A new study published recently in the journal Nature Communications describes a system created by American scientists to produce biofuels on Mars, which would increase the independence of settlements that are established on the red planet with respect to resources from Earth.
The bioproduction process It would use three native resources on Mars: carbon dioxide, sunlight, and frozen water. It would also need two microbes that would arrive from Earth: cyanobacteria (algae), which would take carbon dioxide from the Martian atmosphere and use sunlight to create sugars, and a specifically designed variety of E. coli bacteria, which would convert those sugars into a fuel capable of fueling rockets and other propulsion devices.
Independence of land resources
Being an on-site production system, power generation could be used to propel rockets and other spacecraft on their return to Earth, eliminating dependence on Earth’s resources. Currently, rocket engines traveling from Mars to our planet are expected to be powered by methane and liquid oxygen: both fuels do not exist on the Martian surface, therefore they should be transported from Earth.
According to a press release from the Georgia Institute of Technology, the transportation of these fuels It is not economical at all: transporting 30 tons of methane and liquid oxygen from Earth to Mars takes around 7 billion euros. That figure would be the necessary to make a single trip.
With the purpose of reduce economic impact and increase the viability of future missions, NASA has set out to develop a chemical catalysis process that allows transform Martian carbon dioxide into liquid oxygen. However, even if this process were feasible, it would still be essential to transport methane from our planet.
On the contrary, the scheme created by Georgia Tech specialists supposes a total independence from the elements arriving from Earth: the biotechnology-based on-site resource utilization it would make it possible to produce both the biofuel to propel the ships and generate liquid oxygen from the carbon dioxide present on Mars.
Related Topic: The air on Mars could be turned into rocket fuel.
Supporting the human colonization of Mars
In this way, not only would the cost of the missions be reduced, but it would also produce high-value surpluses for future settlements established on Mars: the biofuel generation process, called bio-ISRU, would produce exactly 44 tons of excess clean oxygen in each cycle, which could be used for various purposes in the framework of human colonization projects on the red planet.
Although the biofuel proposed by the researchers is already produced on Earth, until now it had not been thought of as a rocket propellant or its development on Mars. Called 2,3-butanediol, its production requires 32% less energy in relation to the strategy of sending methane from Earth and generating liquid oxygen through chemical catalysis.
As the gravity on mars it is only a third of the Earth’s, scientists took into account that much less energy is needed to lift off from the red planet. This allowed them to consider different chemicals that are not designed for launching rockets on Earth.
In addition, they analyzed the difference in solar spectrum on Mars, originated both in the distance from the Sun and in the absence of atmospheric filtering of sunlight. This was crucial to prevent high levels of ultraviolet radiation from damaging the cyanobacteria used in the process.
Designing the bioproduction of Martian rocket propellant via a biotechnology-enabled in situ resource utilization strategy. Kruyer, N.S., Realff, M.J., Sun, W. et al. Nature Communications (2021).DOI:https://doi.org/10.1038/s41467-021-26393-7