Scientists transform human waste into food for long-haul space travel

Researchers from the University of Pennsylvania have come up with a novel solution to one of the most intractable problems of deep space travel – food supply. And it starts with something astronauts will likely not run out of – human faeces.

Astronauts recycle their own waste, particularly urine, which is filtered and turned into drinking water, but recycling faeces is an altogether different proposal. But scientists from the university have developed a system capable of converting solid human waste into something not only edible, but nutritious as well.

''We envisioned and tested the concept of simultaneously treating astronauts' waste with microbes while producing a biomass that is edible either directly or indirectly depending on safety concerns,'' Christopher House, a professor of geosciences at Penn State, explains, bgr.com reported. ''It's a little strange, but the concept would be a little bit like Marmite or Vegemite where you're eating a smear of 'microbial goo.'''

In simple terms microbes would be applied astronaut poop in order to break it down and while these microbes digest the waste, they produce copious amounts of methane. The gas it then used to grow a different type of microbe called Methylococcus capsulatus which is already used today as animal feed. The microbes, which are 52 per cent protein and 36 per cent fat, could provide a sustainable food source for long haul space travel.

According to experts even though the process may sound rather unappetising, mastering its benefits would allow astronauts to go on longer trips and venture deeper into space than ever before.

According to the researchers, reaching 85 per cent efficiency, the percentage of carbon and nitrogen successfully recycled from waste would be a "fantastic development" for deep-space travel.

This is not the first time that science has found a way to use waste. In 2017, Phys.org reported researchers had devised a method of recycling urine and exhaled air into new chemicals via microorganisms, allowing for the creation of nutrients along with "small amounts of polyesters."