1. every gram you need to send to space is costly, a issue you don't have at ground level
2. cooling is a catastrophe, sure space is cold, but also a vacuum, so the cooling rate is roughly the infrared radiation rate. This means if you are not careful with the surface of a satellite it can end up being very slowly cooked by sunlight alone not including running any higher heat producing component (as it absorbs more heat from sunlight then it emits, there is a reason satellites are mostly white, silver or reflective gold in color). Sure better surface materials fix that, but not to a point where you would want to run any heavy compute on it.
3. zero repair-ability, most long running satellites have a lot of redundancy. Also at least if you are bulk buying Nvidea GPGPUs on single digit Million Euro basis it's not rare that 30% have some level of defect. Not necessary "fully broken" but "performs less good then it should/compared to other units" kind of broken.
4. radiation/solar wind protections, is a huge problem. Heck even if you run things on earth it's a problem as long as your operations scale is large enough. In space things are magnitudes worse.
5. every rocket lunch causes atmospheric damage, so does every satellite evaporating on re-entry. That wasn't that relevant in the past, but might become a problem just for keeping stuff like Starlink running. We don't need to make it worse by putting datacenters into space.
6. Kessler Syndrom is real and could seriously hurt humanity as a whole, no reason to make it much more likely by putting things into space which don't need to go there.
Last but not least, wtf would you even want to do it?
There is zero benefit, non nada.
Space is a vacuum. i.e. The lack-of-a-thing that makes a thermos great at keeping your drink hot. A satellite is, if nothing else, a fantastic thermos. A data center in space would necessarily rely completely on cooling by radiation, unlike a terrestrial data center that can make use of convection and conduction. You can't just pipe heat out into the atmosphere or build a heat exchanger. You can't exchange heat with vacuum. You can only radiate heat into it.
Heat is going to limit the compute that can be done in a satellite data centre and radiative cooling solutions are going to massively increase weight. It makes far more sense to build data centers in the arctic.
Musk is up to something here. This could be another hyperloop (i.e. A distracting promise meant to sabotage competition). It could be a legal dodge. It could be a power grab. What it will not be is a useful source of computing power. Anyone who takes this venture seriously is probably going to be burned.
It probably increases Elon's share of the combined entity.
It delivers on a promise to investors that he will make money for them, even as the underlying businesses are lousy.
A Starlink satellite uses about 5K Watts of solar power. It needs to dissipate around that amount (+ the sun power on it) just to operate. There are around 10K starlink satellites already in orbit, which means that the Starlink constellation is already effectively equivalent to a 50 Mega-watt (in a rough, back of the envelope feasibility way).
Isn't 50MW already by itself equivalent to the energy consumption of a typical hyperscaler cloud?
Why is starlink possible and other computations are not? Starlink is also already financially viable. Wouldn't it also become significantly cheaper as we improve our orbital launch vehicles?
1. The capital costs are higher, you have to expend tons of energy to put it into orbit
2. The maintenance costs are higher because the lifetime of satellites is pretty low
3. Refurbishment is next to impossible
4. Networking is harder, either you are ok with a relatively small datacenter or you have to deal with radio or laser links between satellites
For starlink this isn't as important. Starlink provides something that can't really be provided any other way, but even so just the US uses 176 terawatt-hours of power for data centers so starlink is 1/400th of that assuming your estimate is accurate (and I'm not sure it is, does it account for the night cycle?)
Minus one big one: permitting. Every datacentre I know going up right now is spending 90% of their bullshit budget on battlig state and local governments.
Presumably they're planning on doing in-orbit propellant transfer to reboost the satellites so that they don't have to let their GPUs crash into the ocean...
Hell, you're going to lose some fraction of chips to entropy every year. What if you could process those into reaction mass?
A single AI rack consumes 60kW, and there is apparently a single DC that alone consumes 650MW.
When Microsoft puts in a DC, the machines are done in units of a "stamp", ie a couple racks together. These aren't scaled by dollar or sqft, but by the MW.
