Microbes could be used to make rocket fuel on Mars

A team of scientists at the Georgia Institute of Technology have come up with a concept that would see bacteria shipped to Mars produce rocket fuel and liquid oxygen from atmospheric CO2 to power a spacecraft on its return journey to Earth.

Around the end of the decade, a rocket will lift off from Mars containing about half a kilogram (1 lb) of geological samples collected by NASA's robotic Perseverance rover. Though the rocket will only be sending the samples and their container into Mars orbit for retrieval by another spacecraft for the trip home, it will weigh about 880 lb (400 kg), with most of that taken up by the solid rocket fuel needed for the ascent.
To cut down on costs and free up payload space for something more useful than fuel for the return trip, the Georgia Tech team wants to use cyanobacteria and genetically engineered E. coli to produce an alternative fuel, which is used on Earth to make synthetic rubber and other polymers.