Keeping astronauts breathing aboard the International Space Station (ISS) and other space vehicles is a complicated and costly process. An international team of scientists have proposed a potentially better way to make oxygen for astronauts in space using magnetism.
The study, published in npj Microgravity, demonstrates for the first time that gas bubbles can be 'attracted to' and 'repelled from' a simple neodymium magnet in microgravity by immersing it in different types of aqueous solution.
The research could open up new avenues for scientists and engineers developing oxygen systems as well as other space research involving liquid-to-gas phase changes.
On the ISS, oxygen is generated using an electrolytic cell that splits water into hydrogen and oxygen, but then you have to get those gases out of the system.
Imagine a glass of fizzy soda. On Earth, the bubbles of CO2 quickly float to the top, but in the absence of gravity, those bubbles have nowhere to go. They instead stay suspended in the liquid.
NASA currently uses centrifuges to force the gases out, but those machines are large and require significant mass, power, and maintenance. Meanwhile, the team has conducted experiments demonstrating magnets could achieve the same results in some cases.
Although diamagnetic forces are well known and understood, their use by engineers in space applications have not been fully explored because gravity makes the technology difficult to demonstrate on Earth.
In the study, the team successfully conducted experimental tests at a special drop tower facility that simulates microgravity conditions.
They developed a procedure to detach gas bubbles from electrode surfaces in microgravity environments generated for 9.2s at the Bremen Drop Tower.
"These effects have tremendous consequences for the further development of phase separation systems, such as for long-term space missions, suggesting that efficient oxygen and, for example, hydrogen production in water (photo-)electrolyzer systems can be achieved even in the near-absence of the buoyant-force," Dr. Katharina Brinkert, from the Department of Chemistry at the University of Warwick, UK.
"After years of analytical and computational research, being able to use this amazing drop tower in Germany provided concrete proof that this concept will function in the zero-g space environment," added Professor Hanspeter Schaub of University of Colorado Boulder.