So my bet would be that just ordering a bunch of sodium batteries and a bunch of solar panels (or you know using a source of energy that is constant) is cheaper then going threw all the effort of putting things into space.
I have been following everything space for decades, and not once have I thought, wow putting super complex engineering things into space so easy and you should do it for things that have an easy alternative on earth.
You're concentrating it into a very small area of compute.
If you don't spread that heat back out, it's going to find a much higher thermal equilibrium than the solar panels themselves would find just absorbing the sunlight and radiating the energy back into space.
It's like you've pointed a magnifying glass at your compute, except with electricity, which means you can reach temperatures higher than you can with a magnifying glass.
It’s not like only idiots who know nothing about space are pointing out the cooling issue: https://taranis.ie/datacenters-in-space-are-a-terrible-horri...
"you don't lose that much power through the atmosphere"
Assuming you can point the orbiting panels at the sun and remain direct, you lose 80% of your power through the atmosphere (from angle and day/night). On the ground you lose 25% even if your panel is directly below the sun pointed exactly at it, which is never the case in many latitudes.
And of course it's not trivial to radiate heat. But it's also a fairly simple mechanical problem. You pump the heat to spread it out, and radiate it. You've already got the surface area shaded by the panels (which is more than enough, because the panels don't absorb 100% of solar radiation).
Sure, you need a lot of them. Starship V3 is probably about to get us past 100 tons of payload capacity - even if they blow up a few first.
The key people miss is that you don't have to spend money on ongoing cooling once the thing is in space. This isn't going to save money now, but the cost lines are going to cross.
When people say "you don't lose that much power on the ground", it's in the context of cost.
So a solar panel is 5x more efficient in space. You solve that in the ground by buying 5x more solar panels.
Solar panels cost -- rounding up -- $10/kg.
Lifting things into space costs -- rounding down -- $1000/kg.
For the same amount of money, you can put 100X solar panels into a ground based array as a space based array. You don't lose that much power on the ground. You aren't overcoming that difference because solar panels are more efficient in space.
It's the same way that Sam Altman talks about the risks of AI deciding to kill humanity: because that's dramatic and attention grabbing, and also the most unlikely outcome. Talking about it keeps us from talking about the real, ground level problems like the massive, unplanned-for disruption in jobs and education.
They just need to keep the money tap flowing, and tomorrow can worry about itself. Who's going to hold them accountable for data-centres-in-space five years from now, when they don't exist? Has Musk suffered any blowback from his hyping the Hyperloop that never materialized?
It might even be useful in other circumstances. Better radiative cooling systems, hardening commercial high-end compute for space, etc etc. R&D you can feel proud of, even if your bosses are only paying you to do it to fleece rubes who think it's the next trillion dollar industry.
How many smart people worked quietly at Theranos, knowing that a drop sample from a thumb was incapable of carrying sufficient blood volume for a legitimate sample, but thought "hey, maybe someone will figure something miraculous out that violates a basic tenet of my professional experience"?
Grandparent is trying to argue that a lot of smart people working quietly on something confers plausibility upon the premise of their work (i.e., "they must know something you don't"). I've rebutted with two examples showing that large numbers of smart people working on something don't make plausible a premise that is obviously flawed for other reasons [*].
[*] (ETA) and is known at the time by the smart people.
Also hard radiation is not something transistors like.
And about starlink .. as far as I know the fail quite often but work, because of redundancy. So they get replaced.
If you want to ship GPU's to the orbit, then this surely works somehow, if you are willing to replace them often, which is expensive. Or you shield them, but then you will need to get up heavy shields. In general, of course computers work in space, but it is not cheap.
You make a H100, ship it to a space dock, load it onto a rocket (rocket requires fuuel, the rocket, etc.) send it up, deploy it, monitor it live 24/7, have means of adjusting its orbit, if it breaks, its immediade full loss, otherwise it will degenerate faster in space than on earth, now it needs a high speed up/downlink to do anything reasonable which also requires a base station. The base station has to track this satelite.
One H100 costs 40k, consumes 700 Watt peak and need probably at a minimum 5 square meter of area for cooling and solar.
The colossus datacenter from musk has 250.000 of these.
Now you have to track 250.000 single satelites, you have to coordinate the communication between the, up and downlink to earth.
250.000 * 5 square meter of area.
This alone increases the potential debris in space.
And this is ONE 300 MW Datacenter replacement. ONE.
Now different people have different points where they quit when things get hard.
This is true for even everyday things in life. Quitting triggers exist for people at various points in the ladder. The end of ladder and path both exist, its upto you to decide if you wish to continue climbing, or give up and quit.
Your mileage may vary.
We are nowere near any resource limitation on planet earth for AI Datacenters.
Musk sells this story because he has Starship which needs payload to make financial sense. The payload doesn't exist so he inventes DC in Space.
