DEEP DIVE INTO SPACE TOILETS Urine and fecal collection on the...

Urine and fecal collection on the first US manned spacecraft
The first two U.S. manned Mercury flights (Mercury-3: Alan Shepard, May 5, 1961; Mercury-4: Virgil Grissom, July 21, 1961) were short suborbital missions (15–16 minutes) with no urine or feces collection systems onboard.
The original urine collection system designed for Gemini-3 and Gemini-4 used a urinal connected to a hand-pumped "accordion" receiver that generated thrust to move urine.
Major drawbacks: The hand pump required assistance from the second astronaut.
The flawed accordion design frequently ejected urine outward instead of properly transferring it.
The bag had an adhesive neck and had to be taped to the buttocks around the anus. After defecation, it was necessary to insert one's fingers into the special finger cot, separate the feces from the body, and push them further into the bag so that they would remain contained
Urine and air formed a gas-liquid mix in microgravity. It was pulled through a hose into a capillary-based moisture collector filled with porous TPVF foam cubes. The cubes absorbed the liquid completely while labyrinth channels let air pass with low resistance. A deodorizing filter cleaned the air before a fan returned it to the cabin.
Shuttle WCS featured dual redundant separator fans for high reliability. Urine was pumped and separated; feces were air-transported under the seat, gathered by vanes, vacuum-dried to slow decay, then returned to Earth. It was mostly automated but needed training for the big seat alignment. Later upgraded with Oxone tablets to prevent urine mineral buildup. A big leap forward in space toilets.
2008: 2nd Russian-style toilet (ASU-SPK-UM-IB) in US WHC — international collab, automated urine transfer to UPA, orthophosphoric acid pretreatment.
2021: 3rd Russian toilet on Nauka module (ASU-SPK-UM MLM) with integrated urine processor.
2020: New US-designed Universal Waste Management System (UWMS) in USOS.
All evolved from earlier Russian designs.















