Last year, NASA produced oxygen on Mars. Now, scientists experimenting here on Earth may have found a much more efficient method of doing this for future missions. The resulting equipment could also be used to produce the materials needed for human colonization.
Write in the Journal of Applied Physicsan international boffins team led by University of Lisbon physicist Vasco Guerra said they had successfully tested a design capable of doing the same thing as the Mars In Situ Oxygen Resource Utilization Experiment (MOXIE ) from NASA – but without needing for intense heat and pressure.
Not only does their design improve MOXIE’s ability to harvest breathable oxygen, but it can also be used to create fuels, carbon-based fertilizers, and animal feed. It can also synthesize a variety of organic molecules, the researchers said.
Are you moving on MOXIE?
MOXIE produced oxygen on Mars in a unit the size of a toaster, but it required very specific conditions to do so: it had to heat Martian air to 800°C (1,472°F) and repressurize it in an Earth atmosphere, which made it much denser than the pressure on the Red Planet.
Guerra’s team, meanwhile, proposes using non-thermal plasma and specialized conductive membranes. Combined, the design forms a plasma reactor that can operate directly under Martian conditions without the need for heat or repressurization. According to the article, Mars’ atmospheric pressure is actually “ideal for plasma ignition.”
In the paper, the researchers detail the two separate oxygen-generating experiments they performed: the first using supercooled DC glow discharge plasma at Martian temperatures, and a second using microwave discharges operating in a simulated Martian atmosphere.
The paper describes the results as “very encouraging given that the plasma setup used was designed for basic research and is far from suitable for prototype development.” The DC experiment would have reached CO2 dissociation rates (the separation of carbon and oxygen) as high as 30%, while the MW experiment achieved a conversion rate of 35%.
Based on their preliminary results, the team sketched out what an optimized system could produce and arrived at 14 grams of oxygen per hour in a plasma reactor weighing 6 kilograms – 2.3 grams of oxygen per kilogram of equipment.
For comparison, NASA’s MOXIE unit weighs 17.7 kilograms and can reach 10 grams of oxygen per hour, the space agency said.
not so fast
The fact that MOXIE actually made oxygen on Mars weighs heavily in its favor, as do some major downsides that experimenters concede, as MOXIE lead and MIT experimental scientist Michael Hecht. reiterated at Science.
The membrane used in Guerra’s experiment, known as a mixed ion-electron conduction (MIEC) membrane, is in its “very early stages” of development by being plasma-coupled, the paper notes. Additionally, the researchers list “the stability of CO2 and the possibility of reverse reactions” that can reduce membrane efficiency as challenges to the use of MIEC. We speculate that these are challenges to be overcome in order to fabricate a practical device.
Hecht said Science that energy requirements and oxygen storage requirements could make Guerra’s device bulkier than MOXIE, negating much of its benefits. “There’s nothing wrong with the plasma technique except that it’s much less mature,” Hecht said, adding that an infusion of funds from a space agency could make the technology mature enough. to be transported to Mars. ®