Oxygen is vital for life support, producing fuels and supporting agriculture. Being able to harvest it on Mars will be vital for future crewed missions. But producing oxygen on the Red Planet is challenging. Although there’s plenty of the element in the Martian atmosphere, it’s locked up in carbon dioxide molecules, which are very difficult to break. And any oxygen produced from this then needs to be separated from a gas mixture that also contains, among other things, carbon dioxide and carbon monoxide.
Plasma contains free charged particles, including electrons which are light and easily accelerated to very high energies with electric fields. “When bullet-like electrons collide with a carbon dioxide molecule, they can directly decompose it or transfer energy to make it vibrate,” said Vasco Guerra, a physicist at the University of Lisbon in Portugal. “This energy can be channelled, to a large extent, into carbon dioxide decomposition.” Researchers hope that the technique could deliver high rates of oxygen production with relatively lightweight instrumentation – always a factor when launching from Earth.