An international team of researchers has devised a plasma-based approach to producing oxygen on Mars to support exploration.
Oxygen is vital: it breathable environments, life support, producing fuels and supporting agriculture. Being able to harvest it locally on Mars will be vital for future crewed missions. However, producing oxygen on the Red Planet is challenging. Although there is plenty of the element oxygen in the Martian atmosphere, it is locked up in carbon dioxide molecules, which are very difficult to break. And what oxygen is produced from this then needs to be separated from a gas mixture that also contains, for example, carbon dioxide and carbon monoxide.
"We're looking at these two steps in a holistic way to solve both challenges at the same time," said author Vasco Guerra, a physicist at the University of Lisbon in Portugal, in a statement (opens in new tab). "This is where plasmas can help."
Plasma contains free charged particles including electrons, which are light and easily accelerated to very high energies with electric fields.
"When bulletlike electrons collide with a carbon dioxide molecule, they can directly decompose it or transfer energy to make it vibrate," Guerra said. "This energy can be channeled, to a large extent, into carbon dioxide decomposition."
The researchers hope that the technique could deliver high rates of oxygen production with relatively light-weight instrumentation, always a factor when launching from Earth.
"Together with our colleagues in France and the Netherlands, we experimentally demonstrated the validity of these theories," Guerra said. "Moreover, the heat generated in the plasma is also beneficial for the separation of oxygen."
The approach could complement NASA's Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE), a technology demonstration aboard the Perseverance rover. MOXIE extracts carbon dioxide from the atmosphere and turns it into oxygen and carbon monoxide, but in order to make that happen at a meaningful scale, a similar device would need to consume a huge amount of power.
The article was published in the Journal of Applied Physics.