Its the same thing as SpaceX buying Tesla Cybertrucks.
His old colossus datacenter is a 300MW Datacenter he now rents out to Anthropic because he doesn't even need his own compute. Colossus DC is probably 10x cheaper than his whole Space AI DC Story and will be for a long time.
The first line of the post that you are supposedly replying to is:
> Of course it works, the question is how this would look like and if its financial feasable.
Unless is cost-comparable to a data centre on Earth, and I am told that it very much is not, then there is no financial feasibility for space datacentres.
Basically a Starlink v3 satellite has an estimated power budget of 20kW. Add in the heat absorbed from the environment (both directly from sunlight and reflected off of the Earth) and you’ll find that it must reject about 22kW of heat. That’s a fair amount, but at 65°C it can radiate it all away just using it’s own surface area! No radiator required at all!
Of course the power density of computer racks has been going up over the years. If you want to reach 100kW per satellite then they will need a modest radiator, but nothing extravagant. It would still be smaller than the solar panels, and far smaller than the ones on the ISS. And don’t forget that because radiated heat goes up as the fourth power of temperature, raising the temperature of the system by even a small amount raises the radiation emitted by a lot. If you design the system to run hotter you can minimize the size of the radiator. Most chips these days are designed to max out at 100°C to 110°C without lasting damage, although running them at that temperature 24/7 may reduce their lifespan. There will be some sweet spot in the middle.
And it turns out that a Starlink v3 already has a volume somewhat larger than a 48U rack. You talk about launching 250k satellites in order to have 250k GPUs in orbit, but that’s ridiculous. A real compute swarm will be hundreds or thousands of satellites each equivalent to a whole rack of GPUs.
But you’re not wrong to be skeptical. The economics might not work out even if the cooling is easy enough. It’s just that rejecting the idea takes a lot more than back–of–the–envelope calculations.
The Starlink v3 doesn't exist yet in space, it also needs Starship apparently and Musk said it will have the size of a Boeing 737 fully deployed. So it will not be small and its not proofen yet.
A rack with 48u will either have 12 or 24 GPUs which equals to 9kW or 17kW. Than its not 250k satellites for a 'small' 300MW DC but only 25k. Still a very crazy number.
I would love to see all of this scifi stuff happening. Spaceship in space, travel gates, dyson sphere but there is just no current breakthrough in our society which would indicate that this makes sense.
In my opinion, we as a society will have to get rid of capitalism first before we will do the next step and just because Musk needs a story to sell to keep his construct alive, doesn't mean its the right time.
True but not really relevant. All prior versions of Starlink worked well enough, so there’s no reason to suspect that v3 won’t.
> … it will have the size of a Boeing 737 fully deployed. So it will not be small…
Irrelevant. Size is a weird measure here. You should ignore it because it is a marketing thing. All that is meant by it is that once the solar panels are extended they span a distance larger than the wingspan of a 737, nothing more. A Starlink v3 satellite has far less mass, interior volume, or complexity than a 737. I could get a long 30m rope and tell you that it was “larger than a 737”, but you wouldn’t be very impressed.
> A rack with 48u will either have 12 or 24 GPUs which equals to 9kW or 17kW. Than its not 250k satellites for a 'small' 300MW DC but only 25k. Still a very crazy number.
Are you sure? That fits within the estimated power budget of a Starlink v3, but I was assuming that GPUs were denser than that these days. I’m not an expert though. I figured a rack would hold somewhere between 96 and 128 GPUs depending on whether they had to be in 3u or 4u servers. They would need between 60kw and 90kW of power, and would need a modest radiator. The solar panels would be far larger than the radiator.
> I would love to see all of this scifi stuff happening. Spaceship in space, travel gates, dyson sphere but there is just no current breakthrough in our society which would indicate that this makes sense.
Ok, see, your problem is that you haven’t properly distinguished between different types of fiction. You put those three things in one category as if they were all equally fictional, but that cannot be true.
The first one is ambiguous, since the Space Shuttle was definitely a “spaceship in space”, so perhaps you just mean FTL travel like in Star Trek or Star Wars. By “travel gates” I assume you mean something like the eponymous gates from Stargate SG–1. Those are both ruled out by the laws of physics, and we can only tell stories about them because people willingly suspend their disbelief. Campbell said that a true science fiction story can only include one thing that requires the reader to suspend their disbelief. If it includes more than that then it is a fantasy instead.
But a Dyson sphere, or more accurately a Dyson swarm, is not an impossibility at all. If I can put one solar–powered satellite in orbit around the sun then if I am really industrious I could put ten, or a hundred, or a trillion. As many as I wanted and could afford, right? The laws of physics don’t say that a sun can only have 8 satellites around it, or any other number. Dyson knew that enough such satellites would eventually blot out the sun. They would absorb all the sunlight it could emit, and then the satellites would all emit infrared waste heat. If all of those satellites were doing something useful then whoever put them there would have a lot of useful work being done at their command. Even if it’s just trillions of GPUs making AI–powered cat memes, or simulating the minds of a bunch of human uploads, or even if they’re all just mirrors to redirect that light somewhere else, that’s a lot of power at our command. It is fictional only because it is an idea that nobody has actually gotten around to implementing yet. Once we’ve done it then it won't be fictional anymore.
