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> it is possible to put 500 to 1000 TW/year of AI satellites into deep space, meaningfully ascend the Kardashev scale and harness a non-trivial percentage of the Sun’s power

We currently make around 1 TW of photovoltaic cells per year, globally. The proposal here is to launch that much to space every 9 hours, complete with attached computers, continuously, from the moon.

edit: Also, this would capture a very trivial percentage of the Sun's power. A few trillionths per year.

We also shouldn't overlook the fact that the proposal entirely glosses over the implication of the alternative benefits we might realize if humanity achieved the incredible engineering and technical capacity necessary to make this version of space AI happen.

Think about it. Elon conjures up a vision of the future where we've managed to increase our solar cell manufacturing capacity by two whole orders of magnitude and have the space launch capability for all of it along with tons and tons of other stuff and the best he comes up with is...GPUs in orbit?

This is essentially the superhero gadget technology problem, where comic books and movies gloss over the the civilization changing implications of some technology the hero invents to punch bad guys harder. Don't get me wrong, the idea of orbiting data centers is kind of cool if we can pull it off. But being able to pull if off implies an ability to do a lot more interesting things. The problem is that this is both wildly overambitious and somehow incredibly myopic at the same time.

A lot of great inventions we now take for granted initially came with little motivation other than being able to kill each other more effectively. GPS, radar, jet engines, drones, super glue, microwaves, canned food, computers, even the internet. Contrary to the narrative of the internet being about sharing science, ARPANET was pushed by the DoD as a means of maintaining comms during nuclear war. It was then adopted by universities and research labs and started along the trajectory most are more familiar with.

The tale of computers is even more absurd. The first programmable, electric, and general-purpose digital computer was ENIAC. [1] It was built to... calculate artillery firing tables. I expect in the future that the idea of putting a bunch of solar into space to run GPUs for LLMs will probably seem, at the minimum - quaint, but that doesn't mean the story ends there.

[1] - https://en.wikipedia.org/wiki/ENIAC

That’s not the point of the person you are replying to. They are saying if we somehow come up with the tech that makes harnessing the sun a thing, the best we can still do is put a bunch of GPUs in space? It makes no sense.

It kinda does make sense if you consider that solar panels in space have been used for a very long time (to power satellites). However, getting the electricity they generate down to Earth is very complicated, so you end up having to use it in space, and one of few things that would make sense for that is indeed data centers, because getting the data to Earth is easier (and Elon already handily has a solution for that).

However I'm curious how many solar panels you would need to power a typical data center. Are we talking something like a large satellite, or rather a huge satellite with ISS-size solar arrays bolted on? Getting rid of the copious amounts of heat that data centers generate might also be a challenge (https://en.wikipedia.org/wiki/Spacecraft_thermal_control)...

> It kinda does make sense if you consider that solar panels in space have been used for a very long time (to power satellites).

It stops making sense the second you ask how you’d dissipate the heat any GPU would create. Sure, you could have vapour chambers. To where? Would this need square kilometers of radiators on top of square kilometers of solar panels? All this just to have Grok in space?

You have a dark radiating side on the back of the solar panels. You can spread the GPUs around the solar panels. All the energy in comes from the sun so the temperature should be much the same as any dark panel like object floating in sunlight in space.

Random objects floating in space do not have GPUs on them which generate heat. You need to move the heat from GPUs to a radiator, so you are describing the actual solution of radiators in a roundabout way. Radiators weigh an amount and cost money. The consequence of factoring this in with optimistic assumptions is that it's about 1/4 as efficient to build space compute as earth compute. It's hype bullshit.

Or something like that - the temperature goes hot and cold as the things go into light and shadow so they have insulation.

Elon already answered this type of question before, albeit quite sarcastically iirc, tho I can't find the tweet right now

Elon is not a good person to ask on technical matters like this given both his history of saying really silly things about space-related technologies and his enormous incentive to lie to attract investors.

> It stops making sense the second you ask how you’d dissipate the heat any GPU would create.

The answer, as you surmised, is indeed radiators.

But space is very cold, so no problem there /sarcasm

The plan seems to be for lots and lots of smaller satellites.

For inferencing it can work well. One satellite could contain a handful of CPUs and do batch inferencing of even very large models, perhaps in the beginning at low speeds. Currently most AI workloads are interactive but I can't see that staying true for long, as things improve and they can be trusted to work independently for longer it makes more sense to just queue stuff up and not worry about exactly how high your TTFT is.

For training I don't see it today. In future maybe. But then, most AI workloads in future should be inferencing not training anyway.

Latency means this still makes no sense to me. Perhaps some batch background processing job such as research or something but that's stretching.

A 10MW data center would require square kilometers of solar arrays, even in space.

It’s just as real as the 25k Model 3.

0.2 sq km approx.

>Getting rid of the copious amounts of heat that data centers generate might also be a challenge

at 70 Celsius - normal for GPU - 1.5m2 radiates something like 1KWt (which requires 4m2 of panels to collect), so doesn't look to a be an issue. (some look to ISS which is a bad example - the ISS needs 20 Celsius, and black body radiation is T^4)

So for the ISS at 20c you'd get 481 W/m^2 so you'd only need 2.3m2. So comparing the ISS at 20c to space datacenters at 70c you get an improvement of 63%. Nice, but doesn't feel game-changing.

The power radiated is T^4, but 70c is only about 17.1% warmer than 20c because you need to compare in kelvin.

>The power radiated is T^4, but 70c is only about 17.1% warmer than 20c because you need to compare in kelvin.

17% in T^4 is almost 2x - plugging 293 (in Kelvin of course) in the calculator i get 417 W/m2 vs. 784W/m2 that i got earlier for the 343 (Kelvin for the 70 Celsius).

The ISS targets rejecting 70KW and has something like 140m2 of radiators. These radiators are attached to the ISS and use a lot of plumbing to carry the cooling liquid.

Where is GPUs and everything can be attached directly to the radiators and solar panels. So 70KW - 70 GPUs - can be placed right onto the 10m by 10m radiator panel. In front of those GPUs sitting on that radiator - a 15m by 20m solar panels assembly. Whole thing is less than 1 ton. Between $10K and $100K on Starship.

give us a break, you have to start somewhere, and find someone willing to start it all

Sending post-compute radio waves to Earth is much safer than sending back TW of power.

That's even more reason that if we manage to increase the amount of solar energy cells by 1000x there are so many more effective ways to use it than immediately flinging them into space. They're not getting constructed as satellites mid-orbit, after all.

The problem Elon is trying to address is a societal one, not a technical one. The amount of push back on clean energy generation and manufacturing prevents data centers on earth from being as feasible as they should be. He only got his newly opened xAI data center open using temporary generators on trailers and skirting the permitting process by using laws designed for things like traveling circuses.

Maybe pushback is valid. Why do we need an order of magnitude more datacenters with attendant energy demand and strain on the surround people and environment? What is this meant to achieve?

Interesting phrasing. Does our society exist to see that no billionaires flavor of the month whims go unfulfilled?

I'm not supporter of capitalism, but what Elon is doing is the same as any other business or capitalist participant. He is seeing current demand and anticipating future demand and building systems to meet that demand. I have no desire for society to fulfill whims of the ruling elite but I don't think Elon is doing this on a whim anymore than any business doing any thing likely to make them money.

>the best we can

oh, we'll sure find a way to weaponize that energy for example - just imagine all those panels simultaneously turning their reflective back in a way to form gigantic mirror to focus reflected solar energy on your enemy, be that enemy in space or on the Earth/Moon/Mars ground. Basically space-scale version of 'death ray scyscrapper' https://www.businessinsider.com/death-ray-skyscraper-is-wrea....

Back in the day the Star Wars program was intending to use nuclear explosions to power the lasers, i guess once all that solar for AI gets deployed in space we wouldn't need the explosions anymore.

Interesting that such space deployment can deny access to space to anybody else, and that means that any competitive superpower has to rush to deploy similar scale system of their own. Space race v2.

Pick any Gundam series and watch the last 5 or 6 episodes, at least through the Gundam SEED/Destiny era. At least part of the plot will invariably include a space-based superweapon being deployed by one side of the war to end all wars and the the plot for a few episodes will include the other side engaging in a series of challenges to keep that from firing again and destroying it if possible.

I think the Colossus[1] predated the ENIAC but is still in line with your general theme of doing stuff for the military. In this case it was used for cipher breaking, not firing calculations.

You could argue that it doesn't really count though because it was only turing complete in theory: "A Colossus computer was thus not a fully Turing complete machine. However, University of San Francisco professor Benjamin Wells has shown that if all ten Colossus machines made were rearranged in a specific cluster, then the entire set of computers could have simulated a universal Turing machine, and thus be Turing complete."

[1] https://en.wikipedia.org/wiki/Colossus_computer

> You could argue that it doesn't really count though because it was only turing complete in theory

Then you have to also count the Z3 which predates the Colossus by 2 years.

[1] https://en.wikipedia.org/wiki/Z3_(computer)

Yes, but isn't that pretty much the point of the person you replied to? We know that a lot of inventions were motivated by that, and so it is incredibly myopic to not pause and try to think through the likely far broader implications.

OK, so what are they?

Scaling photovoltaic production doesn't seem likely to have many broader implications on its own. At best, it makes it easier to change the grid to renewable power, if you ignore the intermittency problem that still exists even at huge scales. PV fabs aren't really reusable for other purposes though, and PV tech is pretty mature already, so it's not clear what scaling that up will do.

Scaling rocketry has several fascinating implications but Elon already covered many of them in his blog post.

Scaling AI - just read the HN front page every day ;)

What are we missing here? Some combinatoric thing?

Scaling up PV production to the point where we could convert the entire Earth's electricity generation to solar is incredibly significant.

Yes there's the problem of intermittency, varying sun availability and so forth - which is why solar will never provide 100% of our power and we'll also need grid-scale storage facilities and domestic batteries and all sorts of stuff - but just imagine being able to make that many panels in the first place! Literally solar on every roof, that's transformative.

But sure, let's send it all to space to power questionable "AI" datacentres so we can make more fake nudes.

> doesn't seem likely to have many broader implications on its own

Considering how foundational energy is to our modern economy, energy several orders of magnitude cheaper seems quite likely to have massive implications.

Yes it might be intermittent, but I'm quite confident that somebody will figure out how to effectively convert intermittent energy costing millicents into useful products and services.

If nothing else, incredibly cheap intermittent energy can be cheaply converted to non-intermittent energy inefficiently, or to produce the enablers for that.

> Scaling photovoltaic production doesn't seem likely to have many broader implications on its own

Musk is suggesting manufacture at a scale sufficient to keep the Earth's entire land area tiled in working PV.

If the maths I've just looked at is correct (first glance said yes but I wouldn't swear to it), that on the ground would warm the earth by 22 C just by being darker than soil; that in the correct orbit would cool it by 33 C by blocking sunlight.

Just scratching at the surface, assuming the increase in production capacity is only realistically possible if you can bring prices down (or this "project" would start to consume a proportion of economic output large enough to seem implausible), you can address the intermittency problem in several ways:

Driving down the cost makes massive overprovision a means of reducing the intermittency because you will be able to cover demand at proportionally far lower output, which also means you'll be able to cover demands in far larger areas, even before looking at storage.

But lower solar costs would also make storage more cost effective, since power cost will be a lower proportion of the amortised cost of the total system. Same with increasing transmission investments to allow smoothing load. Ever cost drop for solar will make it able to cover a larger proportion of total power demand, and we're nowhere near maximising viable total capacity even at current costs.

A whole lot of industrial costs are also affected by energy prices. Drive down this down, and you should expect price drops in other areas as well as industrial uses where energy expensive processes are not cost-effective today.

The geopolitical consequences of a dramatic acceleration of the drop in dependency on oil and gas would also take decades to play out.

At the same time, if you can drive down the cost of energy by making solar so much cheaper, you also make earth-bound data centres more cost-competive, and the cost-advantage of space-bound data centres would be accordingly lower.

I think it's an interesting idea to explore (but there's the whole issue of cooling being far harder in space), but I also think the effects would be far broader. By all means, if Musk wants to poor resources into making solar cheap enough for this kind of project to be viable, he should go ahead - maybe it'll consume enough of time to give him less time to plan a teenage edgelor - because I think the societal effects of driving down energy costs would generally be positive, AI or not, it just screams of being a justification for an xAI purchase done mostly for his personal financial engineering.

The only purely military thing is rockets and everything space related, there's just no way private businesses would've poured so much money into it

Computers and internet being storage, processing and communication systems are clearly useful for civilian purposes

Yes, but as Ron Perlman famously said in the beginning of Fallout, "War never changes".

I would be more shocked that we eliminated war than if we achieved this version of Elon's future.

It makes sense to think that we will continue to make scientific progress through war and self defense.

Reason being, nothing is more motivating than wanting to survive

I'm starting to wonder if a person like Elon with his... morals... is who we want to be creating a vision for the future.

You phrased it in a way as we decided to or somebody even asked us. I don't think that's how it works. Humans don't sit together and decide their future, we aren't that coordinated or united. But people like Elon and other people or groups, with the right resources, network, luck, talent and money build their vision of the future and how it turns out nobody knows until it happens.

Starting?

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Bollocks, by your standards we can't discuss the most vile people because 'nobody's perfect' but there is a huge gap between the likes of Musk and ordinary people.

Indeed, at least a $700 billion gap. One is reminded of a great Mark Twain quote, "Whereas principle is a great and noble protection against showy and degrading vanities and vices, poverty is worth six of it."

The problem is that the Venn diagram of 'vile people' and 'billionaires' has a lot of overlap so these people are doing a disproportionate amount of damage.

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Not to go heads I win, tails you lose, but even if we go down this path - it's the same story because militaries are investing heavily in LLM stuff, both overtly and covertly. Outside of its obvious uses in modeling, data management, and other such things - there also seems to be a fairly widespread belief, among the powers that be, that if you just say the magic words to somebody, that you can make them believe anything. So hyper-scaling LLM potential has direct military application, same as Starlink and Starship.

I think it's much simpler: smart mass surveillance. With LLMs you can finally read and analyze all messages people send to each other

The digital internet began with the telegraphy network in the early 1800s.

Many, many network protocols were developed and used.

Really? That is so interesting - which ones? Any ancestors of commonly used ones today?

Off the top of my head BIX, Prodigy, Compuserve, MCIMail, BBS, Ethernet, Token Ring, $25 Network, AOL, Timeshare, Kermit, Fax

Anyone with 2+ computers immediately thought about connecting them.

> with the telegraphy network in the early 1800s.

Late 1700 actually, and war was indeed a key motivation for the deployment of the Télégraphe Chappe.

See "The Victorian Internet: The Remarkable Story of the Telegraph and the Nineteenth Century's On-line Pioneers"

https://www.amazon.com/dp/162040592X

Télégraphe Chappe was a semaphore system using flags. It was not an electrical telegraph, nor was it binary.

"The Victorian Internet" gives it its due. And its drawbacks - didn't work at night or in bad weather. It was very expensive as it needed human operators and towers. Only simple messages could be transmitted. And it was slow.

Morse's electrical single wire telegraph was an instant success and quickly transformed the world. It wasn't an evolutionary advance over the Chappe, it was revolutionary.

There were also electric lights before Edison's lightbulb. But Edison invented a lightbulb that was simple, cheap, reliable, and it worked. Hence his bulb gets the nod. He nailed it.

It was optical. The modern internet mostly goes over optical fiber.

Also, most networks work with non-binary signals.

So in a way, it was closer to the current internet than an electrical telegraph (it was farther in other ways though).

It wasn't binary nor electrical, but it was already digital. Excluding it would be arbitrarily restrictive.

Wouldn’t you also need to include the Ancient Greek phryctoriae military fire signalling system by that logic? It probably wasn’t the first, at that.

It depends, how versatile was the Greek signaling system?

AFAIK the Télégraphe Chappe was the first general purpose telegraph able to send arbitrary messages, and was used by both the administration (for civilian as well as military purpose) and the private sector for business.

Well computers are a funny story. The groundwork had been laid and the theoretical and engineering advances that would produce programmable digital computers were well underway in the 1930s. It would have happened very soon even if there was no war, but of course WWII happened right in 1939, so obviously computers made at that time had the purpose of calculating artillery paths or decrypting German messages. But it would be incorrect to say that military applications in WWII are the reason computers were invented.

> Contrary to the narrative of the internet being about sharing science, ARPANET was pushed by the DoD as a means of maintaining comms during nuclear war.

[citation needed]

Because according to Bob Taylor, who initially got the funding for what became ARPANET:

> Taylor had been the young director of the office within the Defense Department’s Advanced Research Projects Agency overseeing computer research, and he was the one who had started theARPANET . The project had embodied the most peaceful intentions—to link computers at scientific laboratories across the country so that researchers might share computer resources. Taylor knew theARPANET and its progeny, the Internet, had nothing to do with supporting or surviving war—never did.Yet he felt fairly alone in carrying that knowledge.

> Lately, the mainstream press had picked up the grim myth of a nuclear survival scenario and had presented it as an established truth. When* Time magazine committed the error, Taylor wrote a letter to the editor, but the magazine didn’t print it. The effort to set the record straight was like chasing the wind; Taylor was beginning to feel like a crank.

* https://www.goodreads.com/book/show/281818.Where_Wizards_Sta... § Prologue

> Taylor told the ARPA director he needed to discuss funding for a networking experiment he had in mind. Herzfeld had talked about networking with Taylor a bit already, so the idea wasn’t new to him. He had also visited Taylor’s office, where he witnessed the annoying exercise of logging on to three different computers. And a few years earlier he had even fallen under the spell of Licklider himself when he attended Lick’s lectures on interactive computing.

> Taylor gave his boss a quick briefing: IPTO contractors, most of whom were at research universities, were beginning to request more and more computer resources. Every principal investigator, it seemed, wanted his own computer. Not only was there an obvious duplication of effort across the research community, but it was getting damned expensive. Computers weren’t small and they weren’t cheap. Why not try tying them all together? By building a system of electronic links between machines, researchers doing similar work in different parts of the country could share resources and results more easily. […]

* Wizards § Chapter 1

The first four IMPs were UCLA, SRI, UCSB, and Utah. Then BBN, MIT, RAND, System Development Corp., and Harvard. Next Lincoln Laboratory and Stanford, and by the end of 1970 Carnegie-Mellon University and Case Western Reserve University.

It was only "later in the 1970s" that command and control was considered more (Lukasik):

* https://en.wikipedia.org/wiki/ARPANET#Debate_about_design_go...

But the first two people who get the project going, Taylor and Herzfeld, were about the efficient use of expensive computer resources for research. Look at the firs >dozen sites and they were about linking researchers: the first DoD site wasn't connected until 3-4 years after things go going, and there was nothing classified about it. MILNET didn't occur until 1984:

* https://en.wikipedia.org/wiki/ARPANET#Operation

> But being able to pull if off implies an ability to do a lot more interesting things.

Those interesting things won't pump up the perceived value of Musk companies to stratospheric levels - or dare I say - to the moon. He needs the public to believe that to earn the trillion-dollar package from the Tesla-Twitter-SpaceX conglomerate, even if the latter turns out to be the only profitable arm of the conglomerate.

"TwitslaX"

Your argument is that Elon isn't grandiose enough with his statements and timelines?

Yeah it does not make a whole lot of sense as the useful lifespan of the gpus in 4-6 years. Sooo what happens when you need to upgrade or repair?

This is a question that analysts don't even ask on earnings calls for companies with lowly earthbound datacenters full of the same GPUs.

The stock moves based on the same promise that's already unchecked without this new "in space" suffix:

We'll build datacenters using money we don't have yet, fill them with GPUs we haven't secured or even sourced, power them with infrastructure that can't be built in the promised time, and profit on their inference time over an ever-increasing (on paper) lifespan.

> This is a question that analysts don't even ask

On the contrary, data centers continue to pop up deploying thousands of GPUs specifically because the numbers work out.

