Particle physics experiments

Microgravity experiments could help space missions find water

New research on generating oxygen from water could help support long-term missions to the Moon and Mars.

Researchers from the University of Glasgow carried out a series of microgravity flights to study how the planets’ different gravitational attractions might affect the electrolysis process.

Electrolysis uses electric current to split water into its constituent gases, hydrogen and oxygen. Oxygen is vital for space missions for astronauts to breathe and power their rockets.

DR Bethany Lomax, principal investigator of the study during one of the parabolic flights.

Current space missions carry the oxygen they need in bulky reservoirs, but as plans to establish permanent bases on the Moon and Mars gather pace, scientists are proposing to find sources instead.

These sources could be in the form of ice which can be present on both planetary surfaces.

Electrolysis of melted ice could free missions from the need to carry all their own oxygen and help proposed long-term habitations like NASA’s Artemis moon station become self-sufficient.

The process of electrolysis on Earth is well understood, but much less is known about how it might work in low gravity environments like Mars.

In a new article published in Nature Communications, the research team led by Dr. Bethany Lomax described how they set out to find answers to this.

They designed and built an experiment to take into account the microgravity environments created during parabolic flights.

During parabolic flight, aircraft create brief periods of weightlessness by flying in alternating upward and downward arcs.

On board a plane piloted from an airport in Germany by the European Space Agency and Novespace, the researchers deployed four electrolysis cells integrated into a small centrifuge.

In doing so, they were able to recreate the microgravity of the Moon and Mars and measure the oxygen bubbles created at the electrodes of each cell.

The results suggest that the electrochemical cells would produce 11% less oxygen under lower gravity conditions if more power was not supplied to compensate.

Dr Bethany Lomax, lead author of the paper and a PhD student at the University of Glasgow, took part in the flights with co-authors Patrick McHugh and Paul Broadley.

Dr Lomax, now a researcher at the European Space Agency, said: “There seemed to be a gap in the previously reported work, where the drop in efficiency at gravity levels relevant to the Moon and Mars was not studied experimentally.

“The experiments we were able to do on board the parabolic flights in microgravity aimed to fill this gap.

“The process of taking the flights to get these results was difficult, not only the nausea of ​​the constant rises and falls during the dishes, but also arranging a trip from the UK to Germany during the pandemic.

“The whole team worked very hard to get the experiment ready in time for the flight.

“However, it was worth the observations we were able to make, which we hope will be of real use to future space mission planners.”

Researchers from the Universities of Glasgow and Manchester, the European Center for Space Research and Technology in the Netherlands, and the Johns Hopkins University Applied Physics Laboratory in the United States contributed to the article.

The paper, titled “Predicting the Efficiency of Oxygen-Evolving Electrolysis on the Moon and Mars,” is published in Nature Communications.

The research was supported by funding from the European Space Agency Networking/Partnership Initiative, the UK Space Agency, the Engineering and Physical Sciences Research Council (EPSRC), the Institution of Mechanical Engineers and the Royal Society.