Microbes on Mars are being used to make rocket fuel by US scientists

Researchers in the United States have found a method that could aid astronomers in the development of Martian rocket fuel utilising bacteria on the Red Planet. Two bacteria will be delivered from Earth to Mars, while the bioproduction process will utilise three resources unique to Mars: carbon dioxide, sunlight, and frozen water.

According to a team led by Georgia Institute of Technology researchers, the first is cyanobacteria (algae), which would take CO2 from the Martian atmosphere and use sunlight to create sugars, and the second is an engineered E. coli that would convert those sugars into a Mars-specific propellant for rockets and other propulsion devices.

The Martian propellant, known as 2,3-butanediol, is already in use and can be made by E. coli, according to the study, which was published in the journal Nature Communications. On Earth, it’s utilised to manufacture polymers, which are then used to make rubber.

“On Mars, carbon dioxide is one of the few resources available. Biology’s ability to transform CO2 into useful products makes it an excellent fit for making rocket fuel, according to Nick Kruyer of Georgia Tech’s School of Chemical and Biomolecular Engineering (ChBE).

Methane and liquid oxygen are currently planned as fuels for rocket engines launching from Mars (LOX). They must be delivered from Earth to power a return spaceship into Martian orbit because neither exists on Mars.

The cost of transporting the required 30 tonnes of methane and LOX is projected to be over $8 billion. To cut costs, NASA considered converting Martian CO2 to LOX via chemical catalysis, although this still required methane to be brought from Earth.

Georgia Tech researchers presented a biotechnology-based in situ resource utilisation (bio-ISRU) technique that can create both the propellant and LOX from CO2 as an alternative.

The process begins with the delivery of plastic materials to Mars, which will be constructed into four-football-field-sized photobioreactors.

Photosynthesis would allow cyanobacteria to grow in the reactors (which requires carbon dioxide). The cyanobacteria would be broken down into sugars by enzymes in a separate reactor, which would then be given to the E. coli to make the rocket fuel. Advanced separation procedures would be used to extract the propellant from the E. coli fermentation broth.

According to the researchers, producing propellant on Mars with Martian resources could help cut mission costs. Furthermore, the bio-ISRU process will produce 44 tonnes of extra clean oxygen, which might be used for various purposes such as human colonisation.