On a long trip to Mars, two problems become almost immediately apparent. First: What do the astronauts eat? And second: Where do we put all the poop?
A group of scientists from Penn State are have using bacteria. Specifically, their plan involves using poop and bacteria to grow something edible for the astronauts to eat. And who said going to Mars wasn’t going to be glamorous?
You might be asking why the astronauts can’t simply bring food with them on their trip to Mars. They can, of course, but food takes up weight, which means higher costs and more fuel. The astronauts could also grow their food, but a proper hydroponic setup would take up a lot of space and use a lot of energy.
None of these hurdles are insurmountable, but there might be an easier way: edible bacteria. The Penn State researchers found a number of bacteria species that can be easily grown into an edible, nutritious substance. These bacteria can be grown in a small tank, meaning they don’t use nearly as much space or energy as a hydroponic setup.
But that’s only half the equation. The bacteria need nutrients to grow, and those nutrients have to come from somewhere. The researchers found a solution to that problem, too by using more bacteria to turn feces into methane. The methane can then be used to grow the edible bacteria into a food source.
To be clear, the astronauts would never eat the poop directly, nor would the poop be turned into food for the astronauts. The poop would be converted into food for bacteria, which would then become food for humans. The poop is two steps removed from the eating process, much in the same way it is when used for fertilizer. Still, on a tiny spaceship where it's your poop and the connection is so evident, it might not be the most pleasant solution. But it might just be the best one.