I know an anesthesiologist who did a dive medicine tour at NEEMO. The astronauts apparently have safety observers at all times. One of the weirder stories was t

I know an anesthesiologist who did a dive medicine tour at NEEMO. The astronauts apparently have safety observers at all times. One of the weirder stories was their lavatory facility: the bathroom is fully continuous with the ocean, the water level is maintained by pressure. So when they have a bowel movement, they just squat in the water and do their business. And the fish know it. And swim right up to the orifice and a re eating the shit out of the astronauts as fast as they can push.