http://www.abc.net.au/science/k2/moments/s348188.htmhttp://www.waltercunningham.com/the_all_american_boys-chap8.htmAstronaut Walter cunningham, Apollo VII
Our first order of business on waking up (naturally) was to play Pass the Urine Bag (technically the UCD, or Urine Collection Device). After it was filled, a series of valves permitted us to dump the contents of the bag overboard.
Now, that was something worth taking a picture of. If one dumped just at sunset, the flecks of ice coming off the urine dump nozzle would look like a million stars and it would be impossible to take star sightings for about five minutes.
Of course, it's a real experience to see your own urine take on a cosmic quality in space. But it is eye-catching and every crew has taken pictures of it. The ice particles are quite beautiful, the very phenomenon that caused John Glenn to rave about the "fireflies" at sunset. It was considered a mystery at the time of the first reports, and I don't think space officials ever released a clear explanation.