The experiment is part of NASA Perseverance mission rover That landed on Mars in February 2021, is the first time that resources from another planet have been turned into something useful for human missions, the researchers said. The small box, created by NASA’s Jet Propulsion Laboratory and the Massachusetts Institute of Technology, produces enough oxygen to match the output of a small tree on Earth, and can do so during the day and night during Mars’ multiple seasons.
“This is what explorers have done since time immemorial,” said Jeffrey Hoffman, a former NASA astronaut and deputy principal investigator for the MOXIE mission and professor of aeronautical engineering at MIT. “Find out what resources are available where you’re going and learn how to use them.”
Space agencies, scientists and entrepreneurs are calling on humans to explore Mars. NASA’s long-awaited and turbulent Artemis mission to the Moon is a stepping stone to Mars exploration in the next decade or so. China hopes to put people on this planet 2033. Elon Musk, the world’s richest person and CEO of SpaceX, has hinted at doing so through 2029.
Hoffman said that getting humans to Mars requires several complicated things to happen. Astronauts have to endure high levels of cosmic radiation during the long journey to the planet. Traveling to and from Mars can take more than 8 months, so there must be an abundance of food and medicine for space travelers.
Perhaps the most important thing is a reliable supply of oxygen, Hoffman said. Astronauts need it to breathe in any temporary habitat they’ve set up on Mars, as well as in spacesuit tanks when they’re out to explore the planet. It’s also an important motive to provide the rocket with the fuel they need to get back from Mars to Earth.
Hoffman said space agencies could send enough oxygen to Mars for astronauts to breathe and make the trip home, but that doing so would be very expensive, as it would take multiple rocket launches. It would be cheaper to produce oxygen on Mars from carbon dioxide in the atmosphere, he said. The atmosphere of Mars is made up of 96% carbon dioxide.
To test its ability to convert carbon dioxide into oxygen, NASA brought a small gold chest on the Perseverance Rover mission last year. Since April 2021, MOXIE has conducted several tests in which it produced oxygen during different times of the Martian day and during different seasonal conditions. During each experiment, the box produced approximately 6 grams of oxygen per hour, which is equal to the output of a modest tree on Earth. (In its most recent test, which will be published in a future paper, Hoffman said machine production increased to 10 grams per hour.)
If the technology is perfected, scientists will need to scale the machine dramatically and make sure it can run continuously. To sustain a human mission to Mars and bring people back, at least 4.5 to 6.5 pounds of oxygen per hour must be generated during a multi-year mission, Hoffman said. “It would take things several hundred times more,” he said.
The machine can operate during most parts of the Martian day, except for a few specified times.
The only thing we didn’t show is running at dawn or dusk, when the temperature rises [on Mars] “It changes dramatically,” said Michael Hecht, principal investigator for the MOXIE mission at MIT’s Haystack Observatory. “We have an ace up our sleeve that will allow us to do that, and once we test that in the lab, we can reach this last feat to show that we can really run at any time.”
Engineers plan to push the MOXIE instrument to its limits, increase its oxygen-producing capacity and ensure it operates during Mars’ spring, when the planet’s atmosphere is dense and carbon dioxide levels are high. “We will put everything as high as we dare, and let it run for as long as possible,” Hecht said.
Engineers will monitor the machine for wear and tear and see if it can withstand enough stress to suggest it can be converted into a full-scale system that can operate continuously for thousands of hours. If so, the effects could be significant.
“To support a human mission to Mars, we have to bring in a lot of things from Earth,” Hoffman said. “But dumb old oxygen? If you can make it happen, keep it up – you are way ahead of the game.”