Process converts human waste to astronaut food

Astronauts make sacrifices to go into space. Separation from family and friends and a certain amount of discomfort are givens, and food and drink have to be specially modified for the environment. For long missions that are envisaged for the future — such as the months-long trip to Mars — the problem of bringing enough food or growing it en route is a concern to mission planners.

The Penn State team believes they might have found a solution; but it’s one that will take some mental adjustment from astronauts. Recycling urine into drinking water is a given in space, although that’s a loop that is not yet completely closed on the International Space Station. The Penn research goes a stage further: converting solid waste into edible biomass.

It’s not as strange as it sounds, insists research leader Christopher House, a geoscientist. The process uses anaerobic digestion, which is already widely used. "Anaerobic digestion is something we use frequently on Earth for treating waste," said House. "It's an efficient way of getting mass treated and recycled. What was novel about our work was taking the nutrients out of that stream and intentionally putting them into a microbial reactor to grow food."