An experiment onboard NASA’s Mars Perseverance rover has extracted breathable oxygen from carbon dioxide for the very first time on an extraterrestrial world. The milestone is an important proof-of-concept for more advanced technologies that will be necessary to support human exploration of the red planet in the future.
The Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) is about the size of a shoebox and sits near the front of Perseverance’s frame. MOXIE sucks in Martian air, which is 96 percent carbon dioxide, heats it up to about 1,470°F (800°C), and plucks the oxygen atoms out of the carbon dioxide using a process called solid oxide electrolysis.
Scientists have been eager to demonstrate onsite oxygen production on Mars for decades, but MOXIE is the first experiment that actually has made it to the red planet. On April 20, this long-time dream became a reality as MOXIE successfully produced about five grams of oxygen, enough to keep an astronaut alive for 10 minutes.
“This is a critical first step at converting carbon dioxide to oxygen on Mars,” said Jim Reuter, associate administrator for NASA’s Space Technology Mission Directorate, in a statement. “MOXIE has more work to do, but the results from this technology demonstration are full of promise as we move toward our goal of one day seeing humans on Mars.”
“Oxygen isn’t just the stuff we breathe,” Reuter added. “Rocket propellant depends on oxygen, and future explorers will depend on producing propellant on Mars to make the trip home.”
To that point, the volume of oxygen required to fuel a return trip from Mars far outweighs the volume needed for human life support. Blasting a crew off of the Martian surface would take about 55,000 pounds (25 metric tons) of oxygen, about 25 times as much as a Mars-based crew of astronauts would need to breathe over an entire year.
A crewed round-trip to Mars would be an extremely complex, dangerous, and expensive undertaking, forcing mission planners to optimize the limited space and weight available. It would be far more economical to manufacture this key gas at the Martian surface with a future scaled-up iteration of MOXIE, which scientists estimate would weigh about one ton, than it would to haul 25 metric tons of Earth oxygen across the 33-million-mile gulf between the planets.
MOXIE will continue to test its oxygen-making abilities over the next Martian year, a period of 687 days, potentially meeting its peak production rate of 10 grams of oxygen in an hour. Though this is just a technology demonstration, it paves the way for more sophisticated experiments that could eventually support the first human missions to another planet.