocket launch site, and the AI will see, then you get hit by a missile or taken out by a drone first before you get a chance to attack the platform.

It sounds like sci-fi, but in the future, if we let it happen, there could absolutely be nearly invulnerable autonomous AI platforms in space overseeing everything, and making decisions, and issuing commands. Of course there could still be a massive solar flare event, or a Kessler syndrome event that releases us all from AI enforced servitude. Anyway, it's a not so fun thought experiment, and let's hope this stays sci-fi, so we can just enjoy a fun Hollywood film about this rather than experiencing it firsthand.

The biggest problem folks had was even with equipment with 99.9% reliability something breaks every day due the huge raw number of devices involved. And most network equipment is not any where close to being radiation hardened.

I had some fun with it with Bezo’s fist bumping folks because SpaceX was cleaning BlueOrigin clock.

I talked to one of their lawyers and didn’t hear anything afterwards. I left AWS and a couple of years later Amazon announced AWS ground station. I wonder how much my paper contributed to green lighting that project.

Then he talked about datacenters in space and this is something I have some appreciation for, and I immediately knew he couldnt have done much Physics, and sure enough, I was right.

There are "experts" out there who basically have no idea what they are talking about, "it is absolute zero in space in the shadow!", as though radiative cooling is that effective.

And that's not even talking about part failures. How do we replace failed parts in space? This is a scam, but everybody is afraid to openly challenge eloquent "experts" who are confidently wrong.

https://www.nextbigfuture.com/2022/02/spacex-reusable-rocket... -- looks like target price for Starship launch would be $3--$5m according to the author.

Wouldn't the /kg price to SpaceX be:

3000000/100000 = $30/kg -- 5000000/100000 = $50/kg?

If they recover everything and produce fuel at scale, wouldn't it drop the cost even more.

What many people quote here are commercial rates, I think. SpaceX won't pay those prices.

Can someone check my math

Maybe there's a very latency sensitive need to send realtime targeting information to a tomahawk missile in flight? But it's also too bandwidth, compute or cost intensive to send a firehose of raw spy-satellite data to a disposable one-way attack munition?

The data centers in space are actually for the spy satellites to use. That's all I got for practical applications.

Author made a fatal mistake. By flying enough hardware in space, you can simply blot out the sun and steal their solar capacity. Drink their milkshake with a long straw!

I think it’s all farce and technically unsound, but I also think that grok-5-elononly is a helluva drug. It’s really got him ready to rally investors behind “spreading the light of consciousness to the universe”. Oh to see the chat logs of their (Elon and his machine girlfriend)’s machinations.

I also like reading how people argue with not what I wrote but with what they imagined I wrote.

This is the basics, I'm not an expert. But I don't think that you have anything useful at all to say here.

PS. I think the authors argument that millions of satellites might run into each other is silly. There are like 1.5 B cars.

Listen, I totally agree, the tech makes absolutely no sense. It does not. But the fact that someone is willing to spend money on figuring this out is pretty good. The worst thing is going to happen, we'll have a cheaper space travel. And let the guys to have the first hit at it, wasting money on an enormous amount of research needed.

Ain't my money being spent.

As long as we don't have to use Russian rockets to send the US payload to the orbit, I'm cool with it.

The answer to that is that coordination problems are really hard. Much harder even than what are currently unsolved engineering problems. In fact, SpaceX can only launch from California because they have DOD coverage for their launches. Otherwise the California Coastal Commission et al. would have blocked them entirely. Perhaps the innovation for affordable space Internet is combining it with mixed-use technology.

The truth is that in America today self-driving cars (regulated by a state board run by bureaucrats) are easier to build than trains (regulated by every property owner on the train route). Mark Zuckerberg tried to spend some money evaluating a train across the Bay and had to give up. But Robotaxi service is live in San Francisco.

So if there is an angle that makes sense to me it's that they anticipate engineering challenges beatable in a way where regulatory challenges are not.

Even if it's more expensive, Spacex will be able to deploy hardware when no one else can because all the gas turbines and existing power plants have been exhausted and the lead time to build new ones is 5+ years out because of the bureaucratic overhead.

Tesla's valuation has been nuts for a while. The music was going to stop playing at some point, so something something robotaxis, something something androids, something something AI. Keep the investors duped while you can move money around and leverage it to stay relevant.

Cars are out, social media as well (especially X), but Space is still in, and even more so AI. So let's move the cost center with world domination potential (AI) over to the one company that's making money and has a still has a cash-out potential via an IPO.

