Spacecraft in LEO deal with corrosion from - among other causes - atomic oxygen atoms up there, which are eager to cause oxidation in almost anything they come in contact with. The rate of this can be greater than on Earth's surface, though I'm not sure how oceans compare for corrosion.
Overall it's probably true that it's less of an issue than with sea water, but it's not a nonissue either.
A single B200 can consume up to 1200W. A single GB300 system needs 14.5kW. So, you can only have ~15 (incl. satellite's energy needs) GB300 with ISS' solar panels, which is absurd. See [1] for the size of the panels we're talking about.
People dream about Starlink-style close flying systems to aggregate them to a single data center. With these power requirements, it's more like an AI hallucination. If we can build way more efficient chips or run smaller models on modest hardware, etc. We may go there, but needing ISS sized solar panels to run frontier models in space?
Also, don't forget the radiators. You also need those to pump that heat out of these systems.
The outlook doesn't look good at this point.
[0]: https://en.wikipedia.org/wiki/Solar_panels_on_spacecraft#Spa...
[1]: https://www.sgmk.edu.pl/wp-content/uploads/2025/10/iss.png
On earth, you can build a power plant miles from the DC. And you can use all sorts of different sources of power, tidal, wind, nuclear, solar, fossil fuels. All options. And like the DC, if there's a problem with any of those sources, you can go fix it or replace it with different power sources. If there's a problem with the solar panels in space, your DC is dead.
That's both easier and a lot more flexible.