Gone are the days when Fred Haise, of the Apollo 13 crew, could
remark on how his urine looked as if a golden string of
glittering stars as they passed out of the evacuation chamber of
the space capsule in which he’d just relieved himself. Or at
least gone are the days when Bill Paxton in the character of
Haise could say something like that in a movie and be accurate.
These days our astronauts drink the water recycled from their
pee — and find clever new uses for their poop too. On the
International Space Station, they use an automated system to
remove extract water from waste for use once more. On the
private Mars shot that will launch in 2018, Inspiration Mars,
they will use a simpler, but perhaps more elegant, method: a
technique called forward osmosis. Water likes to move to diffuse
concentrations whenever possible from high to low, in an effort
to even things out. So when it’s confronted with a solution that
contains a solution with a high concentration of salt, which has
a high osmotic potential, this t