[spikels]

It has been widely reported for weeks that SpaceX is planning to go public in a few months. The reason is they have big plans to run a vast network of AI servers in orbit and will need to raise a massive amount of funding. xAI merger fits with that plan. I'd assume SpaceX still plans to go public.

Was ignored on HN but here's an article explaining:

https://arstechnica.com/space/2025/12/after-years-of-resisti...

[kevin_thibedeau]

> a vast network of AI servers in orbit

That story makes no technical sense. There's no benefit to doing this. Nobody should believe it any more than boots on Mars by 2030.

[colinbartlett]

Or any more than "full self driving" by 2017.

[ru552]

sure it does, Bezo's space company and Google are both planning the same

Here's Sundar talking about doing it by 2027: https://www.businessinsider.com/google-project-suncatcher-su...

[kevin_thibedeau]

It's all BS. There is no viable way to put industrial levels of compute into a space based platform that can work within the severe thermal, power, mass/volume, radiation, reliability, and economic demands. It is just stupid smoke blowing to separate idiot investors from their money. J-school grads don't have a clue what they're parroting about.

[airza]

it wasn't ignored on HN, there were many articles correctly noting that building data centers in space is a stupid stupid idea because cooling things there is infeasible

[spikels]

Google, Blue Origin and at least 5 other smaller companies have announced plans to build data centers in space. My understanding is the cooling issue is not the show stopper you assume.

[bhadass]

yup, bezos said "we will be able to beat the cost of terrestrial data centers in space in the next couple of decades". presumably this means they'll need huge ass radiators, so its all about bringing down launch costs since they'll need to increase mass.

[woah]

Was doing some back of the envelope math with chatGPT so take it with a grain of salt, but it sounds like in ideal conditions a radiator of 1m square could dissipate 300w. If this is the case, then it seems like you could approach a viable solution if putting stuff in space was free. What i can't figure out is how the cost of launch makes sense and what the benefit over building it on the ground could be

[spikels]

What temperature were you assuming?

Because the amount of energy radiated varies with the temperature to the fourth power (P=εσT^4).

Assuming very good emissivity (ε=0.95) and ~75C (~350K) operating temperature I get 808 W/m2.

[woah]

I was adding some generous padding and rounding up. I assume they'd try to get it to operate as hot as possible

[fouc]

They would most likely launch with TPUs designed for space and target lower temperatures, closer to 60C.

[kortex]

lol WHAT?

AI datacenters are bottlenecked by power, bandwidth, cooling, and maintenance. Ok sure maybe the Sun provides ample power, but if you are in LEO, you still have to deal with Earth's shadow, which means batteries, which means weight. Bandwidth you have via starlink, fine. But cooling in space is not trivial. And maintenance is out, unless they are also planning some kooky docking astromech satellite repair robot ecosystem.

Maybe the Olney's lesions are starting to take their toll.

Weirdest freaking timeline.

[crote]

The shadow thing can be solved by using a sun-synchronous orbit. See for example the TRACE solar observation satellite, which used a dawn/dusk orbit to maintain a constant view of the sun.

Cooling, on the other hand? No way in hell.

[clausz]

Every telco satellite can cool its electronics. However, more than a few kW is difficult. The ISS has around 100kW and is huge and in a shadow half the time.

[SJC_Hacker]

> Cooling, on the other hand? No way in hell.

Space is actually really cold when the sun is blocked

So, solar panels on side, GPUs on the other, maybe with a big ass radiator ...

[kristjansson]

Space is empty, not cold.

[SJC_Hacker]

> Space is empty, not cold.

The "dark" side of the JWST has temperature of about 40 K (-233 C)

[derrida]

How does a radiator work in a vacuum?

[giancarlostoro]

The cooling is the bit where I'm lost on, but it will be interesting to see what they pull off. It feels like everyone forgets Elon hires very smart people to work on these problems, it's not all figured out by Elon Musk solely.

[spikels]

Google, Blue Origin and a bunch of other companies have announced plans for data centers in space. I don't think cooling is the showstopper some assume.

[giancarlostoro]

Good call out, and really interesting. SpaceX being the cheapest way to get things into space, it seems like SpaceX is about to become extremely lucrative.