New Astronaut Food Recipe Combines Human Waste and Bacteria

Sunday, 28 January 2018 - 1:11PM
Space
Weird Science
Sunday, 28 January 2018 - 1:11PM
New Astronaut Food Recipe Combines Human Waste and Bacteria
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NASA
We could start by asking a hypothetical yes-or-no question here, but if you've read the headline, you know the answer would almost certainly be "no, I would absolutely not eat food made from human waste."

But for astronauts making the long and possibly perilous journey to Mars, the question of "If you could turn your excrement into food, would you eat it?" may not be something they have the luxury of refusing. Food supplies will always be limited, and storing waste will always be an issue, and the opportunity to kill two birds with one stone isn't an easy one to pass up.

Which is why researchers at Penn State are developing such a method of using microbes to break down waste and grow food, intending to create a useful source of nutrients for long space trips. It wouldn't be like the potatoes that Matt Damon grew in a somewhat related manner in The Martian, but it would be more like an edible paste.

So it's not appetizing, but it is edible. Christopher House, a geoscience professor at Penn State, compared the food to spreads like Marmite and Vegemite in a press statement:

Opening quote
"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. 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.'"
Closing quote


Apart from growing crops onboard the spacecraft using hydroponics, which would be costly and intensive and liable to go wrong, this technique would be a much more reliable way to make sure nobody starves (unless they're a picky eater regarding where their food comes from).

As for how they could create this substance, the researchers took a small, enclosed environment (think of it as a cylindrical fish tank) and added a variety of bacteria and some artificial waste for them to chow down on. Using a process of anaerobic digestion, the bacteria began to convert the waste into methane, which could then be used to grow a bacteria called Methylococcus capsulatus, commonly used in animal feed.

With that, they'd essentially created an ingenious way of entering waste into the tank, and then being able to harvest a nutritious source of protein and fats after a short time. 



What's particularly interesting is how the researchers originally devised the idea, looking at the way an average aquarium tank can filter out waste from all the fish inside. House goes on to explain how similar this was to aquarium techniques:

Opening quote
"We used materials from the commercial aquarium industry but adapted them for methane production. On the surface of the material are microbes that take solid waste from the stream and convert it to fatty acids, which are converted to methane gas by a different set of microbes on the same surface."
Closing quote


This method is fast, much faster than any other methods for growing food, and it could become invaluable on any extended missions to Mars, or even farther voyages to Titan, Europa or beyond later down the line. So long as the astronauts don't think too much about where this food came from, of course.

They might need to bring some spices too, as there's no word on how it tastes. Which is never a good sign.
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