How the space toilet works On the shuttle, urine is handled differently than solid waste, so it doesn't go through the 4-inch opening. On Jones’ missions, crewmembers stored their towels in …

A urine collector, located on the wall just below the fecal collector, also utilized airflow as a substitute for gravity to draw the urine through a receiver and hose into a urine collection bag. Because they can't simply drop their space suit and go, astronauts typically use a superabsorbent adult diaper. The crewmen could urinate from either a standing or sitting position. Astronauts also used the toilet’s closed-off space on the shuttles for changing clothes and wiping themselves down with bath towels. Beside the main toilet bowl, there is a hose, which is utilized as a urinal by men and women. The astronauts' "toilet" (if we can call it that) was basically a hole in the wall, hooked up to a fan and a baggie. Instead, a long hose … Astronauts use adult diapers during take-offs and landings as well. Astronauts go through "positional training" on Earth to make sure solid waste goes directly into the narrow opening of these space toilets, Roberts explained. Going to the bathroom becomes even more challenging when astronauts take a walk outside their spacecraft.
Astronauts in spacesuits go to the bathroom in high-tech diapers called Maximum Absorption Garments but the International Space Station use a 19 million dollar toilet that uses suction for pooping in plastic bags and in a hose for urine that’s recycled into drinking water to be used by the crew.

Since the system operates on a vacuum, a tight seal is essential. Astronauts must use straps to hold their feet against the floor and pivoting bars swing across the thighs, ensuring the user remains seated. These diapers are able to hold up to a quart of liquid.
A separate fecal bag was used for each defecation.