zlacker

>>meetpa+(OP)
> In the right orbit, a solar panel can be up to 8 times more productive than on earth, and produce power nearly continuously, reducing the need for batteries.

Sure. Now do cooling. That this isn't in the "key challenges" section makes this pretty non-serious.

A surprising amount of the ISS is dedicated to this, and they aren't running a GPU farm. https://en.wikipedia.org/wiki/External_Active_Thermal_Contro...

>>ceejay+a7
Point solar panels away from the Sun and they work as rudimentary radiators :).

More seriously though, the paper itself touches on cooling and radiators. Not much, but that's reasonable - cooling isn't rocket science :), it's a solved problem. Talking about it here makes as much sense as taking about basic attitude control. Cooling the satellite and pointing it in the right direction are solved problems. They're important to detail in full system design, but not interesting enough for a paper that's about "data centers, but in space!".

>>TeMPOr+yl
Cooling at this scale in space is very much not a solved problem. Some individual datacenter racks use more power than the entire ISS cooling system can handle.

It's solved on Earth because we have relatively easy (and relatively scalable) ways of getting rid of it - ventilation and water.

>>ceejay+Vl
No, I meant in space. This is a solved engineering problem for this kind of missions. Whether they can make it work within the power and budget constraints is the actual challenge, but that's economics. No new tech is needed.

>>TeMPOr+Cm
It's solved for low power cooling.

We do not have a solution for getting rid of megawatts or gigawatts of heat in space.

What the sibling comment is pointing out is that you cannot simply scale up any and every technology to any problem scale. If you want to get rid of megawatts of heat with our current technology, you need to ship up several tons of radiators and then build massive kilometer-scale radiation panels. The only way to dump heat in space is to let a hot object radiate infrared light into the void. This is an incredibly slow and inefficient process, which is directly controlled by the surface area of your radiator.

The amount of radiators you need for a scheme like this is entirely out of the question.

>>estima+us
They literally have a solution, it's a trivial one and described in the paper. I'll try to paraphrase the whole thing, because apparently no one read it.

1. Take existing satellite designs like Starlink, which obviously manage to utilize certain amount of power successfully, meaning they solved both collection and heat rejection.

2. Pick one, swap out its payload for however many TPUs it can power instead. Since TPUs aren't an energy source, the solar/thermal calculation does not change. Let X be the compute this gives you.

3. Observe that thermal design of a satellite is independent from whether you launch 1 or 10000 of them. Per point 2, thermals for one satellite are already solved, therefore this problem is boring and not worth further mention. Instead, go find some X that's enough to give a useful unit of scaling for compute.

4. Play with some wacky ideas about formations to improve parameters like bandwidth, while considering payload-specific issues like radiation hardening, NONE OF WHICH HAVE ANY IMPACT ON THERMALS[0]. This is the interesting part. Publish it as a paper.

5. Have someone make a press release about the paper. A common mistake.

6. Watch everyone get hung up on the press release and not bother clicking through to the actual paper.

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[0] - Well, some do. Note that fact in the paper.