Comment by rybosworld

If you think the primary source of electricity is solar (which clearly Musk does), then space increases the amount of compute per solar cell by ~5x, and eliminates the relatively large battery required for 24/7 operation. The thermal radiators and radiation effects are manageable.

The basic idea of putting compute in space to avoid inefficient power beaming goes back to NASA in the 60s, but the problem was always the high cost to orbit. Clearly Musk expects Starship will change that.

How much maintenance do you need? Lets say you have hardware whose useful lifespan due to obsolescence is 5 years, and in 4, the satellite will crash into the atmosphere anyways.

Let's say given component failure rates, you can expect for 20% of the GPUs to fail in that time. I'd say that's acceptable.

The idea here is that the economics of launch are changing with Starship such that the "incredible cost" and "overspeccing" of space will become much less relevant. There's a world where, because the cost per kg is so low, a data center satellite's compute payload is just the same hardware you'd put in a terrestrial rack, and the satellite bus itself is mass-produced to not-particularly-challenging specs. And they don't have to last 30 years, just 4-ish, when the computer is ready for retirement anyway.

Will that come to be? I'm skeptical, especially within the next several years. Starship would have to perform perfectly, and a lot of other assumptions hold, to make this make sense. But that's the idea.

If you ramp up the economies of scale to make those things - radiation protection and cost per pound - the calculus changes. It's supposed to synergize with Starship, and immediately take advantage of the reduced cost per pound.

If the cost per pound, power, regulatory burden, networking, and radiation shielding can be gamed out, as well as the thousand other technically difficult and probably expensive problems that can crop up, they have to sum to less than the effective cost of running that same datacenter here on earth. It's interesting that it doesn't play into Jevon's paradox the way it might otherwise - there's a reduction in power consumption planetside, if compute gets moved to space, but no equivalent expansion since the resource isn't transferable.

I think some sort of space junk recycling would be necessary, especially at the terawatt scale being proposed - at some point vaporizing a bunch of arbitrary high temperature chemistry in the upper atmosphere isn't likely to be conducive to human well-being. Copper and aluminum and gold and so on are also probably worth recovering over allowing to be vaporized. With that much infrastructure in space, you start looking at recycling, manufacturing, collection in order to do cost reductions, so maybe part of the intent is to push into off-planet manufacturing and resource logistics?

The whole thing's fascinating - if it works, that's a lot of compute. If it doesn't work, that's a lot of very expensive compute and shooting stars.

Note how Musk cleverly doesn't claim that not doing maintenance drives down costs.

Nothing in there is a lie, but any substance is at best implied. Yes, 1,000,000 tons/year * 100kW/ton is 100GW. Yes, there would be no maintenance and negligible operational cost. Yes, there is some path to launching 1TW/year (whether that path is realistic isn't mentioned, neither what a realistic timeline would be). And then without providing any rationale Elon states his estimate that the cheapest way to do AI compute will be in space in a couple years. Elon is famously bad at estimating, so we can also assume that this is his honest belief. That makes a chain of obviously true statements (or close to true, in the case of operating costs), but none of them actually tell us that this will be cheap or economically attractive. And all of them are complete non-sequiturs.

Elon might have a scoop on getting things to orbit cheaper than everyone else.

Radiation is an even bigger problem, especially in the polar orbits they are talking about.

I don't think it was a stunt. It was an experiment.

I think passive cooling (running hot) reduced some of the advantages of undersea compute.

I was listening to a Darknet Diaries episode where Maxie Reynolds seems to make it work: https://subseacloud.com/ I don't know how profitable they are, and I doubt this is scalable enough, but it can work as a business.

Ironically a benefit of underwater datacenters would be reduced cosmic rays. Not so great in orbit, I imagine!

What about a data centre only running SQLite?

Well the thing is that it seemed to have been successful beyond all expectations despite being that? They had fewer failures due to the controlled atmosphere, great cooling that took no extra power, and low latency due to being close to offshore backbones. And I presume you don't really need to pay for the land you're using cause it's not really on land. Can one buy water?

Space is pretty ridicolous, but underwater might genuinely be a good fit in certain areas.

