MOXIE experiment successfully creates oxygen on Mars
That’s about two months after it touched down on the surface of Mars as part of NASA’s Perseverance rover and Mars 2020 mission.
In a study published in Science Advances on August 31, local time, the researchers reported that by the end of 2021, MOXIE could produce oxygen in seven experimental runs. These were performed under a variety of atmospheric conditions — both during the day and at night — and during different Martian seasons. In each experimental run, the instrument reached its goal of producing 6 grams of oxygen per hour. This is about the rate of an average tree on Earth.
Scientists envision that a scaled-up version of MOXIE could be sent to Mars ahead of a human mission, where it could continuously produce oxygen at the rate of a few hundred trees. At this capability, the system should produce enough oxygen to sustain humans once they arrive and to fuel the astronauts’ rockets back to Earth.
So far, the ongoing production of MOXIE is a promising first step toward that goal.
“We’ve learned a lot that will inform larger-scale systems in the future,” said Michael Hecht, senior researcher on the MOXIE mission at MIT Haystack Observatory.
MOXIE’s oxygen production on Mars also represents the first demonstration of “in situ resource utilization.” It’s the idea of harvesting and using a planet’s raw materials to make resources like oxygen that would otherwise have to be transported from Earth.
MOXIE Deputy Principal Investigator Jeffrey Hoffman said: “This is the first demonstration of actually taking resources from the surface of another planetary body and chemically converting it into something useful for human missions. In that sense, it’s historic. of.”
Hoffman and Hecht’s MIT co-authors include MOXIE team members Jason SooHoo, Andrew Liu, Eric Hinterman, Maya Nasr, Shravan Hariharan, Kyle Horn, and collaborators from multiple institutions — including NASA’s Jet Propulsion Laboratory (JPL), The lab manages MOXIE development, flight software, packaging and pre-launch testing.
The current version of MOXIE is designed to be small enough to fit on the Perseverance rover. It’s built for short-term operations, with each run turning on and off, depending on the rover’s exploration schedule and mission responsibilities. By contrast, a full-scale Martian oxygen plant would include larger units, preferably operating continuously.
Despite the necessary limitations of MOXIE’s current design, the instrument has shown that it can efficiently and reliably convert Mars’ atmosphere into pure oxygen. It does this by first pulling Martian air through a filter to remove contaminants from it. The air is then pressurized and sent to a solid oxide electrolyzer (SOXE). Developed and built by OxEon Energy, the instrument electrochemically separates carbon dioxide-rich air into oxygen ions and carbon monoxide.
The oxygen ions are then separated and recombined to form breathable molecular oxygen (O2). MOXIE then measures the quantity and purity of this output before releasing it harmlessly back into the air along with carbon monoxide and other atmospheric gases.
MOXIE engineers have activated the instrument seven times throughout the year on Mars since the rover landed in February 2021. Each time it takes a few hours to warm up, then another hour to make oxygen before powering down. Each run was scheduled at different times of the day or night and in different seasons to check if MOXIE could adapt to changes in the planet’s atmospheric conditions.
“Mars has a lot more atmosphere than Earth,” Hoffman said. “The density of the air can vary by a factor of two over the course of a year, and the temperature can vary by 100 degrees. One goal is to show that we can operate in all seasons.”
So far, MOXIE has demonstrated that it can produce oxygen at almost any time of day and year on Mars.
“The only thing we haven’t proven is running at dawn or dusk, when the temperature is changing significantly,” Hecht said. “We do have a trump card that will allow us to do that, and once we test it in the lab we can get to the end.” A milestone where we can really run at any time.”
As MOXIE continues to produce oxygen on Mars, engineers plan to improve its capabilities and increase its production, especially during the Martian spring, when atmospheric density and carbon dioxide levels are high.
“The next run will be at the highest density of the year, and we just want to make as much oxygen as possible,” Hecht said, “so we’ll set everything up as high as possible and let it run for as long as possible. “
They will also monitor the system for signs of wear. Since MOXIE is just one of several experiments on Perseverance, it cannot run continuously like a full-scale system. Instead, the instrument must be turned on and off for each run. This will cause thermal stress and degrade the system over time.
If MOXIE can operate successfully with repeated switching on and off, it would suggest that a full-scale system designed to operate continuously can operate for thousands of hours continuously.
“To support a human mission to Mars, we have to bring a lot of stuff from Earth like computers, space suits and habitats,” Hoffman said. “But stupid old oxygen? If you can do it, do it — you Already leading the game.”