The Mars Oxygen In-Situ Resource Utilization Experiment — better known as MOXIE — has successfully created oxygen from Mars’ carbon dioxide-rich atmosphere in a series of tests, as part of NASA’s Perseverance rover mission, which landed on Mars in February 2021.
In each run, MOXIE reached its goal of producing six grams of oxygen per hour — about the rate of a modest tree on Earth.
“This is the first demonstration of actually taking resources on the surface of another planetary body and chemically transforming them into something that would be useful for a human mission,” said Jeffrey Hoffman, MOXIE’s deputy principal investigator. a retired astronaut and professor in the Massachusetts Institute of Technology’s division of aeronautics and space exploration in a press release.
“In that sense, it’s historic.”
MOXIE is small – about the size of a toaster – to fit aboard the Perseverance rover. It’s built to run for short periods of time, starting up and shutting down on each run, to align with the rover’s reconnaissance schedule and other mission responsibilities.
A scaled-up MOXIE would contain larger units that could spin continuously and potentially be sent to Mars ahead of a human mission to produce oxygen at a rate of several hundred trees. This would allow generating — and storing — enough oxygen to both support humans once they arrive, and fuel a rocket to bring astronauts back to Earth.
MOXIE’s steady output since its arrival on Mars is a promising first step toward that goal, the researchers said, though more tuning is needed to make sure it can operate at dawn and dusk — times when the temperature of the planet’s hotter. the planet is changing significantly, said Michael Hecht, principal investigator on the MOXIE mission at MIT’s Haystack Observatory.
How MOXIE works
Mars’ thin atmosphere is 96% carbon dioxide, which doesn’t help much for oxygen-breathing humans.
It is also much more variable than Earth’s atmosphere. “Air density can vary by a factor of two throughout the year, and temperature can vary by 100 degrees,” Hoffman said. “One goal is to show that we can run (MOXIE) in all seasons.”
MOXIE works by breaking up carbon dioxide molecules, which are made up of one carbon atom and two oxygen atoms – hence the chemical formula CO2. It secretes the oxygen molecules and emits carbon monoxide as a waste product.
Engineers are still testing MOXIE. They plan to increase capacity and increase production, with a focus on the spring months on Mars, when researchers said atmospheric density and carbon dioxide levels are particularly high. high.
“The next run coming up will be during the highest density of the year, and we just want to make as much oxygen as possible,” Hecht said. “We set everything as high as we dare, and let it run for as long as possible.”
MOXIE also appears to be hardy. It has worked successfully despite having to turn itself on and off repeatedly for the test runs – a thermal stress that can degrade the system over time. This would suggest that a full-scale system designed to run continuously could do this for thousands of hours, the MIT press release said.
“To support a human mission to Mars, we need to bring a lot of stuff from Earth, such as computers, spacesuits and habitats,” Hoffman said in the statement. “But stupid old oxygen? If you can make it, go for it — you’re way ahead of the game.”