And on top of that... That's a bunch of satellites not even trying to crunch data at top speed. No where near the right order of magnitude.
xAI’s first data center buildout was in the 300MW range and their second is in the Gigawatt range. There are planned buildouts from other companies even bigger than that.
So data center buildouts in the AI era need 1-2 orders of magnitude more power and cooling than your 50MW estimate.
Even a single NVL72 rack, just one rack, needs 120kW.
You might only care about coding models, but text is dominating the market share right now and Grok is the #2 model for that in arena rankings.
It's a way to get cheap capital to get cool tech. (Personal opinion.)
Like dark fibre in the 1990s, there will absolutely–someday–be a need for liquid-droplet radiators [1]. Nobody is funding it today. But if you stick a GPU on one end, maybe they will let you build a space station.
[1] https://en.wikipedia.org/wiki/Liquid_droplet_radiator
Also the same issue with radiative cooling pops up for space solar cells - they tend to run way hotter than on Earth and that lowers their efficiency relative to what you could get terrestrially.
Sufficient hype funds more work for his rocket company.
The more work they have the faster they can develop the systems to get to Mars. His pet project.
I really think it's that simple.
We can tell because it’s not being treated as a serious goal. 100% of the focus is on the big vroom vroom part that’s really exciting to kids who get particularly excited by things that go vroom, and approximately 0% of the focus is on developing all the less glamorous but equally essential components of a successful Mars mission, like making sure the crew stays healthy.
Oh, that crap again.
I keep seeing that term, but if it does not mean "AI arms race" or "AI surveillance race", what does it mean?
Those are the only explanations that I have found, and neither is any race that I would like to see anyone win.
But when they say, "Win the AI race," they mean, "Build the machine god first." Make of this what you will.
Data centers in space are the same kind of justification imo.
Off on a tangent here but I'd love for anyone to seriously explain how they believe the "AI race" is economically winnable in any meaningful way.
Like what is the believed inflection point that changes us from the current situation (where all of the state-of-the-art models are roughly equal if you squint, and the open models are only like one release cycle behind) to one where someone achieves a clear advantage that won't be reproduced by everyone else in the "race" virtually immediately.
This is just a question. I have no expertise at all with this.
All in all, the cooling system would likely consume more energy than the compute parts.
requires a lot of weight (cooling fluid). requires a lot of materials science (dont want to burn out radiator). requires a lot of moving parts (sun shutters if your orbit ever faces the sun - radiator is going to be both ways).
so that sounds all well and good (wow! 4th power efficiency!) but it's still insanely expensive and if your radiator solution fucks up in any way (in famously easy to service environment space) then your entire investment is toast
now i havent run the math on cost or what elon thinks the cost is, but my extremely favorable back of hand math suggests he's full of it
There should be some temperature where incoming radiation (sunlight) balances outgoing radiation (thermal IR). As long as you're ok with whatever that temperature is at our distance from the sun, I'd think the only real issue would be making sure your satellite has enough thermal conductivity.
Specifically: Starship makes no economic sense. There simply isn’t any pre-existing demand for the kind of heavy lift capacity and cadence that Starship is designed to deliver. Nor is there anyone who isn’t currently launching heavy payloads to LEO but the only thing holding them back is that they need weekly launches because their use case demands a whole lot of heavy stuff in space on a tight schedule and that’s an all-or-nothing thing for them.
So nobody else has a reason to buy 50 Starship launches per year. And the planned Starlink satellites are already mostly in orbit. So what do you do? Just sell Starship to xAI, the same way he fixed Cybertruck’s demand problem by selling heaps of them to SpaceX.
Where will they go, nobody knows!
That's wise.
However, TFA's purpose in assuming cooling (and other difficulties) have been worked out (even though they most definitely have not) was to talk about other things that make orbital datacenters in space economically dubious. As mentioned:
Sure, space is cold. Good luck cooling your gear with a vacuum.