The H100 launched at $30k GPU and rented for $2.50/hr. It's been 3 years since launch, the rent price is still around $2.50.

During these 3 years, it has brought in $65k in revenue.

They worked out because there was an excess of energy and water to handle it.

We will see how the maths works out given there is 19 GW shortage of power. 7 year lead time for Siemens power turbines, 3-5 years for transformers.

Raw commodities are shooting up, not enough education to cover nuclear and SMEs and the RoI is already underwater.

My cynical take is that it'll works out just fine for the data centers, but the neighbouring communities won't care for the constant rolling blackouts.

Okay but even in that case the hardware suffers significant under utilisation which massively hits RoI. (I think I read they only achieve 30% utilisation in this scenario)

Why would that be the case if we assume the grid prioritizes the data centers?

That is not a correct assumption. https://ig.ft.com/ai-power/

Reports in North Virginia and Texas are stating existing data centres are being capped 30% to prevent residential brownouts.

That article appears to be stuck behind a paywall, so I can't speak to it.

That's good for now, but considering the federal push to prevent states from creating AI regulations, and the overall technological oligopoly we have going on, I wonder if, in the near future, their energy requirements might get prioritized. Again, cynical. Possibly making up scenarios. I'm just concerned when more and more centers pop up in communities with less protections.

Beyond GPUs themselves, you also have other costs such as data centers, servers and networking, electricity, staff and interest payments.

I think building and operating data center infrastructure is a high risk, low margin business.

They can run these things at 100% utilization for 3 years straight? And not burn them out? That's impressive.

Not really. GPUs are stateless so your bounded lifetime regardless of how much you use them is the lifetime of the shitties capacitor on there (essentially). Modulo a design defect or manufacturing defect, I’d expect a usable lifetime of at least 10 years, well beyond the manufacturer’s desire to support the drivers for it (ie the sw should “fail” first).

The silicon itself does wear out. Dopant migration or something, I'm not an expert. Three years is probably too low but they do die. GPUs dying during training runs was a major engineering problem that had to be tackled to build LLMs.

> GPUs dying during training runs was a major engineering problem that had to be tackled to build LLMs.

The scale there is a little bit different. If you're training an LLM with 10,000 tightly-coupled GPUs where one failure could kill the entire job, then your mean time to failure drops by that factor of 10,000. What is a trivial risk in a single-GPU home setup would become a daily occurrence at that scale.

I don't see anything impressive here?

> the useful lifespan of the gpus in 4-6 years. Sooo what happens when you need to upgrade or repair?

Average life of starlink satellite is around 4-5 years

Starlink yes, at 480 km LEO. But the article says "put AI satellites into deep space". Also if you think about it, LEO orbits have dark periods so not great.

A better orbit might be Sun Synchronous (SSO) which is around 705 km, still not "deep space" but reachable for maintenance or short life deorbit if that's the plan. https://science.nasa.gov/earth/earth-observatory/catalog-of-...

And of course there are the LaGrange points which have no reason to deorbit, just keep using the old ones and adding newer.

damn. at this point its not even about a pretense for progress, just a fetish for a very dirty space

It's essentially a military network (which is why other power sphere want their own) and a way to feed money into spacex

They re-enter and burn up entirely. Old starlinks don't stay in space.

So they pollute the upper atmosphere instead!

Same that happens with Starlink satellites that are obsolete or exhausted their fuel - they burn up in the atmosphere.

With zero energy cost it will run until it stops working or runs out of fuel, which I'm guessing is between 5-7 years.

5 to 7 months given they want 100kw Per ton and magical mystery sauce shielding is going to do shit all.

> Sooo what happens when you need to upgrade or repair?

The satellite deorbits and you launch the next one.

so, instead of recycling as many components as possible (a lot of these GPU have valuable resources inside) you simply burn them up.

I'm guessing the next argument in the chain will be that we can mine materials from asteroids and such?

Such a waste of resources

not to mention that radiation hardening of chips has a big impact on cost and performance

You could immersion cool them and get radiation resistance as a bonus.

Yes, because launching then immersed in something that will greatly increase the launch weight will help...

A "fully and rapidly reusable" Starship would bring the cost of launch down orders of magnitude, perhaps to a level where it makes sense to send up satellites to repair/refuel other satellites.

I feel like the proposal also glosses over why a merger is necessary and desirable to accomplish the goals.

Why couldn't xAI just, you know, contract with SpaceX to launch its future Datacenters In Space?

Wouldn't a company focused on a single mission, Datacenters In Space, be better at seeing that goal to fruition, instead of a Space Launch Company with a submission of Datacenters In Space, which might decide to drop the project in three years to focus on their core mission of being a Space Launch Company?

Even granting the goal as desirable and possible, why is a merger the best way to pull it off?

Probably because its just a shitty justification to move money around.

So what are the other things? You said he glossed over them and didn't mention a single one.

Reliably and efficiently transport energy generated in space back to earth, for starters

Or let me guess, its going to be profitable to mine crypto in space (thereby solving the problem of transporting the "work" back to earth)

Overview energy has done interesting work in this area.

Beaming energy always sucks. Without some very fundamental discoveries in physics nobody will every make this work economically. This isn't just an engineering problem, it's a physics problem.

Beaming energy does suck, but it might be something to do before we launch thousands of terawatts of GPUs to space.

It's always better to generate electricity on the ground than attempt to beam it to the ground from space. The efficiency loss of beamed power is huge.

The efficiency loss of nighttime is approximately 100% if we’re talking about solar energy. At least at a most basic level, it’s not totally absurd to stick some kind of power beaming contraption in space where it is mostly not shadowed by the Earth and beam power to a ground station.

I concur it’s not necessarily totally absurd — but when you consider that such contraptions require large — very large! — receiving arrays to be built on the ground, it’s hard to avoid concluding that building gigantic photovoltaic arrays in, say Arizona (for the US) along with batteries for overnight buffering and transmission lines would still be massively more efficient.

Is that more or less absurd than making deals with our neighbours to share their electricity? Build some solar farms around the planet and then distribute it over wire.

I honestly don't know the answer. I know there's some efficiency loss running over long wires too but I don't know what's more realistic.

In theory you can do HVDC over long distances. In practice that doesn't help much. Power would normally want to run north to south (not gonna do HVDC across the oceans anytime soon), and so the terminator hits you at the same time everywhere. It's got to be batteries if you want PV at scale.

The practical difficulties aren't really long distance transmission though. They're political and engineering. Spain had a massive blackout recently because a PV farm in the south west developed a timing glitch and they couldn't control the grid frequency - that nearly took out all of Europe and the power wasn't even being transmitted long distance! The level of trust you need to build a giant integrated continent-wide power grid is off the charts and it's not clear it's sustainable over the long run. E.g. the EU threatened to cut Britain's electricity supplies during Brexit as a negotiating tactic and that wasn't even war.

HVDC would be a lot less connected than an AC grid.

The real question is, why do you expect Space to have fewer political and engineering issues.

The political issues in space are mostly launch related, right? Once you have the birds up nobody cares about anything except space junk and bandwidth. They're getting experience of solving those with Starlink already. And if you can find a way to put the satellites really far out there's plenty of space - inferencing satellites don't need to be close to Earth, low latency chat stuff can stay on the ground and the flying servers can just do batch.

The politics on the ground is much harder. Countries own the land, you need lots of permits, electricity generation is in contest with other uses.

There is absolutely nothing realistic about power transmission from space to earth, wired or wireless.

We have these things called batteries, you charge them during the day, and drain them at night.

A solar+battery setup is already cheaper than a new gas plant. Beaming power from space is absolutely asinine, quite frankly. The losses are absurd, the sun already does it 24/7, and we know how to make wires and batteries to shuffle the sun's power around however we need to. Why on earth would we involve satellites?

Why would you transfer the energy to earth? The energy powers ai compute = $

Dead on, You can transmit data to and from space and have the compute completed at potentially fractions of the cost.

Tell me about your cooling medium in space

A large piece of aluminum with ammonia pumped through it?

Nothing about this is sounding economically competitive with ground based solutions

Right up to the radiation limit and then you'll either have to throttle your precious GPUs or you'll be melting your satellite or at least the guts of it. You're looking at an absolutely massive radiator here, many times larger than the solar panels that collect the energy to begin with.

not really, for A_radiator / A_PV = ~3; you can keep the satellite cool to about 27 deg C (300K) check my example calculation (Ctrl-F: pyramid)

> > absolutely massive radiator here, many times larger than the solar panels

> A_radiator / A_PV = ~3;

Seems like you're in agreement. There's a couple more issues here--

1. Solar panels are typically big compared to the rest of the satellite bus. How much radiator area do you need per 700W GPU at some reasonable solar panel efficiency?

2. Getting the satellite overall to an average 27C temperature doesn't necessarily keep the GPU cool; the satellite is not isothermal.

My back of the envelope estimate says you need about 2.5 square meters of radiator (perhaps more) to cool a 700W GPU and the solar panel powering the GPU. You can fit about 100 of these GPUs in a typical liquid-cooled rack, so you need about 250 square meters of radiator to match one rack. And, unfortunately, you can't easily use an inflatable structure, etc, because you need to conduct or convect heat into that radiator.

This assumes that you lose no additional heat in moving heat or in power conversion.

And they’re going to mass a -lot-. Not that anyone would use a pyramid— you would want panels with the side facing the sun radiating too. There are plenty of surfaces that radiate more than they absorb at reasonable temperatures in sunlight.

First of all a note on my calculations: they appear very simple, and its intentional, its not actually optimized, its intended to give programmers (who enjoyed basic high school physics but not more) the insight that cooling in space while hard, is still feasible. If you look around the thread you'll find categorical statements that cooling in space is essentially impossible etc.

The most efficient design and the most theoretically convincing one are not in general the same. I intentionally veer towards a configuration that shows it's possible without requiring radiating surface with an area of a square Astronomical Unit. Minimizing the physics and mathematics prerequisites results in a suboptimal but comprehensible design. This forum is not filled with physicists and engineers in the physical sciences, most commenters are programmers. To convince them I should only add the absolute minimum and configure my design to eliminate annoying integrals (for example the heat radiated by earth on the satellite is sidestepped by simply sacrificing 2 of the triangular sides of the pyramid to be mere reflectors of emissivity ~0, this way we can ignore the presence of a nearby lukewarm earth). Another example is the choice of a pyramid: it is convex and none of the surfaces are exactly parallel to the sun rays (which would result in ambiguity or doubt, or make the configuration sensitive to the exact orientation of the satellite), a more important consequence of selecting a convex shape is that we don't have to worry about heat radiated from one part of the satellite surface, being reabsorbed by another surface of the satellite (in view of the first surface), a convex shape insures no surface patch can see another surface patch of the satellite. And yes I pretend no heat is radiated by the solar panel itself, which is entirely achievable. So I intentionally sacrifice a lot of opportunities for more optimal design to show programmers (who are not trained in mathematical analysis, and not trained with physics textbook theorem-proof-theorem-proof-definition-theorem-proof-...) that physically it is not in the real of the impossible and doesn't result in absurdly high radiator/solar panel area ratios.

To convince a skeptic you 1) make pessimistic suboptimal estimates with a lot of room for improvement and 2) make sure those estimates require as little math and physics as possible, just the bare minimum to qualitatively and quantitatively understand the thermodynamics of a simple example.

You are asking the right questions :)

Given the considerations just discussed I feel OK forwarding you to the example mini cluster in the following section:

https://news.ycombinator.com/item?id=46867402

It describes a 230 kW system that can pretrain a 405B parameter model in ~17 days and is composed of 16x DGX B200 nodes, each node carrying 8x B200 GPUs. The naive but simple to understand pyramid satellite would require a square base (solar PV) side length of 30 m. This means the tip of the pyramid is ~90m away from the center of the solar panel square. This gives a general idea of a machine capable of training a 405B parameter model in 17 days.

We can naively scale down from 230 kW to 700 W and conclude the square base PV side length can then be 1.66 m; and the tip being 5 m "higher".

For 100 such 700 W GPU's we just multiply by 10: 16.6 m side length and the tip of the pyramid being 50 m out of the plane of the square solar panel base.

Why bother with all this crazy geometry? Why not just area as I've done above? You can design a radiator so that barely any of the light shines back on the spacecraft.

Your differences from my number: A) you're working based on spacecraft average temperature and not realizing you're going to have a substantial thermal drop; B) you're assuming just one side of the surface radiates. They're on the same order of magnitude. Both of us are assuming that cooling systems, power systems, and other support systems make no heat.

You can pick a color that absorbs very little visible light but readily emits in infrared-- so being in the sun doesn't matter so much, and since planetshine is pulling you towards something less than room temperature, it's not too bad either.

None of these numbers make me think "oh, that's easy". You're proposing a structure that's a big fraction of the size of the ISS for one rack of GPUs.

I don't really think cooling in space is easy. The things I have to do to get rid of an intermittent load of 40W on a small satellite are very very annoying. The idea of getting rid of a constant load of tens of kilowatts, or more, makes me sweat.

As I said, my geometry and properties are chosen to be easy to understand with a minimum of knowledge and mathematics.

Yes, I could make more optimistic calculations: use the steradians occupied by earth, find and use the thermal IR emissivities of solar panels place many thin layers of glass before the solar panel allowing energy generating photons through and forming a series of thermal IR black body radiators as a heat shield in thermal IR, the base also radiates heat outwards and at a higher temperature, use nonsquare base, target a somewhat higher but still acceptable temperature, etc... but all of those complicate the explanation, risking to lose readers in the details, readers that confuse the low net radiative heat transfer between similar temperature objects and room walls in the same room as if similar situation applies for radiative heat transfer when the counterbody is 4 K. Readers that half understand vacuum flasks / dewars: no or fewer gas particles in a vacuum means no or less energy those particles can collectively transport, that is correct but ignores the measures taken to prevent radiative heat loss. For example if the vacuum flask wasn't mirror coated but black-body coated then 100 deg C tea isolated from room temperature in a vacuum flask is roughly 400 K versus 300 K, but Stefan Boltzmann carries it to the fourth power (4/3) ^ 4 = 3.16 ! That vacuum flask would work very poorly if the heat radiated from the tea side to the room-temperature side was 3 times higher than the heat radiated by the room temperature side to the tea-side. The mirroring is critical in a vacuum flask. A lot of people think its just the vacuum effect and blindly generalize it to space. Just read the myriad of comments in these discussions. People seriously underestimate the capabilities of radiative cooling because the few situations they have encountered it, it was intentionally minimized or the heat flows were balanced by equilibrium, not representative for a system optimized to exploit radiative heat transfer.

Some small corrections:

>Both of us are assuming that cooling systems, power systems, and other support systems make no heat.

I do not make this assumption! all heat generated in the cooling, power and other support systems stem from electrical energy used to power them, and that energy came from the solar panels. The sum of the heat generated in the solar panel and the electrical energy liberated in the solar panel must equal the unreflected incident optical power. So we can ignore how efficient the solar panel is for the rest temperature calculation, any electrical energy will be transformed to heat and needs to be dissipated but by conservation of energy this sum total of heat and electrical energies turned into heat must simply equal the unreflected energy incident on the solar panel... The solar panel efficiencies do of course matter a lot for the final dimensions and mass of the satellite, but the rest temperature is dictated by the ratio of the height of the pyramid to the square base side length.

>You can pick a color that absorbs very little visible light but readily emits in infrared-- so being in the sun doesn't matter so much, and since planetshine is pulling you towards something less than room temperature, it's not too bad either.

emissivity (between 0 and 1) simultaneously dials how well it absorbs photons at that wavelength as well as how efficiently it sheds energy at that wavelength. A higher emissivity allows the solar panel to cool faster spontaneously, but at the cost of absorbing thermal photons from the sun more easily! Perhaps you are recollecting the optimization for the thermal IR window of our atmosphere, the reason that works is because it works comparatively to solar panels that don't exploit maximum emissivity in this small window. The atmospheric IR window location in the spectrum is irrelevant in space however.

> A) you're working based on spacecraft average temperature and not realizing you're going to have a substantial thermal drop;

of course I realize there will be a thermal gradient from base to apex of the pyramidal satellite, it is in fact good news: near the solar panel base the triangular sides have wider area and hotter temperature, so it sheds heat faster than assuming a homogenous temperature (since the shedding is proportional to the fourth power of temperature). When I ignore it it's not because I'm handwaving it away, it's because I don't wish to bore computer science audience with integral calculations, even if they bring better news. Before bringing the better news you need to bring the good news that its possible with similar order of magnitude areas for the radiator compared to the solar panels, without their insight that its feasible first, its impossible to make them understand the more complicated realistic and better news picture, especially if they want to not believe it... Without such proof many people would assume the surface of the radiator would need to be 10's to 100's of times the surface area of the solar panels...

> B) you're assuming just one side of the surface radiates.

No, I even explicitly state I only utilize 2 of the 4 side triangles of the pyramid (to sidestep criticisms that earth is also radiating heat onto the satellite). So I make a more pessimistic calculation and handicap my didactic example just to show you get non-extreme surface ratios even when handicapping the design. If you look at history of physics, you will often find that insights were obtained much earlier by prior individuals, but the community only accepted the new insights when the experimental design was simplified to such an extent that every criticism is implicitly encoded in the design by making it irrelevant in the setup, this is not explicitly visible in many of the designs.

Where does the heat collected by amminia get evacuated?

Through thermal radiation, it's called radiative cooling.

But it's not trivial indeed, especially if you want good power density in your space data center.

Datacenter capacity (and thus heat) grows by the cube law, but the ability to radiate heat grows by the square law, so it seems like it would be advantageous to have a bunch of smaller satellites, if you were concerned about cooling them.

> it would be advantageous to have a bunch of smaller satellites, if you were concerned about cooling them.

...That's only relevant if you start from the position that your datacenters have to be space.

You could already make smaller datacenters on earth, and still have better cooling, if you were concerned about that. We don't do that because on earth it's more efficient to have one large datacenter than many small ones.

Not sure why this is downvoted. Much cheaper to transfer data than energy.

If we (as in "civilization") were able to produce that many solar panels, we should cover all the deserts with them. It will also shift the local climate balance towards a more habitable ecosystem, enabling first vegetation and then slowly growing the rest of the food chain.

> It will also shift the local climate balance towards a more habitable ecosystem, enabling first vegetation and then slowly growing the rest of the food chain.

Depends on the deserts in question and knock-on effects: Saharan Dust Feeds Amazon’s Plants.

* https://www.nasa.gov/centers-and-facilities/goddard/nasa-sat...

Helping vegetation in one place to grow may hinder it somewhere else. How important this is still appears to be an open question:

* https://www.nature.com/articles/s43247-020-00071-w

I'm not sure if humans are wise enough yet to try 'geo-hacking' (we're already messing things up: see carbon dumping).

for solar panels that are say 25% efficient, that means 75% of optical energy is turned into heat, whereas the sand had a relatively high albedo, its going to significantly heat up the local environment!

That is not what 25% efficiency means for solar panels.

care to expand on your comment? or are is this just remarking that some light was reflected?

No. It is enough for me to see such a single ridiculous statement of such magnitude to discount the rest of your voluminous contributions to this thread.

I'm dumbfounded, most light incident on a solar panel is not reflected, so logically photons were absorbed, some generated useful electron hole pairs pushing current around the load loop, others recombined and produced heat.

Its an entirely reasonable position in solar panel discussions to say that a 20% solar panel will heat as if 80% of the optical energy incident on the panel was turned into heat. Conservation of energy dictates that the input energy must equal the sum of the output work (useful energy) and output heat.

Not sure what you are driving at here, and just calling a statement ridiculous does not explain your position.

You have not done any real world verification on any of this, you are arguing from a very flawed and overly simplistic lay-persons theoretical model of how solar panels must function in space and then you draw all kinds of conclusions from that model, none of which have been born out by experiment. 25% efficiency for a solar panel means that 25% of the sunlight incident on a panel was turned into electricity. It has nothing to do with how big a fraction is turned into heat, though obviously the more of it is turned into electricity the less there is available to be converted into heat. And it does not account for other parts of the spectrum that are outside of the range that the panel can capture.

