Space Shuttle toilets have always been mounted on the floor, but you would not call them normal. The original shuttle toilet bowl featured a set of 1,200 rpm Waring blender blades positioned a brief 6 inches below the sitter's anatomy. The macerator would pulp the feces and tissue--meaning, if all went well, the paper, not the scrotal, variety--and fling it to the sides of a holding tank.