The space data center hypothesis relies on compute supply growing faster than power supply. (Both are bottlenecked on parts of the supply chain that will take ages to scale.)
Even if you believe that's the case, the point at which orbital data centers start making sense is incredibly sensitive to the exact growth rates.
The economics are vastly different when opex is near zero for these things
H100 rental prices are still as high as when the cards were brand new. The prices vastly exceed the power costs.
In a world where power or DC permits are the current bottleneck those H100s would be getting retired in favor of Blackwells. But they aren't. They are instead being locked in for years long contracts.
If silicon were relatively abundant and power/DC space scarce, you'd get an order of magnitude more bang for the Watt by replacing the H100s with newer GPUs.
But nobody is doing that. Blackwells are being installed as additional capacity, not Hopper replacements.
So it is pretty clear that silicon is the primary bottleneck.
That said eventually they can be lifted to higher orbits and have robots deliver and swap updated compute (if not made in space itself!).