It's not a technical problem. It's a people problem. Every data center project over the last year has experienced some form of pushback no matter where they're built

By definition, a data center in space is remote, is self-reliant on electrical power and doesn't use potable water. These characteristics require technical solution to be practical, and if one has cracked that, they have disarmed all the push-back arguments people have raised against data centers. It's telling that the data centers want to build-out near population centers, i.e. where someone else has paid for fiber, grid and water infrastructure; it's a good old fashioned raid of the commons

This is first order thinking, of course buildings are built near builders…

building where people live is raiding the commons? Lol

Likely because the AI companies that are going to use those data centers have the absolute worst marketing imaginable. "We're going to take away your job and might accidently kill everybody on earth!" It's no wonder they get pushback.

If all the energy for a space appliance comes from the sun, in steady state they only have to radiate away the same amount that hits them. All long-lived spacecraft manage it.

Whether they can be worth the money it cost to put them in orbit is another story.

> All long-lived spacecraft manage it.

Apples to oranges, long-luver satellites have modest power needs. Doing a back-of-the napkin math on required size of solar array and radiative elements for a single-rack's worth of energy is a sobering exercise for those who are a overly exuberant on the topic. The all-in power estimate for a single GB300 chip is 2.1kW

Well, it can’t use more than it can get from the sun that hits it. So it can’t need to radiate more than that away. So it’s radiator size needs are in proportion to its solar panel size needs, and no worse than that.

> Well, it can’t use more than it can get from the sun that hits it. So it can’t need to radiate more than that away

You are correct that the first law of thermodynamics dictates the energy, but anyone who has parked a car in the sun will tell you, the temperature where the absorption/radiation equilibrium is achieved is often ill-suited for normal operation.

The average temperature of a rock or the ISS in earth orbit is about -18C.

It's this huge misconception that space is super cold. A better mind model is that space doesn't have much of a temperature at all just cause there's nothing there. Vacuum doesn't have a temperature.

You won't immediately freeze if you enter space without a suit. You'll die almost immediately, but it will be because your blood will begin to boil because of the lack of pressure kinda like an extreme form of divers sickness - it's just not the cold that'll get you first.

That’s all true. But stuff in space has a temperature, and once I’d been dead a while in LEO, mine would be -18C.

> mine would be -18C

FYI; that's not how it works, you and the rock you mentioned in a different comment cannot have the same temperature of -18C. This is due to differences in material, and geometry to a lesser extent.

Even if you were rock-shaped, the rates of energy absorption and radiation is what determines your remains' temperature, this ratio differs for different materials, and thus difference fiilnal temperatures.

Sure it varies a bit. ISS average skin temp is 10C, for example. A difference that doesn’t matter.

Why keep pushing back on this point? The total available energy from the sun in LEO averages about 1.36KW/m^2, and more than this can be radiated away by current deployed technology.

Solar powered space data centers probably make no economic sense. But not because we can’t cool them. We wouldn’t be able to run them very hot because there isn’t enough power there to do so.

> Sure it varies a bit

No, not just a bit. It varies by hundreds of degrees depending on the materials α/ε ratio.

Your mental model is off: materials that good absorbers but poor emitters will get very hot, and the flip-side stay cool, and are used to make the cooling elements in the ISS . The temperature of ball of black nickel at 1 AU will settle at balmy 239C - not -18C. Polished Aluminum -> roughly 145C.

I’ve made a note not to make my space data center a black nickel sphere, and instead to make it like we generally make satellites.

My nickel guy is gonna be so disappointed.

Again, just to remind you, I didn’t claim space datacenters are economically rational.

My original claim, in its entirety, was "You'll also get much better cooling for free via convection."

You sure will. My contribution is that you don’t need much better cooling.

Well yes, but what matters is how hot that rock gets. Some rocks melt or vaporise in space (see comets).

An object in low earth orbit has an average temperature of -18C.

That’s right, and it’s not very hot: -18C on average.

The Earth and moon have rock crusts and don’t melt.

There is the additional problem that the GPUs are not in the panels, so to radiate the heat you must first transport it from the GPUs, then distribute it uniformly over the entire surface of the radiators, otherwise some parts will overheat.

Without gravity, it is likely that this can be done only by pumping continuously a lot of liquid, which will increase the power consumption and it will reduce reliability.

Not really. In sun synchronous orbit you can use solar power without battery backup. You can't do that on Earth because of night time.

Remote towns with populations of 43 are exactly the sorts of places that are pushing back on having datacenters in their areas.

And space is the ultimate physical protection. In reality a bigger issue than GPU thefts are protests or leftist groups trying to firebomb you. See the problems the Tesla factory in Germany has had with leftist violence, like setting its electricity pylons on fire (because electric cars "consume natural resources and are not sustainable", lol). The left has become very anti-AI and so the risk of attacks on facilities, especially if built outside the USA, is quite high which in turn means you have to overbuild physical security like high fences.

The number of slots in the sun synchronous orbits is limited. More slots can be accommodated if the satellites can maneuver to avoid collisions.

Moreover, a datacenter in a sun synchronous orbit must be able to maneuver anyway, otherwise without adjusting the orbit it will enter in the shadow of the Earth after a month or two, due to the revolution of the Earth around the Sun.

If the datacenter must make periodic adjustments of the orbit, it will need to carry a lot of fuel, especially because a datacenter will be much heavier than a typical satellite, so much more fuel will be needed for orbit changes.

Thus it is not certain that a sun synchronous orbit is the best choice. It is possible that the extra fuel required for it may make this choice worse than using another orbit where the datacenter will not have power for half of the time.

That's an interesting choice. All the discussion I saw before assumed sun-synchronous, you're the first to suggest otherwise.

Do you know what the capacity of this orbit is?

Antipathy towards AI isn't just on the left, you know. At least in the US it seems widespread, and the remote towns with population 43 are far more likely to have right wing inhabitants than left wing.

> A remote town with a population of 43 will be happy for a data center to employ 2 locals, but data center operators aren't doing that today

This isn’t true, many of these DCs are in very very rural areas and get pushback from people not even living there. Governors get pressure from people hundreds of miles away of the site and then shut it down or impose moratoriums. It’s FUD on social media trying to slow AI advancement that is the root of all of it. The genie is out of the bottle, it’s like blacksmiths trying to slow industrialization. It’s already happened.