That 25% is peak efficiency. It does not take into account:

(1) the temperature of the panel (higher temp->lower efficiency), hence the need for passive cooling of the panels in space due to a lack of working fluid (air).

(2) the angle of the incidence: both angles have to be 'perfect' for that 25% to happen, which in practice puts all kinds of constraints on orientation, especially when coupled with requirements placed on the rest of the satellite.

(3) the effects of aging (which can be considerable, especially in space), for instance, due to solar wind particles, thermal cycling and so on

(4) the effect of defects in the panels causing local failure that can cascade across strings of cells and even strings of panels

(5) the effects of the backing and the glass

(6) in space: the damage over time due to mechanical effects of micro meteorite impact on cells and cover; these can affect the panels both mechanically and electrically

To minimize all of these effects (which affect both operational life span of panels as well as momentary yield) and effectively to pretend they do not exist is proof that you are clueless, and yet you make these (loud) proclamations. Gell-Mann had something to say about this, so now your other contributions suffer from de-rating.

1) yes solar panels should be cooled, but this is feasible with thermal radiation (yes it takes surface area)

2) pointing the panels straight at the sun for a sun-synchronous orbit is not exactly unobtainium technology

3) through 6) agreed, these issues need to be taken into account but I don't see how that meaningfully invalidates my claim that a solar panel operated at 25% efficiency turns ballpark ~75% of incident photons into heat. Thats basic thermodynamics.

http://english.scio.gov.cn/m/chinavoices/2025-10/23/content_...

In your opinion, how credible is this story?

OK I read the story (it was shorten than expected).

So simplistically put there are 3 periods:

1) the grassy period before overgrazing, lot of wind

2) the overgrazed period, loss of moisture retained by plants and loss of root systems, lot of wind results in soil run-away erosion without sufficient root systems

3) the solar PV period: at higher heights still lots of wind, but the installation of the panels unexpectedly allowed the grass to regrow, because wind erosion is halted.

The PV panels actually increase the local heating, but that doesn't need to directly equate to temperature: the wind just carried away the heat so it's someone else's problem :). Also the return of soil moisture thanks to the plants means a return of a sensible heat buffer, so the high temperature in the overgrazed period before solar panel introduction may not actually be an average temperature increase, but an increase in peak temperature during the summer. Imagine problematic summer temperatures, everybody would be talking about the increased temperature, when they are really just experiencing the loss of a heat buffer.

At least thats my impression from the story.

I am unable to access this site, if you could mirror the page I will take a look.

EDIT: found it on the Internet Archive:

https://web.archive.org/web/20251208110913/http://english.sc...

I will come back and give you my opinions.

Reed Richards is Useless

https://tvtropes.org/pmwiki/pmwiki.php/Main/ReedRichardsIsUs...

But everyone is crazy about GPU’s right now. Why not ride that wave for extra investment? All the benefits transfer to all the other things we can do with it.

You really can't grasp that GPUs scaled at this level is the most ambitious thing possible? That it will be the foundation of unfathomable technological innovation?

"In space" is the new blockchain.

Every time I hear stuff like this I think of Tim Curry just barely keeping it together during that one cut scene in Red Alert 3, except this time it's the ultra capitalists trying to corrupt space with capitalism.

https://www.youtube.com/watch?v=g1Sq1Nr58hM

"corrupt space with capitalism"

I think this is how the masses feel at this point. Progress bad. Capitalism inherently bad. Anything non-natural, bad.

Capitalism, as in the worship of capital and its accumulation, is responsible for some major evils in our current world. I am not saying that it is the worst system in existence, just that it is tragically insufficient and we need to seriously think about what we are doing. There are major issues we need to solve that market forces will only make worse.

Will it, though?

Perhaps parent was being sarcastic.

no

> the most ambitious thing possible

really?

Yup lol

why can't they grasp it?

[dead]

I am no Elon fan but the biggest obstacle to AI is definitely power and then cooling. Space solves both.

Hard to argue with the basic idea here.

How does space solve cooling?

It's much more difficult to cool things in space than on earth.

I'd be more interested in how they'll deal with radiation hardening than the cooling factor when compared to how the JWST currently handles it.

Do we need rockets to put satelittes to the space? Cant it be done with baloons? https://www.youtube.com/watch?v=NFieAD5Gpms

Balloons work by displacing the atmosphere (mostly nitrogen with some oxygen) with something lighter (helium or hydrogen). This causes buoyancy, and makes the balloon rise.

This only works so long as the atmosphere being displaced weighs more than the balloon plus the payload. As soon as the air gets thin enough that the weight of the balloon+payload is equal to the weight of the air that would fill the volume of the balloon, then it stops rising. (Or, more likely the balloon rips open because it expanded farther than it could stretch).

Usually, this is really high in the atmosphere, but it's definitely not space.

This is all ignoring that orbit requires going sideways really, really fast (so fast, actually, that it requires falling, but going sideways so fast that the earth curves away and you miss).

"Space" aka Orbit, is done not by going high, but by going fast.

This is such a hypebeast paragraph.

Datacenters in space are a TERRIBLE idea.

Figure out how to get rid of the waste heat and get back to me.

That's not a new problem that no one has dealt with before. The ISS for instance has its External Active Thermal Control System (EACTS).

It's not so much a matter of whether it's an unsolvable problem but more like, how expensive is it to solve this problem, what are its limitations, and does the project still makes economic sense once you factor all that in?

It's worth noting that the EACTS can at maximum dissipate 70kW of waste heat. And EEACTS (the original heat exchange system) can only dissipate another 14kW.

That is together less than a single AI inference rack.

And to achieve that the EACTS needs 6 radiator ORUs each spanning 23 meters by 11 meters and with a mass of 1100 kg. So that's 1500 square meters and 6 and a half metric tons before you factor in any of the actual refrigerant, pumps, support beams, valve assemblies, rotary joints, or cold side heat exchangers all of which will probably together double the mass you need to put in orbit.

There is no situation where that makes sense.

-----------

Manufacturing in space makes sense (all kinds of techniques are theoretically easier in zero G and hard vacuum).

Mining asteroids, etc makes sense.

Datacenters in space for people on earth? That's just stupid.

Your calculations are based on cooling to 20c, which is exponentially harder than cooling to 70c where GPUs are happy. Radiators would be roughly 1/3 the size of the panels for 70c.

I'm a total noob on this.

I get that vacuum is a really good insulator, which is why we use it to insulate our drinks bottles. So disposing of the heat is a problem.

Can't we use it, though? Like, I dunno, to take a really stupid example: boil water and run a turbine with the waste heat? Convert some of it back to electricity?

What do you do with the steam afterwards? If you eject it, you have to bring lots of it with your spacecraft, and that costs serious money. If you let it condensate to get water again, all you did is moving some heat inside the spacecraft, almost certainly creating even more heat when doing that.

It's a good question, but in a closed system (like you have in space) the heat from the turbine loop has to go somewhere in order to make it useful. Let's say you have a coolant loop for the gpus (maybe glycol). You take the hot glycol, run it through your heat exchanger and heat up your cool, pressurized ammonia. The ammonia gets hot (and now the glycol is cool, send it back). You then take the ammonia and send it through the turbine and it evaporates as it expands and loses pressure to spin the turbine. But now what? You have warm, vaporized, low pressure ammonia, and now you need to cool it down to start over. Once it's cool you can pressurize it again so you can heat it up to use again, but you have to cool it, and that's the crux of the issue.

The problem is essentially that everything you do releases waste heat, so you either reject it, or everything continues to heat up until something breaks. Developing useful work from that heat only helps if it helps reject it, but it's more efficient to reject it immediately.

A better, more direct way to think about this might be to look at the Seebeck effect. If you have a giant radiator, you could put a Peltier module between it and you GPU cooling loop and generate a little electricity, but that would necessarily also create some waste heat, so you're better off cooling the GPU directly.

You can't easily use low grade heat.

However there are workarounds. People are talking like the only radiator design is the one on the ISS. There are other ways to build radiators. It's all about surface area. One way is to heat up a liquid and then spray it openly into space on a level trajectory towards a collecting dish. Because the liquid is now lots of tiny droplets the surface area is huge, so they can radiate a lot of heat. You don't need a large amount of material as long as you can scoop up the droplets the other end of the "pipe" and avoid wasting too much. Maybe small amounts of loss are OK if you have an automated space robot that goes around docking with them and topping them up again.

Harder to direct waste heat in space if you dont have gravity for convection.

> Datacenters in space for people on earth? That's just stupid.

But if completes the vision of ancestors who thought god living in the sky

So "Lord give me a sign from heavens" may obtain a whole new meaning

The ISS consumes roughly 90kW. That’s about *one* modern AI/ML server rack. To do that they need 1000 m^2 of radiator panels (EACTS). So that’s the math: every rack needs another square kilometer of stuff put into orbit. Doesn’t make sense to me.

1000m2 is not a square kilometer (1 square kilometer is 1mil m2)

1000 square meters really isn't that big in space.

And what happens every time a rack (or node) fails? Does someone go out and try to fix it? Do we just "deorbit" it? How many tons per second of crap would we be burning in the upper atmosphere now? What are the consequences of that?

How do the racks (or nodes) talk to eachother? Radios? Lasers?

What about the Kessler Syndrome?

Not a rocket scientist but 100% agree this sounds like a dead end.

Communication is a well-understood problem, and SpaceX already has Starlink. They might need pretty high bandwidth, but that's not necessarily much of a problem in space. Latency could be a problem, except that AI training isn't the sort of problem where you care about latency.

I'd be curious where exactly they plan to put these datacenters... In low Earth orbit they would eventually reenter, which makes them a pollution source and you'd have no solar power half the time.

Parking them at the Earth-Sun L1 point would be better for solar power, but it would be more expensive to get stuff there.

> SpaceX already has Starlink. They might need pretty high bandwidth

you mean the network that has less capacity than a fibre pair per coverage area?

> you'd have no solar power half the time

Polar orbit.

Seasons mess that up unless you're burning fuel to make minor plane changes every day. Otherwise you have an equinox where your plane faces the sun (equivalent to an equatorial orbit) and a solstice where your plane is parallel to the sun (the ideal case).

https://en.wikipedia.org/wiki/Sun-synchronous_orbit A Sun Synchronous orbit at the Day-Night terminator solves this issue

I didn't think of that! I should have had a V8. Thanks for the info.

True. It would a tradeoff with the fuel consumed vs doubling power output.

Heat exchanger melts salts, salts boil off? Some kind of potential in there to use evaporants for attitude/altitude correction. Spitballing. Once your use case also has a business case, scope to innovate grows.

It makes sense to target a higher operating temperature, like 375K. At some point, the energy budget would reach an equilibrium. The Earth constantly absorbs solar energy and also dissipates the heat only by radiative cooling. But the equilibrium temperature of the Earth is still kind of cool.

I guess the trick lies in the operating temperature and the geometry of the satellites.

It's a minor point but the Earth doesn't radiate all of that heat to equilibrium, that's why we have climate change.

Asking for a friend (who sucks at thermodynamics:) could you use a heat pump to cool down the cold end more and heat up the hot end much higher? Heat radiation works better the higher the temperature?

Not sure about the effectiveness of a heat pump in this use case.

>Heat radiation works better the higher the temperature?

The power output is proportional to T^4 according to the Stefan-Boltzmann law.

https://www.mdpi.com/1996-1073/16/10/4010

40% isn't much in the grand scheme of things, but maybe they can reach higher reduction with more research/materials. Mass and power are pretty cheap for spaceX, so shipping more solar panels and a heap pump might not be a deal breaker.

Would e.g. a reduction of 90% in radiator area change the overall picture on the overall feasibility? I think not, it would still be ludicrous, but I'd be happy to be proven wrong.

The radiator area is probably not what they need to worry about that much as we thought. When the energy input comes from solar 100%, they just need to optimize the ratio of the sectional area facing the sun over the total surface area of the satellite. If the ratio is low enough, like a fin or cone shaped object, it will be harder to be hot.

I agree that data centers in space is nuts.

But I think there's solutions to the waste heat issue

https://www.nasa.gov/centers-and-facilities/goddard/engineer...

The distinction is that what they are doing for Webb is trying to dissipate small amounts of heat that would warm up sensors past cryogenic temperatures.

Like on the order of tens or hundreds of watts but -100C.

Dissipating heat for an AI datacenter is a different game. A single AI inference or training rack is going to be putting out somewhere around 100kW of waste heat. Temps don't have to be cryogenic but it's the difference between chiselling a marble or jade statue and excavating a quarry.

That's a solution for minuscule amounts of heat that nevertheless disturb extremely sensitive scientific experiments. Using gold, no less. This does not scale to a crapton of GPU waste heat.

Just have to size radiators correctly. Not a physics problem. Just an economic one.

Main physics problem is actually that the math works better at higher GPU temps for efficiency reasons and that might have reliability trade off.

Anything is possible here, it's just there's no goddamn reason to do any of this. You're giving up the easiest means of cooling for no benefit and you add other big downsides.

It's scifi nonsense for no purpose other than to sound cool.

It's about creating a flywheel for scale.

Getting better at creating and erecting solar panels & AI datacenters on earth is all well and good, but it doesn't advance SpaceX or humanity very much. At lot of the bottlenecks there are around moving physical mass and paperwork.

Whereas combining SpaceX & xAI together means the margins for AI are used to force the economies of scale which drives the manufacturing efficiencies needed to drive down launch etc.

Which opens up new markets like Mars etc.

It is also pushing their competitive advantage. It leaves a massive moat which makes it very hard for competitors. If xAI ends up with a lower cost of capital (big if - like Amazon this might take 20 years horizon to realize) but it would give them a massive moat to be vertically integrated. OpenAI and others would be priced out.

If xAI wants to double AI capacity then it's a purely an automation of manufacturing problem which plays to Elons strengths (Tesla & automation). For anyone on earth doubling capacity means working with electricity restrictions, licensing, bureaucracy, etc. For example all turbines needed for electricity plants are sold years in advance. You can't get a new thermal plant built & online within 5 years even if you had infinite money as turbines are highly complex and just not available.

Hmm, Elon really did run that flywheel pretty well. He built the Roadster to drum up some cash and excitement so he could develop the Model S, then he used that success to do the Model X, and then he expanded capacity to develop the 3 and Y, and he reinvested the profits to develop the Model 2, finally bringing EVs to the masses, displacing ICEs everywhere, and becoming the undisputed leader of both EV and battery manufacturering.

Oh wait, that didn’t actually happen, because he got distracted or something? He doesn’t really have battery capacity worth writing home about, the Chinese are surpassing Tesla in EV manufacturing, and Waymo is far ahead in self-driving.

The amazing space computation cost reduction process sounds rather more challenging than the Model 2, and I’m not sure why anyone should bet on Elon pulling it off.

> Oh wait, that didn’t actually happen

Not sure how you can say that. Nothing lasts forever, especially in the face of Chinese market dumping, but for a while there Tesla really was the undisputed king of EV manufacturing, that flywheel is how he got there, he did release all the patents because he said from day one he didn't anticipate or aim for 100% market share for Tesla and assumed there'd always be lots of EV manufacturers in future. All that sounds like - mission accomplished?

As for Waymo being ahead, maybe today. But Waymo's tech stack is largely pre-DL, they rely heavily on unscalable techniques like LIDAR and continuous mapping. Tesla is betting big on the "scale up neural networks" model we know works well and their FSD can drive everywhere. They're perhaps behind Waymo in some ways, but they're also in different markets - Waymo won't sell anyone a self driving car and Tesla will. I wouldn't count them out. Their trajectory is the right one.

> I’m not sure why anyone should bet on Elon pulling it off.

PayPal, SpaceX existing at all, then doing reusable rockets, Tesla, FSD, large scale battery manufacturing, Starlink, X ("he can't fire 80% of employees it'll crash immediately"), robotics, training a SOTA LLM so fast even Jensen Huang was shocked ... the man consistently pulls off impossible seeming things in the face of huge skepticism. How many examples does it take before people start taking the guy seriously? Infinity examples?

> > Oh wait, that didn’t actually happen

> Not sure how you can say that.

Because Elon canceled the Model 2.

> unscalable techniques like LIDAR

What, exactly, is unscalable about LiDAR? BYD appears to be planning to include LiDAR (one unit, presumably forward facing) in even their cheapest cars effective quite soon, and they seem to have a few tens of thousands of LiDAR units already on the road.

And Waymo’s solution is expensive but seems to scale fine.

Meanwhile, there is certainly nothing inherently that prevents scaling a pure-vision approach that relies on massive in-car computation, but Tesla wants to use their AI5 chips and they seem to be struggling to produce and scale them. (They also apparently want to launch them into space, but it’s not really clear that they exist.)

I really find the goalpost moving is shocking..

Paypal is in no way a Musk creation, no one makes that claim and in fact they got rid of him quite quickly.

X has plummeted in value, and is worth a fraction of what he paid for it? How is this "pulling it off" by shrinking the user base, revenue, etc? While we don't have publicly audited figures, they announced a net loss for the first three quarters of 2025, while it posted profits prior to his purchase.

FSD isn't even real? Why would you cite a feature that doesn't actually exist as an example of "Elon pulling it off"? He promised FSD would be available over a decade ago, and it's still not real.

> How many examples does it take before people start taking the guy seriously?

I'd personally settle for real examples, and not the false ones cited above.

How did he have time for all that while begging to go partying with Epstein?

We must be living in parallel universes.

Tesla invested into the first Lotus roadster - and put that cash into the S then the X. Used that cash to build the worlds largest factories and make the 3 & Y which sold at enormous volumes - so large in fact that the S & X are now tiny single percentages of sales which is why Tesla is stopping manufacturing them now.

Tesla is one of the very few vehicle manufactures which makes a profit manufacturing vehicles. Tesla throws off cash which allows the flywheel to keep spinning.

Tesla is now operating fully autonomous rides. They've constantly proved their naysayers wrong at every turn in time. What the Chinese are doing in battery tech is irrelevant to US vehicles as they will never be allowed to sell in the US which is Teslas largest market.

The model 2 has the possibility of being profitable at insanely low purchase price which has the potential to completely disrupt the economics of US sales in such a way that legacy auto could well be bankrupt in 5-10 years. Who will be making Waymo's vehicles then?

The Model 2 vehicle program was killed[1].

[1]: https://www.reuters.com/business/autos-transportation/tesla-...

> Tesla is now operating fully autonomous rides.

There's been a lot of reporting saying otherwise. Still requiring follow cars. FSD is still trying to kill the driver at random.

> the 3 & Y which sold at enormous volumes

Tesla isn't even in the top 15 auto manufacturers by volume? The largest manufacturer Toyota produces 9x the cars Tesla does. Tesla is also on a multiyear sales drop with no sign of sales improvement.

The top 15 car makers produced 70 million cars, to Tesla's 1.7m. They have no enormous volume, at all.

https://en.wikipedia.org/wiki/List_of_automotive_manufacture...

If Tesla's stock traded in line with its competitors, its a $30-40B company. The hype around future growth (now completely off the charts) is the only reason the stock price is out of line with reality. There is no reason to expect Tesla's sales figures to improve going forward, in fact, they will continue to decrease.

> Tesla throws off cash which allows the flywheel to keep spinning

Tesla had a profit of $3.8b in 2025 (this is a 46% drop from 2024 and a second year over year drop). It's revenue was $94b (also less than 2024), which places it 12th among auto manufacturers. It's profit is 6th, which is a decent margin compared to legacy makers, but as mentioned above, the profit is plummeting as Tesla struggles to sell cars. It's revenue among all global companies is not even in the top 100.

It does not "throw off cash", the business is in a tailspin.

