The viability of space DCs seem to depend entirely on the existence of higher latency, lower throughput, single card to single server workloads, which IMO isn't the primary class of workload today (and if one holds the belief that frontier models will maintain their dominant position, this will remain rack/row/facility level, which isn't viable for orbital facilities to handle as currently designed).

If that workload does expand in usage, and the economics of orbital DCs make sense (with high launch costs, zero ability to do maintenance, and weight penalties for shielding and radiators), then surely ocean based data centers (e.g. Panthalassa) make more sense (lower 'launch' costs, high but existant latency on maintenance, no weight penalties), and if those make sense then surely the distributed land based facilities (e.g. Rune Energy) or home based facilities (e.g. Span XFRA) make even more sense (easier maintenance, low/no permitting overhead because they're covered by existing permits, reasonable quality terrestrial fiber internet).

The article makes several big assumptions that are questionable (experimental cooling can scale, permit issues on land will only become worse, etc). But more importantly, their analysis of the risks of placing a data center in orbit is completely off. They mention that it costs tens of millions to launch a missile to destroy a satellite, and it might be cheaper to simply replace it (based on launch costs). But one strike can hit many targets, those targets may contain hardware costing multiple times the value of their launch, and you will be out of compute while you scramble to launch a replacement. We can also assume that placing big fat valuable targets in space would have many actors wondering how to make it cheaper to destroy them.

For those reasons alone, and because compute will become more and more strategic for defense, I find it very hard to believe that data centers in space will represent even 5% of all compute in the next 10 years. I think a higher proportion will rather be underground or in bunkers than in space.

From the article:

Conclusions

Orbital data centers look more viable than we expected going in and the case rests primarily on launch cost. The engineering challenges seem significant but none appear intractable. Commercial off-the-shelf solar, passive radiators, and standard error-correcting codes seem sufficient for a baseline architecture. We expect limited demos and shipments of compute to orbit in the coming years but our best estimate is that orbital data centers are unlikely to represent a meaningful share of compute before 2030. They might scale quickly thereafter however, and are more likely to be bottlenecked by chip production rates rather than by launch cadence. A generally important dynamic is that terrestrial data centers likely face headwinds that worsen as compute scales up while orbital data centers face constraints that relax with scale.

Even put launch cost aside and assuming the best case for starship, most of the whitepapers I've seen seem to hand-wave the weight, cost, and complexity of cooling. You need large panels with special coating, pumps, and pipes - and that will get hit with micro-meteors so you need redundancy.

Land based or even sea wave-based datacenters are all much more feasible.

This premise always struck me as a solution in search of a problem, which when implemented introduces even more problems.

The more I read HN the more I realize that I am more of an empiricist than a rationalist.

So many people here are opining as if they are correct. I have a large amount of doubt and I like the fact that the world is structured so that people can try things out and see if it works.

If the world was run by the naysayers in this thread, almost nothing would ever get done.

You can put computers in space, but can you really call it a data centre at the scale that it can be done at?

Surely a single AWS/GCP/Azure/etc DC on earth is so big we won't be getting close to a similar amount of compute in space for the foreseeable?

The economic case also needs to be explained. What are people going to do with a DC in space?

The only use case for datacenter in space is to have high communication speed with satellites that have low compute. Though that does beg the question of why not just add more compute to those satellites going forward.

Outside cost of launch I have understood that scaling it to sufficient power envelope with needed cooling is biggest step which most likely makes it unreasonable at scale. That is being able to use enough power to get reasonable amount of compute. Scale it small and low power enough and it is pretty simple. But at that point you might not be talking about amount of compute you expect.

Especially fun when you consider how often gigawatts are talked about with AI. And what that would mean just for cooling as in area... Or then dividing that to sufficient number of individual satellites...

Perhaps companies should consider putting their data centers underground (out of sight and out of mind). Space seems incredibly expensive and risky in comparison.