The Mars Oxygenator - Making Oxygen on Mars

Living on Mars - Making Oxygen

The first chapter in our Living on Mars series -- a collection of articles on what technology and systems will be needed to survive - and thrive - on Mars.

Other articles in the series include:

When it comes to Mars, the essentials that we, as humans, need to survive aren't readily available.  Food, water, shelter, heat -- these are all things we will need if we want to sustain a somewhat comfortable life on the Red Planet.

But there’s one other element that is absolutely critical - -oxygen.

in 1996, Robert Zubrin published his ground-breaking work, The Case for Mars.  In the book, he pointed out that Mars has everything we need to survive -- it just may not be in a form we can immediately use.

With a little ingenuity, however, and using simple science and technology, it is possible to use the natural resources freely available on Mars and convert them into the things we need.

The Mars Oxygenator is one of those technologies.

Made famous in the book The Martian, by Andy Weir, the Mars Oxygenator converts carbon dioxide, the primary element in the martian atmosphere, into oxygen.

But how will it actually work?

The Mars Oxygenator

Converting carbon dioxide into oxygen is a well known process.  

On Earth, it's done naturally. Trees and other plants take in the carbon dioxide and produce oxygen through the chemical reactions of photosynthesis.  Photosynthesis requires some other pieces, though, to be effective. Namely, if you add light and water you get a reaction.

Basically, it goes like this:

Photosynthesis process

​In other words, take a little carbon dioxide, add a little water and light and what do you get? A carbohydrate and some oxygen. 

Pretty simple, right?

This is a well known and long-studied process. But on Mars it will need to be done artificially.  

​And this is where the Mars oxygenator comes in.

​The atmosphere of Mars is 96 per cent carbon dioxide. By simply pumping and storing the martian air, it can be put through ceramic catalysts that, along with high heat,  convert the CO2 directly into O2.  No need for the water - or the light.

Mars oxygenator CO2 conversion process

During the process, which basically uses a solid oxide electrolysis cell, the oxygen is separated from the CO2 as a single oxygen ion. Using applied electrical currents, the ion is attracted to an anode in the electrolysis cell where it can combine naturally with another oxygen ion and become the stable version we all know as O2.

It is now fairly simple to pump the oxygen into storage tanks for later use.

NASA had planned to actually test this process on Mars back in 2001. The Mars ISPP Precursor ("MIP")  was designed and built to fly on the Mars Surveyor 2001 Lander mission, but the mission was cancelled following the failure of the 1998 Mars Polar Lander.

Mars Oxygenator - the MOXIE

MOXIE - a testbed Mars Oxygenator. Credit: NASA

Now, however, NASA wants to try again.

​As part of the Mars 2020 Rover, NASA is including the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE). It is one of seven instruments NASA will place in the 2020 rover.

As Mars Exploration Project lead scientist Michael Meyer said:

It's extremely useful for future production of rocket fuel, or for when humans explore Mars. It's a real step forward in helping future human exploration of Mars, being able to produce oxygen on the surface of Mars.

NASA won't actually store any oxygen during this mission. It is simply meant as a test to validate the process.  After conversion, the oxygen, as well as the carbon monoxide by-product will be released back into the air.

Mars 2020 Rover to test Mars oxygenator

Mars 2020 Rover. Source: NASA

But proving the technology works will have important implications for future missions - and not just for breathable air, but fuel as well.

All fuels need oxygen to burn and, with a functioning Mars oxygenator, rockets could be pre-positioned on the Martian surface and fill their oxygen tanks directly from the atmosphere over a year and half or so.

Just like Zubrin laid out twenty years ago.

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