Coffee in a donut

In the 50s° farming-latitudes over Venus, the floating terraced cities will need water and food. How about we give them coffee and a donut.

Yesterday I was thinking about the distribution of weight in a Landis spheroid. For that, we wish to focus the stress in as few places as possible, for maintainability. I had it tapering to the bottom, which is how I figured the habitations would be spiral-terraced. That well at the bottom is where the trash would accumulate - more so when it gets normal human plebs raising little kids. Which is what we want, somewhere at a self-sufficient planet. The inhabited surface area is a function of the radius. The people here need water, too, which has to be stored somewhere.

Meanwhile, for farms, we'd like to maximise surface-area. Also we don't wish that a single puncture drain away all the water at once. And I think we'd have to start with farming - at least, after visit-and-go missions.

To get internal density 1.3369 g/L, we want proportions of water at 1000 g/L against breathable air at 1.18 g/L - remembering that one displaces the other. I calculate 99.9843% air-volume. That makes for a small pool of water at the base of a sphere, and then we'd have to pump it back up the sides. Instead I recommend flooding strategic pools in a donut - a "torus".

The more total volume, again, the more water we get to carry.

In the hole of the water-bearing donut would be some central nexus, also a human-inhabited bubble: at least docking for aircraft, a market, an assembly, a cookery, and a clinic. The nexus lies snug between two nets, each attached at six points to the inner side of the donut.

Some of these tori will be given over to wildlife-preserves, starting at the desert level. These are popular for tourism. Savannah will be mooted later, for fatter rings.

It is not allowed to light fires in the torus. This whole setup should be designed to use as little electricity as possible. But over Venus heating and burning food is the least of problems.