We Could Fuel Astronauts With Human Waste Says Research

Future astronauts and planetary colonists may end up breathing and watering plants with human waste, not to mention traveling in vehicles powered by it, if one research team has its way. NASA tasked the group at the University of Florida with figuring out what to do with the inevitable outcome of astronaut's freeze-dried meals, preferably something more productive than simply flushing it away into the nearest black hole. While the initial goal was lightening the load for space-faring folk, though, the research could have new implications down on Earth, too.

Currently, human waste – whether it's produced on the International Space Station or during other missions – is released to burn up in the planet's atmosphere, having been stored in large tanks until the volumes are sufficiently worth disposing of.

However, back in 2006 NASA decided more practical applications were probably out there. As part of its plans for an inhabited moon base, for installation sometime between 2019 and 2024, it asked researchers at the University of Florida to look into what processing technologies could take a waste product and eke something more valuable from it.

The result is an anaerobic digester created by Pratap Pullammanappallil and Abhishek Dhoble. Presented with a sample – NASA formulated a special fake waste, including simulated food, towels, wash clothes, clothing, and packaging materials – it first kills off any pathogens in the waste, and then through multiple stages changes it into methane and carbon dioxide.

After a week, the system could produce 290 liters of methane, per crew, per day, the researchers say. That methane could be used to power systems.

Meanwhile, although non-potable, water created as a side-product – around 200 gallons a year, roughly – could keep plants and vegetables irrigated, or alternatively be split into oxygen and hydrogen using electrolysis. Astronauts could therefore end up breathing the product, while the hydrogen and carbon dioxide could theoretically be combined to produce further water and methane.

Servicing space isn't the only application, however. Back on Earth, the methane produced by such a system could be used for heating or powering various methods of transportation.

SOURCE University of Florida