[dizzystar]

I hope this is connected, but how much oxygen would it take to sustain these craft? A cursory look seems to suggest that the ISS generates oxygen from water electrolysis, which generates about 20lbs of oxygen a day.

The big difference is you can fire off a rocket and get water to the ISS in comparatively shorter time and less fuel, which makes it feel much more challenging to get in the sky of Venus.

I obviously have no idea what I'm talking about here, but I'm thinking the continued challenges of floating -vs- hard ground will be very high. Plus we don't really have any direct experience with that, right?

[Symmetry]

Water is on the order of 50 parts per million in that part of Venus's atmosphere which is pretty dry compared to Earth but still straightforward to extract from the air. In Venus's atmosphere you basically have all the Hydrogen, Nitrogen, Carbon, Oxygen, Sulfur, and Argon you need and pretty good access to Helium, Neon, Chlorine, and Florine. It's everything else that's the problem, like Silicon or metals.