>They've constantly proved their naysayers wrong at every turn in time

Musk has been promising full self driving mode is within six months to a year away. He first made those claims in the mid 2010s? Do Tesla's have full self driving mode in 2026?

There is a decade long trail of failed claims from Musk and Tesla.

In 2019, Musk predicted 1 million Tesla robotaxis on the road by 2020. How many Tesla robotaxis are on the road in 2026? Fifty? One hundred? It's a rounding error compared to the claim that they'd have a million in 2020...

Musk said in 2019 that he believed Tesla vehicles were not traditional depreciating assets and instead could appreciate because they contained future-value technologies, especially Full Self-Driving (FSD): “I think the most profound thing is that if you buy a Tesla today, I believe you are buying an appreciating asset — not a depreciating asset.”

In fact, Tesla's are among the worst depreciating vehicles on the market today, their depreciation compares to the low end car market of Nissan, Hyundai and other low quality manfacturers.

Elon projected 250-500k Cybertruck sales per year. In reality, they sold 38k in 2024, and just 16k in 2025.

>They've constantly proved their naysayers wrong at every turn in time

Hey remember that time someone had their Tesla running down the highway and the superior self-driving capability failed to see an 18 wheeler that crossed the road and the person was decapitated and there are videos of that complete with blood spray?

> We must be living in parallel universes.

It looks that way...

> They've constantly proved their naysayers wrong at every turn in time.

They have not done anything of the sort.

> Which opens up new markets like Mars etc.

What do you project out of the Martian market?

This was one of the first things that made me realise how un-serious Musk was about Mars.

Paraphrasing him, "You can be the first pizza restaurant owners on Mars" and "The price of a ticket isn't far off the price of a house, normal people can get a loan for it". What bank in their right mind would lend even just $100k to a normal person for a ticket to a place, let alone one with worse economic prospects than La Güera in Western Sahara?*

Don't get me wrong, if there was any seriousness behind this I was, and might still be, excited by the prospect of a new world… but even if I had not soured on Musk politically, I would not trust his plans when they come with this level of attention to detail (not even in rhetoric).

* I don't trust LLMs where I can't verify them, but I did ask it for a vibe check about the cost of research needed for making a pizza from ISRU on mars, and the first step was water purification for which it estimated a few hundred million, and a combined cost with all the other steps 4-10 billion (before launches)

There is nothing we need on Mars other than science. It's not a market because there isn't money to be made outside of what is required to do whatever economically useless but scientifically valuable efforts we can convince people to fund.

We can't build an independent colony we can't live there any time soon. Arguably it may never make sense to live there.

With that attitude mankind would still be living in caves. Why build a farm and stay in one place - we should follow the animals around.

1. Mankind never systematically lived in caves; that's just where remains and rock paintings are more likely to have survived.

2. Farming didn't evolve from a vision of "let's stay in one place, so let's find a way to do it"; it evolved from the gradual application of accumulated practical knowledge under real constraints until eventually it was possible to stay in one place. If Paleoelon had somehow convinced early humanity to abandon hunter-gathering and settle into a sedentary life because he had a vision for new markets around farming it would have led to the earliest famine.

While what you say is mostly correct, the lifestyle switch to farming was determined not by some random gradual accumulation of knowledge during the previous million years, but by accelerated accumulation of knowledge during a few thousand years at most, which was caused by the dwindling hunting resources, which forced humans to abandon the lifestyle that they had for a couple million years and switch to a lifestyle where the staple food consisted of plant seeds, with anything else providing much less of the nutrient intake. Only after a few more thousand years, raising domestic animals allowed the return to a more diverse diet.

Switching to a farming lifestyle was certainly not done by choice, but to avoid death by starvation, as we now know that this has caused various health problems, especially in the beginning, presumably until experience has taught them to achieve a more balanced diet, by combining at least 3 kinds of plant seeds, 2 with complementary amino acid profile and 1 kind of oily seeds for essential fatty acids (the most ancient farming societies have combined barley or einkorn or emmer wheat with lentils or peas or a few other legumes less used today and with flax seeds).

Yes, your description of how farming and sedentary lifestyle progressed is much more accurate than my somewhat clumsy attempt. My intention was to emphasise that such a transformative event in human history did not take place thanks to visionaries going against the grain [0] , but rather through a long and complex process.

[0] Well, technically in favour of the grain! Pun not initially intended: https://en.wikipedia.org/wiki/Against_the_Grain:_A_Deep_Hist...

> Mankind never systematically lived in caves

Define systematically?

In this context, 'systematically' is a qualifier to the adverb 'never'. It serves as a disclaimer to avoid someone pointing out that, well actually, some humans have lived in caves and do so to the present day.

And that's why the best way to use Superman's powers is in making him turn a giant crank

(yes I fully agree with you!)

Honestly, there's not a lot else I can think of if your goal is find some practical and profitable way to take advantage of relatively cheap access to near-Earth space. Communication is a big one, but Starlink is already doing that.

One of the things space has going for it is abundant cheap energy in the form of solar power. What can you do with megawatts of power in space though? What would you do with it? People have thought about beaming it back to Earth, but you'd take a big efficiency hit.

AI training needs lots of power, and it's not latency sensitive. That makes it a good candidate for space-based compute.

I'm willing to believe it's the best low-hanging fruit at the moment. You don't need any major technological advances to build a proof-of-concept. Whether it's possible for this to work well enough that it's actually cheaper than an equivalent terrestrial datacenter now or in the near future is something I can't answer.

You don't need any major technological advances to build a proof-of-concept

You do - cooling those datacenters in space is an unsolved problem.

Sure it is, just not economically at that scale yet. But if Starship brings the cost to orbit down significantly, maybe.

We have radiators on the ISS. Even if you kept the terrible performance of those ancient radiator designs (regularly exposed to sunlight, simplistic ammonia coolant, low temperature) you could just make them bigger and radiate the needed energy. Yes it would require a bit of engineering but to call it an "unsolved problem" is just exaggerating.

It's a solved problem. The physics is simply such that it's really inefficient.

> ... we'd need a system 12.5 times bigger, i.e., roughly 531 square metres, or about 2.6 times the size of the relevant solar array. This is now going to be a very large satellite, dwarfing the ISS in area, all for the equivalent of three standard server racks on Earth.

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

The gist of it is that about 99% of cooling on earth works by cold air molecules (or water) bumping into hot ones, and transferring heat. There's no air in space, so you need a radiator 99x larger than you would down here. That adds up real fast.

That’s the secret plan - cover LEO with solar cells and radiators, limiting sunlight on the ground, rendering ground base solar ineffective, cool earth and create more demand for heating; then sell expensive space electricity at a huge premium. Genius!

I think you may be thinking of cooling to habitable temperatures (20c). You can run GPUs at 70c , so radiative cooling density goes up exponentially. You should need about 1/3 of the array in radiators.

A really painfully laboured way of just saying conduction.

Bezos has been pushing manufacturing-in-space for a long time, as a ideal candidate for what to do in space that you might prefer to not do on Earth. Robotics, AI automation, manufacturing - combo it in space, let the robots manufacture for us in space. Abundant energy, low concerns about most forms of pollution. We'll need to dramatically improve our ability to transit mass to and from cheaply first of course (we're obviously talking many decades into the future).

> Bezos has been pushing manufacturing-in-space for a long time, as a ideal candidate for what to do in space that you might prefer to not do on Earth. Robotics, AI automation, manufacturing - combo it in space, let the robots manufacture for us in space.

LOL, this seems so far off from the reality of what manufacturing looks like in reality. - sending raw materials up there - service technicians are necessary ALL THE TIME, in fully automated production lines - sending stuff back down

Maybe I lack vision, but data centers in space is a 1000x times better idea and that is already a terrible idea.

Space manufacturing is a real thing, there are already companies trialling it. The factory is small, satellite sized, and it deorbits when the manufacturing run is done. The results are protected enough for them to be picked up from Earth.

The justification (today) is that you can do very exotic things in zero-G that aren't possible on Earth. Growing ultra-pure crystals and fibre optics and similar.

Ok, that I might buy. If there is a product one can build in zero-G that one cannot build on earth. Especially something like growing crystalls. Sure. But trying to compete with something that can just as well be build on earth on the premise that it will be cheaper to do the same thing just in space is insane.

It's the same issue that I have with data centers in space. I don't think there is any big technical hurdle to send a GPU rack into space and run it there. The problem is that I have a hard time to believe it is cheaper to run a datacenter in space. When you have to compete solely on cost, it will super hard.

I don't think it's insane. It might not work or be competitive but it's not obviously insane.

In a frictionless economy governed by spherical cows it'd be insane. But back here on Earth, AI is heavily bottlenecked by the refusal or inability of the supply chain to scale up. They think AI firms are in a bubble and will collapse, so don't want to be bag holders. A very sane concern indeed. But it does mean that inferencing (the bit that makes money) is constantly saturated even with the industry straining every sinew to build out capacity.

One bottleneck is TSMC. Not much that can be done about that. The other is the grid. Grid equipment manufacturers and CCGT makers like Siemens aren't spinning up extra manufacturing capacity, again because they fear being bag holders when Altman runs out of cash. Then you have massive interconnection backlogs, environmentalists attacking you and other practical problems.

Is it easier to get access to stable electricity supplies in space? It's not inconceivable. At the very least, in space Elon controls the full stack with nearly no regulations getting in the way after launch - it's a pure engineering problem of the sort SpaceX are good at. If he needs more power he can just build it, he doesn't have to try and convince some local government utility to scale up or give him air permits to run generators. In space, nobody can hear you(r GPUs) scream.

> "At the very least, in space Elon controls the full stack with nearly no regulations getting in the way after launch - it's a pure engineering problem of the sort SpaceX are good at. If he needs more power he can just build it, he doesn't have to try and convince some local government utility to scale up or give him air permits to run generators. In space, nobody can hear you(r GPUs) scream."

Wouldn't he be able to float solar panels and GPUs out into international waters and run them on cargo ships powered by bunker fuel much (much much) cheaper than launching them into space?

Building nuclear-powered and solar powered datacenters in places with low population density will still be cheaper. Do you think Mongolian government won't allow China to build datacenters if the price is right?

It might be easier in China but that doesn't help Elon or Americans.

Solar powered datacenters on Earth don't make sense to me. The GPUs are so expensive you want to run them 24/7 and power cycling them stresses the components a lot so increases failure rate. Once it boots up you need to keep the datacenter powered, you can't shut it down at night. Maybe for CPU datacenters solar power can make sense sometimes, but not for AI at the moment.

Nuclear is super hard and expensive to build. It probably really is easier to put servers in space than build nuclear.

The show For All Mankind kind-of hinted at how the labor problem would be solved: recruit like the military and promise huge bonuses that will probably not be realized because space is risky business

Well you see, what you do is send a bunch of humanoid robots up there to do all the work.

(please don't ask what we do when those break down)

I think it makes more sense if you invert the manufacturing cycle.

Automated asteroid mining, and asteroid harvesting, are potential areas where we have strong tech, a reasonable pure automation story, and huge financial upsides. Trillion dollar asteroids... If we’re sourcing metals out there, and producing for orbital operations or interplanetary shenanigans, the need for computing and automation up there emerges.

And I imagine for the billionaire investor class now is the window to make those kinds of plays. A whole set of galactic robber barons is gonna be crowned, and orbital automation is critical to deciding who that is.

>>sending raw materials up there

That's what asteroid mining is for.

>>service technicians are necessary ALL THE TIME

Optimus is already very well tele-operated. Even though over time it can likely be trained to do specific tasks far better than even humans.

> That's what asteroid mining is for.

It’s not necessarily cheaper energetically to get stuff from an asteroid than from Earth. You’d have to accelerate stuff from a wildly different orbit, and then steer it and slow it down. Metric tonnes of stuff. It’s not physically impossible, but it is wildly expensive (in pure energy terms, not even talking about money) and completely impractical with current technology. We just don’t have engines capable of doing this outside the atmosphere.

> Optimus is already very well tele-operated

It can't even serve popcorn in a diner.

> That's what asteroid mining is for.

I think you might have no sense of what it takes to go from a raw mined material to something that can be used in a factory. I am not saying it cannot be done. I am just saying it cannot be done in a way that is cheaper than on earth.

When Bezos first mentioned drone delivery, many intelligent, serious people laughed at it and accused of Bezos running out of ideas as Amazon was stagnant

That is a fun thought experiment, as we wouldn't want to manufacture too far away from earth we may still be within the earth's atmosphere. I wonder what effect dumping greenhouse gases into the very upper levels of the atmosphere would have in comparison to doing it lower down. My assumption is it would eventually sink to a lower density layer, having more or less the same impact.

Hate to say this, but manufacturing bitcoin would make the most sense. And hard to see how even that would work.

We also shouldn't overlook the benefits we might realize if humanity achieved the incredible engineering and technical capacity necessary to make this version of porcine flight happen.

IDK, what about the side-benefits of applying the "incredible engineering and technical capacity" to something useful instead? Rather than finding rationalisations for space spambots.

"The problem is that this is both wildly overambitious and somehow incredibly myopic at the same time."

Im sorry, but this is literally every single figurehead in society today.

[dead]

The data centers in space is 100% about Golden Dome,

https://wikipedia.org/wiki/Golden_Dome_(missile_defense_syst...

Nope, it's 100% about building the stock valuation of SpaceX for an IPO in the face of significant risk from a cold war its CEO started on X with the U.S. federal government and increasing competition from Blue Origin, Quinfan and Guowang. DOD will play Bedrock vs Grok until there is feature parity and then make a decision not based on the features.

Disclaimer: Not an Elon hater, but far from a sycophant, similar to how I felt about Steve Jobs for 40+ years.

Exactly, this is about attaching the AI hype bubble to all of his dealings before he offloads with an IPO (that still leaves him with 75% of the stock).

All right, so how is it that all you geniuses out here are totally right about this, but all the dullards at SpaceX and XAI, who have accomplished nothing compared to you lot, are somehow wrong about what they do every day?

I know being right without responsibility feels amazing but results are a brutal filter.

I once had a job mopping floors and was quite successful at it, even if I say so myself. Based on my experience, do you think it is reasonable for me to claim that I will eventually develop techniques for cleaning the oceans of all plastic waste? Folks are criticizing the pie in the sky claims, not that they can do anything at all.

Seems a bit of both. But no disparagement to your floor mopping (as I once was a dishwasher in a commercial kitchen myself), but there's a big gap between cleaning a floor, or a dish, and creating frontier models and spaceships.

That said: I think solar is niche, and a moon-shot for how they want it. Nuclear is the future of reliable energy for human civilization.

I think the K-scale is the wrong metric. I don't think we should be trying to take all the sun's energy as a goal (don't blot out the sun! don't hide it in a bushel!), or as a civilizational utiltiy - I'm sure better power supplies will come along.

Data centers ultimately need to provide power and remove heat. Solar might be a little easier for power in space, maybe, but heat is an absolute no-go, stop, this will never ever work. You can't engineer your way out of the fact that space is a vacuum.

if the thermal radiation panels have ~3 x the area of the solar panels, the temperature of the satellite can be contained to about 300 K (27 deg C). Ctrl+F:pyramid to find my calculations.

I looked, and you outlined a solution that would be hard to achieve in a vacuum chamber on earth. Now we're going to launch it into orbit and it will work great?

Building data centers in Antarctica with nuclear power would be easier. And still way harder than necessary.

Yes, how would you simulate a 4K background in a vacuum chamber on earth... or you could just trust a law that has withstood 150 years the test of time by physicists...

What have the engineers at XAI accomplished? From the ground level, it seems they followed the same research all the other LLM chatbot companies did. They followed along and made a sassy mecha hitler who makes revenge porn.

XAI isn't a serious venture.

So, the much lauded xAI is overhyped, underwhelming and ... kind of evil? In stark contrast to every other AI company, I suppose?

And people are using it for revenge porn? I haven't seen that. I've just seen that grok pioneered really good deep web search, is less woke than other LLMs and grok imagine has really good video generation and pretty good image gen. Plus the X timeline feed is really good!

> And people are using it for revenge porn? I haven't seen that.

https://oag.ca.gov/news/press-releases/attorney-general-bont...

https://www.reuters.com/legal/litigation/grok-says-safeguard...

https://www.nytimes.com/2026/01/09/technology/grok-deepfakes...

https://www.vogue.com/article/grok-deepfakes-trend-essay

https://www.the-independent.com/tech/ai-grok-twitter-fake-im...

https://techpolicy.press/the-policy-implications-of-groks-ma...

https://www.rollingstone.com/culture/culture-features/grok-s...

The French raided the X offices in Paris.

> https://www.theguardian.com/technology/2026/feb/03/french-he...

> It said the alleged offences it was investigating now included complicity in the possession and organised distribution of child abuse images, violation of image rights through sexualised deepfakes, and denial of crimes against humanity.

This vision doesn't come from those great engineers, but from Elon, the guy who promised Hyperloop, FSD in 2 years 10 years ago, and lots of other BS

When a cultist hits you with their side of, ahm, facts, it invariably ends up being some kind of a logical fallacy. Is there a name for this phenomenon?

In this case it is the "how we dare not trusting all the experts at spaceX."

But even the fallacy itself is applied incorrectly, as we hear zero from anyone else other than the cult leader himself.

So I am a cultist and Elon is cult leader? I think the problem with that is they actually create value in terms of products that work and sell. A cult leader would be more about rhetoric and less about results, I guess? Why does Elon make you so mad?

There's no reason to think the brilliant minds at SpaceX are supportive of focusing their mission in any manner-what-so-ever on datacenters in space. You can't call on their genius as the supportive argument accordingly.

I disagree, I think the idea of a cabal of reactionary comrades inside SpaceX is activist fantasy. I think SpaceX only does what it does with full committment of its people: mind, body, spirit.

I think there's a scenario where that's true: one where the head of your company is collaborative and deferential to expertise.

There's another scenario, though: one where the head of your company is a bull in a China shop, whose successes have come almost exclusively through a Barnum-esque scheme of cascading bravado and marketing genius without much expertise, but a marvelous ability to sell any idea purely via unearned gravitas.

The former is less sexy: I've compiled loads of talented people, and we're going to solve very hard problems, even some that seem impossible.

The latter is very sexy: I'm a genius and we're going to accomplish the impossible in one year via sheer force of my grand will. And even if it doesn't actually happen, I'll sell you on the next vision.

It seems like you’re ascribing to Elon some kind of magic, where you feel he’s breaking the rules of what should be allowed in order to achieve success. Is it impossible you simply don’t understand how what he does works?

I think you may have misread my comment, because no.

So your hypothesis is Elon's domineering personality creates a culture of terrified silence where everybody wants to revolt but Elon is simply too powerful and they have no choice - and this extends to customers, sales and even technology - reality itself bends to the will of mighty Elon? And that's ... unfair?

I didn't say that, so ... no?

[dead]

spacex is one thing but xai accomplished what? the most racist csam prone llm?

I'm not aware of this - What's that?

Probably shouldn't speak to the brilliance of xAI engineers when you've never heard of their work

Is whatever that is their work?

Not just that, it's their one and only product, to my knowledge

This place has derangement syndrome unfortunately. Such pessimists, it’s a bit sad

I've seen things you people wouldn't believe. Cooling systems fail in geostationary orbit. I watched thermal loads glitter in the dark near Lagrange Point 2. RAID arrays degraded by Van Allen radiation. Micrometeorite impacts at 2 AM. Legacy Perl scripts no one dared to touch, running on hardware we couldn't replace because the launch windows had closed. All those moments will be lost in time, like packets in space. Time to reboot.

Kudos to your reference to Blade Runner

Only people who never interacted with data center reliability think it's doable to maintain servers with no human intervention.

Microsoft did do the experiment (Project Natick) where they had "datacenters" in pods under the sea with really good results. The idea was simply to ship enough extra capacity, but due to the environment, the failure rates where 1/8th of normal.

Still, dropping a pod into the sea makes more sense than launching it into space. At least cooling, power, connectivity and eventual maintenance is simpler.

