← Back to context

Comment by jedberg

9 months ago

I've been saying for a long time that we should consider remote areas for building datacenters for batch processing.

At first I thought the poles (of the planet) might be good. The cooling is basically free. But the energy and internet connectivity would be a problem. At the poles you can really only get solar about three months a year, and even then you need a lot of panels. Most of Antarctica is powered diesel because of this.

So the next thought was space. At the time, launching to space was way too costly for it to ever make sense. But now, with much cheaper launches, space is accessible.

Power seems easily solved. You can get lots of free energy from the sun with some modest panels. But to do that requires an odd orbit where you wouldn't be over the same spot on earth, which could make internet access difficult. Or you can go geostationary over a powerful ground station, but then you'd need some really big batteries for all the time you aren't in the sun.

But cooling is a huge problem. Space is cold, but there is no medium to transfer the heat away from the hot objects. I think this will be the biggest sticking point, unless they came up with an innovative solution.

Their whitepaper explains their cooling "solution": https://starcloudinc.github.io/wp.pdf

> As conduction and convection to the environment are not available in space, this means the data center will require radiators capable of radiatively dissipating gigawatts of thermal load. To achieve this, Starcloud is developing a lightweight deployable radiator design with a very large area - by far the largest radiators deployed in space - radiating primarily towards deep space...

They claim they can radiate "633.08 W / m^2". At that rate, they're looking at square kilometers of radiators to dissipate gigawatts of thermal load, perhaps hectares of radiators.

They also claim that they can "dramatically increase" heat dissipation with heat pumps.

So, there you have it: "all you have to do" is deploy a few hectares of radiators in space, combined with heat pumps that can dissipate gigawatts of thermal load with no maintenance at all over a lifetime of decades.

This seems like the sort of "not technically impossible" problem that can attract a large amount of VC funding, as VCs buy lottery tickets that the problem can be solved.

  • Or we could build a large vacuum chamber here on Earth and put a data center in it, if the goal is to make cooling as difficult as possible. "My data center is too hot! It's burning me!" "Put it in a giant thermos, then you won't feel it anymore."

    > They also claim that they can "dramatically increase" heat dissipation with heat pumps.

    Right, great idea. Start with the heat where you don't want it -- in the chip -- and pump it out to where it can't go anywhere. Then you can recirculate the medium back and have slightly older heat that you can mix with the new heat! It'll be a heat party!

    It's just like a terrestrial heat pump, where you pump the heat out to where you have a huge environmental sink to transfer the heat to. In space, you have something like a hundred thousand hydrogen atoms per cubic meter to take up the heat. A HUNDRED THOUSAND! That's a bigly number, it must work out. We can always make those atoms go really, really fast!

    Did an AI invent this whole scheme?

  • Obviously use the heat pumps to concentrate the thermal energy up to 2700k, then conduct it along a bunch of tungsten filaments, now it's the world's biggest incandescent lightbulb on top of being the first datacenter in space. Maybe get it up to 4000k for a more modern lighting look. Guess we're gonna assume the dark forest hypothesis is false.

  • I was trying to put these sizes in rough perspective. ISS is the largest man-made object in space, which is basically the size of a football field (half a hectare) and cost $150B. https://www.nasa.gov/image-article/comparison-of-size-of-int...

    The whitepaper shows a 4km x 4km solar array, which is 1600 hectares (3200 International Space Stations). Would assume the array they're proposing would be cheaper since its structurally more homogenous, but $480 trillion dollars is a whole lot of money.

  • An object of that size in orbit seems like it'd run into problems developing sizable holes due to space junk and whathaveyou. There's probably some maintenance...

  • > So, there you have it: "all you have to do" is deploy a few hectares of radiators in space, combined with heat pumps that can dissipate gigawatts of thermal load…

    Starcloud’s whitepaper suggests a 4 km × 4 km radiator. For comparison, the James Web Space Telescope has a sunshield measuring 21 m × 14 m and the International Space Station measures 109 m × 73 m.

  • Heat pumps could dramatically impact performance by increasing the temperature of the radiators. The hotter they are, the more power they can dissipate per unit time & area.

    Doubling the radiator temperature would give you 16x more radiated power.

  • I don't get it--are the founders just grifters? How did this startup even make it off the drawing board?

    • Probably because space companies will invest in you to feed their bubble.

      You have to find trillions of dollars of future launches to justify current valuations.

    • It’s only a grift if they know they can’t solve the cooling issue and they falsify data around their proposed solution and they publicly embarrass their investors a la Theranos.

      Outside of that, accepting money and saying “I will simply solve the enormous problem with my idea by solving it” is not only normal, but actively encouraged and rewarded in the VC sphere. Suggesting that that way of operating is anything short of the standard that should be aspired to is actually seen as derisive and offensive on here and can get you labeled as gauche or combative.

      1 reply →

  •   >  they're looking at square kilometers of radiators to dissipate gigawatts of thermal load
    

    Presumably they'll put them behind the 4km2 solar panels!

    I mean this is a ridiculous concept. We've never put anything remotely that size into space. To argue that this would be cheaper than putting something underwater or in the middle of nowhere is crazy. I'd rather deal with salt than deal with radiation.

> I've been saying for a long time that we should consider remote areas for building datacenters for batch processing.

FWIW there's a reason that Sweden has a bunch of datacenters in the north that are peanuts compared to hosting in Virginia.

