zlacker

[parent] [thread] 20 comments
1. smlacy+(OP)[view] [source] 2025-11-04 18:58:21
The ultimate "out of sight out of mind" solution to a problem?

I'm surprised that Google has drunken the "Datacenters IN SPACE!!!1!!" kool-aid. Honestly I expected more.

It's so easy to poke a hole in these systems that it's comical. Answer just one question: How/why is this better than an enormous solar-powered datacenter in someplace like the middle of the Mojave Desert?

replies(4): >>alooPo+v >>incogn+v1 >>TeMPOr+B2 >>ben_w+nU1
2. alooPo+v[view] [source] 2025-11-04 19:00:45
>>smlacy+(OP)
From the post they claim 8 times more solar energy and no need for batteries because they are continuously in the sun. Presumably at some scale and some cost/kg to orbit this starts to pencil out?
replies(2): >>ceejay+E2 >>morale+g3
3. incogn+v1[view] [source] 2025-11-04 19:07:03
>>smlacy+(OP)
I think the atmosphere absorbs something like 25% of energy. If that's correct, you get a free 33% increase in compute by putting more compute behind a solar power in LEO
replies(1): >>wongar+T3
4. TeMPOr+B2[view] [source] 2025-11-04 19:13:35
>>smlacy+(OP)
Think to any near-future spacecraft, or idea for spaceships cruising between Earth and the Moon or Mars, that aren't single use. What are (will be) such spacecraft? Basically data centers with some rockets glued to the floor.

It's probably not why they're interested in it, but I'd like to imagine someone with a vision for the next couple decades realized that their company already has data centers and powering them as their core competency, and all they're missing is some space experience...

replies(1): >>ceejay+S2
◧◩
5. ceejay+E2[view] [source] [discussion] 2025-11-04 19:13:41
>>alooPo+v
You're trading an 8x smaller low-maintenance solid-state solar field for a massive probably high-maintenance liquid-based radiator field.
replies(1): >>wongar+t4
◧◩
6. ceejay+S2[view] [source] [discussion] 2025-11-04 19:14:24
>>TeMPOr+B2
Sure, if you don't mind boiling the passengers.
replies(1): >>TeMPOr+g5
◧◩
7. morale+g3[view] [source] [discussion] 2025-11-04 19:17:07
>>alooPo+v
No infrastructure, no need for security, no premises, no water.

I think it's a good idea, actually.

replies(1): >>ceejay+Z5
◧◩
8. wongar+T3[view] [source] [discussion] 2025-11-04 19:21:22
>>incogn+v1
And you can pretty much choose how long you want your day to be (within limits). The ISS has a sunrise every 90 minutes. A ~45 minute night is obviously much easier to bridge with batteries than the ~12 hours of night in the surface. And if you spend a bunch more fuel on getting into a better orbit you even get perpetual sunlight, again more than doubling your energy output (and thermal challenges)

I have my doubts that it's worth it with current or near future launch costs. But at least it's more realistic than putting solar arrays in orbit and beaming the power down

◧◩◪
9. wongar+t4[view] [source] [discussion] 2025-11-04 19:24:52
>>ceejay+E2
Can't be high maintenance if we just make it uncrewed, unserviceable and send any data center with catastrophically failed cooling to Point Nemo /s
replies(1): >>TeMPOr+Gg
◧◩◪
10. TeMPOr+g5[view] [source] [discussion] 2025-11-04 19:29:30
>>ceejay+S2
Heat management is table stakes. It's important, but boring. Nothing to obsess about.
replies(1): >>ceejay+D5
◧◩◪◨
11. ceejay+D5[view] [source] [discussion] 2025-11-04 19:31:16
>>TeMPOr+g5
> It's important, but boring.

It gets very exciting if you don't have enough.

> Nothing to obsess about.

It's one of the primary reasons these "AI datacenters… in space!" projects are goofy.

◧◩◪
12. ceejay+Z5[view] [source] [discussion] 2025-11-04 19:33:21
>>morale+g3
> No infrastructure

A giant space station?

> no need for security

There will be if launch costs get low enough to make any of this feasible.

> no premises

Again… the space station?

> no water

That makes things harder, not easier.

replies(1): >>morale+H9
◧◩◪◨
13. morale+H9[view] [source] [discussion] 2025-11-04 19:55:20
>>ceejay+Z5
This is not a giant space station ...

>There will be if launch costs get low enough to make any of this feasible.

I don't know what you mean by that.

replies(1): >>ceejay+Aa
◧◩◪◨⬒
14. ceejay+Aa[view] [source] [discussion] 2025-11-04 20:03:38
>>morale+H9
> This is not a giant space station …

Fundamentally, it is, just in the form of a swarm. With added challenges!

> I don't know what you mean by that.