The whole thing makes no sense and is seems like it's just Musk doing financial manipulation again.

https://news.microsoft.com/source/features/sustainability/pr...

> The whole thing makes no sense and is seems like it's just Musk doing financial manipulation again.

It's a fig leaf for getting two IPOs in one. There's no sense in analyzing it any further.

Exactly. He can croon about DOGE all day, but the reality is his entire fortune was built on feeding at the trough of government largess. That's why he talks about Mars all the time. He's not stupid enough to think we could actually live there, but damn if he couldn't make a couple trillion skimming off the top of the world's most expensive space program.

No, I think he is that stupid.

Right, let's not forget that he's selling it to himself in an all stock deal. He could have priced it at eleventy kajillion dollars and it would have had the same meaning.

He's basically trading two cypto coins with himself and sending out a press release.

The experiment may have been successful, but if it was why don't we see underwater datacenters everywhere? It probably is a similar reason why we won't see space datacenters in the near future either.

Space has solar energy going for itself. With underwater you don't need to lug a 1420 ton rocket with a datacenter payload to space.

Salt water absolutely murders things, combined with constant movement almost anything will be torn apart in very little time. It's an extremely harsh environment compared to space, which is not anything. If you can get past the solar extremes without earths shield, it's almost perfect for computers. A vacuum, energy source available 24/7 at unlimited capacity, no dust, etc.

The vacuum is the problem. It might be cold but has terrible heat transfer properties. The area of radiators it would take to dissipate a data center dwarfs absolutely anything we’ve ever sent to orbit

Also solar wind, cosmic rays etc. We don't have perfect shielding for that yet. Cooling would be tricky and has to be completely radiative which is very slow in space. Vacuum is a perfect insulator after all, look how thermos work.

I can't see any reason to put them underwater rather than in a field somewhere. I think the space rationale is you may run out of fields.

Placing them underwater means you get free, unlimited cooling.

Exactly the opposite of space, where all cooling must happen through radiation, which is expensive/inefficient

Whoa there, space-faring sysadmin. You really want that off-world contract tho?

Haha, hard pass on the job. I prefer my oxygen at 1 atm.

I'm not a data center technician myself, but I have deep respect for those folks and the complexity they manage. It's quite surprising the market still buys Musk's claims day after day.

> It's quite surprising the market still buys Musk's claims day after day.

More disturbing than surprising.

There are a class of people who may seem smart until they start talking about a subject you know about. Hank Green is a great example of this.

For many on HN, Elon buying Twitter was a wake up call because he suddenly started talking about software and servers and data centers and reliability and a ton of people with experience with those things were like "oh... this guy's an idiot".

Data centers in space are exactly like this. Your comment (correctly) alludes to this.

Companies like Google, Meta, Amazon and Microsoft all have so many servers that parts are failing constantly. They fail so often on large scales that it's expected things like a hard drive will fail while a single job might be running.

So all of these companies build systems to detect failures, disable running on that node until it's fixed, alerting someone to what the problem is and then bringing the node back online once the problem it's addressed. Everything will fail. Hard drives, RAM, CPUs, GPUs, SSDs, power supplies, fans, NICs, cables, etc.

So all data centers will have a number of technicians who are constantly fixing problems. IIRC Google's ratio tended to be about 10,000 servers per technician. Good technicians could handle higher ratios. When a node goes offline it's not clear why. Techs would take known good parts and basically replacce all of them and then figure out what the problem is later, dispose of any bad parts and put tested good parts into the pool of known good parts for a later incident.

Data centers in space lose all of this ability. So if you have a large number of orbital servers, they're going to be failing constantly with no ability to fix them. You can really only deorbit them and replace them and that gets real expensive.

Electronics and chips on satellites also aren't consumer grade. They're not even enterprise grade. They're orders of magnitude more reliable than that because they have to deal with error correction terrestial components don't due to cosmic rays and the solar wind. That's why they're a fraction of the power of something you can buy from Amazon but they cost 1000x as much. Because they need to last years and not fail, something no home computer or data center server has to deal with.

Put it this way, a hardened satellite or probe CPU is like paying $1 million for a Raspberry Pi.

And anybody who has dealt with data centers knows this.

Great comment on hardware and maintenance costs, and in comparison Elon wrote "My estimate is that within 2 to 3 years, the lowest cost way to generate AI compute will be in space." It's a pity this reads like the entire acquisition of xAi is based on "Elon's napkin math" (maybe he checked it with Grok)

The deal they made values xAI at $230 Billion. It’s a made up number, with no trustworthy financial justification to back it up. It is set to provide a certain return to xAI’s investors (the valuation decides the amount you get per share), who in turn are bailing out the earlier acquisition of X (Twitter). All of this is basically a shell game where Elon is using one company to bail out another. It’s a way of reducing the risk of new ventures by spreading them out between his companies. It’s also really bad for SpaceX employees and investors, who are basically subsidizing other companies.

The thing is, everyone knows Elon is not a real CEO of any of these companies. There isn’t enough time to even be the CEO of one company and a parent. This guy has 10 companies and 10 children. He’s just holding the position and preventing others from being in that position, so he can enact changes like this. And his boards are all stacked with family members, close friends, and sycophants who won’t oppose his agenda.

As both are private companies none of this matters if the investors of both companies are happy.

Most of the investors don’t even have a choice. Nor do all the other shareholders like employees. And the boards of Musk companies are stacked with his yes men.

Ah yes, my favourite kind of engineering: financial engineering

He's bailing out one of his failing ventures with one of his so far successful ones. The BS napkin math isn't the reason he's doing it. It's the excuse for doing it.

Or he's having another mental break because he knocked up yet another woman and is going to have yet another kid he can't remember the name of.

Can you provide a link for that quote, because that quote is absolute stupidity.

It's in the article that you're commenting on, https://www.spacex.com/updates#xai-joins-spacex.

Oh, ffs.

Haha. It's less than 1,000 words that would take less than 5 minutes to read.

I bet much less than half of the hundreds of HN commenters here bother to read it. Many are clearly unfamiliar with its content.

I can't, I don't want it in my head :/

Thanks for putting words to that; the paragraph which most stuck out to me as outlandish is (emphasis mine):

    The basic math is that launching a million tons per year of satellites generating 100 kW of compute power per ton would add 100 gigawatts of AI compute capacity annually, *with no ongoing operational or maintenance needs*.

"what if we move all our data center needs into my imagination, things are running so much smoother there"

I'm pretty sure they don't harden compute in space anymore, that's one thing SpaceX pioneered with their cost-cutting approach early on.

for me trying to apply some liquid TIM on a CPU in a space station in a big ass suit would be a total nightmare, maybe robots could make it bearable but the racks would get greassy fast from many failed attempts

Excellent comment.

Might be why he's also investing in building their own fabs - if he can keep the silicon costs low then that flips a lot of the math here.

> but they cost 1000x as much

Compute power has increased more than 1000x while the cost came down.

I recall paying $3000 for my first IBM PC.

> they need to last years and not fail

Not if they are cheap enough to build and launch. Quantity has a quality all its own.

Have you heard of cosmic radiation?

Cosmic rays take time to destroy them.

It's not only about destruction. It's also about reliability. Without proper shielding and error correction you're going to have lots and lots of reliability issues and data corruption. And if we're talking about AI and given the current reliability problems of the Nvidia hardware, plus the radiation, plus the difficulty for refrigerating all that stuff on space... That's a big problem. And we still haven't started to talk about the energy generation.

I think there's a very interesting use case on edge computing (edge of space, if you wanna make the joke) that in fact some satellites are already doing, were they preprocess data before sending back to Earth. But datacenter-power-level computing is not even near.

I have no idea and numbers to back it up, but I feel it would be even easier to set up a Moon datacenter than an orbital datacenter (when talking about that size of datacenter)

We'll see!

Keep in mind that the current state of space electronics is centered around one-off very expensive launches, where the electronics failure would be a fiscal disaster. (See JWST)

Being able to rapidly launch cheap electronics may very well change the whole outlook on this.

People already do that (launch cheap, redundant, unshielded electronics) for LEO, but sounds like these data centers would pretty explicitly not be in LEO.

Also AI GPUs are the exact opposite of cheap electronics

First of all Twitter had basically no downtime since he bought it, so all the 'internet experts' posting their thoughts were completely dead wrong. If anything Twitter was far more reliable than Microsoft has been these past few years.

You are assuming things need to run the same way in space, for instance you mentioned fans, you won't have any in space. You also won't have any air, dust, static, or any moving parts.

You are assuming the costs to launch to orbit are high, when the entire point of Spacex's latest ship is to bring the cost to launch so low that it is cheaper per ton than an airplane flight.

Maintenance would be nice but you are saying this like Elon Musk's company doesn't already manage the most powerful datacenters on the planet.

You have no clue what you are talking about regarding cosmic rays and solar wind, these will literally be solar powered and behind panels and shielding 100% of the time.

> Twitter had basically no downtime since he bought it

I'm sorry, but what? Not only has it had multiple half days of downtime, two full days+, but just two weeks ago had significant downtime.

https://www.thebiglead.com/is-x-down-twitter-suffers-major-o...

The sock puppet account is angry!

I went looking through your comments. 75% of them (and probably 90% in the lasst 2 years) were Elon related. Tesla, SpaceX, Grok, Twitter, DOGE, etc. Quite a lot of comments for 101 karma if I'm being real.

Why do you feel this kneejerk reaction to defend Elon and his companies? You'll never be him. He doesn't care about you. He'd use you for reactor shielding for an uptick in Tesla share price without a second's hesitation. This is cultish behavior.

Do you have any idea who you're defending? I'll give you just one example. A right-wing influencer named Dom Lucre uploaded CSAM to Twitter, a video. But he didn't just upload it. He watermarked it first so had it on his computer and then postporcessed it. It was I believe up for days. This was apparently a video so bad that mere possession should land you in prison. And the fact that the FBI didn't arrest him basically tells you he'd an FBI asset. After taking days to ban him, Elon personally intervened to unban him. Why? Because reasons.

And this is the same man who it's becoming clear was deeply linked with Jeffrey Epstein, as was his brother [1].

Bringing this back to the original point: this is why Twitter lost 80% of its value after Elon acquired it. Advertisers fled because it became a shithole for CSAM and Nazis.

As for "basically no downtime" that's hilarious. I even found you commenting the classic anecdote "it was fine for me" (paraphrased) on one such incident when Twitter DDOSed itself [2].

Your cultish devotion here is pretty obvious eg [3]. I'm genuinely asking: what do you get out of all this?

[1]: https://www.axios.com/local/boulder/2026/02/02/kimbal-musk-j...

[2]: https://news.ycombinator.com/item?id=36555897

[3]: https://news.ycombinator.com/item?id=42836560

Lol, did you spot one of his alts?

But yeah, otherwise agree that his conduct, within a corporate context and otherwise, do not merit the kind of public adulation he's getting.

I also remember (vividly at that) his comments on distributed systems when he bought twitter back in the day and was starting to take it over. I remember thinking to myself, if he's just spewing so much bullshit on this, and I can understand this because it's closer to my body of knowledge, what other such stuff is he pronouncing authoritatively on other domains I don't know so much about?

I'd assume datacenters built for space would have different reliability standards. I mean, if a communication satellite (which already has a lot of electronic and computing components) can work unattended, then a satellite working as a server could too.

You are right. But in the future we'll be refueling the satellites anyway. Might as well maintain the servers using robots all in one go.

Right now that’s not the case. Satellites just store whatever fuel they need for orbital adjustments and by default, they fall back to earth and burn up at the end of their life. All the Starlink satellites are configured to fall back to earth within 5 years (the fuel is used to re-raise their orbit). The new proposed datacenters would sit in a higher orbit to avoid debris, allegedly, but that means it is even more expensive to get to them and refuel them, and the potential for future debris is far worse (since it wouldn’t fall back to earth and burn up for centuries or millennia).

But … but what if we had solar-powered AI SREs to fix the solar-powered AI satellites… /in space/?

Maintaining modern accelerators requires frequent hands-on intervention -- replacing hardware, reseating chips, and checking cable integrity.

Because these platforms are experimental and rapidly evolving, they aren't 'space-ready.' Space-grade hardware must be 'rad-hardened' and proven over years of testing.

By the time an accelerator is reliable enough for orbit, it’s several generations obsolete, making it nearly impossible to compete or turn a profit against ground-based clusters.

Thank you. The waste heat problem is so bad but no one gets around to mentioning the fact that you can't have AI grade chips and space at the same time.

On the other hand, Tesla vehicles have similar hardware built into them, and don't require such hands-on intervention. (And that's the hardware that will be going up.)

Car-grade inference hardware is fundamentally different from data center-grade inference hardware, let alone the specialized, interconnected hardware used for training (like NVLink or complex optical fabrics). These are different beasts in terms of power density, thermal stress, and signaling sensitivity.

Beyond that, we don't actually know the failure rate of the Tesla fleet. I’ve never had a personal computer fail from use in my life, but that’s just anecdotal and holds no weight against the law of large numbers. When you operate at the scale of a massive cluster, "one-in-a-million" failures become a daily statistical certainty.

Claiming that because you don't personally see cars failing on the side of the road means they require zero intervention actually proves my original point: people who haven't managed data center reliability underestimate the sheer volume of "rare" failures that occur at scale.

https://x.com/elonmusk/status/2017792776415682639

For what it's worth, this project plans to use Tesla AI5/AI6 hardware for the first launches.

Not only the sibling comments points, but cars aren't exposed to the radiation of space...

Well, one car is... and it's a Tesla!

Do they need to be maintained? If one compute node breaks, you just turn it off and don't worry about it. You just assume you'll have some amount of unrecoverable errors and build that into the cost/benefit analysis. As long as failures are in line with projections, it's baked in as a cost of doing business.

The idea itself may be sound, though that's unrelated to the question of whether Elon Musk can be relied on to be honest with investors about what their real failure projections and cost estimates are and whether it actually makes financial sense to do this now or in the near future.

AI clusters are heavily interconnected, the blast radius for single component failure is much larger than running single nodes -- you would fragment it beyond recovery to be able to use it meaningfully.

I can't get in detail about real numbers but it's not doable with current hardware by a large margin.

eh? They're not gonna lay cable in space. The laser links will be retargetable.

How are you doing pci express x16 with lasers without fiber optics? Have you touched data center hardware in your life?

Lasers, space, super geniuses, and most importantly money. You're worrying too much about the details and not enough about the awesomeness.

But seriously, why are all the stans in these comments as unknowledgeable as Elon himself? Is that just what is required to stan for this type of garbage?

What if every installed twitter app just acted as a proxy for grok to post as millions of different elon stans? Diabolical.

This guy invented reusable rockets that land themselves. I'm sure xAI is not just one guy. Plenty of talented people work there.

Context missing. This is in reference to a vision the (distant?) future where the satellites are manufactured in factories on the Moon and sent into space with mass drivers.

Full paragraph quote comes from:

> While launching AI satellites from Earth is the immediate focus, Starship’s capabilities will also enable operations on other worlds. Thanks to advancements like in-space propellant transfer, Starship will be capable of landing massive amounts of cargo on the Moon. Once there, it will be possible to establish a permanent presence for scientific and manufacturing pursuits. Factories on the Moon can take advantage of lunar resources to manufacture satellites and deploy them further into space. By using an electromagnetic mass driver and lunar manufacturing, it is possible to put 500 to 1000 TW/year of AI satellites into deep space, meaningfully ascend the Kardashev scale and harness a non-trivial percentage of the Sun’s power. >

> This is in reference to a vision the (distant?) future where the satellites are manufactured in factories on the Moon and sent into space with mass drivers.

In the meantime, how about affordable insulin for everybody?

Isn't it already somewhat affordable? https://worldpopulationreview.com/country-rankings/cost-of-i...

It's a political problem, not a tech problem

Exactly; most of the world's problems are political problems.

Which Musk has no intention to fix, of course, because he's more about money and (buying) status with it. He had an opportunity but decided to aid the regime in extracting people's data instead (probably selling it to adversaries).

Why is it cheaper to ship all of the materials to space, then to the moon for assembly (which also includes shipping all of the people and supplies to keep them alive), then back into space vs just…

building them on earth and then shipping them up?

We’re not exactly at a loss for land over here.

> which also includes shipping all of the people and supplies to keep them alive)

What do you mean, "people" ? I'm pretty sure Musk is only expecting to send self-assembling Optimus robots [1] to do the whole manufacturing.

[1] "pre-order now, expected delivery any time soon"

(Oh, those times where you try to be sarcastic and realize: "wait, maybe that's the actual plan".)

https://en.wikipedia.org/wiki/Lunar_resources

In situ manufacturing. You just have to send enough to build the thing that builds the factory.

It's not like satellites need anything like computer chips, which are finicky things to build that require parts with a sole supplier on the entire planet.

You can make propellant on the Moon (aluminum based solid fuels), and the energy to get into orbit or into deep space is far, far less that from Earth’s surface.

That makes much more sense tbh. I believe Musk predicted in 2021 that we would land humans on the moon by 2024 [0]. That obviously has been deprioritized but how many Starships have delivered 50+ tons of payload to the moon so far?

[0] https://www.foxbusiness.com/business-leaders/spacex-boss-elo...

Why would satellites be manufactured on the moon? There's nothing on the moon. The raw materials would have to be ferried over first. What would be the point?

It would appeal to naive technofetishists, the same crowd of investors enamored by many of Elon's other impossible schemes.

The moon mfg makes significantly more sense than the hilarious plan to establish a permanent Mars base in the next 50 years, but that's not saying much.

> Why would satellites be manufactured on the moon? There's nothing on the moon. The raw materials would have to be ferried over first. What would be the point?

From lunar regolith you would extract: oxygen, iron, aluminum, titanium, silicon, calcium, and magnesium.

From the poles you can get fuel (water ice -> water + hydrogen + oxygen).

The real constraint is not materials, but rather power generation, automation reliability, and initial capital investment.

So you have to shuttle machines, energy systems, and electronics.

The moon can supply mass, oxygen, fuel, and structure.

Satellites that would benefit most are: huge comms platforms, space-based power satellites, large radar arrays, deep-space telescopes, etc.

>From lunar regolith you would extract: oxygen, iron, aluminum, titanium, silicon, calcium, and magnesium.

Do we actually know how to do that?

>From the poles

From the poles! So the proposal includes building a planetary-scale railway network on bumpy lunar terrain.

>The moon can supply mass, oxygen, fuel, and structure.

None of those are things we are hurting for down here, though.

> So the proposal includes building a planetary-scale railway network on bumpy lunar terrain.

And that’s from a fascist who barely managed to dig ONE small one lane tunnel under Las Vegas and called it a revolution.

I’m sorry to be rude but people who are still giving musk any credit are stupid at this point.

Oh boy, IA data centers in space. It’s not only ridiculous, but it’s also boring and not even exciting at all.

> [...] and initial capital investment.

This is the big one - Musk knows that if he convinces enough people, they will invest the billions / trillions necessary, making him stupendously rich.

But anyone investing in that is... not a good investor, to be politically correct, because what's the expected return on investment? Who are the customers? What is the monetization? Or bar that, how does it benefit humanity?

It's throwing money down the drain. If you're an investor and are considering this, consider investing in earth instead. Real projects with real benefits. There's enough money to fix hunger, poverty, housing, education, and everything. Enough money to buy and / or fund politicians to make the necessary changes.

> There's enough money to fix hunger, poverty, housing, education, and everything. Enough money to buy and / or fund politicians to make the necessary changes.

Perhaps. But I can also see someone wanting to use their money to fund space exploration because it is more exciting.

As an aside, I strongly suspect that to solve the problems you think are more worthy, it isn't money that is the problem, but rather social, structural, cultural, and other issues mostly.

If you successfully solve hunger, poverty, housing, education, etc. Then humanity will back you doing whatever billionaire space or submarine shit you want.

