Since arriving at the Martian surface in February, NASA’s Perseverance mission has gained admiration for accomplishing feats thought to be possible only in science fiction, such as flying a helicopter there, this week. Mars’s pioneering rover has now added another feather to its cap.
A US space agency has announced that a device on board the rover was able to produce oxygen from a thin Martian atmosphere for the first time on Tuesday – a development that has brought joy to the scientific community, as it promises hope for crew missions in the future can rely on this technology for astronauts to breathe and return to Earth.
How Did Persistence Produce Oxygen on Mars?
In its first operation since arriving at the Red Planet, Mars In-Situ Oxygen Resource Use Experiment (MOXIE) produced 5 grams of oxygen of carbon dioxide in the Martian atmosphere, enough for an astronaut to breathe for 10 minutes.
On Mars, carbon dioxide makes up ~ 96% of the gas in the planet’s atmosphere. Oxygen is only 0.13%, compared to 21% in Earth’s atmosphere. Like a tree on Earth, MOXIE breathes carbon dioxide and breathes oxygen.
To produce oxygen, MOXIE separates oxygen atoms from carbon dioxide molecules. It does so by using heat at temperatures of about 800 degrees Celsius, and in the process also produces carbon monoxide as a waste product, which it releases in the Martian atmosphere.
A technology demonstrator, MOXIE is designed to produce up to 10 grams of oxygen per hour, and is installed inside the Persistence rover. The battery size of a car, weighs 37.7 lbs (17.1 kg) on Earth, but is only 14.14 lbs (6.41 kg) on planet Mars.
Through its first successful run, MOXIE managed to show that it survived its launch of Earth, a nearly seven-month journey through deep space, and landed on the Martian surface with Persistence. Over the next two years, MOXIE is expected to extract oxygen a further nine times.
MOXIE is just a test model. Future oxygen generators falling short of its technology must be about 100 times larger to support human missions on Mars.
But, why is oxygen production on the Red Planet so important?
A large amount of oxygen supply on Mars is essential for crew missions intending to get there – not just for spacefighters but for rockets to use as fuel on return to Earth.
According to NASA’s press release, for four astronauts to take off from Mars, a future mission would require about 7 tonnes of rocket fuel and 25 tonnes of oxygen – around the weight of an entire space shuttle . Astronauts living and working on Mars, by contrast, would require significantly less oxygen to breathe, perhaps around one tonne.
Scientists believe that transporting the 25 tonnes of oxygen from Earth to Mars for the return journey will be a huge challenge, and that their job would become significantly easier if the liquefied oxygen on the Red Planet. This is where the role of MOXIE comes in.
“When we send humans to Mars, we want them to return safely, and to do that they need a rocket to get off the planet. A liquid oxygen driver is something we could do there and not have to bring it with us. One idea would be to bring an empty oxygen tank and fill it on the planet Mars, ”said Michael Hecht, MOXIE Principal Investigator.
NASA hopes to build a larger technological descendant of the experimental MOXIE that can do this job. A one-ton oxygen converter of this kind would be far more economical and practical to take to Mars, instead of 25 tonnes of oxygen, the agency argues.
Jim Reuter, associate administrator for NASA’s Space Technology Mission (STMD) Directorate, called the MOXIE feat “an essential first step in converting carbon dioxide into oxygen on Mars”.
“MOXIE has more work to do, but the results of this technology demonstration are very promising as we move towards our goal of one day seeing human beings on Mars. Oxygen is not just the things we breathe. A rocket driver relies on oxygen, and future explorers will rely on producing a driver on Mars to make the trip home. ”