Plastic waste is a nagging problem both on Earth and in space, but a team is now experimenting with a novel method for converting discarded PET into useful material while floating aboard a station in space. Short for polyethylene terephthalate, PET is the most commonly used form of plastic on Earth, and it is used in everything from plastic bottles and fabrics to automotive parts and even spacecraft applications. In spacecraft and satellites, plastic is used in parts like bearings, insulators, magnetometers, optical lens elements, and valves, among others.
Logistical waste is the core concern for astronauts before planning for long-term missions, and unsurprisingly, plastics again form a significant chunk of that discarded material. As per NASA, a four-person team will produce as much as 5,700 pounds of waste in a year, which includes everything from human excreta and wipes to clothes and packaging. Plus, given the current pace of revived interest in space exploration and the looming commercial tourism, the problem of space trash is only going to worsen, especially plastics.
The National Renewable Energy Laboratory aims to solve the problem using a combination of a lab-synthesized plastic-breaking enzyme and a biologically engineered strain of bacteria. The idea here is that a mixture of PETase enzyme and the Pseudomonas putida bacteria will create a solution for upcycling polyethylene terephthalate, commonly known as PET. The experiment, which launched recently with the SpX-26 resupply mission, is currently in progress aboard the International Space Station. The project is a collaborative effort between the U. S. Department of Energy and experts from Harvard, MIT, and Seed Health, while funding was offered by the National Renewable Energy Laboratory.
Turning Bad Plastic Into Good Plastic
The whole process of upcycling PET in space begins with the PETase enzyme breaking down the plastic into its building block, terephthalic acid. The acid is then fed to the bacteria, which transforms it into another compound that serves as a precursor for making nylon. The most promising aspect of the latest experiment is that it will work all on its own without human supervision, letting the bacterial soup slowly do its job of breaking down plastic.
“The experiment will proceed entirely on its own in a custom payload designed for autonomous cultivation and sampling,” says the NREL press release. Everything from sampling and microbial cultivation to material passage and logging core process data happens automatically inside the “compact, modular, spaceflight-ready bio-culturing system.”
Another cool side to the landmark experiment is that the whole system is going the open-source route, which means independent experts will be able to modify the core systems to their own liking without any copyright or licensing hassles, which is great for fostering further improvements, research, and innovation. The entire hardware can either be 3D-printed or easily be availed from retail, and can be deployed in other challenging environments like deep oceanic biomes and sub-zero polar regions.
NASA is also actively experimenting with space management in space with the Orbital Syngas/Commodity Augmentation Reactor (OSCAR) project. The system will expose discarded material to high temperatures and convert it into usable material. The first microgravity test of the OSCAR project was conducted in 2019 when it launched aboard Blue Origin’s New Shepard rocket. In July, NASA awarded a cash prize to three teams that are building reactors to turn space trash into gas, as part of the Waste to Base Materials Challenge: Sustainable Reprocessing in Space challenge.
