While the Moon still has my “heart” when it comes to offworld destinations, I’ve long been interested in the idea of Venus Cloud Colonies (some references here and here and this article from earlier today). As several others have pointed out in these articles, at about 50km altitude, the atmospheric density on Venus is close to “sea level” density on earth, and temperatures are basically Mediterranean, you get plenty of sunlight, and the CO2 atmosphere is sufficiently denser than air on earth that a breathable air mix provides about half the buoyancy on Venus as Helium does on Earth. Basically, at 50km you could build multiple-km-scale flying cities that would be extremely roomy since more air space means you can support more mass. Or in other words, Lando Calrissian, eat your heart out.
But a question that commonly comes up is that while sure you can make a super large city like that float in the Venusian atmosphere, how do you get it there in the first place? There’s also the question of why you’d want to, but I want to focus this series on how you might build your castles in the sky. What I’d like to suggest in this blog post series is that the Venusian atmosphere may provide most of the raw materials needed to build such flying cities using in-situ resources, and many of those resources may be readily extractable. I’m not a chemical engineer, so consider the following blog posts to be more of a starting point than a finished product, but I wanted to at least spur the conversation.
First Topic: The Benefits of Atmospheric-Feedstock ISRU