Scientists conducted experiments on parabolic flight to assess the efficiency of oxygen-evolving electrolysis on the Moon and Mars.
The advance of the universities of Manchester and Glasgow would provide valuable insights for establishing human habitats beyond Earth.
Electrolysis can be used to extract oxygen from moon rocks or to split water into hydrogen and oxygen. This can be useful for life support systems and in-situ production of rocket propellant.
Lower gravitational fields on the moon (1/6e of the Earth’s gravity) and Mars (1/3rd of the Earth’s gravity) and their impact on gas-evolving electrolysis compared to conditions on Earth have not been studied in detail. Lower gravity can have a significant impact on the efficiency of the electrolysis, as bubbles can stick to the electrode surfaces and form a resistive layer.
New research published in nature communication shows how the researchers conducted experiments to determine how the potentially life-sustaining electrolysis method worked in reduced-gravity conditions.
In a statement, chief engineer Gunter Just said: “We designed and built a small centrifuge that can generate a range of gravity levels relevant to the Moon and Mars, and actuated on parabolic flight during microgravity, to reduce the influence of the gravity of the If you’re doing an experiment in the lab, you can’t escape the Earth’s gravity, but in the near-zero-g background in the plane, our electrolytic cells were only affected by the centrifugal force and so we couldn’t control the gravity level of tune each experiment by changing the rotational speed.
“The centrifuge had four 25 cm arms each containing an electrolysis cell equipped with a variety of sensors, so during each parabola of about 18 seconds we did four simultaneous experiments on the spin system.
“We also performed the same experiments in the laboratory on the centrifuge between 1 and 8 g. In this configuration, we had the arms swinging to account for downward gravity. It was found that the observed trend below 1 g was consistent with the trend above 1 g, confirming experimentally that high-gravity platforms can be used to predict electrolysis behavior in lunar gravity, removing the constraints of expensive and complex microgravity conditions. In our system, we found that 11 percent less oxygen was produced by the moon’s gravity, using the same operating parameters as on Earth.”
According to the University of Manchester, the additional power requirement was more modest at about one percent. These specific values are only relevant for the small test cell, but show that the reduced efficiency in low-gravity environments must be taken into account when planning energy budgets or product output for a system operating on the Moon or Mars.
If the impact on power or product output is considered too great for a system to function properly, some adjustments can be made that can reduce the effect of gravity, such as using a specially structured electrode surface or introducing flow or stir.
