"One of the most beautiful sights is a
urine dump at
sunset, because as the stuff comes out [in space] and as it hits the exit
nozzle, it instantly flashes into 10
million little
ice crystals, which go out almost in a hemisphere, because, you know, you're exiting into essentially a perfect vacuum, and so the stuff goes in every direction, and radially out from the spacecraft at relatively high
velocity. It's surprising, and it's an incredible stream - a spray of sparkles almost. It's really a spectacular sight." -
Russell Schweickart,
Apollo astronaut.
During rocket take-off (and landing, I think), astronauts wear
diapers. During flight, they use
texas catheters,
IIRC.