Trying to do billionaire space shit while there is extreme poverty is a dangerous game imo; but I guess flaunting their wealth hasn't had any consequences so far.

Power would almost certainly mostly come from solar panels. The SpaceX-xAI press release mentions using mass drivers which are electrically powered. Could make Hydrogen-Oxygen rocket fuel but not needed in Moon's lower gravity/thin atmosphere.

> The real constraint is not materials

It's solvents, lubricants, cooling, and all the other boring industrial components and feedstocks that people seem to forget exist. Just because raw materials exist in lunar regolith doesn't mean much if you can't actually smelt and refine it into useful forms.

Both China and the US are working on building nuclear reactors on the moon, so presumably they see line of sight on those matters?

https://spectrum.ieee.org/lunar-nuclear-reactor-nasa-moon

I couldn't believe that was an actual quote from the article. It is.

These people are legit insane.

Not insane at all. They are perfectly sane and know words can be twisted to justify just about anything, when stating the actual goals is unsavory.

No it's just Musk's Big Idea for spacex to hype it before IPO. It's their version of FSD, robots etc.

You've got to hand it to him, he is a bullshitter par excellence.

How people still believe his bullshit is unfathomable.

You don't have to believe one's bullshit. You just have to believe others will believe the bullshit.

This is the moving force behind all investments of the past decade or so. Crypto? Everyone involved knows it's empty, but they hype it up anyway because they believe some people buy the bullshit, and plenty of people gobble it up and signal boost it because they think they're ahead of the pack. NFTs, same thing. Tesla stocks was probably the one that started it. Pokemon cards.

It's just one pump and dump scheme after another. The difference now is every one of them is too big to fail.

In a way, it's perfect. If what you're promising is sufficiently vacuous and you're a true believer, you can get away with. If you're promising something concrete and deliverable, fraud is so much easier to prove.

Yeah, I remember people saying that about making 1m model 3s per year, landing rockets, getting 10k+ satellite privately into orbit, and getting millions of subscribers using internet via those satellites.

Maybe just maybe the guy does actually get things done, and if you didn't hate him you'd see that?

(yes, there are some things he hasn't gotten done. That doesn't take away from what he has gotten done)

Please understand that his companies succeeding in some things doesn’t make the things that are exaggerated, overpromised, or just plain naked hype with no backing somehow practical. It’s an interesting effect of our age that for some figures to some people if any criticism is considered unwarranted then all criticism must be disregarded.

It reminds me of growing up in the evangelical church and all the pastors who’d still keep their followers even after they show up in new cars or fly first class, taking the tithes from old ladies on their pension.

This mofo threw a Nazi salute and danced around on stage like an idiot with a chainsaw. Then he illegally downloaded the entire US treasury payment database and ran it through his AI and faced zero consequences. After promising to find a trillion in fraud and abuse, he left after less than half a year and declared there wasn't that much fraud after all.

To most normal people this long history of overblown claims and complete failures would disqualify him from serious consideration. To most normal people, a massive illegal siphoning of US government data would be beyond the pale and worthy of jail time.

But in today's age, there's enough smoke and mirrors that such a charlatan can just float on a sea of adulations right on past any consequences.

> some things he hasn't gotten done

That's really understating things. He has promised so many things at various times that the "hits" are at best 10% of what he says. You can't just cherry pick his successes and say "well maybe this will work too" with a track record like that.

[dead]

Musk is a slimey salesman. His job as CEO is to hype bullshit.

Smart people call it "story telling" /s. Musk bullshit and constant lie made him the richest person in the world. No reason not to continue.

> We currently make around 1 TW of photovoltaic cells per year, globally.

Doubling every three years; at that rate it would take about 30 years for 1TW to become 1000TW. Whether on not the trend continues largely depends on demand, but as of right now humanity seems to have an insatiable demand for power.

I think it largely depends on what bottlenecks exist that we haven’t hit yet.

We’re not going to use 100% of our solar panel manufacturing capacity to power space data centers, specifically because everyone else on the ground is so power-hungry. If we’re being generous, it could maybe top out at 1%, which adds another ~20 years to your timeline for a total of 50. I think it’s safe to say this part is bunk (along with everything else about this plan which is also bunk).

We seem to be using 100% of our DRAM manufacturing for AI. So it's not completely out of the question.

Space to put them, terrestrially, is not infinite. Demand has a hard ceiling.

Plenty of space still, but we're running into other scaling issues now - power grids are at their limits. And on sunny days there's a lot more supply than demand, but that can be mitigated by adding more (battery) storage.

That's a supply ceiling. Funnily, it's also one that's solved by putting them in space.

unless demand comes from space

In fairness, solar cells can be about 5x more efficient in space (irradiance, uptime).

The quoted "1 TW of photovoltaic cells per year, globally" is the peak output, not the average output. They're only about 20% higher peak output in space… well, if you can keep them cool at least.

But there are no clouds in space and with the right orbit they are always facing the sun

You know how people sometimes dismiss PV by saying "what happens at night or in cloudy weather?"?

Well, what happens over the course of a year of night and clouds is that 1 TW-peak becomes an average of about 110 to 160 GW.

We're making ~1 TW-peak per year of PV right now.

but then you have answered the earlier question: solar panels in space pay themselves back ~7-8 times faster

That wasn't the original question. The head of this thread was quoting Musk's claim, which I repeat here:

> it is possible to put 500 to 1000 TW/year of AI satellites into deep space

This is 500-1000 times as much as current global production.

Musk is talking about building on the Moon 500-1000 times as much factory capacity as currently exists in aggregate across all of Earth, and launching the products electromagnetically.

Given how long PV modules last, that much per year is enough to keep all of Earth's land area paved with contiguous PV. PV doesn't last as long in space, but likewise the Moon would be totally tiled in PV (and much darker as a consequence) at this production rate.

In fact, given it does tile the moon, I suspect Musk may have started from "tile moon with PV" and estimated the maximum productive output of that power supply being used to make more PV.

I mean, don't get me wrong, in the *long term* I buy that. It's just that by "long term" I mean Musk's likely to have buried (given him, in a cryogenic tube) for decades by the time that happens.

Even being optimistic, given the lack of literally any experience building a factory up there and how our lunar mining experience is little more than a dozen people and a handful of rovers picking up interesting looking rocks, versus given how much experience we need down here to get things right, even Musk's organisation skills and ability to enthuse people and raise capital has limits. But these are timescales where those skills don't last (even if he resolves his political toxicity that currently means the next Democrat administration will hate his guts and do what they can to remove most of his power), because he will have died of old age.

I wasn't referencing Elon's claim, but your reply to

> In fairness, solar cells can be about 5x more efficient in space (irradiance, uptime).

Clearly this person was referencing a financial efficiency predominantly through uptime.

Your other points: I agree :)

> Clearly this person was referencing a financial efficiency predominantly through uptime.

I read the person you are quoting differently, as them misunderstanding and thinking that the current 1 TW-peak/year manufacturing was 1 TW-after-capacity-factor-losses/year.

The 1TW is the rated peak power output. It's essentially the same in space. The thing that changes is the average fraction of this sustained over time (due to day/night/seasons/atmosphere, or the lack of all of the above).

It's still the same 1TW theoretical peak in space, it's just that you can actually use close to that full capacity all the time, whereas on earth you'd need to over-provision substantially and add storage, so 1TW of panels can only drive perhaps a few hundred GW of average load.

> the whole capacity

Wouldn’t something like half of the panels be in shadow at any time?

Depends where you put them. The current vogue option is a sun-synchronous orbit: https://en.wikipedia.org/wiki/Sun-synchronous_orbit

polar orbit

It is more than 5x less expensive to get surface area on earth’s surface.

The dominant factor is "balance of system" aka soft costs, which are well over 50%.[0]

Orbit gets you the advantage of 1/5th the PV and no large daily smoothing battery, but also no on-site installation cost, no grid interconnect fees, no custom engineering drawings, no environmental permitting fees, no grid of concrete footers, no heavy steel frames to resist wind and snow loads. The "on-site installation" is just the panels unfolding, and during launch they're compact so the support structure can be relatively lightweight.

When you cost building the datacenter alone, it's cheaper on earth. When you cost building the solar + batteries + datacenter, it (can be) cheaper in space, if you build it right and have cheap orbital launch.

[0] https://en.wikipedia.org/wiki/Balance_of_system

Funny, I would have included transportation as part of the installation cost. You didn't mention that one.

I do say it's predicated on cheap orbital launch. Clearly they expect Starship to deliver, and they're "skating to where the puck will be" on overall system cost per unit of compute.

But yeah, I didn't include that delivering all that stuff by truck (including all the personnel) to a terrestrial PV site isn't free either.

Yeah, soft costs like permitting and inspections are supposedly the main reason US residential solar costs $3/watt while Australian residential solar costs $1/watt. It was definitely the worst and least efficient part of our solar install, everything else was pretty straightforward. Also, running a pretty sizable array at our house, the seasonal variation is huge, and seasonal battery storage isn’t really a thing.

Besides making PV much more consistent, the main thing this seems to avoid is just the red tape around developing at huge scale, and basically being totally sovereign, which seems like it might be more important as tensions around this stuff ramp up. There’s clearly a backlash brewing against terrestrial data centers driving up utility bills, at least on the East Coast of the US.

The more I think about it, the more this seems like maybe not a terrible idea.

So far most of the datacenters are built in very convenient places and people will start to build them in inconvenient places like Sahara or Mongolia way before they will building them in space

Maybe. But for SpaceX, it’s more aligned with what they’re trying to do to just learn to manufacture them at scale and lob them into space. And one of the benefits there is the uniformity of it - they can treat them all the same, rather than dealing with a bunch in different geographies with different power issues, governmental issues, etc. That’s been one of the major issues with rolling out solar. In the US, there are >20,000 AHJs, each with different rules and processes. A huge constellation of satellites seems easier to reason about and build systems to maintain en masse, because it’s more uniform.

I’m not saying this is a good idea. I’ve got a lot of SpaceX stock, and I wasn’t really happy to hear the news, this is mostly me trying to understand why they might think this is a good idea, and brainstorming out loud, with a dash of coping. Seems most here think that it’s just stupid, but then, most commenters thought Starlink was stupid, iirc, and that turned out to be wildly wrong. But it might also just be stupid this time.

Do you imagine there'd be less red tape involved in launching multiple rockets per day carrying heavy payloads?

Like this argument just gets absurd: you're claiming building a data center on earth will be harder from a permitting perspective than FAA flight approval for multiple heavy lift rocket launch and landing cycles.

Mining companies routinely open and close enormous surface area mines all over the world and manage permitting for that just fine.

There's plenty of land no one will care if your build anything on, and being remote with maybe poor access roads is still going to be enormously cheaper then launching a state of the art heavy lift rocket which doesn't actually exist yet.

Ok, why are so many being built in Northern Virginia, rather than in the middle of nowhere where there will be no backlash?

And permitting is challenging in part because it’s so different from place to place. Their permitting process with the FAA seems pretty streamlined.

> Ok, why are so many being built in Northern Virginia, rather than in the middle of nowhere where there will be no backlash?

Right? So if that's the case why would putting them in Space, far less accessible in every conceivable way, with numerous additional expenses and engineering constraints, be cheaper?

Yeah, I don't know if it wins on cheaper, even with $2M fully reusable starship launches. Maybe rollout speed vs piecing together BD deals with a bunch of different infra providers? The expansion of the grid is going to be hamstrung until congress finally passes energy permitting reform, which they've tried and failed at repeatedly. But they could do non-interconnected microgrids in the desert like Redwood Materials has been trying.

Maybe there's a concentration in VA because there's a set of deals/procedures in place with infra providers there that make it easy to scale up, similar to how DE has well developed corporate infrastructure, so everyone incorporates there. But that stops when the area hits its limit in power provision (which seems to be happening right now). In which case, being able to do this yourself end to end by putting this stuff in space with your own power generation makes it the ultimate scale-up opportunity - no real limits on space or power availability, so once you get that method down, you can mass-scale and get great economies of scale. Maintenance isn't a thing, these will be disposable.

I think that's it, money's not the limiting factor if they can pitch this successfully, which I think they will. They want massive scale without the constraints you hit when doing it on earth. I think he's aiming for scale that we haven't seen in DCs on earth.

> There's plenty of land no one will care if you build anything on

I wonder if this is actually true.

The fuel costs alone would dwarf a data center build out.

Just based on weight, looks like a Block 4 starship should be able to bring up ~150 30 panel pallets of 550W panels, about 2 MW. They're trying to get a starship launch down to $2M with full reuse. GPU DCs are frequently in the neighborhood of 500GW, so maybe 250 launches for just the power generation, or $500M? And then there's radiators, so let's say $1B for launch of power and heat dissipation. For comparison, 500MW of H100 machines retails for >$10B, and the launch cost for those shouldn't be too bad compared to the power, since they're more value dense. And then there's land and ongoing power and cooling spending for the terrestrial version, which you don't have for the space version. So actually, doesn't seem terrible economically? This is obviously very back-of-the-envelope, and predicated on the optimistic scenario for starship launch cost.

No maintenance either

Right now it is.

However, the amount of available land is fixed and the demand for its use is growing. Solar isn't the only buyer in this real estate market.

We have so much excess land with no real use for it that our government actually pays farmers to grow corn on it to burn in cars.

Availability of land for solar production isn't remotely a real problem in the near term.

This is really underselling it tbh. Any land that's growing corn in a developed country is likely top 1% of land on earth. Half of the earth is desert and tundra. Which is still incredibly easier to work with than space because you can ship there with a pickup very cheaply. Maybe when nevada and central australia are wall-to-wall solar panels we can check back on space.

The Technology Connections Youtube channel recently did a great video arguing pretty convincingly that the land used to grow corn for cars would be vastly more efficiently used from an energy perspective if we covered it with solar panels.

This.

I feel like everyone just lost their mind.

You just have to remember, most of these people live in high density regions and have little comprehension about how much surface area humanity truly occupies... And that isn't even accounting for offshore constructs.

Realizing the impracticality of it (and that such approaches often collapse under the infeasibility of it) ... wouldn't it be better to... say... cover the Sahara in solar panels instead? That's gotta be cheaper than shipping them into space.

https://inhabitat.com/worlds-largest-solar-project-sahara-de...

https://www.theguardian.com/business/2009/nov/01/solar-power...

(and a retrospective from 2023 - https://www.ecomena.org/desertec/ )

From an engineering perspective, with today’s costs, yes. But don’t forget the political complications of dealing with all those countries that own the Sahara, that’s going to come at it’s own cost.

So now we get the political complications of dealing with all those countries that own ASAT weapons.

the demand is pretty much fake and AI isn't actually making money, just gobbling investors money

Solar can always just go on the roof...

Does that include all the required radiators to vent heat?

and of course, the continuous opposite boost needed to prevent the heat vent from knocking them out of orbit.

I think this is all ridiculous, to be clear, but re: this problem couldn't the radiators in theory be oriented so that they vent in opposite directions and cancel out any thrust that would be generated?

Fortunately there are no downsides to launching solar cells into space that would offset those gains.

Solar cells have exactly the same power rating on earth as in space surely? What would change is their capacity factor and so energy generation.

Solar modules you can buy for your house usually have quoted power ratings at "max STC" or Standard Testing Conditions, which are based on insolation on Earth's surface.

https://wiki.pvmet.org/index.php?title=Standard_Test_Conditi...

So, a "400W panel" is rated to produce 400W at standard testing conditions.

I'm not sure how relevant that is to the numbers being thrown around in this thread, but thought I'd provide context.

That's super interesting.

STC uses an irradiance of irradiance 1000W/m2, in space it seems like you get closer to 1400W/m2. That's definitely better, but also not enormously better.

Seems also like they are rated at 25C, I am certainly not a space engineer but that seems kind of temperate for space where cooling is more of a challenge.

Seems like it might balance out to more like 1.1x to 1.3x more power in space?

Satellites can adjust attitude so that the panels are always normal to the incident rays for maximum energy capture. And no weather/dust.

You also don't usually use the same exact kind of panels as terrestrial solar farms. Since you are going to space, you spend the extra money to get the highest possible efficiency in terms of W/kg. Terrestrial usually optimizes for W/$ nameplate capacity LCOE, which also includes installation and other costs.

For one or a few-off expensive satellites that are intended to last 10-20 years, then yes. But in this case the satellites will be more disposable and the game plan is to launch tons of them at the lowest cost per satellite and let the sheer numbers take care of reliability concerns.

It is similar to the biological tradeoff of having a few offspring and investing heavily in their safety and growth vs having thousands off offspring and investing nothing in their safety and growth.

The atmosphere is in the way, and they get pretty dirty on earth. Also it doesn't rain or get cloudy in space

Sure but like, just use even more solar panels? You can probably buy a lot of them for the cost of a satellite.

The cost of putting them up there is a lot more than the cost of the cells

  >just use even more solar panels

“This scale” is not realistic in terms of demand or even capability. We may as well talk about mining Sagittarius A* for neutrons.

You don't even need a particularly large scale, it's efficient resource utilization.

Humanity has a finite (and too small) capacity for building solar panels. AI requires lots of power already. So the question is, do you want AI to consume X (where X is a pretty big chunk of the pie), or five times X, from that total supply?

Using less PV is great, but only if the total cost ends up cheaper than installing 5X the capacity as terrestrial PV farms, along with daily smoothing batteries.

SpaceX is only skating to where they predict the cost puck will be.

You seem to be ignoring the substantial resource cost of putting them up there.

And in geostationary, the planet hardly ever gets in the way. They get full sun 99.5% of the year.

Boosting to geostationary orbit knocks a big chunk out of your payload capacity. Falcon 9 expendable will do 22 tons to LEO and about 8 tons to GTO.

That's still a smaller ratio than the ~4X gain in irradiance over LEO. But if you're doing it at scale you could use orbital tugs with ion drives or something, and use much less fuel per transfer.

It's probably not competitive at all without having fully reusable launch rockets, so the cost to LEO is a lot lower.

8 tons over 22 is a little over 1/3rd the original payload to LEO. If 4x the solar generation potential (not irradiance - the sun is not 4x brighter in space at Earth's orbital radius) is the reward, that's putting an incredible premium on a 3x multiplier on launch costs per kg (at minimum - likely higher, you're also inheriting a worse radiation environment).

But those two parameters are not equals: 3x the cost per kg is a much higher number then 4x the solar power.

My response is already contained in my comment above, in the sentences after the first.

even at 10% (say putting it on some northen pile of snow) it is still cheaper to put it on earth than launch it

would you prefer big tech to piss their waste heat into your rivers, soils and atmosphere?

or would you prefer them to go to the bathroom upstairs?

at some point big tech is in a "damned if you do, damned if you don't" situation...

I don't disagree

Here in Maine in the depths of winter (late December), 1 m^2 of ground can collect 4 kwh per day (weird units).

That's why people are trying to build solar here. Our power is expensive due partially to failing to build basically any new generation, and some land is very cheap, and the operational cost of a solar farm is minuscule.

Solar farming is basically an idle game in real life and my addiction is making me itchy.

You can overprovision, and you should with how stupidly cheap solar is.

That we aren't spending billions of Federal dollars building solar anywhere we can, as much as we can, is pathetic and stupid and a national tragedy.

We got so excited about dam building that there's no where to build useful dams anymore, and there is significant value to be gained by removing those dams, yet somehow we aren't deploying as much solar as we possibly can?

It's a national security issue. China knows this, and is building appropriately.

The southwest should be generating so much solar power that we sequester carbon from the atmosphere simply because there is nothing else left to do with the power.

I'm all for efficiency, but I would think a hailstorm of space junk hits a lot harder than one of ice out on the farm.

Except it doesn't melt like regular hail so when further storms come up you could end being hit by the same hail more than once :\

Atmospheric derating brings insolation from about 1.367KW/m2 to about 1.0.

And then there’s that pesky night time and those annoying seasons.

It’s still not even remotely reasonable, but it’s definitely much higher in space.

