Waste makes haste
Getting rid of bodily wastes during long space flights is a problem…. A bizarre possible solution … involves whipping the wastes in with some other ingredients to produce the most unusual rocket fuel…. The four ingredients — carbon, ammonium, nitrate and aluminum — and the waste material are just blended together, and they’re ready to go…. [The material] would probably be used to help a spacecraft change position or to nudge a long-life space station occasionally to keep it up in orbit. –Science News, September 2, 1967
Researchers are still trying to figure out how to turn astronaut excrement into something useful. Another process proposed in 2014 would use microbes to convert the waste and other organic material into fuel. But waste might have other uses that would be especially helpful during long-term flights. Synthetic biologists at Clemson University in South Carolina are working with NASA to use algae and genetically modified yeast to turn astronaut urine into 3-D printable plastics and nutritional omega-3 fats.