The race to make oxygen on the surface of Mars has begun

SpaceX founder Elon Musk has predicted that a manned mission to Mars would touch down in 2029 — the first step in humankind's attempts at interplanetary colonization.

But there's much to consider, not least the near total lack of oxygen on the Red Planet, essential not just to sustain human life, but also to make a return trip to Earth possible.

To this end, scientists have been racing to devise ways to extract oxygen from the resources found on Mars that could allow them to manufacture enough rocket propellant to blast an ascent vehicle into orbit and return astronauts home. Doing so would save scientists from having to send hundreds of tons of material from Earth to Mars to transport the required oxygen, at a high cost.

Working with the MIT-led Mars Oxygen In-Situ Resource Utilization Experiment, better known as Moxie, NASA has been converting carbon dioxide from the Martian atmosphere into oxygen through a toaster-sized device embedded inside the Perseverance rover that landed in 2021.

Seven times last year, throughout the Martian seasons, Moxie was able to produce about six grams (0.2 ounces) of oxygen per hour, said MIT professor Jeffrey Hoffman, former NASA astronaut and lead author of a paper on the Moxie experiments published in Science Advances.

"That's roughly the equivalent of what a tree produces," said Hoffman. "Not enough to support an adult human, but it could keep a small dog alive if produced continuously," he said.

To get to the stage where the planet could house a human-staffed science base would require a full-scale oxygen production plant with a continuous source of power, Hoffman said, while the paper suggested a Moxie-like system, scaled up several hundred times, could produce three kilos of oxygen per hour — enough to launch an ascent vehicle within 26 months.

Hoffman said Oxeon, the company that manufactured the electrolysis unit for Moxie, had already "built and tested a system for NASA that's over 100 times larger."

On Aug. 16, the Journal of Applied Physics reported that a lab-based plasma reactor had created about 14 grams of oxygen per hour, while another possibility would be to extract the gas from the permafrost blanketing much of Mars.