Scientists at the Georgia Institute of Technology (Georgia Tech) have submitted a proposal to send bacteria to Mars for fuel production. The concept is intended to provide the aerospace industry with a strategic resource, and cheaper, to bring spacecraft back to Earth with astronauts from exploratory missions on the red planet.
The idea is to create a viable alternative to reduce the high costs — estimated at about $8 billion — around powering rocket engines the way they work today, based on methane and liquid oxygen. Because such sources do not exist on Mars, a future trip to the site would require ships to transport the compounds to be launched back to Earth.
The researchers described a biotechnological method for building an installation on Mars, consisting of four steps. Initially, plastic materials would be sent to the site to be assembled photobioreactors (the size of 4 football fields). There, cyanobacteria (algae) taken from Earth could grow through photosynthesis from carbon dioxide in the atmosphere.
The process for fuel generation on Mars involves the cultivation of bacteria on the Red PlanetSource: Georgia Tech/Reproduction
Then enzymes from a separate reactor would use sunlight to break down these bacteria and create sugars. In turn, terrestrial microbes would be added to this product E. coli genetically engineered to produce fuel for rockets and other propulsion vehicles, called 2,3-butanediol. This alternative fuel already exists on Earth, but is used in the production of rubber.
“Carbon dioxide is one of the few resources available on Mars. Turn this gas into a useful product [para a indústria aeroespacial] it is a good alternative for the creation of fuel that rockets require”, said Nick Kruyer, leader of the work, in an official statement from the institute. “2,3-butanediol has been around for a long time, but we never thought of using it as a propellant. After analysis and preliminary experimental study, we realized that it is a really good candidate”, added researcher Wenting Sun.
“You need a lot less energy to take off on Mars [devido à força da gravidade ser um terço do que é sentida no nosso planeta], which gave us the flexibility to consider different chemicals that are not designed for rocket launching on Earth. We started to consider ways to take advantage of the planet’s low gravity and lack of oxygen to create solutions that aren’t relevant here,” commented Pamela Peralta-Yahya, also involved in the research.
According to scientists, this process should generate 44 tons of clean oxygen, ready to be stored and used for other purposes, including as sustenance for future human colonization.
Conceptual art of a possible installation for a future colonization of MarsSource: NASA/Reproduction
However, the team highlighted that it is necessary to recognize other differences between the two planets in order to think about the application of efficient technologies for the production of fuel on Mars. Therefore, the next step will be to test the method in laboratories, as well as to think of solutions to possibly reduce the project dimensions and the payload of transporting Earth equipment.
“We need to carry out experiments to demonstrate that cyanobacteria can be grown under Martian conditions, and to consider the difference in the solar spectrum from Mars due to distance from the Sun and the lack of atmospheric filtration of sunlight. High ultraviolet levels can damage cyanobacteria,” said Matthew Realff, a scientist working on the analysis of algae-based processes.
The research entitled “Designing the bioproduction of Martian rocket propellant via a biotechnology-enabled in situ resource utilization strategy” was published in the journal Nature Communications. The work is the result of a multidisciplinary team at the institution, made up of chemical, mechanical and aerospace engineers.
ARTICLE Nature Communications: doi.org/10.1038/s41467-021-26393-7