Astronauts already drink their own urine—not straight, thankfully, but after it's been filtered and recycled into drinking water. It's a harsh reality, and one rarely mentioned in any conversation surrounding humanity's slow and steady exploration of outer space.
Neither is the fact that astronauts and Mars colonists may one day be surviving on eating tomatoes grown with human urine, much like Matt Damon's feces-based potatoes in The Martian. And while all of this space waste talk might sound gross here on Earth, the vacuous hostility of the cosmos means that every atom of human byproduct can have survival value outside of our atmosphere.
The spectrum of waste-based technology continues to widen as researchers from Clemson University plan to turn cosmonaut urine into nutrients and plastics that could make years-long space trips if not palatable, then at least viable.
Lead researcher Mark A. Blenner, Ph.D. emphasized that a "waste not, want not" mindset has to be applied on the most micro and macro levels. "If astronauts are going to make journeys that span several years, we'll need to find a way to reuse and recycle everything they bring with them," He said in a press release. "Atom economy will become really important."
And the key to Blenner's findings, besides human piss, is a yeast called Yarrowia lipolytica which Blenner and his team were able to genetically manipulate and "feed" with algae, bacteria, as well as nitrogen from urine and carbon from human breath.
The resulting strains created omega-3 fatty acids and even a chemical monomer that could be fed into a 3-D print to create plastic objects like a wrench. This is a great development for science fiction writers; imagine if Ripley from Alien could have just peed into a cup of Yarrowia lipolytica and 3-D printed the requisite firepower to deal with face-hugging aliens, instead of having to rely purely on her wit and speed.
Pop culture implications aside, Blenner is now finding out firsthand what bread- and booze-makers have known for millennia; that yeasts are capricious little fungi, but capable of very great things. "We're learning that Y. lipolytica is quite a bit different than other yeast in their genetics and biochemical nature," he said. "Every new organism has some amount of quirkiness that you have to focus on and understand better."
But in matters of space travel, quirkiness can be very useful. "These yeast tolerate some unusual conditions, such high and low pH, high salt, ionic strength, and human urine," Blenner told MUNCHIES. "It makes it a really useful host for making products using less refined and waste substrates."
Blenner, whose research was funded in part by NASA's Space Technology Research Grants Program, presented these findings at the 254th National Meeting & Exposition of the American Chemical Society, the world's largest scientific society, last Tuesday. It turned out to be a barnburner this year, including a separate presentation about new "smart labels" that could tell us when food is expired.
Like those smart labels, the technology here remains in its infancy, but the practical implications are clear. "We are still a long way from producing useable amounts of plastics from the fixed-CO2 waste," says Blenner. "However, the use of urea could be more beneficial in terms of product formation and cost compared to other nitrogen sources in industrial fermentation and omega-3 production from this yeast is already commercialized from non-waste substrates."
Yeast has already given us pizza, beer, and wine, but it may one day make human life possible on Mars. Thanks, yeast!