- As someone working in aerospace, orbital data centres are almost certainly impossible or very impractical, at least at the scale being sold by the AI salesmen.
What would they be cheaper on? Solar panels are a little bit more effective and they will have a 24/7 coverage if placed in the correct orbit.
However, they would be much harder to cool (space is cold, yes, but heat transfer in vacuum does not work easily and most large structures, such as ISS, require dedicated cooling radiators that take up a large amount of space.) The launch costs would be still very high, maintenance impractical and the large, large surface area of solar panels and radiators would just be primed for being struck by debris.
What orbital data centres are though, is a good dream to sell, a fine way to dismiss environmental concerns of data centres on the ground - “We’re soon going to start putting them in space, but just for now we have to build them on earth. Please approve our requests.”
- What is the math on data transport?
If you put them in low earth orbit, now you need complex ground stations and/or phased array antennae to track them and move data. And then your cat image generator is on the other side of the planet every 60 minutes unless you have fancy lasers relaying stuff between satellites.
If you put it into geosynchronous orbit, the transmission is easier but now you've introduced a huge delay in your packets.
And I can't even do the first steps on computing what a typical data center needs in network bandwidth. A few terabits per second? A few petabits? More?
- > If you put it into geosynchronous orbit, the transmission is easier but now you've introduced a huge delay in your packets.
How does that introduce a delay?
- It's radio waves. Takes about 125 mSec for a request to reach the satellite (it's 36,000 km up there) and then the same amount of time to come back down.
If you can reach a terrestrial data center in 10 mSec over fiber, the flying data center is 25x slower.
- The distance is greater = higher latency.
It’s why satellite internet was usually pretty terrible. A simple TCP handshake becomes a multi-second endeavor.
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- Some of the original hype was similar to the solar in space hype and clearly being pushed by people who wanted funding to build rockets and were prepared to sell magic beans to pay for it.
- My back of the napkin math says you need launch prices of about $100/kg to $200/kg for it to make sense.
The cooling problem is vastly exaggerated, you need around 0.5x the area of your solar panels in radiators.
I think AI inference in space is definitely possible, but it's very unlikely we'll get launch costs cheap enough that they make economical sense.
- As someone with a vacuum flask, I can assert orbital data centers are definitely NOT a good idea.
- They are a great idea and they are technically possible. But the cost is currently unknown and the maybe impossible from a business case perspective. Its not going to happen tomorrow, there is still years of r&d ahead.
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- The upside is it avoids the power, cooling, connectivity, location, environmental, staffing and physical security complexities of terrestrial data centers.
- Just adds a bunch of new problems. ”We need a replacement cable. Guess we have to send a rocket and it’s gonna take a few months to plan”
- Sure, it's got a loooooot of complexities that undermine those upsides.
But sometimes problems get solved, undersea cables faced (and still present) a lot of challenges too.
- And replaces them with the famously environmentally friendly launch vehicle business.
- It doesn’t?
> power
It still needs power, you’re most likely going to do it with solar if you’re on earth orbit but that isn’t free and you will have periods of no sunlight so a significant amount of batteries will be needed.
> cooling
Cooling off in a vacuum is hard. You’ll need radiators to emit the heat, you’ll need a lot of radiators for data center level heat. This is more mass you need to get into orbit
> location
The location is in space, it’s significantly more expensive to get mass into space than it is to move it someone else on the planet
> environmental
The day to day operations of a space based data center seem like they would be a benefit, but I haven’t seen the math on the environmental cost of the rocket launches vs the lifetime of a terrestrial data center
> staffing
Why would the location in space vs terrestrial change the staffing at all? Any technological change that could/would reduce staffing could be applied to terrestrial data centers as well
> physical security
You’re more secure from people, but now you’ve introduced the physical security risk of space debris where something with the mass of pocket lint could cause serious damage if it impacts your system.
The whole space data center idea is just Musk trying to gin up more demand for his SpaceX IPO with no real benefit behind the idea. He’s been lying like this for years for money like with “Full Self Driving”(lol, don’t take your hands off the wheel because we’ll disengage right before a crash and it’s your problem) or his “robots”(actually remote controlled by humans). I don’t know why anyone listens to him anymore if he doesn’t show up with concrete results first.
It’s like people want to be conned.
8 points by aronowb14 1 hour ago | 14 comments