A trip to Mars would be difficult, to say the least. Human spaceflight has become a regular occurrence in near-Earth space in recent decades, but it takes a lot of rocket power to leave our gravity. It takes a great deal of force to leave the planet and return to Earth.

But NASA, other spaceflight agencies, and private companies have their sights set on sending humans to Mars and safely returning them to Earth. As such, engineers and scientists are working to find ways to create enough propellant to enable such travel.

Oxygen, which is essential for rocket propulsion, is difficult to obtain on Mars. However, results from the Mars prototype machine suggest that elements could be drawn out of the air. This suggests future production to power rocket launches, but it’s still not enough for humans to breathe Martian air directly.

“It would be very difficult, if not impossible, to design a manned Mars mission,” says Carol Stoker, a planetary scientist at the NASA Ames Research Center who was not involved with the project. “on site.”

A lunchbox-sized device now aboard the Perseverance rover has opened the door for producing propellants from resources found on Mars. The Mars Oxygen In-Situ Experiment (MOXIE) has successfully produced oxygen on Mars.

From Perseverance’s landing in February 2021 until the end of the year, MOXIE produced about 50 grams of oxygen in seven runs, according to a report published in the Journal on Wednesday. scientific progressMOXIE has continued to experiment under various conditions through 2022, said Jeffrey Hoffman, MOXIE’s associate principal investigator and professor of aeronautics and astronautics at the Massachusetts Institute of Technology.

The device can produce 6-10 grams per hour, depending on atmospheric conditions. Maximum production rates were set at the end of August, when the Martian atmosphere was at its densest, Hoffman said.

As for MOXIE’s purpose, Hoffman states: And that said, we’re on track. “

[Related: 5 new insights about Mars from Perseverance’s rocky roving]

MOXIE uses the molecules that make up the Martian atmosphere to produce oxygen. But it’s not a simple extraction. Mars’ atmosphere is 95% carbon dioxide (Earth’s atmosphere is mostly nitrogen and mostly oxygen). MOXIE must break down the CO2 molecule into carbon monoxide and oxygen.

First, MOXIE draws in air through a HEPA filter. Then, as Hoffman explains, Martian air isn’t dense enough for the oxygen-producing process, so it goes through a compressor. The device compresses the Martian air, greatly increasing its density: from 1/100 to about half the thickness of Earth’s atmosphere.

The carbon dioxide is then heated to approximately 1,500°F (800°C). Once the heat is up, it’s time for the main event. Go through an electrolysis unit that uses electricity to create a chemical reaction. There, the carbon dioxide encounters a catalyst, such as nickel, that dissociates the carbon dioxide molecule into carbon monoxide (CO) and oxygen ions. Electricity is then used to pull the oxygen ions through a filter into another chamber where they bond to oxygen molecules. The result is pure oxygen that can be used for breathing and rockets.

“The beauty of MOXIE is that from the oxygen side, all it needs is air,” Hoffman says. “So wherever you are, you can go where you want to go, and there’s atmosphere.”

[Related: This miniature rocket could be the first NASA craft launched from Mars]

MOXIE has produced oxygen during Martian nights, days, and multiple seasons, even winter. During the coldest months at the poles of Mars, carbon dioxide deposits as ice on the polar surface, reducing the density of the atmosphere. This means that MOXIE will have less CO2 available every six months, explains Margaret Landis, a research scientist at the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder. Still, it produced about 6 grams per hour during periods of thinning air.

“MOXIE could run on Mars anytime,” says Hoffman. “If I can run it a little longer, I will try running it at dawn and dusk when the conditions change rapidly. I can show that MOXIE can adapt to such changing conditions.”

However, a rate of 6-10 grams per hour would not produce enough oxygen for a manned mission to Mars. According to Hoffman, the average human breathes just under a kilogram of oxygen each day, and rockets need even more O2. Dozens, possibly hundreds, of tons of oxygen are needed to power a rocket that launches people off the surface of Mars. But that oxygen builds up over time. A full-fledged version of a system like MOXIE would need to produce around two to three kilograms of oxygen per hour to accumulate enough liquid oxygen for use in a rocket launch system, Hoffman said. says Mr.

Engineers already have prototypes of such large devices, he says. MOXIE had to be hitchhiked in his Perseverance rover, so it was kept small, but future missions could send a larger MOXIE-like device to Mars by itself. Hoffman says such a device might also have more features, perhaps including the ability to turn carbon monoxide products into something useful.

Just because you can produce oxygen doesn’t mean your rocket is ready to launch to Mars. Oxygen is just part of the rocket launch equation, says NASA’s Stoker. Rockets provide half the combustion reaction, the oxidizer, but rockets still need other ingredients for fuel. But oxygen could supply more than three-fourths of her mass needed to propel a rocket, greatly reducing the amount of material that would have to be transported from Earth to Mars. she added.

As technologies like MOXIE are scaled up, it’s worth considering the environmental impact this process could have on Mars, says Landis. “CO2 is a major component of the Martian atmosphere and plays a very important role in its seasonal cycles, so we need to think about it,” she says. “We still have a lot to learn about the exact implications of what will happen if we start altering this equilibrium between her CO2 on the surface and in the atmosphere,” said Kind of Gas.

“Sometimes it feels like we’re living in a science fiction future,” says Landis. “It’s a testament to how much we’ve accomplished on Mars.”