> And then there’s that pesky night time and those annoying seasons.

The two options there are cluttering up the dawn dusk polar orbit more or going to high earth orbit so that you stay out of the shadow of the earth... and geostationary orbits are also in rather high demand.

Put them super super far away and focus all the energy into one very narrow death laser that we trust the tech company to be careful with.

Now do waste heat.

Here you go:

https://news.ycombinator.com/item?id=46862869

And how much of that power would be spent on high speed communications with Earth that aren't, you know, a megabit or two per second

I grew up on a rural farm in California with a dial-up connection that significantly hampered my ability to participate in the internet as a teenager. I got Starlink installed at my parents' house about five years ago, and it's resulted in me being able to spend considerably more time at home.

Even with their cheapest home plan, we're getting like 100 Mbps down and maybe 20 to 50 up. So it's just not true at all that you would have connections that are a megabit or two per second.

That's not what I'm suggesting. The post says "deep space". If you're going to try to harvest even a tiny percentage of the sun's energy, you're not doing that in Earth's orbit. The comparison is a webcam feed from Mars.

That's pretty much a solved problem. We've had geostationary constellations for TV broadcast at hundreds of megabytes for decades now, and lasers for sat-to-sat comms seems to be making decent progress as well.

> it is possible to put 500 to 1000 TW/year of AI satellites into deep space, meaningfully ascend the Kardashev scale and harness a non-trivial percentage of the Sun’s power

Which satellites are operating from "deep space"?

Those are for video. AI Chat workflows use a fraction of the data.

That's silly on so many levels.

1. the latency is going to be insane.

2. AI video exists.

3. vLLMa exist and take video and images as input.

4. When a new model checkpoint needs to go up, are we supposed to wait months for it to transfer?

5. A one million token context window is ~4MB. That's a few milliseconds terrestrially. Assuming zero packet loss, that's many seconds

6. You're not using TCP for this because the round trip time is so high. So you can't cancel any jobs if a user disconnects.

7. How do you scale this? How many megabits has anyone actually ever successfully sent per second over the distances in question? We literally don't know how to get a data center worth of throughput to something not in our orbit, let alone more than double digit megabits per second.

Grok doesn’t have video as far as I know. I don’t think it’s so absurd. I don’t know how you scale this. But it seems pretty straightforward.

The intractable problem is heat dissipation. There is to little matter in space to absorb excess heat. You'd need thermal fins bigger than the solar cells. The satellite's mass would be dominated by the solar panels and heat fins such that maybe 1% of the mass would be usable compute. It would be 1000x easier to leave them on the moon and dissipate into the ground and 100000x easier to just keep making them on earth.

> The intractable problem is heat dissipation.

3 times the area of the heat dissipating surface compared to solar panel surface brings the satellite temp down to 27 deg C (300 K):

https://news.ycombinator.com/item?id=46862869

> There is to little matter in space to absorb excess heat.

If that were true the Earth would have overheated, molten and turned to plasma long ago. Earth cools by.... radiative cooling. Dark space is 4 K, thats -267.15 deg C or -452.47 deg Fahrenheit. Stefan-Boltzmann law can cool your satellite just fine.

> You'd need thermal fins bigger than the solar cells.

Correct, my pessimistic calculation results in a factor of 3,...

but also Incorrect, there wouldn't be "fins" thats only useful for heat conduction and convection.

and, of course and inter-satellite comms and earth base station links to get the data up and down. Starlink is one thing at just above LEO a few hundred km and 20km apart, but spreading these around 10s of thousands of km and thosands of km apart is another thing

> We currently make around 1 TW of photovoltaic cells per year, globally.

China made 1.8 TW of solar cells in 2025.

The raw materials required to make these are incredibly abundant, we make as much as we need.

you realize the factor of 2 you introduce doesn't meaningfully change the order of magnitude that the previous poster is implying right?

You missed the point.

We can make ten or hundred times the number of solar cells we make right now, we just don't have a reason to. The technology is fairly ancient unless you want to compete on efficiency, and the raw materials abundant.

  >We can make ten or hundred times the number of solar cells we make right now

The limit isn't just about the current capacity or the maximum theoretical capacity, it's also about the maximum speed you can ramp.

>Tomorrow?

Eventually :)

Markets are forward looking, and not really bound to 'tomorrow'.

Oh sure we can do anything if we just handwave all requirements, all needs for reality, all actual thought

Do we really need to say (on HN especially) that time-to-market does matter?

Not just for startups either. If you ramp up the Polio vaccine in 1 year vs 10 years, that has a big impact on human wellbeing. The two scenarios are not equivalent outcomes, even though it still happens "eventually."

Speed matters.

Sure, speed matters.

Developing new technology happens to matter more.

I'm sure investors are going to do their own analysis on this and reach their own conclusions, you should try betting against it.

Surely the constraint will be the rate at which you can get them into and installed orbit, not the manufacturing rate

you would need 200 times the number of solar cells. I don't think you appreciate the scale that 200x is, especially when China is already:

1. quite good at making solar cells

2. quite motivated to increase their energy production via solar

The bottleneck is deploying solar physically, not making the cells.

We have increased the manufacturing of pretty much every piece of technology you see in front you by 200x at some point in history. Often in a matter of years.

I agree that part of the bottleneck is deploying solar physically. China is the best in the world in deploying solar panels. They are only managing linear increases in their solar capacity, year over year.

This is all based on bad math. The people proposing these things don't even have proper scientific and mathematical training to determine what is achievable.

They never did any math at all. They knew their supporters would burn thousands of hours and bend over backwards doing dishonest math for them and provide cover for what is a looting operation.

Whilst I agree that this glosses over a huge number of technical obstacles, space based solar power could scale more easily than that on earth. Lack of variable weather and gravity means rather than using photovoltaic cells, you can just set up paper thin huge mirrors to focus light and generate steam.

Caveat: my understanding of this largely comes from the book The High Frontier, which is really old and probably inaccurate. I can't think of a reason why this particular point would be wrong though.

This idea is physically possible. So is a Dyson sphere. I’m surprised Elon didn’t suggest that too.

>space based solar power could scale more easily than that on earth.

Actually provide an argument instead of just asserting this.

On earth, deployment of a built solar panel is screwing it into a dirt cheap frame on the ground.

To deploy a solar panel in space, you must attach it to a satellite that no one involved has even pretended to claim is designed, so you need a factory for those on the same order of magnitude as your panels, you need enough boost capacity, so a factory for rockets, and a much larger fuel industry, and then you need all the immense engineering required to do any of that at all, and then you need to spin up the industries to supply this brand new industry, and then you need to manage all those satellites in space, and then you still don't get any actual power because it's all in space so you haven't scaled SHIT

It's all absolute horseshit. No, none of this is planned. He's just going to cash in on the IPO.

You're not considering some important multipliers. In space you're already getting a substantial immediate boost due to greater solar irradiance - no atmosphere or anything getting in the way of those juicy photons. You can also get 24 hour coverage in space. And finally they mention "deep space" - it's unclear what that means but solar irradiance increases on an inverse square law - get half way to the sun and you're getting another 4x boost in power. I'm sure there's other factors I'm not considering as well - space and solar just go quite well together.

Earth does have plenty of sand and iron. Literally all you have to do is grow the sand into a crystal, slice it up, etch some patterns onto it, then add some metal.

Making only 1TW of pv cells per year is a skill issue.

Sure, and copper, and aluminium

He just says shit that sounds smart and then rides the vibes to financial success, but it's not working anymore.

10 years ago when Tesla actually revolutionized the retail EV industry everyone took his word for it. Then after a few failed prognostications the nerds started to doubt his credibility, a few more years of this and the tech press started to see through it, and now he's reduced to only the MAGA-faithful falling for his Phony Stark act. The ground is coming up fast.

I wonder what the plan is to recycle those. Without a plan to safely bring back all this hardware and recycling it, we'll deplete earth from it's mineral. The matter used to build things on earth stays within earth's ecosystem.

Moving matter out continusously at industrial scale with no plan to bring 100% of it back in the ecosystem other than burning it seems quite unsustainable and irresponsable.

Has anyone done the math on how much liquid methane and oxygen this would take to launch on Starship? Seems like an impossibility alone without digging into the numbers.

Is there a credible way to cool a space-based data center on that scale?

There's not even a credible way to transfer meaningful amounts of data to and from a deep-space based data center.

What good is compute if you can't interface with it? This is where we are now: https://en.wikipedia.org/wiki/Deep_Space_Optical_Communicati...

SpaceX may be leading in short-range (few hundred km) space-to-space data transfer but there is a long way to go for terabit/s deep-space links.

See Dyson Sphere: https://en.wikipedia.org/wiki/Dyson_sphere

Dyson's paper was literally written in jest.

What do you mean?

>In an interview with Robert Wright in 2003, Dyson referred to his paper on the search for Dyson spheres as "a little joke" and commented that "you get to be famous only for the things you don't think are serious" [...]

To be fair, he later added this:

>in a later interview with students from The University of Edinburgh in 2018, he referred to the premise of the Dyson sphere as being "correct and uncontroversial".[13] In other interviews, while lamenting the naming of the object, Dyson commented that "the idea was a good one", and referred to his contribution to a paper on disassembling planets as a means of constructing one.

Sources are in: https://en.wikipedia.org/wiki/Dyson_sphere

Thanks for pointing out those follow ups. Interesting stuff!

> correct and uncontraversial

From the original quote it is clear he was referring to the idea of aliens being detectable by infrared because they will absorb all of their sun's energy. Later in the same paragraph he says:

> Unfortunately I went on to speculate about possible ways of building a shell, for example by using the mass of Jupiter... > These remarks about building a shell were only order-of-magnitude estimates, but were misunderstood by journalists and science-fiction writers as describing real objects. The essential idea of an advanced civilization emitting infrared radiation was already published by Olaf Stapledon in his science fiction novel Star Maker in 1937.

So the Dyson Sphere is a rhetorical vehicle to make an order-of-magnitude estimate, not a description of a thing that he thought could physically exist.

Full quote from the video cited before "the idea was a good one":

> science fiction writers got hold of this phrase and imagined it then to be a spherical rigid object. And the aliens would be living on some kind of artificial shell. a rigid structure surrounding a star. which wasn't exactly what I had in mind, but then in any case, that's become then a favorite object of science fiction writers. They call it the Dyson sphere, which was a name I don't altogether approve of, but anyway, I mean that's I'm stuck with it. But the idea was a good one.

Again he explicitly says this "wasn't exactly what I had in mind." This one hedges a bit more and could be interpreted as his saying the idea of a Dyson Sphere is a good one. He may have meant that in the sense of it being a good science fiction idea though, and he subsequently goes on to talk about that.

The Dyson Sphere is good for order-of-magnitude calculations about hypothetical aliens, and also for selling vapourware to the types of people who uncritically think that vapourware is real.

https://www.youtube.com/watch?v=fLzEX1TPBFM

Have you read the paper itself, not just summaries of the idea? It's obvious from the way he wrote it, dripping in sarcasm. Talking about "Malthusian principles" and "Lebensraum", while hand waving away any common sense questions about how the mass of Jupiter would even be smeared into a sphere around the sun, just saying that he can conceive of it and therefore we should spend public money looking for it. He's having a lark.

Also, he literally said it was a joke, and was miffed that he was best know for something he didn't take seriously.

It is a single page shit post.

He thought SETI listening to space radio waves was dumb, so made essentially a satirical paper saying we should look for heat instead, because "an advanced civilization would be using these Shells to capture all star energy, so we could only see the heat"

The "dyson sphere" was a made up and entirely unfounded claim, without justification.

He was throwing shade.

Yeah, that's the point ... it's stupid to believe humanity is capable of deploying that much infrastructure. We cannot do even 0.01% of it.

What do you think the limiting factor is? I don't see why we can't scale manufacturing of satellites up as far as we want. If we mine out a substantial fraction of the mass of the earth, we can go harvest asteroids or something.

>> Dyson Sphere

> What do you think the limiting factor is?

You need to be able to harness enough raw material and energy to build something that can surround the sun. That does not exist in the solar system and we do not yet have the means to travel further out to collect, move, and construct such an incredibly huge structure. It seems like a fantasy.

The inner planets contain enough mass to create a shell of 1 AU radius with mass of 42 kg/m^2. That sounds like a plausible thickness and density for a sandwich of photovoltaics - GPUs - heat sinks.

You don't build a rigid shell of course, you build a swarm of free-floating satellites in a range of orbits.

See https://www.aleph.se/Nada/dysonFAQ.html#ENOUGH for numbers.

I am dying to know where you’ll get the energy and manufacturing scale in order to achieve this with current, or current+50-years technology.

Do tell.

The energy to build the system comes from the partial assembled system, plus some initial bootstrap energy. It grows exponentially. We seem to have enough today to build small factories in orbit.

The manufacturing scale comes from designing factory factories. They aren't that far in the future. Most factory machinery is made in factories which could be entirely automated, so you just need some robots to install machines into factories.

I was told ca. 2003 or so that because features on computer chips were getting smaller at some rate, and processor speed was getting faster at some other rate, that given exponential this or that I'd have tiny artificial haemo-goblins[1] bombing around my circulatory system that would make me swim like a fish under the sea for hours on end. But it turned out to be utter bullshit. Just like this.

[1] https://www.writingsbyraykurzweil.com/respirocytes

Great. Now run the numbers to find the energy required to disassemble the planets and accelerating the pieces to their desired locations. For reference, it takes over 10 times of propellant and oxidant mass to put something in LEO.

The burned propellant and oxygen mass (as H2O and CO2) almost all ends up back in the atmosphere when you launch to LEO, so you can keep running electrolysis (powered by solar) to convert it back to fuel.

Sure, but if we're talking about solar engineering, that mass is going to be dispersed in orbit around the sun. You're not going to be reaccumulating that any time soon.

Also it's gravitationally unstable, like Dyson Rings, where as soon as you have any perturbance from the center means that the closer side is more attracted to the sun so it enters a feedback loop.

> What do you think the limiting factor is? I don't see why we can't scale manufacturing of satellites up as far as we want.

A reason. I'm sure that theoretically it's possible, assuming infinite money and an interest to do so. But literally, why would we? There's no practical ways to get the power back on earth, it's cheaper to build a solar field, etc.

And I don't believe datacenters in space are viable, cost wise. Not until we can no longer fit them on earth, AND demand is still increasing.

There are only so many people who can make satellites; there are only so many things to make satellites out of; and there are only so many orbits to put them in. There are only so many reasons why a person might want a satellite. There are only so many ways of placing satellites in orbit and each requires some amount of energy, and we have access to a finite amount of energy over time.

Finally, if we limited ourselves to earth-based raw materials, we would eventually reach a point where the remaining mass of the earth would have less gravitational effect on the satellite fleet than the fleet itself, which would have deleterious effects on the satellite fleet.

Seven reasons are intuitive; I’m sure there are many others.

People can build a factory that makes satellites. And then a factory that makes factories to make satellites.

There is plenty of material in the solar system (see my other response), and plenty of orbits, and launch capability can scale with energy harvested so the launch rate can grow exponentially.

Lots of people will probably decide they don't want any more satellites. But it only takes a few highly determined people to get it done anyway.

>Just imbest[1] and it will grow exponentially.

That's how that argument sounds like, particularly when you hear it from someone who is as broke as it can be.

It's easy to type those ideas in a comment, or a novel, or a scientific paper ... bring them to reality, oh surprise! that's the hard part.

1: The dumb version to invest

> Finally, if we limited ourselves to earth-based raw materials, we would eventually reach a point where the remaining mass of the earth would have less gravitational effect on the satellite fleet than the fleet itself, which would have deleterious effects on the satellite fleet.

The Earth's crust has an average thickness of about 15-20 km. Practically we can only get at maybe the top 1-2 km, as drill bits start to fail the deeper you go.

The Earth's radius is 6,371 km.

So even if we could somehow dug up entire crust we can get to and flung it into orbit, that would barely be noticeable to anything in orbit.

Once you dig up the top kilometer of a planet's crust, what's under your feet? The next kilometer!

That would suck to do to Earth, but we can launch all of Mars's mass into the swarm.

After a few decades, you need to start replacing all the solar panels.

And the robot army being used to do the construction and resource extraction will likely have a much shorter lifespan. So needs to be self-replicating/repairing/recycling.

The physical amount of material in the solar system is a pretty big limiting factor.

Yeah, but besides not having the physical amount of material available in the solar system, or the availability of any technology to transfer power generated to a destination where it can serve a meaningful purpose in the foreseeable future, or having the political climate or capital necessary for even initiating such an effort, or not being able to do so without severely kneecapping the habitability of our planet, there are aren't really any meaningful barriers that I can see.

Are you suggesting that beggars would ride, if only wishes were horses!?

In 2026? Grift.

But the factory ~~can~~must grow.

We will have cyber taxis and FSD 100% next year.

Doesn't this risk some unforeseen effects on Earth or the rest of the solar system at that scale? Disruption of magnetic shield, some not yet known law of physics suddenly getting felt etc.?

It's not really going to happen so we don't have to worry about that.

Pfft that would just require setting up an entire lunar mineral extraction and refining system larger than we have on earth, just minor details.

Not to mention… how do you repair it when components fail, especially sensitive electronics against cosmic radiation

It has some Highlander 2 vibes...

Help me understand something. We make 1 TW of cells per year but we're struggling with bringing 1 GW consuming data centers online?

Nameplate capacity needs a derate for availability, so you can drop it down to about 200GW(e) equivalent continuous power assuming we're making and deploying enough batteries to support it. More, obviously, if those panels are going to an equatorial desert, less if they're going to sunny Svalbard in the winter time.

What concerns me are the implications if the Dark Forest Theory is correct.

Of course, we are stripping the earth bare to build word-guessers GPUs in orbit, but aliens are definitely the problem.

Considering we’re not actually “stripping the earth bare” and that’s fear mongering hysteria… I’d be interested to know the facts if true.

Ok. And number will go up.

You also have all that heat to dissipate....

Photovoltaic production has been doubling every year. That's not a huge amount of doubling!

Sounds badass

Yeah

I don't know where this delusion of "Servers in space" came from, I think of it as the new NFTs

But I bet those pushing for it are very interested in feeding the grift

[flagged]

> And not delivering products

2024 revenue of >$100b is quite impressive for not delivering any products

You know what they mean. Full self-driving was promised what, 10 years ago? Tesla Roadster? Sub-25K car? etc etc etc

I should say delivering promised products.

Anyway they just canned the S and X lines so that's done as well...

What kind of nonsense is that. SpaceX 2024 revenue barely broke $10B, if that. Launch was probably ~$4B and Starlink probably ~$5B. I'll give them the benefit of the doubt and double those just for shits and giggles and that's still less than $20B and you're claiming >$100B? Horse shit. Nonsense.

Tesla

At best, he should be a persona non grata across just about every aspect of society.

Even if you discount all the Nazi crap, he's directly responsible for deaths of 600,000+ people, mostly kids, for his illegal destruction of USAID.

What a tremendous failure it is that this guy is still allowed such a prominent place in society.

:eye roll:

This schtick is so, so tiresome.

What is tiring is people defending it. Everyone goes down with this ship...

A former NASA engineer with a PhD in space electronics who later worked at Google for 10 years wrote an article about why datacenters in space are very technically challenging:

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

I don't have any specialized knowledge of the physics but I saw an article suggesting the real reason for the push to build them in space is to hedge against political pushback preventing construction on Earth.

I can't find the original article but here is one about datacenter pushback:

https://www.bloomberg.com/opinion/articles/2025-08-20/ai-and...

But even if political pushback on Earth is the real reason, it still seems datacenters in space are extremely technically challenging/impossible to build.

