What can parabolic flights teach scientists and engineers about electrolyzers and how the latter can help advance human missions to the Moon and Mars? This is the goal of a recent grant awarded to the Mars Atmospheric Reactor for Synthesis of Consumables (MARS-C) project, which is sponsored by the Southwest Research Institute (SwRI) and The University of Texas at San Antonio (UTSA). The $500,000 award for this research is part of NASA’s TechLeap Prize program with the goal of testing experimental electrolyzer technology that can be used for future missions.
Parabolic flights are frequently used by NASA, research agencies, and academic institutions to simulate short-term microgravity for astronauts and scientific experiments. The simulations are conducted when the aircraft performs a bell-shaped curve by flying upward, then straight, then pitching downward, resulting in approximately 20 seconds of weightlessness for all passengers and experiments. It is estimated that each mission conducts between 15-20 parabolas, enabling consistent data and personal experience in weightlessness. The purpose of parabolic flights is to conduct Earth-based research that can’t be conducted in outer space or could serve as a precursor to a space-based experiment, as this study hopes to demonstrate.
“Humans have an intrinsic drive to push the boundaries of what’s possible,” said Kevin Supak, who is a Program Manager at the SwRI San Antonio office and project co-lead. “Exploring space catalyzes technological advancements that have far-reaching benefits in our daily lives—often unanticipated innovations arise as a direct result of overcoming the unique challenges of space exploration. Establishing permanent presences on other planetary bodies could pave the way for unprecedented scientific discoveries and technological breakthroughs.”
This research comes after similar work conducted in 2024 by Subak and SwRI in collaboration with Texas A&M University using parabolic flights to test boiling liquids under reduced gravity environments. Also, like this most recent work, the 2024 research aimed to explore how liquids boiled on different planetary surfaces, especially with the Moon and Mars exhibiting one-sixth and one-third the gravity of Earth, respectively. One aspect of that study was to evaluate the rate and amount of boiling that occurred on different surfaces, including stainless steel and plastic.
As its name implies, electrolyzers use electric currents to separate liquid water into their molecular components of hydrogen and oxygen using a process called electrolysis. On Earth, electrolyzers are used for a myriad of industrial and commercial applications, including vehicle fuel, renewable energy, and fertilizer production. For space applications, electrolyzers are currently used on the International Space Station (ISS) to provide the rotating crew with breathable oxygen while venting the hydrogen into space.
Like the ISS, future crews on the Moon and Mars will require the appropriate infrastructure for producing breathable oxygen and learning how to use electrolyzers in those reduced gravity environments could prove valuable, as the ISS’ zero-gravity environment has demonstrated their efficiency and reliability. Also like the ISS, having an electrolyzer on the Moon or Mars would negate the need for oxygen resupplies from Earth. Additionally, while the ISS vents unused hydrogen into space, astronauts on the Moon and Mars could use this hydrogen for fuel on return trips back to Earth, also resulting in negating fuel resupplies from Earth.
“In a partial gravity environment, like the Moon or Mars, a reduced buoyancy effect on gas bubbles in an electrolyzer poses challenges that aren’t present on Earth,” said Supak. “We lack an understanding about chemical processes that leverage bubble nucleation in low gravity, which is the gap we aim to fill.”
How will electrolyzers contribute to future missions to the Moon and Mars in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!