0-Gee Toilet

Different cultures have different ways of dealing with the elimination of solid body wastes. "Western" cultures invented a specific "sit down" toilet system for accommodating the task, while at least some "Eastern" cultures merely expanded upon the classic-for-all "chamber pot" system (the pot connects to the sewer line). A squatting position is employed when using a chamber pot, not a sitting position.

Now consider that squatting position, and how scrunched- up-into-a-small space the body is. Let us imagine a kind of "drum" big enough to surround that squatting body (the person's back is against the curved wall).

In Space such a drum could be rotated to generate a centrifugal effect. It could be rotated from the outside, by a motorized roller that contacts its outer surface, with other rollers holding it in place. Some weights could be added at appropriate places on the inside of the drum, to arrange that the center-of-mass is close to the rotation axis, which makes the rotation more smooth. The weights could be adjustable, for different persons using this system. The weights could be a double-duty thing (part of the overall food-storage queue, maybe).

The drum doesn't need to rotate super-fast (perhaps once per second); it merely needs to provide an environment in which solid wastes can "fall" away from the body; there should be no risk of causing dizziness.

On the inner wall of this drum we permanently mount a special chamber pot. Before using it, we put a plastic bag into it (the special-ness of the pot lets it hold the bag in place). There should also be a roll of toilet paper handy. The user would adjust the weights and install the bag and check the roll for sufficient paper, first of all, of course.

So now the needy person gets into a squatting position, moves sideways into the drum, pulls a curtain over the opening, and pushes a button to begin the drum's rotation. The other side of the drum is "open", but a stationary wall, part of the spacecraft, is there. The button can be located on that wall right in the center of the circular drum-opening.

Clothing is moved out of the way, and the necessary task can be performed. It should be possible for this system to accommodate either type of body waste, regardless of the sex of the person using it.

The edges of the plastic bag can be pulled from the chamber pot, and the bag can be sealed. Clothing is re- adjusted and the button on the wall is pushed again -- easy to get at even while the drum rotates, because of being located in the center of that non-rotating side- wall.

The drum's rotation gradually slows to a stop. Ideally, we would want the final stop-orientation (because of location of chamber pot on inside of drum, and the relative orientation of the outside curtain) to always be the same place. The curtain is pulled aside and the person can exit, taking the bag along for final disposal or recycling-of-biomass.

Finally, for the sake of complete dynamic balance, there should be a second drum that rotates the opposite direction. The mass it rotates could also be, for example, part of the overall food-storage queue. Or maybe a water tank. It doesn't especially need to be adjustable; accelerometers can reveal the masses of both drums when rotation begins, and the rotation rates can be computer- controlled, so that both drums have equal and opposite total angular momentum.