Don't even get me started on radiation, or even lack of gravity when it comes to trying to run high powered compute in space. If you think you are just going to plop a 1-4U server up there designed for use on earth, you are going to have some very interesting problems pop up. Anything not hardened for space is going to have a very high error/failure rate, and that includes anything socketed...
No. Nearly everyone that talks about data centers in space talks about cooling. The point of this article was to talk about other problems that would remain even if the most commonly talked about problems were solved.
It says:
> But even if we stipulate that radiation, cooling, latency, and launch costs are all solved, other fundamental issues still make orbital data centers, at least as SpaceX understands them, a complete fantasy.
and then talks about some of those other issues.
Next up in the equation is surface emissivity which we’ve got a lot of experience in the automotive sector.
And finally surface area, once again, getting quite good here with nanotechnology.
Yes he’s distracting, no it’s not as impossible as many people think.
So your hot thing is radiating directly onto the next hot thing over, the one that also needs to cool down?
It's not physically impossible. Of course not. It's been done thousands of times already. But it doesn't make any economic sense. It's like putting a McDonald's at the top of Everest. Is it possible? Of course. Is it worth the enormous difficulty and expense to put one there? Not even a little.
Same with datacenters in space, not today, but in 1000 years definitely, 100 surely, 10?
As for the economics, it makes about as much sense as running jet engines at full tilt to power them.
My car doesn't spend too much time driving in vacuum, does yours?
Seems like quite a massive difference to ignore.
[0] https://images-assets.nasa.gov/image/jsc2021e064215_alt/jsc2...
https://en.wikipedia.org/wiki/External_Active_Thermal_Contro...
[1] https://en.wikipedia.org/wiki/External_Active_Thermal_Contro...
That specific aspect is NOT true in space because there's nothing stopping thermal radiation.
Now you're correct that you can't remove heat by conduction or convection in space, but it's not that hard to radiate away energy in space. In fact rocket engine nozzle extensions of rocket upper stages depend on thermal radiation to avoid melting. They glow cherry red and emit a lot of energy.
By Stefan–Boltzmann law, thermal radiation goes up with temperature to the 4th power. If you use a coolant that lets your radiator glow you can conduct heat away very efficiently. This is generally problematic to do on Earth because of the danger of such a thing and also because such heat would cause significant chemical reactions of the radiator with our corrosive oxygen atmosphere.
Even without making them super hot, there's already significant energy density on SpaceX's satellites. They're at around 75 kW of energy generation that needs to be radiated away.
And on your final statement, hyperloop was not used as a "distraction" as he never even funded it. He had been talking about it for years and years until fanboys on twitter finally talked him into releasing that hastily put together white paper. The various hyperloop companies out there never had any investment from him.
> Musk admitted to his biographer Ashlee Vance that Hyperloop was all about trying to get legislators to cancel plans for high-speed rail in California—even though he had no plans to build it.
https://time.com/6203815/elon-musk-flaws-billionaire-visions...
Once upon a time there was a bonkers "rods from god" mass bomb idea, but that didn't work either.
https://www.cbc.ca/news/canada/saskatoon/spacex-cbc-debris-s...
The question isn't whether it's possible, the question is why you'd do it just for data centers. We put computers in space because they're needed to do things that can only be done from there. Data centers work just fine on the ground. What's so great about data centers in space that makes them worth the immense cost and difficulty.
I know a lot of prominent people are talking about this. I do not understand it. pg says "when you look at the tradeoffs" well what exactly is he looking at? Because when I look at the tradeoffs, the whole concept makes no damned sense. Sure, you can put a bunch of GPUs in space. But why would you do that when you can put them in a building for orders of magnitude less money?
I liked one comment someone made: if it's just about dodging regulation, then put the data centers on container ships. At any given time, there are thousands of them sailing in international waters, and I'm sure their operators would love to gain that business.
That being said, space would be a good place to move heat around with Peltier elements. A lot of the criticisms revolve around the substantial amount of coolant plumbing that will be needed, but that may not necessarily be what SpaceX has in mind.