How magnets could help astronauts explore the moon and Mars

Scientists have developed a more efficient way to generate oxygen for astronauts that could help with future missions into deep space.

Current life-support systems such as those on the International Space Station (ISS) rely on bulky centrifuges to separate the oxygen and hydrogen bubbles created when water is split by electricity, a process known as electrolysis. On Earth, bubbles rise away from electrodes, but in microgravity, spinning is required to separate them. This method works, but the equipment is heavy, power-hungry and is ill-suited for long-duration missions to the moon or Mars.

A new study led by Alvaro Romero-Calvo of the Georgia Institute of Technology, in collaboration with colleagues at the University of Bremen’s Center of Applied Space Technology and Microgravity (ZARM) and the University of Warwick, has demonstrated a simpler, lighter and more sustainable solution in the form of magnets.

The team has shown that magnetic forces can guide gas bubbles in microgravity to collection spots, eliminating the need for mechanical spinning from heavy centrifuges. Their findings were published this month in the journal Nature Chemistry.

"In this paper, we demonstrate that two largely unexplored magnetic interactions — diamagnetism and magnetohydrodynamics — provide an exciting pathway to solve this problem and develop alternative oxygen production architectures," Romero-Calvo said in a statement.

Using Zarm’s 479-foot-tall (146 meters) drop tower in Bremen, Germany, the team tested the technology, producing an increase in bubble detachment efficiency of up to 240%, which would translate to much more effective electrolysis cells and oxygen generation.

"After four years of hard work, showing that magnetic forces can control electrochemical bubbly flows in microgravity is an exciting step towards more efficient and reliable spacecraft life support systems," said Romero-Calvo.

The approach was first developed by Romero-Calvo as part of his doctoral thesis, and then proven feasible through a grant from the NASA Innovative Advanced Concepts (NIAC) program.

The team is now set to continue the research under NIAC and European Space Agency (ESA) programs to assess the implementation, scalability and long-term efficiency of different water-splitting architectures relying on magnetism using both the microgravity drop tower and suborbital rocket experiments. The German Aerospace Center (DLR) also supported the research.