They're "poorly" connected (by virtue of being a bit out of the way), but the free cooling and power from renewables make them extremely attractive. There was a time where they were the favourite of crypto-miners for the same reason as they would be attractive to AI training farms.

Fortlax has some I believe; https://www.fortlax.se

-----

As for the meat of the paper. Anyone with a passing understanding of space will be quick to point out that:

A) Heat is a problem in space, it's either way-way-way to hot (IE; you're in the path of the Sun) or it's way-way-way too cold (IE; you're out of the sun) and the shift between the two means you need to build for both. You also can't dissipate heat as there's no air to take the heat away.

B) Power is not so abundant and solar panels degrade; a huge amount of satellite building is essentially managing a decline in the capability of hardware. That's part of why there are so many up there.

C) Getting reasonably sized hardware up there is beyond improbable, though I'll grant you that most of the weight in a computer is the cooling components and chassis.

D) Cosmic Rays. No electromagnetic barrier from earth and extremely tight lithographies. I mean... there's a reason NASA is still using CPU's measured in the megahertz range.

  • > D) Cosmic Rays.

    AFAIK someone (Mars Ingenuity helicopter team) discovered that some chips handle them much better than others, so they just test a bunch and keep resistant ones.

>But cooling is a huge problem. Space is cold, but there is no medium to transfer the heat away from the hot objects. I think this will be the biggest sticking point, unless they came up with an innovative solution.

Their main tech breakthrough would have to be in this area otherwise the company is worthless imo.

  • It's possible to do all of this with current technology. Just... Why? The cost would be exorbitant; even with really clever deployment tech, the launch costs are gonna be dominated by solar panels and radiators.

    This is a super cool idea and seems like perfect investor-bait. That's about where it ends.

    • Genuinely most "AI" DCs are spending less than 9KW on cooling for every 100KW of servers. If you were that bothered about getting that to zero, you could literally sink them into the ocean, build a heat network so the town can take the heat for free or use any of a dozen more established and practical ways to do that.

      6 replies →

  • I don't think they can bend the laws of physics though. Vacuum means the only way to dissipate heat is through thermal radiation, hence the huge infrared radiators.

I have no clue about space technology but many comments point the difficulty to cool anything in space. If Starcloud had an innovative solution to this problem, why on Earth (sic) focus on data centers when they could help the entire space industry? It does not smell good.

> Or you can go geostationary over a powerful ground station, but then you'd need some really big batteries for all the time you aren't in the sun.

Geostationary satellites only go into Earth's shadow on around 20 days on each side of an equinox. That leave 280+ days each year where they are in sun all day. Maybe that's enough to be worth it?

Or if you do need to keep the things working even on those ~80 days a year when they do spend part of the day in shadow maybe they could be powered by energy beamed in from those not in shadow? You'd put a bunch in geostationary orbits spread out evenly so that each is close enough to its neighbors for power beaming.

I wonder if something crazy might work? Could you actually connect adjacent satellites by an actual physical power cable, which would also be in geostationary orbit?

I'd guess you'd actually need two conductors in your cable, carrying current in opposite direction to cancel out interactions with Earth's magnetic field so the system doesn't get pushed out of its orbit (which would probably be bad).

There would probably be gravitational interactions like with the Moon that might also make it hard to keep everything in place, but maybe by purposefully sending different currents in opposite directions on some of the links you could purposefully use interactions with the Earth's magnetic field to move the cable back where you wanted?

If the satellites are connected by cables then maybe they could actually be slightly higher than geostationary but moving faster than circular orbital speed at that altitude so there is a net outward force from that, which could be countered by tension in the power cables to force them into a circular path that is still geostationary.

Perhaps I'm missing something, but if the only energy they get is coming from the sun, then they only need to dissipate that same amount of heat (minus whatever energy was needed for beaming data down to Earth).

  • What you're missing is that you'd have a huge solar array that powers something much smaller, so that energy gets concentrated into a small area.

    • That’s not how it works. With conservation of energy, all the energy coming in to power the computers has to be emitted somehow. Powering computers doesn’t get rid of the energy, it just makes it unusable and converts it into heat.

      5 replies →

- "But to do that requires an odd orbit where you wouldn't be over the same spot on earth, which could make internet access difficult".

Surely you'd want to use satellite constellations as relays? There's thousands of those satellites in line-of-sight all the time.

It's strictly superior on pure geometry anyway (I think). You have a finite channel capacity between your satellite and your ground station; but different satellites, in non-overlapping microwave spots, are in separate spatial channels.

Cooling at the south pole is not free- it's actually hard work to keep data centers cool at the pole. My friend helped run the IceCube data center at the station and got to fly down and stay there for a week, basically to insert debian CDs and press buttons.

> At first I thought the poles (of the planet) might be good. The cooling is basically free.

Yes, let's go ahead and finish melting the ice caps, great idea

I vote we aim the heat dishes at passing comets to steer them into moon to give it temporary oceans and atmosphere.

> But to do that requires an odd orbit where you wouldn't be over the same spot on earth, which could make internet access difficult

Routing through starlink should have direct LoS at all times.

  • Whether Starlink can keep up with the bandwidth demands of orbital datacenters is another question though.

    (probably not)

    • I'd imagine the bandwidth limitations are physical and similar for Starlink or other satellites either now or very soon. I was replying to the LoS concerns, I agree overall this doesn't work, but I don't think it's because of LoS problems.

Integrate compute units + Starlink into solar panels so people can buy them to earn money/tokens. Much cheaper than tangling massive power lines around the planet.