Since April 2021, the MIT-led Mars Oxygen In Situ Resource Utilization Experiment (MOXIE) has been successfully converting carbon dioxide (CO₂) from the martian atmosphere into oxygen (O₂). MOXIE is part of the Mars 2020 Perseverance rover and has operated seven times in 18 months. Led by Dr. Jeffrey Hoffman of MIT, the MOXIE team estimates that during each operation, MOXIE produced oxygen at an average rate of six grams per hour, equivalent to that of a small tree on Earth.

About the size of a lunch box, MOXIE is designed to fit within the car-sized Perseverance rover. MOXIE efficiently produces oxygen from the thin, CO­₂-rich martian atmosphere by first drawing in air and filtering out dust. The air is then pressurized, heated to 800˚C, and passed through a solid oxide electrolyzer (SOXE) assembly where CO₂ is electrochemically broken down into oxygen ions and carbon monoxide (CO). The density of the martian atmosphere varies by a factor of two throughout the year, and the surface temperature varies by 100˚C. Therefore, the outstanding feature of MOXIE is its ability to reliably produce oxygen at any time of day and during any season on Mars. The team anticipates that the next operation will be in the spring when the atmospheric density and CO₂ levels are highest.

The primary demonstration goal of MOXIE is to produce oxygen, one of the two components of rocket propellant. Returning a mission crew to Earth might require more than 30 tons of oxygen, which is too much weight to carry on board. Therefore, a scaled-up version of MOXIE would be sent to Mars ahead of a planned mission and operated continuously to produce oxygen reserves that would become rocket propellant (along with methane fuel brought from Earth), as well as sustain the crew during their mission. READ MORE