> Its just so much more expensive than just doing it in a dessert and putting fibre and solar panels and batteries there.
No one here is arguing that it isn’t. It might still be cheaper to build datacenters on Earth. But most of the people who say that it’s _definitely_ still cheaper to build them on Earth are overestimating the difficulties, and therefore the costs, of doing it in orbit instead. We’re getting to the point where launch costs are low enough that it is no longer a given that it is cheaper.
For one thing, actually building things in the desert is expensive. You have to build all the necessary infrastructure yourself. Roads, power, water, fuel, etc, etc. You might as well be launching everything into space! No, if you want it to be cheaper you need to build somewhere closer to home, like Ohio.
If the economics make it too expensive not to use freshwater on Earth, I don't see how closed-loop cooling suddenly becomes affordable in space where dispersing heat is already more difficult.
Similarly, a satellite only needs a cooling system so that it can move the heat from the internal components outward towards the hull. A satellite containing a rack’s worth of GPUs might literally have heat spreaders that touch the chips on one side and the outer hull of the satellite on the other. Combine that with some heat pipes or something to spread the heat out efficiently and you hardly need anything else. A satellite the size and shape of a Starlink v3 already has enough surface area to dissipate something like 28kW at 80°C, and more if you run it hotter. If you want more than ~30–40 GPUs per satellite then you might need a small radiator to increase the surface area, or you might just make the thing thinner and wider instead. You’ll need more solar panel area anyway, so making the bus wider to match the wider solar panels is fine. The “closed–loop cooling system” you say is so unaffordable might be no more than a bunch of heat pipes. Or it might be an aquarium motor that pumps a few kilos of ammonia through some pipes or channels in the hull of the satellite.
The more power you consume, the more power you need to dissipate. These constelations wouldn't be small at all. It would also take a interesting solution to be able to move this heat from very small very intense areas to very big cooling areas. How?
And space is not easy. Space is very very cold which puts a lot of stress on materials. It has radiation. And it has A LOT of microasteroids. Stuff in Space breaks down due to this. You would need to replace all of this stuff regularly with resources from the planet earth.
You would basically just spend a lot of resources throwing a lot of resources out into space. You can't even recycle all of this.
Its still lunatic at our current state of our current system. There is so so much space on our planet. Its ridicoulous
The only reason Musk is saying stuff like this is because he knows there is no market and he needs to keep his system alive
If you plug eleventy trillion dollars of hope that the aristos can finally replace the working class into the issue, Earth loses access to low orbit from orbital debris almost immediately.
Their entire mindset cannot deal with this. Low orbit is a physically-enforced type of commons, inextricably tied to tragedy if overpopulated. You cannot privatize it and scale indefinitely. There is no defense, and any pissed off individual actor who gets malicious can burn it to the ground.
Chinese mega constellations on higher orbits & their spent stages left in space are a bigger issues.
Still in case it got going & made higher orbits unusable, starlink would likely still work just fine on the lower self-cleaning orbits, not to mention using a partial (and hopefully soon full) RLV for replenishment.
This 1 Trillion Dollar has to be translated to either sending up A LOT of foreign payload OR his payload; All of this payload = new Satelites. Its not like we are sending earth resource up in space to build a dyson sphere.
SpaceX immediately responded by lowering its target orbits by 70km, the maximum it could legally do without renegotiating formally.
When a high orbit develops Kessler Syndrome, the billions of pieces of debris rain down on lower orbits and cause cascading collisions there, and they keep doing it for centuries.
Not understanding how any of this works, the scientists not being capable of convincing the politicos, or the leaders not being able to escape their local maxima of public stances to recognize a real threat, is a massive, civilizational level hubris. This is pass/fail - the math does not care about our level of understanding or maturity.
Stop trying to make Kessler Syndrome a thing. It was never a thing, it won’t be a thing, it will never be a thing.
Every collision increases the chance of additional collisions.
"Weeks"? SpaceX is aiming to be within the guideline of 25 years for the intact spacecraft, with solar panels unfurled. The want at minimum five years of business operations out of it. Half a spacecraft is still going to be decades (if not centuries if they lose the panels), and small chunks of spacecraft years.
This orbit has to rotate about a degree every day to follow the terminator as the earth orbits the Sun. It uses the equatorial bulge of the earth to achieve that rotation without have to spend rocket fuel. It is really quite interesting.
A few datacenters could occupy some slots, but it would be difficult to accept a large number of datacenters obstructing such orbits.