The delivery and return of astronauts and cargo to the space station are measured in hours. But unlike the journey to the Moon, any journey to Mars will take many months each way, and early return is not an option. The conditions on the planet are also more difficult than those on the Moon due to the dust storms that hit Mars and make it difficult to collect solar energy. Therefore, preparing for these long journeys and human habitats on Mars is extremely challenging. One of the most pressing challenges is: How can you get enough fuel for the spacecraft to fly back to Earth?
Researchers have now discovered a more efficient way of creating methane-based rocket fuel theoretically on the surface of Mars, making the return trip all more feasible. According to a recent blog post on the University of California, Irvine, the discovery could add crucial flexibility to future astronaut missions to the Red Planet.
The process uses a single-atom zinc catalyst that will synthesize the current two-step process into a single-step reaction using a more compact and portable device. “The zinc is fundamentally a great catalyst,” says Houlin Xin, an assistant professor in physics & astronomy. “It has time, selectivity, and portability – a big plus for space travel.“
The method developed by Xin and his team will use anatomically dispersed zinc to act as a synthetic enzyme, catalyzing the carbon dioxide and initializing the process for making methane-based fuel. This will require much less space and can efficiently produce methane using materials and under conditions similar to those found on the surface of Mars.
“The process we developed bypasses the water-to-hydrogen process, and instead efficiently converts CO2 into methane with high selectivity,” Xin says.
The process of creating methane-based fuel returning rockets has been theorized before, initially by Elon Musk and Space X. They have developed and are currently testing a methane fuel-based engine, known as the Space X Raptor, that will power Space X’s next generation of spacecraft named Starship and Super Heavy.
Musk’s process utilized a solar infrastructure to generate electricity, resulting in the electrolysis of carbon dioxide, which produces methane when mixed with water from the ice found on Mars. Although successful on the massive orbiting laboratory, this process, known as the Sabatier process, is not efficient on Mars, according to Xin.
Despite the breakthrough, the process developed by Xin is still a ‘proof of concept,’ meaning that while it has been tested and proven in a lab, it has yet to be tested in the real world – or planet – conditions.
“Lots of engineering and research is needed before this can be fully implemented,” he says. “But the results are very promising.”