Data centers in space makes no sense • Hacker News Board

Re: Data centers in space makes no sense

#501

Post by z3t4 » Wed, Feb 04, 2026, 7:06 AM UTC

rockemsockem wrote: post #487

adastra22 wrote: post #451

Earlier quoted context omitted.

The story here is even simpler. SpaceX is going public this year. Elon made a monumentally shitty investment in Twitter and then poured a stupid amount of money into xAI at the peak of the cycle. By having SpaceX buy xAI, he gets to swap worthless shares in that company for more SpaceX liquidity. Simple as that.

Really seems silly to think that the guy with $800 billion is spending most of his time maximizing his money.

He probably have 700 billion in loans and need to pay rent

Re: Data centers in space makes no sense

#502

Post by ViewTrick1002 » Wed, Feb 04, 2026, 7:12 AM UTC

MadnessASAP wrote: post #479

gpt5 wrote: post #235

Earlier quoted context omitted.

I'm confused about the level of conversation here. Can we actually run the math on heat dissipation and feasibility? A Starlink satellite uses about 5K Watts of solar power. It needs to dissipate around that amount (+ the sun power on it) just to operate. There are around 10K starlink satellites already in orbit, which means that the Starlink constellation is already effectively equivalent to a 50 Mega-watt (in a rou…

I ran the math the last time this topic camps up The short answer is that ~100m2 of steel plate at 1400C (just below its melting point) will shed 50MW of power in black body radiation. https://news.ycombinator.com/item?id=46087616#46093316

Which GPU runs at 1400C?

Re: Data centers in space makes no sense

#503

Post by FabHK » Wed, Feb 04, 2026, 7:15 AM UTC

parl_match wrote: post #278

pokot0 wrote: post #262

Earlier quoted context omitted.

Can’t you heat exchange inside the satellite, and make one part of the satellite incredibly hot so that it radiates a lot and dissipates. This is just a question. I have no expertise at all with this.

yes. it is how sats currently handle this. its actually exponentially effective too P = E S A T^4 requires a lot of weight (cooling fluid). requires a lot of materials science (dont want to burn out radiator). requires a lot of moving parts (sun shutters if your orbit ever faces the sun - radiator is going to be both ways). so that sounds all well and good (wow! 4th power efficiency!) but it's still insanely expensiv…

Pet peeve:

T^4 is not exponential in T, it’s polynomial. For exponential, T must be in the exponent, e.g. 2^T or so.

Still, pretty effective.

Having said that, agree that Elon is full of it.

Re: Data centers in space makes no sense

#504

Post by FabHK » Wed, Feb 04, 2026, 7:23 AM UTC

stogot wrote: post #447

beloch wrote: post #115

I would not assume cooling has been worked out. Space is a vacuum. i.e. The lack-of-a-thing that makes a thermos great at keeping your drink hot. A satellite is, if nothing else, a fantastic thermos. A data center in space would necessarily rely completely on cooling by radiation, unlike a terrestrial data center that can make use of convection and conduction. You can't just pipe heat out into the atmosphere or build…

> You can't exchange heat with vacuum. You can only radiate heat into it. I don’t remember the difference from my science classes, isn’t This the same thing essentially?

The other two methods of heat transfer apart from radiation are conduction (through “touch”, adjacent molecules, eg from the outside of a chicken on the BBQ to the inside) and convection (through movement, eg cold air or water flowing past).

Re: Data centers in space makes no sense

#505

Post by audunw » Wed, Feb 04, 2026, 7:24 AM UTC

benl wrote: post #379

Data centers in space may or may not make sense (personally I'm quite skeptical) but the objections in the article certainly don't make sense. 1. The only reason there are 15,000 satellites in space is because SpaceX launched about 9,500 of them (Starlink is 65% of all satellites) on their semi-reusable Falcon 9. If fully-reusable Starship pans out, they will be launching satellites at 10x the rate of Falcon 9 at the…

3. The falling costs won’t benefit space as much. The cost of sending mass to space will still be a big factor in the space solar panel costs. Much of the reason why solar is getting cheaper is not the panels themselves, but due to innovations that reduce installation costs. Those don’t apply to space (outside of the already assumed reductions in sending mass to space to make this viable)

Re: Data centers in space makes no sense

#506

Post by afiori » Wed, Feb 04, 2026, 7:25 AM UTC

pokot0 wrote: post #262

beloch wrote: post #115

I would not assume cooling has been worked out. Space is a vacuum. i.e. The lack-of-a-thing that makes a thermos great at keeping your drink hot. A satellite is, if nothing else, a fantastic thermos. A data center in space would necessarily rely completely on cooling by radiation, unlike a terrestrial data center that can make use of convection and conduction. You can't just pipe heat out into the atmosphere or build…

Can’t you heat exchange inside the satellite, and make one part of the satellite incredibly hot so that it radiates a lot and dissipates. This is just a question. I have no expertise at all with this.

Sure but if it was a good idea we could do it on earth too and datacenters could stop gurgling a city worth of water

Re: Data centers in space makes no sense

#507

Post by [deleted] » Wed, Feb 04, 2026, 7:32 AM UTC

general1465 wrote: post #67

Starman_Jones wrote: post #3

Very confused by this plan. Data centers on Earth are struggling with how to get rid of waste heat. It's really, really hard to get rid of waste heat in space. That seems to be about the worst possible place to put a data center.

Well the issue is that a lot of people believe that space is cold. If you will ask Google/Gemini what is a temperature of space, it will tell you: The average temperature of deep space is approximately -270.45°C or 2.73 Kelvin), which is just above absolute zero. This baseline temperature is set by the Cosmic Microwave Background (CMB) radiatio... Which is absolute nonsense, because vacuum has no temperature.

[deleted]

Re: Data centers in space makes no sense

#508

Post by mlyle » Wed, Feb 04, 2026, 7:33 AM UTC

tensor wrote: post #425

hirsin wrote: post #310

Earlier quoted context omitted.

Simply put no, 50MW is not the typical hyperscaler cloud size. It's not even the typical single datacenter size. A single AI rack consumes 60kW, and there is apparently a single DC that alone consumes 650MW. When Microsoft puts in a DC, the machines are done in units of a "stamp", ie a couple racks together. These aren't scaled by dollar or sqft, but by the MW. And on top of that... That's a bunch of satellites not e…

How much of that power is radiated as the radio waves it sends?

I doubt half the power is to the transmitter, and radio efficiency is poor -- 20% might be a good starting point.

Re: Data centers in space makes no sense

#509

Post by Juliate » Wed, Feb 04, 2026, 7:33 AM UTC

If someone had the tech to cool stuff in space, that is required for this to happen, they’d have tons of easier and more lucrative opportunities right now on Earth to become the new richest person.

Where is the tech?

Re: Data centers in space makes no sense

#510

Post by hdgvhicv » Wed, Feb 04, 2026, 7:34 AM UTC

adastra22 wrote: post #445

dathinab wrote: post #322

The really crazy thing is you don't need to know more then basic (non Hollywood) physics to know how dump this is 1. every gram you need to send to space is costly, a issue you don't have at ground level 2. cooling is a catastrophe, sure space is cold, but also a vacuum, so the cooling rate is roughly the infrared radiation rate. This means if you are not careful with the surface of a satellite it can end up being ve…

> sure space is cold Even this isn't true. It's ~120 degC in daylight in LEO. It only gets cold in the shade, but a solar powered data center is pretty useless in the shade.

The solar labels are in the sun. Behind them they are in the shade.