Summarizer

> 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.

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?

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.

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

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

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.

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.

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

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.

> 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.

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.

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.

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.

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.

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.

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*. I'm deeply disillusioned to arrive at this conclusion but the Occam's Razor in me feels this whole acquisition is more likely a play to increase the perceptual value of SpaceX before a planned IPO.

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.

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.

> 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.

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

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)

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 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.

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.

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.

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.

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

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.

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/ )

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

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

>just use even more solar panels I think it's because at this scale a significant limit becomes the global production capacity for solar cells, and SpaceX is in the business of cheaper satellites and launch.

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.

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

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.

> 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.

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.

Surely the constraint will be the rate at which you can get them into and installed orbit, not the manufacturing rate

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.

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. 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.

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.

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.

>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.

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.

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.

> Assuming a Falcon Heavy with 60,000 kg payload Casually six times more than it has ever lifted.

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...

And is that "Minor" ? Is that actually practical on a reasonable budget? Aren't there better uses for the solar panels etc?

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.

Just like rockets landing themselves

It's a matter of deploying it for cheaper or with fewer downsides than what can be done on earth. Launching things to space is expensive even with reusable rockets, and a single server blade would need a lot of accompanying tech to power it, cool it, and connect to other satellites and earth. Right now only upsides an expensive satellite acting as a server node would be physical security and avoiding various local environmental laws and effects

> Right now only upsides ... You are missing some pretty important upsides. Lower latency is a major one. And not having to buy land and water to power/cool it. Both are fairly limited as far as resources go, and gets exponentially expensive with competition. The major downside is, of course, cost. In my opinion, this has never really stopped humans from building and scaling up things until the economies of scale work out. > connect to other satellites and earth If only there was a large number of satellites in low earth orbit and a company with expertise building these ;)