3D printing has been touted as a means to create lightweight parts for space vessels more cheaply and efficiently. But, for astronauts, the materials needed to take full advantage of 3D printing aren’t conducive to the light loads that space voyagers are restricted. So, NASA and its partners are going a bit outside of the box, considering whether human waste will be worth its weight as a material which astronauts can use to print tools and other objects using additive manufacturing.
Tools aren’t the first object which NASA’s brightest minds have considered crafting from the astronaut excrement. Earlier this year, it was reported that researchers at Penn State University were brainstorming, of all things, methods to turn solid and liquid human waste into human food that is, believe it or not, actually hygienic.
Astronauts will likely prefer the idea of using additive manufacturing to create plastic tools from their waste rather than granola bars. The researchers at the University of Calgary seem to be a bit more sympathetic towards the plight of the space cadet, as they have gone all-in on creating a use for astronauts’ feces and urine that doesn’t involve ingestion. If successful, the process would allow astronauts a virtually inexhaustible means of creating tools and other materials which they require and desire along their voyage.
The process depends on the conversion of genetically engineered Escherichia coli bacteria into a type of plastic known as polyhydroxybutyrate. First, the waste must be left to sit for several days, a required step to increase the amount of volatile fatty acids in the sample. After extraction and further fermentation processes are completed, the waste-turned-plastic would be put through a Selective Laser Sintering (SLS) 3D printer to create the objects needed by the astronauts.
In July, two University of Calgary students are planning on testing the processes in Canada’s Falcon 20 aircraft. While the first experiment is aiming only to extract granules of plastic from the waste, the team hopes that, in time, they will be able to create several types of plastic from the same underlying processes, and that those processes will translate successfully in space missions.