MIT researcher to build “gas stations” on Mars. How does it work?

“If we don’t build gas stations on Mars, then it will be very challenging to get humans back to Earth.”

Traveling to Mars will require a large quantity of fuel. Similarly to bring humans back safely to Earth. But it’s really not very practical to ferry this much fuel over a distance of 140 million miles. So Lanie McKinney, a PhD candidate in the Aerospace Plasma Group at Massachusetts Institute of Technology (MIT), is developing technology that can generate rocket fuel directly on Mars using the carbon dioxide, which is already available in abundance in the planet’s atmosphere.

McKinney’s research work is based on the concept of in-situ resource utilization, or ISRU, which focuses on utilizing the resources already existing on a planet as an alternative to ferrying in supplies from Earth. Currently working under the supervision of Carmen Guerra-Garcia, the Esther and Harold E. Edgerton Associate Professor at MIT, McKinney has designed a miniature plasma reactor. Called a Nanosecond Repetitively Pulsed Dielectric Barrier Discharge(NRP-DBD). It uses cold plasma to split carbon dioxide into carbon monoxide and oxygen with the oxygen being able to be used for life support or as an oxidizer in rocket propellant.

“If we don’t build gas stations on Mars, then it will be very challenging to get humans back to Earth,” McKinney told MIT News. “We’re going to need some way to produce the propellant on site.” Although the designed plasma reactor successfully extracts oxygen from carbon dioxide, the main problem is that the separation of oxygen from the mixture produced by the plasma reactor before it recombines with carbon monoxide is a major challenge.

To solve this problem, McKinney has paired the reactor with an oxygen-selective membrane that quickly extracts oxygen to prevent it from recombining. But the integration process is not very well understood and McKinney and her team are not sure how the membrane will be affected by the highly reactive plasma environment. “We are not entirely sure what we will see,” McKinney says.

McKinney has made contributions to other projects aimed at making space missions more self-reliant. As the co-leader of MIT’s CERBERUZ team, she worked on NASA’s LunaRecycle Challenge, which looked into ways to recycle waste into useful materials for lunar and deep-space missions. McKinney and her team designed a device that makes powder out of mixed waste. By using injection molding, this powder can be reused to make 3D-printing filament and spare parts. Another project had McKinney bring together engineers and architects to come up with ways to protect lunar habitats from harmful radiation. The solution the team came up with was to make cast bricks out of lunar regolith that didn’t need mortar or other binders to stack.

As far as making rocket fuel on Mars is concerned, McKinney is not the only one, and in a study published in ACS Catalysis in April this year, Ahmed Badreldin, an assistant professor of chemical engineering at the University of Mississippi, and his team showed that astronauts could convert the carbon dioxide in Mars’ atmosphere to methane using a technique called electrochemical reduction. Methane is what the Raptor engines on Starship, the huge, fully reusable rocket Starship is developing to send humans to the Red Planet.