In order for humans to live comfortably on the surface of Mars, the Moon, or another suitable planetary object a way of generating oxygen will be required. Scientists have undertaken the process of predicting the efficiency of oxygen-evolving electrolysis on the Moon and Mars as means of creating living conditions that will obviate the need for space suits.
The study comes from the University of Manchester and it considers the means of establishing a pathway to generate oxygen for humans to potentially call the Moon or Mars ‘home’ for extended periods of time.
The proposed method is electrolysis. This well-established technique involves passing electricity through a chemical system to drive a reaction. The process is carried out in an electrolytic cell, which is an apparatus consisting of positive and negative electrodes held apart and dipped into a solution containing positively and negatively charged ions.
New studies show how this method can be used to extract oxygen out of lunar rocks or to split water into hydrogen and oxygen. The major challenge was with the gravitational fields on the Moon (1/6th of Earth’s gravity) and Mars (1/3rd of Earth’s gravity) as this affects gas-evolving electrolysis. This is because lower gravity can affect electrolysis efficiency where some of the bubbles remain stuck to electrode surfaces and create a resistive layer.
This was addressed by designing a special centrifuge where different gravitational conditions were tested, and adjustments made. The researchers calculated the amount of additional power required to compensate and electrolysis process so that the same efficiency could be generated on Mars or on the Moon as could be achieved on Earth.
Such modelling demonstrates how this approach could be the key for life support systems. There could also be an application for the in-situ production of rocket propellant.
Other modifications are likely to include a specially structured electrode surface or introducing flow or stirring.
The research findings appear in the journal Nature Communications, titled “Predicting the efficiency of oxygen-evolving electrolysis on the Moon and Mars.”
NASA is experimenting with a device called the Mars Oxygen In-Situ Resource Utilization Experiment or MOXIE. The aim here is to produce oxygen from carbon dioxide in the Martian atmosphere by using solid oxide electrolysis.
