Mars: If the extreme temperatures and exposure to cosmic radiation don’t kill you, the unbreathable air certainly will. Now, a team of researchers has proposed a method of addressing the latter issue, by using plasma to split carbon dioxide — of which Mars has plenty — into carbon and oxygen.
One of the biggest barriers to human habitation of worlds beyond Earth is in-situ resource utilization, or rather, the lack thereof. Until humans can reliably use what’s readily available on Mars to live there, our species can’t have an established presence on the planet.
The recent team proposed using non-thermal plasmas: electrically charged gases whose electron discharge can be channeled toward breaking the bond between carbon and oxygen atoms in a carbon dioxide molecule. In a lab setting, the team demonstrated the ability to cool a plasma down to Martian temperatures. Their research is published in the Journal of Applied Physics.
“The natural conditions on Mars are nearly ideal to [in-situ resource utilization] by plasmas,” said Vasco Guerra, a physicist at the University of Lisbon in Portugal and lead author of the recent paper, in an email to Gizmodo. “In particular, the atmospheric composition, the ambient pressure and temperature all play in favour of a plasma process.”
Oxygen has been produced on the Martian surface before. Last year, the MOXIE experiment aboard NASA’s Perseverance rover extracted a small amount (about 5 grams) of oxygen from the planet’s atmosphere. But MOXIE was just a test of whether oxygen extraction was possible; now that it’s been proven, humans can focus on how to scale that extraction.
Humans need oxygen to breathe, but it also is important for producing fuels and fertilisers. Carbon monoxide could also be used for rocket propellant. All told, humans would have a lot to gain by being able to separate out the Martian atmosphere into its constituent elements.
“This versatile system may one day play a critical role in the development of not only life-support systems on Mars but also feedstock and base chemicals for processing fuels, building materials and fertilisers,” Guerra said.
Non-thermal plasmas and the conducting membranes needed to separate carbon dioxide and store the elements are still emerging technologies, meaning it’ll be some time before humans can have prolonged stays on Mars. But they’re a step forward — or outward, toward an extraterrestrial future.