‘Historic’ box on Mars producing oxygen at the rate of a tree

When NASA’s Perseverance robotic rover blasted off to Mars last year, it brought with it a little golden box called MOXIE, for the Mars Oxygen In Situ Resource Utilization Experiment.

Since then, MOXIE has been producing oxygen from Martian air.

And Wednesday in the journal Science Advances, the team behind this contraption confirmed that MOXIE has been working so well that its oxygen production is comparable to the production rate of a modest terrestrial tree.

In late 2021, a wealth of data showed that MOXIE successfully achieved its target oxygen output of six grams per hour over seven separate experimental runs, as well as in a variety of atmospheric conditions. That includes day and night, different Martian seasons, and other things like that.

“The only thing we haven’t shown is running at dawn or dusk, when the temperature changes substantially,” said Michael Hecht, principal investigator for the MOXIE mission at the Massachusetts Institute of Technology’s Haystack Observatory. said in a press release. “We have an ace up our sleeve that will allow us to do that, and once we test it in the lab, we can hit that last milestone to show that we really can run at any time.”

For scientists and space agencies alike, it’s especially exciting that MOXIE’s promise remains strong, because proposed timelines for astronaut-laden Mars expeditions have looming deadlines for learning how to keep future Red Planet space explorers safe. .

SpaceX CEO Elon Musk’s goal of landing humans on Mars appears to be 2029, for example, and NASA’s. upcoming lunar mission Artemis I is intended to pave the way for Martian excursions planned for the years 2030 or 2040. “To support a human mission to Mars, we have to bring back a lot of things from Earth, like computers, spacesuits and habitats,” Jeffrey Hoffman, MOXIE deputy principal investigator and professor at MIT, said in a news release. “But silly old oxygen? If you can get there, go for it, you’re way ahead of the game.”

As it stands, MOXIE is super small (it’s basically the size of a toaster), but this is potentially a good thing. It means that if scientists can somehow increase the size of the modeled cube, MOXIE could produce much more than six grams of oxygen per hour.

“We’ve learned a lot that will inform future larger-scale systems,” Hecht said.

Perhaps one day, the researchers say, it could eventually produce oxygen at the rate of several hundred trees, thereby sustaining astronauts once they reach Mars and powering rockets that require the life-giving element to bring the crew back. return to Earth.

“Astronauts who spend a year on the surface maybe use a metric ton between them,” Hecht said in a NASA news release last year. but, by the space agencyLifting four astronauts off the Martian surface on a future mission would require approximately 15,000 pounds (7 metric tons) of rocket fuel and 55,000 pounds (25 metric tons) of oxygen. Bringing all that oxygen from Earth would be very expensive and inefficient.

So, as Hoffman says, why not produce all the oxygen from the arid planet itself?

How does MOXY work?

On Mars, MOXIE is actively converting carbon dioxide in the Martian atmosphere, where the element makes up 96%, into breathable oxygen.

A bit of chemistry 101 is that carbon dioxide molecules are made up of one carbon atom and two oxygen atoms. Those bits 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 molecules with two oxygen atoms, also 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!

“This is the first demonstration of the actual use of resources on the surface of another planetary body and their chemical transformation into something that would be useful for a human mission,” said Hoffman. “It’s historic in that sense.”

Along the way, this process requires the use of super-high heat, reaching temperatures of approximately 1,470 degrees Fahrenheit (800 Celsius), which is fascinatingly what gives MOXIE its characteristic gold coating.

As with NASA’s pioneering James Webb Space Telescope, MOXIE must be shielded from infrared heat because it runs on heat itself. A gold coating does exactly that, and in fact the JWST’s mirrors are also gold plated for the same reason.

Next, the MOXIE team intends to show that MOXIE works well under even more intense conditions, such as an upcoming run that will occur during the “highest density of the year,” Hecht said. “We’ll put it all up as high as we dare, and let it run as long as we can.”