For a more pleasant aspect, composting toilets, otherwise known as waterless toilets, are available which work to diminish consumption of water as well as to provide a source of nutrient rich material for growing plants.
As supposed space-travelers, intent on the necessity as well as efficiency of recycling programs and procedures, we would do well to be conversant with such equipment.
Yes, we’ve discussed those devices more than once ... but there is still the problem of my HOA regulations.
We do have a compost barrel now, although I haven’t begun to ferment fertilizer yet.