Astronaut feces could make 3D print tools in space

A Filipina-led team of researchers at the University of Calgary has devised a new method for turning feces into plastic, which could come in handy during space travel.

According to New Scientist, interplanetary travellers face two big challenges – how to transport the tools and equipment they need from Earth, and what to do with their waste.

“When you’re planning space missions, there’s no way you can predict everything you’ll need,” professor Mayi Panlilio told the London-based weekly magazine, as she and her colleagues worked to find a solution.

They genetically engineered Escherichia coli bacteria to convert human feces to a type of plastic called polyhydroxybutyrate. Using a 3D printer, they showed this plastic could be made into small tools like wrenches.

“The nice thing about this plastic is that it can be molded into whatever you want,” Panlilio said.

The team envisions astronaut feces being collected by vacuum toilets into tanks. Bacteria would then feed on fatty acids in the stool and produce plastic for tool-making. Any leftover solid waste could be used to make radiation shields, the article published in the April 6 issue said.

The storage tanks, pumps and filters would need to be transported to space, but this hassle would be offset by limitless tool production, Panlilio said, and the total weight of the equipment would be less than one-fifth of that of the water processing unit on the International Space Station.

In July, two of Panlilio’s students will board Canada’s Falcon 20 aircraft to test the plastic-making process in low gravity. Because the aircraft can only simulate microgravity for a few minutes at a time, their aim is to see if they can extract the nanosized plastic granules from the bacteria without the normal pull of gravity.

The researchers are also looking at ways to make different types of plastic, New Scientist said. Their plan is to engineer E. coli bacteria that can convert feces into plastics with varying strengths and flexibilities for different applications.

Panlilio says the study proves sewage can also be converted into plastic on Earth – and unlike other plastics, polyhydroxybutyrate is not made from fossil fuels and is biodegradable, meaning it is kinder on the environment.