A Falcon Heavy takes about 63 tons to LEO, at a cost of about $1,500 per kg. A server with 4x H200s and some RAM and CPU costs about $200k, and weighs about 60kg, with all the cooling gear and thick metal. As is, it would cost $90k to get to LEO, half of the cost of the hardware itself.

I suppose that an orbit-ready server is going to cost more, and weigh less.

The water that serves as the coolant will weigh a lot though, but it can double as a radiation shield, and partly as reaction mass for orbital correction and deorbiting.

Are launch costs really 10x!? Could I get a source for that?

In the back on my head this all seemed astronomically far-fetched, but 5.5 million to get 8 GPUs in space... wild. That isn't even a single TB of VRAM.

Are you maybe factoring in the cost to powering them in space in that 5 million?

Playing devil's advocate, when a GPU dies you don't typically fix it, right? You just replace it.

What if you could keep them in space long enough that by the time they burn up in the atmosphere, there are newer and better GPUs anyway?

Still doesn't seem sustainable to me given launch costs and stuff (hence devil's advocate), but I can sort of see the case if I squint?

Let me rip my bong real quick..

What if you had a fleet of Optimus robots up there who would actually operate a TSMC in space and they would maintain the data centers in space?

Hold on let me enter a K hole…

What if we just did things?

The opposite of down is up, so it wouldn't be completely illogical.

Did we read the same Wikipedia page? It doesn't say the word "failed" anywhere on it.

None, https://www.datacenterdynamics.com/en/news/microsoft-confirm...

Zero.

...and costs pennies compared to putting anything up there, so it can even enjoy those cosmic goodies.

Just like you don’t get much water in space.

The thing is: at the end of the day, making absolute statements about the inevitability of future success is a fool’s errand.

Musk has a documented history of failing to deliver on promises, timescale or no. So it’s best to engage in some actual critical thinking about the claims he is making.

napkin math says sq kms of radiators to cool 100MW, it's just patently ridiculous

Or takes the impossible and puts a half baked version of it behind a $99/ month paywall.

You're right, my fault. I made an math booboo somewhere. Your calc seems right

Okay so that works out to 124 kW/ton for the opal config.

Yeah the main benefits are:

1. solar is very efficient at generating energy, no moving parts, simple physics etc.

2. in space you don't deal with weather or daylight cycle, you can just point your panels at the sun and generate very stable energy, no batteries required

3. environmental factors are simpler, no earthquakes, security, weather. Main problem here is radiation

In theory its a very elegant way to convert energy to compute.

> put a slightly larger solar array on the same equipment on earth?

Land and permitting. I’m not saying the math works. Just that there are envelopes for it to.

Solar in space is a very different energy source in terms of required infrastructure. You don't need batteries, the efficiency is much higher, cooling scales with surface area (radiative cooling doesn't work as well through an atmosphere vs. vacuum), no weather/day cycles. Its a very elegant idea if someone can get it working.

Sun-synchronous orbit means there's no nightime for satellites in that orbit.

Name a unicorn whose early round pitch decks are 100% free of wishful thinking

>SpaceX as a government contractor and that means Elon’s pal Trump can now siphon money into xAI via the federal government.

I wonder how much faith Musk has that the US will never again have a president and/or Congress willing to torpedo such an incestuous deal.

Yes, and as we know Starship will be doing regular commercial launches starting in 2020, maybe 2021.

We're getting close to having the time for Starship's delays to be the same as the actual time for the Saturn 5 to go from plans to manned launches (Jan 1962-Dec 1968).

The average person is not aware or does not care about Elon Musk’s claims and whether or not they come true.

I remember reading somewhere that satellites are extra expensive for 2 reasons:

- launch costs are so high that doing exotic bespoke engineering might be worth it if it can shave off a few pounds

- once again because launches are expensive and rare, you cannot afford to make mistakes, so everything has to work perfectly

If you are willing to launch to lower orbits, and your launch vehicle is cheap, you are building in bulk, then you can compromise on engineering and accept a few broken sats

Undergrads afaik even high schoolers have built cubesats out of aluminum extrusions, hobbyist solar panels, and a tape measure as an antenna. These things probably dont do that much, but they are up there and they do work.

Pet satellites or cattle satellites?

and "Full Self-Driving" was a solved problem in 2016.

Ooh, happy 10th anniversary, FSD?

My point is not to make fun of him, but to help avoid the destruction of humanity via an HN comment. No joke.

