> In the long term, space-based AI is obviously the only way to scale.
In the long term - all mass and energy available is outside of Earth - what is here is not even a rounding error. If you wish to continue scaling compute it then becomes a question of time before you'd want to go off planet. Personally I'm quite keen to see near term space based compute explored, as it could end up becoming a much better trade-off than allocating ever more ground to power and operate terrestrial compute which directly conflict with the biosphere.
SpaceX started the Starlink design phase in 2015 - started launching Starlink satellites in 2019 - and they now have the most dominant satellite constellation ever deployed by a large factor. They have their own launch systems, launch sites, satellite bus, communication stack - both in-house designed and built.
What is really going to be that difficult with space-based compute? Radiation hardening and cooling? These are clear engineering challenges that can be simulated, tested with earth analogs, and then rapidly iterated across design generations. There's napkin math all over the internet on this, but it really seems like small challenges compared to the other engineering SpaceX have already sorted.
Beyond radiation / cooling / servicing - it seems like the biggest hurdle is to crack the scaling of designing / scaling the necessary amount of compute they will need to scale space based compute according to the laid out plans.