On Mars, there are numerous ways to manufacture oxygen.… or there are right now. An international team of researchers has successfully tested a second hypothesis for the production of one of the universe’s most valuable gases following the success of the MOXIE experiment that traveled to Mars with Perseverance in 2021. They could even be able to do it on Mars itself.
Why, after the Mars Oxygen In situ Resource Utilization Experiment (MOXIE(widely )’s reported) success, should researchers be looking for an alternative? MOXIE is less than an ideal solution in a different world for a few technological factors. Solid electrolysis cells are the foundation of MOXIE, and while they are unquestionably successful at converting carbon dioxide into oxygen, they do it inefficiently.
, and under specific environmental conditions.
Their temperatures must exceed 1000 K, and the chamber’s pressure must be at least 1 bar. On Earth, such comparatively low pressures might not sound alarming. Still, on Mars, where the atmosphere’s pressure is only approximately 6.5 millibars or less than 1% of what is required for MOXIE to function correctly, they are unquestionably an issue.
In actual use, the MOXIE system needs big, heavy heaters and pumps to drive the required environmental conditions into an atmosphere that normally deviates greatly from those values. These bulky pieces of equipment come at an increased cost in terms of the mass required to leave Earth, as with everything else in space travel.
Although Perseverance’s MOXIE experiment proved successful, scaling it up would be difficult because just two astronauts would need enough oxygen, which would require 25 kW of power. That is almost equal to the amount of power used by an average American home each day, and that power is used solely to produce breathable oxygen.
Other issues exist, ranging from the electrolysis cell becoming fouled with there are numerous more issues, such as the possibility of Martian dust clogging the intake pumps or the carbon that is the other byproduct of this reaction fouling the electrolysis cell. MOXIE has so many recognized issues that NASA has invested in a NIAC effort to try to solve some of them.
A recent paper, however, takes a completely different tack. This method makes use of a “cold plasma” to try and separate the dissociated oxygen from the carbon monoxide that remains after the atoms are split. A system like combined electronic-ion conducting membranes might then suck the O2 away.
Although the development of these relatively novel materials is still ongoing, low-temperature plasma applications have garnered a lot of attention. Any functional system would be designed by taking into account several variables, such as the “residence time” of the CO2 in the plasma, or how long the gas is exposed to the plasma before the oxygen is drawn out of it.
More than simply a typical oxygen-generating device may be produced as a result of those choices. A single astronaut might be able to walk in the Martian atmosphere without the help of a potentially explosive O2 tank if plasma-based oxygen generation technologies are made small enough to be carried by them. Furthermore, various plasma and gas configurations might produce nitrogen fixation strategies that are essential for any future agriculture on the red planet. Before humans on Mars may breathe any oxygen produced by a cold plasma system, there is still a long way to go. But this study serves as a proof of concept, which is a positive move. Additionally, any method to safely and affordably remove carbon dioxide could have an influence closer to home. Right now, many governments and non-profits would be interested in finding a cheap and safe means to remove carbon dioxide from Earth’s atmosphere, so perhaps the near future of this technology will be closer to home.
Vasco Guerra from the University of Lisbon in Portugal and his colleagues have demonstrated that it is possible to cause plasma, a state of matter resembling a gas consisting of charged particles, to vibrate in such a way that it breaks carbon dioxide down into its parts, carbon, and oxygen. According to Guerra, astronauts might utilize this method to create oxygen on Mars by combining it with a membrane filter. He claims that by employing plasma technology, Mars has “perfect natural circumstances for the synthesis of oxygen.”
On the Perseverance rover, NASA’s Mars Oxygen In situ Resource Utilization Experiment (MOXIE), which produces oxygen, is already present on Mars. The carbon dioxide is separated using high pressures and temperatures, and the oxygen is then filtered out using a membrane constructed of stabilized zirconium. Guerra claims that using plasma instead of MOXIE’s electricity-driven process would be more effective and practical to carry out on the Martian surface.
According to Michael Hecht of the Massachusetts Institute of Technology, who is in charge of the MOXIE project, Guerra and his team’s work represents a significant advancement in plasma technologies. However, Hecht asserts that it is unlikely to be more efficient than MOXIE because MOXIE is now producing oxygen at amounts very close to the theoretical upper limits.
The plasma may, however, be adjusted to vibrate at various chemical frequencies, which enables it to separate other molecules and generate resources that MOXIE cannot, such as nitrogen and nitric oxide. Plasma can be used in other processes that are considerably more adaptable, such as those that produce nitrogen and NO for fertilizers and other products, according to Hecht.
The technology is still not yet prepared for Mars. Once the technology has been successfully tested, Guerra and his team plan to launch a space mission after completing the prototype in the upcoming years.
