Man’s possible future missions to Mars will, of course, need oxygen. A turning point in this sense comes from the discovery that NASA has managed to produce it on the red planet, using only local resources. This is one of the results achieved by the Perseverance rover, which landed on Mars in February 2021 also in order to produce oxygen from the carbon dioxide-rich atmosphere of Mars.
Produce 100 minutes of breathing oxygen
Perseverance succeeded in producing about 100 minutes of breathable oxygen. He did it using a small tool called MOXIE, which stands for “Mars Oxygen In-Situ Resource Utilization Experiment”. Between April and November 2021, MOXIE captured carbon dioxide from Mars (the planet’s atmosphere is 96% CO2) to separate the oxygen atoms from the carbon dioxide molecules. The waste product, carbon monoxide, ended up in the Martian atmosphere along with the oxygen produced. The conversion process requires that the CO2 molecules, previously compressed and filtered to avoid the ingress of dust and earth, reach a temperature of 800 degrees centigrade.
Up to 10 grams from the latest experiments
The leaders of the project, coordinated by the Haystack observatory of MIT, have published a study on oxygen produced by MOXIE. In the seven experiments carried out in 2021, the instrument was able to produce an average of about six grams of oxygen, roughly corresponding to the amount of oxygen produced by a small tree on Earth, with peaks of almost 10 grams in the latest experiments. Another result obtained from the experiment was that it proved effective at different times of the Martian day and in different conditions during the seasons. “The only thing we haven’t been able to prove yet is that it can work at sunrise or sunset, when temperatures on Mars change dramatically,” explained Michael Hecht, principal investigator of the MOXIE experiment at MIT. “But now we have an ace up our sleeve”, added Hecht, “which will allow us to do so and once we have tested it in the laboratory, we will be able to show that we are truly capable of operating at any time.”
The goal is to significantly increase production
The real challenge now is to move from oxygen production of a few grams to other quantities capable not only of supporting a human mission to Mars (between 2 and 3 kilograms per hour), but also to obtain essential oxygen as part propellant to face the return journey of a hypothetical human mission from Mars to Earth. For a crew of six it is assumed that 31 tons of oxygen could be needed, numbers still far from those recorded so far.