I'm just so tired of it all. I actually think 'boutique' businesses (companies that generate real value to real users and are profitable now) are the only thing that can save our economy medium-term, but investors and the government are having none of it. And the result is that these bait-and-switch scams will continue.

Nvidia GPUs, particularly H100s, have a failure rate orders of magnitudes higher than traditional CPU-only hardware. I myself have accidentally melted an H100 during a large-scale training run.

While it’s trivial to replace a broken GPU in the ground, it seems to be infeasible in space during the life of the satellite. Getting a human or robot “fixer” spacecraft to it would likely cost more than the $30K GPU itself.

I'm no expert on solar but I thought there was some upper limit on how much power ground-based solar panels can generate per area based on how much energy gets through the atmosphere all the way to ground - and that panel efficiency was approaching that limit.

However, I don't doubt ground-based panels can continue to improve in cost and other metrics and thus exert competitive pressure on space-based solutions.

First mover advantage, and all.

And hardware that is happy in high-radiation environments is not going to be fast.

As an alleged human, I'd like to preserve my option to interfere.

While technically not impossible, the space data center vision appears primarily designed to support SpaceX’s anticipated mid-2026 IPO and justify a $1.5 trillion valuation rather than solve near-term compute constraints.

You cannot do two things at the same time:

1. Make electronics small. 2. Make electronics radiation resistant.

It’s a numbers game. The denser things are packed, the higher the probability that a random high energy particle or ray will damage something.

20 years ago NASA was buying old chips, because those were less susceptible, modern “radiation hardened by design” chips are better than those, but still slower than those for planetary use.

I'm taking the parts of this write-up I don't have expertise with a grain of salt after seeig this.

Kessler cascades are real. Particularly at high altitudes. They're less of a problem in LEO. And in no case can they "[cripple] our access to space." (At current technology levels. To cripple access to space you need to vaporise material fractions of the Earth's crust into orbit.)

Given the solar constant 1361 W/m^2, you can calculate the temperature range based on the emissivity and absorptivity. With the right shape and “color”, the equilibrium temperature can be cooler than most people thought.

I suppose that a space data center powered 100% by solar is no different than this iron ball in principle.

Also why talk about training not inference? That needs data centers too and could be what they're intending to do.

So this post is clearly not an effort to objectively work out the feasibility but just a biased list of excuses to support the author's unsubstantiated opinion.

Taking a creative step back, perhaps datacenters in space support something with Mars?

As much as that might not seem realistic, I also have to counterbalance it with operationalizing and commercializing SpaceX, Starlink and Tesla relatively quickly when so much stays at the R&D stage for so long.

I’d even bet that when they do IPO, there will be ZERO mention of “space data centres” in the prospectus!

The author forgot to add that this is only true from the perspective of their own bias.

To someone else it might make a lot of sense, e.g. someone who expects militant resistance to the "data centers" from the general public or some other actor that is highly unlikely to achieve space capabilities.

what am I missing here?

(We're just saying random physics things right?)

This is just a question. I have no expertise at all with this.

(Space doesn’t help in cooling GPUs in a satellite - space makes cooling worse)

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.

https://share.google/uXWQyAp7a8nE03qoi

Thermos has 2 parts responsible for thermal isolation: vacuum and some coating that reflects heat radiation

Also in earth conditions, most of thermal radiation goes to surrounding air, heating it. This is not the case with vacuum, so thermal radiation will be even more efficient

I'm pretty his point is that while cooling is an impossibility, it is not the only one!

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.

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.

https://research.33fg.com/analysis/debunking-the-cooling-con...

X failing and can't pay its debts? Welp, better give him a government bailout otherwise no more rockets for you!

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.

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.

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.

I don’t remember the difference from my science classes, isn’t This the same thing essentially?

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...)" ?

The problem is whether it's worth the launch costs for it.

If you put a pipe with hot gas inside, in space, it will get colder by convection.

Blow air through the pipe.

This. Like it would make far more sense to colonize the poles than Mars.

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.

e.g. the lack-of-a-thing that makes a thermos great at keeping your drink cold too

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.

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.

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.

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.

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.

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.

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.

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...

Please, no!

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.

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.

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

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.

How much does it cost to launch just the mass of something that big?

Do you see how unrealistic this is?

Given that budget, I can bundle in a SMR nuclear reactor and still have change left.

You don't have experience of being in space, so your "intuition" about cooling is worth literally nothing without formulas / numbers

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.

(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.

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.