The real reason is, Elon has SpaceX and xAI. He can create an illusion of synergy and orders of magnitude advancements to boost the market cap and pocket all the money. He realized long time ago you don't need to deliver to play the market cap game, in fact it's better if you are selling a story far in the future rather than a something you can deliver now.

both can be true, he can excel at 'narrative' and also deliver me my Tesla and my starlink, it's not either or

Ok, he delivered your Tesla and your Starlink, but so far he has hasn't delivered your Robotaxi, your Optimus, your lunar lander, your space datacenter etc. And the list keeps getting longer instead of shorter...

You don't have to win them all.

He does (or at least a good proportion) if you want to use as precedent for delivering on these promises, though. Especially for the larger more extreme statements and not just buying himself into an existing business.

Why does he?

that's an arbitrary standard set by you.

His investors are quite happy with his success rate. He is constantly building new stuff. And as a consumer who has had great experience with every product I've bought, so am I

No one buys into Elon's firms because he's expecting dividends.

His investors are not investing because of his success rate in delivering on his promises. His investors are investing exclusively because they believe that stock they buy now will be worth more tomorrow. They all know that's most likely not because Elon delivers anything concrete (because he only does that in what, 20% of cases?), but because Elon rides the hype train harder tomorrow. But they don't care if it's hype or substance, as long as numbers go up.

Elon's investors are happy with his success rate only in terms of continuously generating hype. Which, I have to admit, he's been able to keep up longer now than I ever thought possible.

Perhaps my marketing background is clouding my view, but have exceptional hyping skills seems quite useful when attracting investment.

And fact is Musk is building a lot of stuff of real substance. The hype to substance ratio isn't quite as important as some choose to beleive

Theranos were also hyping a lot and trying to build some stuff. There is some threshold (to be decided where) after which something is more of a fraud than a hype.

Also these days stock market doesn't have much relation to real state of economy - it's in many ways a casino.

Not sure who determines the threshold, he certainly goes to court more than your average person, but these are not start ups, they are large companies under a lot of scrutiny. I don't think the comparison is valid

> The hype to substance ratio isn't quite as important as some choose to beleive

Musk's ratio is such that his utterances are completely free from actionable information. If he says something, it may or may not happen and even if it does happen the time frame (and cost) is unlikely to be correct.

I don't get why anyone would invest their money on this basis.

it's more to do with his track record at creating returns for investors?

But the returns are based on more hype rather than delivering. It's recursive.

Some combination of the two, for sure. doesn't mean that Musk can't keep doing it. however you describe it or define it, it's a proven strategy at this point. I'm not sure Larry knew how Musk would make him good on Twitter, but he knew enough about Musk to be confident it would happen.

> but have exceptional hyping skills seems quite useful when attracting investment.

Elizabeth Holmes (Theranos) and a lot of ex-crypto-bros (fraudsters) would agree.

"Exceptional hyping skills" is (today) possibly a more derogatory term than you're expecting.

> And fact is Musk is building a lot of stuff of real substance.

I think the point others are making is this is a more accurate description of Musk ~10 years ago. In the past 5 years its been what, the cybertruck?

It's a derogatory comment among certain types of technical employee, I would agree. Not so much amongst those in leadership or softer roles.

I wouldn't put cybertruck in the win column personally

It's increasingly something the general populace is not a fan of, at least that's been my experience.

so if the cybertruck is not a win, what in the last 5 years is?

I think this is why he gets away with it. A "win" is a product delivered years late for 3x the promised MSRP with 1/10th the expected sales. With wins like these, what would count as a loss?

He gets away with it for one reason only, and because he consistently delivers good returns on capital.

Most of Tesla's revenue derives from Model Y and FSD subs. I agree that Cybertruck was a marketing ploy. Don't think it was ever intended to be materially revenue generating.

> He gets away with it for one reason only, and because he consistently delivers good returns on capital.

Didn't Tesla just have a terrible 2025, with European sales plunging due to the stigma of owning a swasticar?

Revenue has flatlined, but investors' confidence comes from Musk's track record for delivering good returns to investors. I think we can agree Musk succeeded in 2020 to 2025 in this regard. Whether you are confident he can do it again over next five years is the key question.

I'm personally more persuaded by the argument that Tesla is a meme-stock at this point - like much of crypto, it runs on "vibes", not solid fundamentals.

But even if share price is the metric for success, 33.6% over 5 years is like 6% compounded annually, which is okay I guess? [0]

[0] https://www.investopedia.com/magnificent-seven-stocks-840226...

Cynics are often right

Optimists are often rich

>Robotaxi, your Optimus, your lunar lander, your space datacenter etc. And the list keeps getting longer instead of shorter...

Lets go through this one by one

[1]Robotaxi. Someone just drove coast to coast USA fully on autopilot. I drive my tesla every day, and i literally NEVER disengage autopilot. It gets me to work and back home without fail, to the grocery store, to literally anywhere i need. Whats not full self driving about that? I got in two crashes before i got my Tesla cause i was a dumb teen, but i'm sure my Tesla is a much better driver than my younger sister. Politically it's not FSD, but in reality, it has been for a while.

[2] Optimus has gone through three revisions and has hand technology that is 5+ years ahead of the competition. Even if they launched it as a consumer product now, i'm sure a million people would buy it just as a cool toy/ gadget. AKA a successfull product.

[3] Lunar Lander Starship, a fully reusable, 2 stage rocket that has gone through 25 revisions and is 95% flight proven and has even deployed dummy starlinks. 10+ years ahead of everyone except maybe stoke.

[4]Space Datacenter Have you ever used starlink? They have all the pieces they need... Elon build a giant datacenter in 6 monmths when it takes 3-4 years usually. He has more compute than anybody and Grok is the most intelligent AI by all the metrics outside googles. Combine that with Starship, which can launch 10X the capacity for 10% of the cost, and what reason do you have to doubt him here?

Granted... it always takes him longer than he says, but he always eventually comes through.

Eventually comes through? Have you forgotten Hyperloop, new roadster, instant battery swaps, tunnels to replace all traffic, your car appreciating in value, your car being used as a robotaxi during downtime to make you money, semi convoys, etc etc?

> [1]Robotaxi. Someone just drove coast to coast USA fully on autopilot.

Where's the source for this?

Your note on Optimus does a lot of heavy lifting. He hasn’t sold one yet.

exactly. This smells like a way to boost the SpaceX IPO to meme-stock premiums

I mean, personally I'd probably have invested in SpaceX but it's a hard no with xAI attached.

I'm probably an outlier though.

That seems to be exactly what the goal is.

What'd be the point of inflating market caps like this when it's obvious they'll crash the moment the owner tries to liquidate any of it before the promises are kept?

I think you can get loans in the stock. That’s how “most people” live(and die)

Rich people use stock as collateral for loans.

I don't understand the claim. SpaceX is literally delivering? And I don't think there is any delusion about that being optional.

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Yeah yeah, the person you dislike is stupid and the success of his multiple companies is just luck and everybody else does the work.

I’m not the source of this information: https://news.ycombinator.com/item?id=34012719

The product Elon has been most directly involved in is the Cybertruck which is a complete disaster. When talking about Elon you have to specify pre drug addict Elon and ketamine fried brain Elon. The latter makes very bad decisions.

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Source: this HN comment from 2022: https://news.ycombinator.com/item?id=34012719

Please stop posting these throwaway, sneering replies, no matter how bad the comment you're replying to. Just downvote it, and if you must comment, do so substantively.

https://news.ycombinator.com/newsguidelines.html

The wild claim is that they will deliver data centres in space

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Yeah, delivering using Falcon 9.

The Starship stack? Not so much. It's plagued, and will continue to be plagued, by endless problems. BO will beat them with NG.

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We don’t even have a habitable structure in space when the ISS falls, there is no world in which space datacenters are a thing in the next 10, I’d argue even 30 years. People really need to ground themselves in reality.

Edit: okay Tiangong - but that is not a data center.

Who is “we”? https://en.wikipedia.org/wiki/Tiangong_space_station

Good point. Still a long, long way from data centers.

We have 15,000 satellites in orbit that are almost literally the exact same premise currently being proposed - a computer with solar panels attached. We've being doing exactly this for decades.

I don't think any of the companies that say they are working on space data centers intend them to be habitable.

> We don’t even have a habitable structure in space

Silicon is way more forgiving than biology. This isn’t an argument for this proposal. But there is no technical connection between humans in space and data centers other than launch-cost synergies.

Okay, but a human being represents what, 200 W of power? The ISS has a crew of 3, so that's less than a beefy single user AI workstation at full tilt. If the question is whether it's practical to put 1-2 kW worth of computing power in orbit, the answer is obviously yes, but somehow I don't think that's what's meant by "datacenter in space".

I don't know, 10 years seems reasonable for development. There's not that much new technology that needs to be developed. Cooling and communications would just require minor changes to existing designs. Other systems may be able to be lifted wholesale with minimal integration. I think if there were obstacles to building data centers on the ground then we might see them in orbit within the next ten years.

I don't see those obstacles appearing though.

The same things you are saying about data centers in space was said by similar people 10-15 years ago when Elon musk said SpaceX would have a man on Mars in 10-15 years.

We have had the tech to do it since the 90's, we just needed to invest into it.

Same thing with Elon Musks hyperloop, aka the atmospheric train (or vactrain) which has been an idea since 1799! And how far has Elon Musks boring company come to building even a test loop?

Yeah, in theory you could build a data center in space. But unless you have a background in the limitations of space engineering/design brings, you don't truly understand what you are saying. A single AI data center server rack takes up the same energy load of 0.3 to 1 international space station. So by saying Elon musk can reasonable achieve this, is wild to anyone who has done any engineering work with space based tech. Every solar panel generates heat, the racks generate heat, the data communication system generates, heat... Every kW of power generated and every kW of power consumes needs a radiator. And it's not like water cooling, you are trying to radiate heat off into a vacuum. That is a technical challenge and size, the amount of tons to orbit needed to do this... Let alone outside of low earth... Its a moonshot project for sure. And like I said above, Elon musk hasnt really followed through with any of his moonshots.

> A single AI data center server rack takes up the same energy load of 0.3 to 1 international space station.

The ISS is powered by eight Solar Array Wings. Each wing weighs about 1,050kg. The station also has two radiator wings with three radiator orbital replacement units weighing about 1,100kg each. That's about 15,000 kg total so if the ISS can power three racks, that's 5,000kg of payload per rack not including the rack or any other support structure, shielding, heat distribution like heat pipes, and so on.

Assuming a Falcon Heavy with 60,000 kg payload, that's 12 racks launched for about $100 million. That's basically tripling or quadrupling (at least) the cost of each rack, assuming that's the only extra cost and there's zero maintenance.

Falcon Heavy does not cost 100M when launching 60 metric tons.

At 60 metric tons, you're expending all cores and only getting to LEO. These probably shouldn't be in LEO because they don't need to be and you probably don't want to be expending cores for these launches if you care about cost.

The real problem typically isn't weight, it's volume. Can you fit all of that in that fairing? It's onli 13m long by 5m diameter...

Good point on the fairing volume. All of the solar array wings were launched from the shuttle.

I was being charitable on the back of the napkin math.

> Assuming a Falcon Heavy with 60,000 kg payload

Casually six times more than it has ever lifted.

His time estimates are notoriously, um, aggressive. But I think that's part of how his companies are able to accomplish so much. And they do, even if you're upset they haven't put a human on Mars fast enough or built one of his side quests.

"We specialize in making the impossible merely late"

I note that their accomplishments tend to be in the past, prior to his Twitter addiction absorbing his attention. Tesla is a solid decade late on FSD, cutting models, and losing market share rapidly thanks to his influencer stunts. SpaceX has a solid government launch business, which is great, but they’ve been struggling with what’s been the next big thing for a while and none of that talk about Mars has made meaningful progress. Boring Company, Neurolink, etc. show no signs of profit anytime soon no matter how cool they sound.

Being ambitious is good to an extent but you need to be able to deliver to keep a company healthy. Right now, if you’re a sharp engineer you are looking at Tesla’s competition if you want to work on a project which doesn’t get cancelled (like it’s cars) and the stock price being hyped to the moon means that options aren’t going to be as competitive.

I agree he leans into the hype aggressively, and spends too much time on Twitter, but they are making progress regardless.

Starlink is growing rapidly.

Starship has been making steady progress.

Neuralink is helping ~12 real people with spinal cord injuries/ALs.

Optimus seems to be making progress.

Tesla is beginning to roll out robotaxis without safety drivers.

> Cooling and communications would just require minor changes to existing designs.

"Minor" cooling changes, for a radically different operating environment that does not even have a temperature, is a perfect insulator for conduction and convection, and will actively heat things up via incoming radiation? "Minor" ? Citation very much lacking.

Take the area of solar panels, multiply by 3, thats the area of black body thermal radiation surface. The sattelite will chillax to 27 deg C (300 K):

https://news.ycombinator.com/item?id=46862869

And is that "Minor" ? Is that actually practical on a reasonable budget? Aren't there better uses for the solar panels etc?

if you focus on shedding heat and make it sound like an impossibility, don't be surprised when people describe what it would take.

So that's a "no, no and yes".

I don't know what you call minor or major.

I know what physics tells us.

We also don't have fully reusable launch vehicles, yet. But we will shortly. That will decrease the cost of launch by at least an order of magnitude.

Still there will be a lot of engineering problems to solve.

2-3 years seems very short, but 10 years seems long to me.

Ok then short SpaceX stock when it IPOs.

“Markets can remain irrational longer than you can remain solvent.” - John Maynard Keynes

What does stock price have to do with anything?

That someone could put a data center in space for the price of 100 years of eliminating world hunger doesn’t mean shit.

People always make this claim about world hunger elimination with no sources. Keep in mind we make more than enough calories to feed everyone on the planet many times over, it's a problem of distribution, of getting the food to the right areas and continuing cultivation for self sufficiency.

That’s right, it’s an allocation of resources problem, and some people seem to control almost all the resources.

Even the most magnanimous allocators cannot defeat the realities of boots on the ground in terms of distribution. It is a very difficult problem that cannot be solved top down, the only solution we've seen is growth of economic activity via capitalistic means, lifting millions, billions out of poverty as Asia has done in the last century for example.

You can pay for a lot of people when you have a billion dollars. When you have a trillion, you can move countries.

When someone lives in opulence while the rest of the world burns, the rest of the world doesn’t sit idly.

When you have a billion dollars you can't even give each person in China a dollar.

I argue that if you have literal hundreds of billions of hard cash to burn for stupid things like AI datacenters, you could afford to make the lives of millions of starving people not suck instead, pretty easily so. But to do that, you'd have to try, and that would mean actually doing something good for humanity. Can't have that as a billionaire.

Ok but what if I shoot a car into space and buy my own social media company. Surely thats a better use of billions!

Who has hundreds of billions of hard cash for data centers? All of the AI spending has been in IOUs between Nvidia, OpenAI, Coreweave, etc. And even if you did have hard cash, how will you spend those billions? No one actually seems to have a sound plan, like I said. They just claim it can be done.

> SPIEGEL: Mr. Shikwati, the G8 summit at Gleneagles is about to beef up the development aid for Africa…

> [Kenyan Economist] Shikwati: … for God’s sake, please just stop.

> SPIEGEL: Stop? The industrialized nations of the West want to eliminate hunger and poverty.

> Shikwati: Such intentions have been damaging our continent for the past 40 years. If the industrial nations really want to help the Africans, they should finally terminate this awful aid. The countries that have collected the most development aid are also the ones that are in the worst shape. Despite the billions that have poured in to Africa, the continent remains poor.

https://www.aei.org/carpe-diem/kenyan-economics-expert-devel...

Why would you short the stock?

As if company performance actually affected stock price when it comes to anything Elon Musk touches.

For fuck's sake, TSLA has a P/E of a whopping *392*. There is zero justification for how overvalued that stock is. In a sane world, I should be able to short it and 10x my money, but people are buying into Musk's hype on FSD, Robotaxi, and whatever the hell robot they're making. Even if you expected them to be successes, they'd need to 20x the company's entire revenue to justify the current market cap.

If you're hellbent on arguing with a cult, it will be much cheaper to go down to your local Church of Scientology and try to convince them that their e-meter doesn't work.

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It's much easier to find a country or jurisdiction that doesn't care about a bunch of data centers vs launching them into space.

I don't get why we aren't building mixed use buildings, maybe the first floor can be retail and restaurants, the next two floors can be data centers, and then above that apartments.

I think data centers, in the areas where they are most relevant (cold climates), are going to face an uphill battle in the near future.

Where I live, Norway, we've seen that:

1) The data centers don't generate the numbers of jobs they promise. Sure, during building phase, they do generate a lot of business, but during operations and maintenance phase, not so much. Typically these companies will promise hundreds of long-term jobs, while in reality that number is only a fraction.

2) They are extremely power hungry, to the point where households can expect to see their utility bill go up a non-trivial amount. That's for a single data center. In the colder climate areas where data centers are being promoted, power infrastructure might not be able to handle the centers (something seen in northern Norway, for example) at a larger scale, due to decades of stagnation.

3) The environmental effects have come more under scrutiny. And, unfortunately for the companies owning data centers, pretty much all cold-climate western countries have stringent environmental laws.

In Switzerland infomaniak built a data center under apartments and DC heat is used for heating. There are some videos about it.

Americans have trouble understanding something like that. We believe anything short of a 3bdrm house with a lawn and backyard is communism.

I'd love to live in a dense city. My office within waking distance. A Cafe in my apartment building, etc.

The US has district heating systems. The country is very big and varied, as much as people like to paint it as homogenous.

And district cooling.

When I lived on a chilling grid, my summer AC bill was around $80, while friends whose buildings weren't connected paid $200+.

> I'd love to live in a dense city. My office within waking distance. A Cafe in my apartment building, etc.

Then move to one?

> I don't get why we aren't building mixed use buildings, maybe the first floor can be retail and restaurants, the next two floors can be data centers, and then above that apartments.

I mean a DC needs a lot of infrastructure and space. I think the real estate economics in places where people want to live, shop, and eat preclude the kinds of land usage common in DC design. Keep in mind that most DCs are actually like 4 or 5 datahalls tethered together with massive fiber optic networks.

Also people prefer to build parking in those levels that you're proposing to put DCs into.

The cost per square foot goes up as you add more floors. Construction goes multi-story to save space where land is expensive. But data centers don't need to be in places where land is expensive.

Probably for the same reasons they aren't doing mixed use prison and restaurant buildings.

What you don't want to live near the newest poisonous abomination that the whiz kids dreamt up? Do you want China to take over America or something?

Data centers don't do anything other than sit there and turn electricity into heat. They only emit nothing but heat (which could be useful to others in the building).

In America they have "temporary" jet turbines parked next to them burning gas inefficiently with limited oversight on pollution and noise because they are "temporary".

False, come up with new talking points please:

https://www.youtube.com/watch?v=3VJT2JeDCyw

If these things were so safe the rich should build them next to their homes.

Heat and noise. The noise and the increased electrical bills are the main things people living near data centers complain about.

Mixed-use buildings with restaurants on the lower floors and residential on the upper floors are very common. Not sure what prisons have to do with anything.

It's not just "very challenging", it's "very challenging and also solves no actual problem we face".

> A former NASA engineer with a PhD in space electronics who later worked at Google for 10 years wrote an article about why datacenters in space are very technically challenging

It's curious that we live in a world in which I think the majority of people somehow think this ISN'T complicated.

Like, have we long since reached the point where technology is suitably advanced to average people that it seems like magic, where people can almost literally propose companies that just "conjure magic" and the average person thinks that's reasonable?

you can’t tell me the microwave isn’t magic. it’s magic.

I think it counts as necromancy. After all it brings frozen hamsters back to life.

I can put things in a box that uses spooky electromagnetic waves to tickle water molecules to the point that they get hot and maybe boil off, given the chance? Sounds like magic to me

It's just the thought process that comes with shallow understanding:

    "I can buy a server"
    "We can put things in space"
    "What do you mean I can't get a server in space?!"

Google is currently working on AI data centers in space.

https://blog.google/innovation-and-ai/technology/research/go...