This is starting to get really serious.

Ha, I figured that might be the video prior to clicking it. I am a long time fan.

Agreed, when I wrote "just unplug it," this counterargument was present in my mind, but nobody likes a wall of text.

However, my original point was that a distributed solar powered orbital inference platform is even worse! Think about how hard it would be to practically take out Starlink... it's really hard.

Now.. >1M nodes of a neural net in the sky? Why would someone who lives as a god, the richest man in the world, the only person capable of doing this thanks to his control of SpaceX... do the literal worst thing possible?

You're right.

I meant it specifically for figuring out cooling computers in space.

I am pretty sure this is going to be a solvable problem if this is the bottleneck to achieve data centers in space, given that newer chips are much more tolerant to high temperatures.

https://www.marketplace.org/story/2026/01/07/new-ai-chips-wi...

You put it so succinctly and perfectly that I'll have to favorite your comment. Totally agree. The physical world has become little more than noise for people like Musk. I wonder whether the correction will be a slow market dip, a full collapse, or somehow whether he makes it out like a bandit. Baudrillard is, once again, uncomfortably accurate in his diagnosis.

Apparently not, otherwise this silly idea wouldn't exist.

Naysayers probably get fired fast.

Why would they need a cover, though? They can just say “we’re putting AI in space so we can shoot down missiles” and that would be fine.

> It might be possible to scam the Pentagon with some talk about AI and killer satellites that take down ICBMs.

Honestly that story sounds right up Pete Hegseth's alley.

I don't know if you're aware of this, but American markets are hyper competitive. I'd be extremely wary of any instinct to discount the skill level of any top-20 self-made billionaire industrialist, really anywhere in the world, but in the US at least, that skillset is likely heavily skewed toward business excellence.

The techbro cult is filled to bursting with greedy, narcissistic people who are wholly willing to ignore evil because they expect to be the next dispensers of said evil.

You just responded to one of them.

That's the most measured Elon critique I've read today. :)

I've been told by SpaceX folk that Elon's job is to keep a 20 year view in the future and essentially get folks to work backward from that.

I think I might kind of be sold on data-clusters in space in 20 years.

I can understand if I had lift that cost 1/10 what everyone else in the world paid for it, I'd be even more sold on them.

That said, this newfound enthusiasm of his certainly makes a commercially reasonable path forward to turn xAI stock into spacex stock. Elon takes care of his investors, generally speaking.

I believe that he believe the hype will be good for SpaceX IPO.

SpaceX supposedly mostly runs non-rad-hard parts, the ostensible reason being because its more cost effective to double or triple up than buy specialty equipment. Do you have a source for this?

Google tested the radiation tolerance of tpus which include hbm and they performed fine. https://research.google/blog/exploring-a-space-based-scalabl...

Well some stuff you either don't need, or just can't have so you do something different - for instance, transformers to convert grid power - no grid - no transformers. Those are like a 36 month wait list in the US right now. And solar is something like 2x as efficient in space.

I agree those don't seem immediately to be huge wins to me; not dealing with local politics might be a big one, though. Depending on location. There's a lot of red tape in the world.

$/sq foot or meter belies the cost of dealing with every regulatory agency that has claim on that area. There's no environmental commission you've got to pay off if your satellite starts leaking noxious chemicals all over the place, the same way you'd have to if you spilled something at NUMMI in Fremont, California.

But spacex isnt a publicly traded company.

SpaceX stock needs no propping.

That said xAI might need a bit of a rescue.

Pre-requisites:

Ketamine

Only if that bitflip happens somewhere in your actual data, vs. some GPU pipeline register that then locks up the entire system until a power cycle. Or causes a wrong address to be fetched. Or causes other nasty silent errors. Or...

Try doing fault injection on a chip some time. You'll see it's significantly easier to cause a crash / reset / hang than to just flip data bits.

'rad-triggered bit flips don't matter with AI' is a lie spoken by people who have obviously never done any digital design in their life.

As long as they stay below Van Allen belts and deal with weaker magnetic shielding in sun synchronous orbit (high latitudes).

I would say they probably something a little beefier than consumer hardware and just deal with lots of failures and bit flips.

But cooling is a bigger issue probably?

Random bit flips might even improve output.