You can argue that the current costs are too high and you need new physics or new inventions to bring it down to something more reasonable, yes. But the basic science of radiating heat in space is known. There are proposals for alternative designs that might work better. The question is how much can you build them for and what's the resulting cost profile. Which is an engineering question.

Famous investors like to repeat the quote that “when the tide goes out, that’s when we find out who’s wearing no pants.” When Tesla actually weathers its first market downturn is when we find out how much investors interest is maintained When investment dollars are scarce.

It's a casino and the mirage of billionaire competency would vanish instantly if the media were even slightly skeptical.

The media is owned, it's a sham. It's a play.

> And techies fall for his stories every time, hook, line and sinker, because he's speaking about core geek fantasies.

Not all techies, but enough of them to keep the raft afloat.

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?

solar energy reaches the Earth-Sun Lagrange point 2 (\(L_{2}\)), even though it is located behind the Earth, because it sits slightly beyond the reach of Earth's full shadow (umbra). Here is a breakdown of how this works: Location of \(L_{2}\): The \(L_{2}\) point is located approximately 1.5 million kilometers away from Earth on the side opposite the Sun.Earth's Umbra Length: The tip of Earth's main, total shadow (the umbra) ends before it reaches the \(L_{2}\) point, usually around 92% of the distance to \(L_{2}\).Solar Exposure: Because \(L_{2}\) is outside the full umbra, a satellite at this location (like the James Webb Space Telescope) is never in total darkness.Halo Orbits: Spacecraft at \(L_{2}\) usually do not sit exactly at the point but in a "halo" orbit, which keeps them in constant, direct sunlight to power their solar panels.Penumbra: While the Earth may block some sunlight, the region is technically in a partial shadow (penumbra) or outside of it entirely, allowing for consistent solar energy harvesting. In summary, \(L_{2}\) is not in permanent darkness, and solar power is fully functional there.*

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.

The original vacuum flasks were made of glass, and a lot of laboratory grade vacuum flasks and Dewars are still made of glass. The consumer level Thermoses eventually switched to stainless steel.

Actually, why not colonize Venus instead? Sure, it will be hard, at first, with all the sulphuric acid and intense heat and whatnot, but we colonized America, so why not Venus?

We have a record high population, healthier and richer than ever.

In the 1950s everyone thought we were entering the atomic age, an era when electricity would be too cheap to meter. That didn't happen: making nuclear simultaneously safe and cheap turned out to be much harder than anyone anticipated. Eventually people gave up on the Age Of Atoms and started saying that solar and wind were better. Go back in time and try to sell that in the 1950s and everyone would have thought you were insane. Huge land consumption and it only works intermittently? Why would that ever be easier than building a quick reactor?

And so here we are in 2026. The track record of SpaceX making things quickly and cheaply is vastly better than the modern nuclear industry. That's not necessarily the industries fault, but the over-regulation issue is real. If datacenters have the same problem Musk can still win despite the huge starting handicap. And everyone I know with experience of datacenter construction has similar stories. 90% of it is about dealing with governments and electricity suppliers (but that's mostly the grid, which is the government again).

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.

Oh, that crap again.

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...

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.

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.

Peltiers generate a lot of heat to get the job done so even though electricity is pretty much free, probably not a sure bet.

A heat pump is a “ vapor-compression based cooling system” so that tech is an addition-to not an instead-of.

Whether it’s better probably depends on how expensive the additional efficiency is in practice.

> SkyCool’s Panels save 2x – 3x as much energy as a solar panel generates given the same area.

So if you’re area constrained maybe.

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.

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.

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.

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.”

I would also note that the ISS is a very expensive long term project, a greenfields space station like Tiangong from my understanding was about a 10th of the cost. One of these billionaires could pay for the whole thing out of pocket.

Oh.

Is it below the level where mining and blockchain updates become uneconomic yet?

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

There is also no matter to wick the heat away.

Perhaps space based DCs allow for expansion into ITAR controlled countries and/or sanctioned countries/individuals.

Maybe throw in the fact that nobody can REALLY verify system behavior once its up there. So NSA/CIA etc sure are chomping at the bit to allow it.

I'm sure there's others I haven't thought of- probably less outlandish/tinfoily as well.

turns out pit mining is good for the environment after all

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

The rocket equation will kick your ass every time.

I'm not advocating for space GPUs as a logical next step. so many unsolved problems remain

point is that launch costs per kg are a more realistic blocker than cooling

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."

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.)

What is this figure based on?

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.