Inside Perseverance’s belly is a small box that, if all goes well, will turn part of the carbon dioxide-rich atmosphere of the Red Planet into oxygen. The experiment will aim to demonstrate technology that could one day support a manned mission to Mars.
Produce oxygen on Mars
The journey of Perseverance towards Mars is almost finished, with a landing scheduled for Thursday, February 18 in the Jezero crater. Focus today on the small golden box comfortably installed in the belly of the rover: the Experience of using in situ oxygen resources of Mars or MOXIE, an experiment aimed at produce a small amount of oxygen pure from Martian atmospheric carbon dioxide. A bit like trees, in the end, which, on the other hand, are based on much more complex processes.
This is a demonstration of technology that should ultimately allow future Martian explorers to breathe, naturally, but also and above all to fill the tanks oxygen they will need to return to Earth.
Note that MOXIE does not meet one of the main objectives of the Perseverance rover, which is to search for traces of past life. So, as a tech showcase, this little gold case will only work occasionally (maybe once every few months).
Another reason, and not the least, is the technology requires a significant energy input in order to heat a key part of the experiment to around 800 ° C. Each time MOXIE is running, the instrument will spend about two hours warming up, then producing oxygen for about one hour. This process will use most of the rover’s power supply for the day.
Several challenges to overcome
To operate, the instrument will extract carbon dioxide from the thin Martian atmosphere, then separate carbon from oxygen. MOXIE will produce carbon monoxide gas as a by-product so that it can easily dissipate.
Of course, this will not be easy. First, MOXIE will not have to use all the carbon dioxide it absorbs, at the risk of producing carbon soot instead of carbon monoxide, which could clog its instruments.
Another danger: if the instrument does not receive enough electricity, the reaction will reverse. In other words, MOXIE will work like a fuel cell. Instead of drawing oxygen from CO2, it will attempt to produce CO2 from oxygen. And since there is no source of oxygen on Mars, it will start to extract the famous gas from the anode side of the device, which will break down the material.
MOXIE is intended to test this technique of oxygen production only at Small scale. This is indeed all that researchers can afford, since Perseverance only offers 110 watts of power available for the whole rover. By comparison, a full-fledged oxygen plant would have to produce about two hundred times as much oxygen and would probably require about thirty kilowatts of power.
If the demonstration is successful, then we could imagine a much larger technology launched ahead of the first manned launches to Mars, the time to produce enough oxygen to be sure the astronauts can return home, before they even get home. do not leave Earth.