While Joshua Pearce has no plans to open a Michelin-starred restaurant any time soon, the Western University researcher spends much of his free time thinking about feeding the world.
Now, a decade after co-writing Feeding Everyone No Matter What (a how-to guide on combatting an apocalyptic global food crisis), Pearce has taken his big-picture planning off planet with his latest concept: mining asteroids for space food.
After delivering a talk at a conference where Pearce explained his work harvesting protein from plastic-eating bacteria to make food, Western Space research officer Eric Pilles and Ian Nicklin, former mineralogy and geology technician at Royal Ontario Museum, approached him about doing the same thing with asteroids since the carbon-bearing interstellar objects have so much in common with the oft-maligned synthetic material.
"For deep space exploration, as humans, we are always tethered to Earth. If you really want to go far, the only way to do it is to produce food in space. And if you're not carrying carbon along with you, which means packing freeze-dried food packages, then you need a way to be able to use what's in space," said Pilles. "There are lots of asteroids in space, which means there is lots of carbon."
To make food - something not unlike caramel yogurt - from plastic, it must first run through pyrolysis, which is basically cooking without oxygen. This carefully controlled process produces a solid, a gas and an oil. Once complete, the oil is collected and fed into an open-source bioreactor, developed by Western students, where bacteria eat it. After the feeding, the bacteria are harvested as biomass (renewable organic material) or in the case of this study, food.
If the same process is used on the carbon found in asteroids, the interdisciplinary research team has now shown the byproduct can theoretically be turned into food for astronauts.
Pearce, Nicklin and Pilles used the asteroid Bennu as their model space rock for the study. Last year, the high-profile NASA's OSIRIS-REx mission returned to Earth with a canister filled with material from the asteroid. Bennu's total mass is around 85.5 million tons, which the researchers calculated could support six astronauts for at least 100 years.
The findings were published by Cambridge University Press in International Journal of Astrobiology.
Concurrently, Pearce and his collaborators at Michigan Tech University are attempting to make food from plastic waste using a similar process as part of a project funded by the Defense Advanced Research Projects Agency (DARPA) in the United States.
"This paper is really about the physical potential for this process. We have proven that the steps of the process work on Earth," said Pearce, a Western Engineering and Ivey Business School professor. "We know some bacteria eat coal already. Next, we will test the same bacteria we are using to make food from plastic and then we want to try it with simulated asteroids. From there, we move to the real thing."
Pearce has shown the biomass produced by the oil-eating bacteria is not chemically toxic using an open-source toolchain his team developed. It has already been tested on worms and rats, which have shown no ill effects after consuming the caramel yogurt-like product.
To gain full U.S. Food and Drug Administration (FDA) approval, the team is currently conducting long-term studies with animal models. If those are successful, they will conduct research with humans.
"When it's proven safe for humans to eat, I'll be the first to try it," said Pearce, the John M. Thompson Chair in Information Technology and Innovation.