The experiment to make oxygen on Mars has come to an end, with the Perseverance rover’s MOXIE instrument completing its mission. MOXIE, or Mars Oxygen In-Situ Resource Utilization Experiment, is a small box tucked inside the rover that takes in carbon dioxide from the Martian atmosphere and converts it into oxygen. After 16 successful runs, the experiment has now been concluded.
MOXIE works like a fuel cell run in reverse, taking in carbon dioxide and then using electricity to split the molecules into oxygen and carbon monoxide. The idea was well understood on Earth, but had never been tried on Mars before, so the aim of the experiment was just to see if it worked and could be used as potential future technology for crewed missions.
The experiment worked just as planned, producing record amounts of oxygen, and totaling 122 grams produced over its lifetime. The runs were spread over different times of the Martian year to see how it fared in different temperatures and dust environments, and the experiment produced up to 12 grams of oxygen per hour which was twice the original aim.
“MOXIE’s impressive performance shows that it is feasible to extract oxygen from Mars’ atmosphere – oxygen that could help supply breathable air or rocket propellant to future astronauts,” said NASA Deputy Administrator Pam Melroy in a statement. “Developing technologies that let us use resources on the moon and Mars is critical to build a long-term lunar presence, create a robust lunar economy, and allow us to support an initial human exploration campaign to Mars.”
As well as being notable for its own achievements and as a way of producing oxygen for future crewed missions, the experiment also shows the broader utility of an approach called in-situ resource utilization (ISRU). The idea is to use materials and resources that are available in space environments, such as the carbon dioxide atmosphere on Mars or the dusty regolith on the moon, to make the resources needed for missions.
“MOXIE has clearly served as inspiration to the ISRU community,” said the instrument’s principal investigator, Michael Hecht of MIT. “It showed NASA is willing to invest in these kinds of future technologies. And it has been a flagship that has influenced the exciting industry of space resources.”