As a means to save resources, the US astronauts on the International Space Station have resumed recycling their urine into drinking water using a filtration system. This is used as a means to reduce the amount of supply runs back down to Earth. It is interesting to note that Russian crew members do not partake in this practice. For more on how astronauts conserve and reuse water, click here:: US astronauts aboard space station consume recycled urine, but Russians do not