
In short, the algae will use sunlight to transform CO2 into sugars that are then enhanced by bio-engineered E.coli into 2,3-butanediol. Interestingly, 2,3-BDO is not entirely conceptual as it currently exists and is mainly used to produce rubber components. It has just never been thought of as fuel before.
https://www.universal-sci.com/article/producing-rocket-fuel-on-mars-using-microbes?utm_campaign=Universal-Sci%20Weekly&utm_medium=email&utm_source=Revue%20newsletter
Neat. So all the astronauts have to do is bring, uh, how much algae we talking here?
The article doesn’t say, but it does mention a by-product of the process: Oxygen!
That would seem rather helpful. Mars or bust?