NASA's Perseverance Rover Extracts Breathable Oxygen From Martian Atmosphere

Recently, an instrument on NASA's Mars rover Perseverance has produced oxygen from the planet's carbon dioxide atmosphere.

It's the second successful technology demonstration on the mission, which previously flew a mini-helicopter. 

NASA sent the Perseverance rover to Mars with some extra technology: a device (MOXIE) that converts carbon dioxide into oxygen. Dubbed as a "mechanical tree," it uses electricity and chemistry to split carbon dioxide molecules, made up of one carbon atom and two oxygen atoms. Carbon monoxide is released into the Martian atmosphere as a waste product.

"Moxie isn’t just the first instrument to produce oxygen on another world, it’s the first technology of its kind that will help future missions 'live off the land, using elements of another world’s environment, also known as in-situ resource utilization," said Trudy Kortes, director of technology demonstrations within Nasa’s Space Technology Mission Directorate.

The atmosphere of Mars is dominated by carbon dioxide (CO2), which accounts for 96% of the total concentration. The oxygen content is only 0.13 percent, compared to 21 percent in the Earth's atmosphere.

The Mars Oxygen In-Situ Resource Utilization Experiment, or MOXIE, extracted carbon dioxide from the Martian atmosphere to produce its first oxygen. MOXIE had to heat the gas to approximately 1,470 degrees Fahrenheit to convert the carbon dioxide. It produced a small amount - 5.4 grams of oxygen, equivalent to about ten minutes of breathable oxygen. It is capable of producing up to ten grams of oxygen per hour.

That's good news for the possibility of sending humans to Mars, and it may also eliminate the need to transport massive amounts of oxygen from Earth for use as a rocket propellant on the return journey.

Oxygen takes up a lot of space on a spacecraft, and astronauts are unlikely to bring enough with them to Mars. As a result, they'll need to extract their own oxygen from the Martian atmosphere, both for breathing and fueling rockets that will take them back to Earth.

According to NASA, it would take approximately 15,000 pounds of rocket fuel and 55,0000 pounds of oxygen to lift a crew of four astronauts off the Martian surface. According to MOXIE's principal investigator Michael Hecht, a crew of four would indeed require about a metric ton of oxygen to breathe for an entire year.

It would be difficult and expensive to transport all of that oxygen to Mars. That is why scientists are considering in-situ oxygen extraction.

"This is a critical first step at converting carbon dioxide to oxygen on Mars," said Jim Reuter, associate administrator of NASA’s Space Technology Mission Directorate (STMD). "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."

The conversion of carbon dioxide to oxygen isn't the only way future astronauts could live on Mars. Scientists and engineers have also proposed using on-site rocks to construct structures or even mining Martian or lunar ice for drinking water or rocket fuel.