create waste too
On the long space trip from Earth
to Mars “the crew won’t be able to get by with a bag
lunch and Portapotty,” says Arthur Teixeira, a professor
of agricultural and biological engineering at the University of
Florida. Teixeira presented a plan for how NASA could deal with
waste deposal during such a voyage.
Teixeira estimates the Mars trip
would take six to eight months. The ship would likely remain on
the planet for 18 months before Mars and Earth’s orbits
would bring them close enough together for the return trip. In
all, the six-person crew would be off the Earth’s surface
for about three years.
Teixeira’s plan hinges
on patented technology developed by the university called Sequential
Batch Anaerobic Composting (SEBAC) that is currently used in landfills.
That system turns waste into compost by cycling material among
Adapting the technology for space
travel raises numerous problems, the obvious one being zero gravity
to move material among processing containers. The SEBAC II, developed
with space travel in mind, solves this by using additional receptacles
and several pumps. The pumps move the fermenting waste among the
various chambers to create compost.
The SEBAC II system would compost
human waste, inedible food material such as plant stems and roots,
and paper used for things like moist toilettes used by the crew
in the place of baths or showers.
Teixeira says the spaceship would
probably carry enough food in reusable packages to sustain the
crew during the trip to Mars. During a portion of that time, crews
would collect the processed waste for use as compost upon arrival
and established a greenhouse to grow foods.
While on Mars, the crew would
deliberately create leftovers at each meal, which in turn would
complete the cycle when stored in the reusable packages for the