If you can get to space cheaply enough for an orbital AI datacenter to make financial sense, so can your security threats.

replies(1): >>TeMPOr+mf
◧◩◪◨⬒⬓
15. TeMPOr+mf[view] [source] [discussion] 2025-11-04 20:33:24
>>ceejay+Aa
> Fundamentally, it is, just in the form of a swarm. With added challenges!

Right, in the same sense that existing Starlink constellation is a Death Star.

This paper does not describe a giant space station. It describes a couple dozen of satellites in a formation, using gravity and optics to get extra bandwidth for inter-satellite links. The example they gave uses 81 satellites, which is a number made trivial by Starlink (it's also in the blog release itself, so no "not clicking through to the paper" excuses here!).

(In a gist, the paper seems to be describing a small constellation as useful compute unit that can be scaled, indefinitely - basically replicating the scaling design used in terrestrial ML data centers.)

replies(1): >>ceejay+Rj
◧◩◪◨
16. TeMPOr+Gg[view] [source] [discussion] 2025-11-04 20:42:16
>>wongar+t4
If it can be all mostly solid-state, then it's low-maintenace. Also design it to burn up before MTTF, like all cool space kids do these days. Not gonna be worse at Starlink unless this gets massively scaled up, which it's meant to be (ecological footprint left as an exercise to the reader).
◧◩◪◨⬒⬓⬔
17. ceejay+Rj[view] [source] [discussion] 2025-11-04 21:03:37
>>TeMPOr+mf
> Right, in the same sense that existing Starlink constellation is a Death Star.

"The cluster radius is R=1 km, with the distance between next-nearest-neighbor satellites oscillating between ~100–200m, under the influence of Earth’s gravity."

This does not describe anything like Starlink. (Nor does Starlink do heavy onboard computation.)

> The example they gave uses 81 satellites…

Which is great if your whole datacenter fits in a few dozen racks, but that's not what Google's talking about here.

replies(1): >>TeMPOr+dr
◧◩◪◨⬒⬓⬔⧯
18. TeMPOr+dr[view] [source] [discussion] 2025-11-04 21:56:48
>>ceejay+Rj
> This does not describe anything like Starlink. (Nor does Starlink do heavy onboard computation.)

Irrelevant for spacecraft dynamics or for heat management. The problem of keeping satellites from colliding or shedding the watts the craft gets from the Sun are independent of the compute that's done by the payload. It's like, the basic tenet of digital computing.

> Which is great if your whole datacenter fits in a few dozen racks, but that's not what Google's talking about here.

Data center is made of multiplies of some compute units. This paper is describing a single compute unit that makes sense for machine learning work.

replies(1): >>ceejay+Os
◧◩◪◨⬒⬓⬔⧯▣
19. ceejay+Os[view] [source] [discussion] 2025-11-04 22:08:23
>>TeMPOr+dr
> The problem of keeping satellites from colliding or shedding the watts the craft gets from the Sun are independent of the compute that's done by the payload.

The more compute you do, the more heat you generate.

> Data center is made of multiplies of some compute units.

And, thus, we wind up at the "how do we cool and maintain a giant space station?" again. With the added bonus of needing to do a spacewalk if you need to work on more than one rack.

replies(1): >>ben_w+SP1
◧◩◪◨⬒⬓⬔⧯▣▦
20. ben_w+SP1[view] [source] [discussion] 2025-11-05 11:21:37
>>ceejay+Os
> The more compute you do, the more heat you generate.

Yes, and yet I still fail to see the point you're making here.

Max power in space is either "we have x kWt of RTG, therefore our radiators are y m^2" or "we have x m^2 of nearly-black PV, therefore our radiators are y m^2".

Even for cases where the thermal equilibrium has to be human-liveable like the ISS, this isn't hard to achieve. Computer systems can run hotter, and therefore have smaller radiators for the same power draw, making them easier.

> And, thus, we wind up at the "how do we cool and maintain a giant space station?" again. With the added bonus of needing to do a spacewalk if you need to work on more than one rack.

What you're doing here is like saying "cars don't work for a city because a city needs to move a million people each day, and a million-seat car will break the roads": i.e. scaling up the wrong thing.

The (potential, if it even works) scale-up here is "we went from n=1 cluster containing m=81 satellites, to n=10,000 clusters each containing m=[perhaps still 81] satellites".

I am still somewhat skeptical that this moon-shot will be cost-effective, but thermal management isn't why, Musk (or anyone else) actually getting launch costs down to a few hundred USD per kg in that timescale is the main limitation.

21. ben_w+nU1[view] [source] 2025-11-05 12:06:27
>>smlacy+(OP)
> How/why is this better than an enormous solar-powered datacenter in someplace like the middle of the Mojave Desert?

Night.

I mean, how good an idea this actually is depends on what energy storage costs, how much faster PV degrades in space than on the ground, launch costs, how much stuff can be up there before a Kessler cascade, if ground-based lasers get good enough to shoot down things in whatever orbit this is, etc., but "no night unless we want it" is the big potential advantage of putting PV in space.

[go to top]