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Starcloud

ycombinator.com

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Re: Starcloud

#311

Post by alfiedotwtf »

falcor84 wrote: post #307
alfiedotwtf wrote: post #133

Earlier quoted context omitted.

Could they concentrate the energy and beam it down to earth as a source for electricity generation on the ground?

My thermodynamics is rusty, but if they could concentrate it, that would mean that it's part of the "free energy" that could be used to power the data center itself, and given that it's impossible in practice to have perfect efficiency, there will always be excess heat that cannot be concentrated (entropy going up).

It looks like my thermodynamics is rustier than yours!

Re: Starcloud

#312

Post by godelski »

Lanzaa wrote: post #301
godelski wrote: post #209

Earlier quoted context omitted.

This is exactly right, and an important fact is that there is a limited bandwidth for heat radiation. So essentially they need to create a giant lightbulb... > Additionally, deep space is cold, which is accurate in that the "effective" ambient temperature is around -270°C, corresponding to the temperature of the cosmic microwave background. There's a lot of bad information in their document too. This -270C temperatur…

FWIW, i think their description for the radiation shielding is fine. Your analysis is off. If we assume the spherical case, the mass of the shielding is proportional to surface area, not the volume[0]. You might be confusing general radiation shielding and thermal shielding. Thermal shielding is easier because you can point things towards the sun, earth, and moon. I am more concerned about heat dissipation, which sho…

Surface area doesn't have a thickness. It's why I used a delta.

Your thickness is defined by an inner radius and outer.

Re: Starcloud

#313

Post by vasco »

jsheard wrote: post #64
vasco wrote: post #43

Earlier quoted context omitted.

> 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.

Re: Starcloud

#315

Post by FinnKuhn »

echoangle wrote: post #173
amelius wrote: post #135

Earlier quoted context omitted.

Read the "Thermal Management" section, page 8 ...

I believe that it’s physically possible to build something like this, but there’s no way it will be cheaper or simpler than cooling on earth. In their comparison table (table 1), they have earth based cooling for a 40 MW cluster over ten years at 7 million dollars and on the right side calculate the space cost as $0 (although they only imply that it would be cheaper than on earth by saying it’s „more efficient“). If…

It sounds easier to transfer the heat to comets or building the datacenter on the moon.

Re: Starcloud

#316

Post by FinnKuhn »

amluto wrote: post #69
vonneumannstan wrote: post #33

Unless they've figured out some impressive cooling tech, which I would expect would be worth more than the rest of their company combined, then this is pretty much DoA. "More efficient cooling architecture taking advantage of higher ΔT in space" would indeed be useful if you had a nice medium to radiate into. It turns out that thermal radiation is incredibly poor into the vacuum of space lol.

Space (with a sunshade) is a nearly perfect medium into which to radiate heat, in the sense that there’s nothing better. But I agree with your general point. At 100°C, you can radiate about 1kW/m^2. That’s 1000m^2 of radiator per MW of datacenter, assuming you can operate with the radiator at 100°C. You can fudge this a bit with a heat pump (to run the radiator hotter, paying a linear-ish power penalty and gaining a…

I guess you could cool by conduction in space if you build it on the moon?

Re: Starcloud

#319

Post by bongodongobob »

gbear605 wrote: post #123
bongodongobob wrote: post #83

Earlier quoted context omitted.

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.

Yeah, that's my point.
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