Since then, MOXIE has been producing oxygen from thin Martian air. And on Wednesday in the journal Science Advances, the team behind this machine confirmed that MOXIE works so well that its oxygen production is comparable to the production rate of an average Earth tree. By the end of 2021, extensive data showed that MOXIE successfully achieved its target oxygen yield of six grams per hour during seven separate experimental trials, as well as in a variety of atmospheric conditions. This includes day and night, different seasons of Mars and other such things. “The only thing we haven’t proven is running at dawn or dusk, when the temperature changes substantially,” Michael Hecht, principal investigator of the MOXIE mission at the MIT Haystack Observatory, said in a news release. “We have an ace up our sleeve that will allow us to do this, and once we test it in the lab, we can reach this final milestone to show that we can actually run at any time.” Here is MOXIE on the Mars rover. NASA For scientists and space agencies, it’s especially exciting that MOXIE’s promise is strong because proposed timelines for astronaut-laden missions to Mars have looming deadlines to learn how to keep future space explorers safe on the red planet. SpaceX CEO Elon Musk’s goal of landing humans on Mars appears to be 2029, for example, and NASA’s upcoming Artemis I moon mission is intended to pave the way for Mars expeditions planned for 2030s or 2040s. “To support a human mission to Mars, we need to bring a lot of things from Earth, such as computers, spacesuits and habitats,” said Jeffrey Hoffman, MOXIE’s deputy principal investigator and a professor at MIT. in a press release. “But silly old oxygen? If you can get it there, go for it — you’re way ahead of the game.” As it is, the MOXIE is extremely small (it’s basically the size of a toaster), but that’s potentially a good thing. It means that if scientists can somehow increase the size of the shaped cube, MOXIE could produce much more than six grams of oxygen per hour. “We’ve learned a tremendous amount that will inform future systems on a larger scale,” Hecht said. Perhaps one day, the researchers say, it could eventually produce oxygen at the rate of several hundred trees, thus sustaining astronauts once they reach Mars and fueling rockets that require the life-giving element to bring the crew back to Earth. “Astronauts who spend a year on the surface will probably use a metric ton between them,” Hecht said in a NASA press release last year. But getting four astronauts off the surface of Mars on a future mission would require about 15,000 pounds (7 metric tons) of rocket fuel and 55,000 pounds (25 metric tons) of oxygen, according to the space agency. Transporting all this oxygen from Earth would be extremely expensive and inefficient. So, as Hoffman says, why not make all the oxygen on the waterless planet itself?
How does MOXIE work?
On Mars, MOXIE actively converts the carbon dioxide in the Martian atmosphere — of which the element makes up a whopping 96% — into breathable oxygen. A little chemistry 101 is that carbon dioxide molecules are made up of one carbon atom and two oxygen atoms. These pieces are basically glued together. But an instrument inside MOXIE, called the Solid Oxide Electrolyzer, can collect the bits of oxygen inside those CO2 molecules that scientists are interested in. Once complete, all free-floating oxygen particles recombine into O2, also known as two-atom oxygen molecules, otherwise known as the kind of oxygen we know and love. I know it’s different, but I keep thinking of Pixar’s WALL-E doing this. So, as WALL-E would say: Ta-da! Technicians at NASA’s Jet Propulsion Laboratory lower the Mars Oxygen Resource Utilization Experiment (MOXIE) instrument into the belly of the Perseverance rover. NASA/JPL-Caltech “This is the first demonstration of actually taking resources on the surface of another planetary body and converting them chemically into something that would be useful for a human mission,” Hoffman said. “It’s historic in that sense.” Along the way, this process requires the use of ultra-high heat — reaching temperatures of around 1,470 degrees Fahrenheit (800 Celsius) — which is excitingly what gives MOXIE its signature gold coating. As with NASA’s pioneering James Webb Space Telescope, MOXIE must be protected from infrared heat because it runs on heat. A gold coating does just that, and in fact JWST’s mirrors are also gold plated for the exact reason. One wing of the James Webb Space Telescope’s primary mirror snaps into place during a final test of the mirror deployment system in May 2021. Check out this gilded beauty. NASA Next, the MOXIE team plans to demonstrate that MOXIE performs well under even more intense conditions, such as a subsequent run that will occur during the “highest density of the year,” Hecht said. “We’re going to put everything as high as we dare and let it run as long as we can.”
