Supplying oxygen or water is one of the challenges for future manned missions to Mars, towards which the Perseverance rover has taken another step by making breathable oxygen from the planet’s thin atmosphere.
Among the various experiments carried out by the NASA rover is Moxie, a device the size of a lunch box that has been demonstrating, intermittently, for more than a year that it can reliably perform the same work as a tree in any season. little.
The experiment is in charge of the Massachusetts Institute of Technology (MIT), which publishes in Science Advances the results of the seven occasions in which it has been launched, and in all of them it achieved the objective of producing six grams of oxygen per hour, more or minus the pace of a modest tree on Earth.
The good performance of the machine is a step towards the goal of sending manned missions and is also the first demonstration of the use of resources “in situ” to create resources that would otherwise have to be transported from Earth.
Since Perseverance landed in Jezero Crater in February 2021, Moxie has shown that it works in all seasons of the Martian year and in various time slots to extract oxygen from the carbon dioxide-rich Martian atmosphere.
The researchers envision that an enlarged version of Moxie could be sent to Mars before a human mission, to continuously produce oxygen at the rate of several hundred trees, generating enough to sustain people and power a rocket to return them to Earth. the earth.
The principal investigator of this project, Michael Hecht, from MIT, stressed that they have learned “a lot” from this experiment, which will serve as the basis for future larger-scale systems.
The current version is small, to fit aboard Perseverance, and is built to run for short periods, powering up and shutting down with each drive, depending on the rover’s exploration schedule and mission responsibilities.
The machine draws the Martian air through a filter that cleans it of contaminants, after which it is pressurized and sent through the solid oxide electrolyser (SOXE), which electrochemically splits the carbon dioxide-rich air into oxygen ions. and carbon monoxide.
Oxygen ions are isolated and recombined to form breathable molecular oxygen (O2), the quantity and purity of which is measured by Moxie before being released back into the air, along with carbon monoxide and other atmospheric gases.
The experiment has been turned on seven times, at different seasons of the year to test its effectiveness, as the density of Mars’ atmosphere varies much more than on Earth during the year.
“It has also worked at various times of the day, except at dawn and dusk when the temperature changes substantially,” time slots in which it has not yet been tested, Hecht said.
Engineers plan to expand its capacity and increase production, especially in the coming Martian spring, when atmospheric density and carbon dioxide levels are high.
Related news
They will also monitor the system for signs of wear. Moxie is just one of Perseverance’s experiments and cannot run continuously, instead turning itself off and on, creating thermal stress that can degrade the system over time.
If the machine can function successfully despite being repeatedly turned on and off, this would suggest, the team says, that a large-scale system, designed to run continuously, could do so for thousands of hours.