You and I usually don’t think much of our pee, we just dispose of it in a toilet (or wherever nature calls in a boy’s case) and let the sewers deal with it. but astronauts on the International Space Stations are seeing it as a bit more valuable than most. To date, it costs NASA about $33,000 per kilogram to launch materials into low-Earth orbit (LEO) or to be able to reach the International Space Station; but the final frontier does not end in LEO, and the amount of money it would cost to get materials outside of Earth’s orbit would reach staggering amounts.
Turning to urine is one the the possible solutions to the problem, made mostly of water, urine can be reclaimed for nutrients and also electrical power. Water from urine is currently recovered at a rate of 75%, but with the efforts now underway, recovery rate could increase to 85% by next year, and eventually 100%. Crews on extended space missions recycle the water used, the biggest source being from their urine, an individual astronaut producing more than 1.5 liters per day, making up 81% of the space stations waste-water. Urea, the nitrogen rich compound found in urine, is currently disposed of on space stations, but can be converted into ammonia and inserted into a fuel cell producing a small charge. Urea is produced through the process of osmosis, separating the molecules of water and urea as well as other small dissolved molecules. The resulting solution containing urea, is put through a device called a bioreactor, which contains charcoal soaked with urease, an enzyme that breaks down urea.
About 86% of that solution is actually converted into ammonia, which is packed into a battery like fuel cell, and can convert the ammonia into nitrogen and water, emitting power. The power emitted is not much, about 0.2 volts, and a current of 2 milliamps, but again there is room for improvement. This small output places skepticism on the project, or so believes Layne Carter, a systems engineer at NASA’s Marshall Space Flight Center in Huntsville, Alabama, “the limited amount of power that might be harvested from the team’s new process might not recoup the effort or expense.” So the question remains, is all this effort really worth drinking your own pee?
Posted By Thomas Flores (11)