In the interests of clarity, I am a former NASA engineer/scientist with a PhD in space electronics. I also worked at Google for 10 years, in various parts of the company including YouTube and the bit of Cloud responsible for deploying AI capacity, so I'm quite well placed to have an opinion here.
The short version: this is an absolutely terrible idea, and really makes zero sense whatsoever. There are multiple reasons for this, but they all amount to saying that the kind of electronics needed to make a datacenter work, particularly a datacenter deploying AI capacity in the form of GPUs and TPUs, is exactly the opposite of what works in space. If you've not worked specifically in this area before, I'll caution against making gut assumptions, because the reality of making space hardware actually function in space is not necessarily intuitively obvious.
Power
The first reason for doing this that seems to come up is abundant access to power in space. This really isn't the case. You basically have two options: solar and nuclear. Solar means deploying a solar array with photovoltaic cells – something essentially equivalent to what I have on the roof of my house here in Ireland, just in space. It works, but it isn't somehow magically better than installing solar panels on the ground – you don't lose that much power through the atmosphere, so intuition about the area needed transfers pretty well. The biggest solar array ever deployed in space is that of the International Space Station (ISS), which at peak can deliver a bit over 200kW of power. It is important to mention that it took several Shuttle flights and a lot of work to deploy this system – it measures about 2500 square metres, over half the size of an American football field.
Taking the NVIDIA H200 as a reference, the per-GPU-device power requirements are on the order of 0.7kW per chip. These won't work on their own, and power conversion isn't 100% efficient, so in practice 1kW per GPU might be a better baseline. A huge, ISS-sized, array could therefore power roughly 200 GPUs. This sounds like a lot, but lets keep some perspective: OpenAI's upcoming Norway datacenter is intending to house 100,000 GPUs, probably each more power hungry than the H200. To equal this capacity, you'd need to launch 500 ISS-sized satellites. In contrast, a single server rack (as sold by NVIDIA preconfigured) will house 72 GPUs, so each monster satellite is only equivalent to roughly three racks.
Nuclear won't help. We are not talking nuclear reactors here – we are talking about radioisotope thermal generators (RTGs), which typically have a power output of about 50W - 150W. So not enough to even run a single GPU, even if you can persuade someone to give you a subcritical lump of plutonium and not mind you having hundreds of chances to scatter it across a wide area when your launch vehicle explosively self-disassembles.
Thermal Regulation
ISS Advanced Thermal Control System (Boeing)
I've seen quite a few comments about this concept where people are saying things like, "Well, space is cold, so that will make cooling really easy, right?"
Um...
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