The ships and rovers in Generation Mars run on methane and oxygen, produced on Mars by electrolysis and the Sabatier reaction. I haven’t heard of 2,3-butanediol until now, but bioproduction of a Martian fuel sounds interesting.
A new study outlines a biotechnology process to produce rocket fuel on red planet. Researchers at the Georgia Institute of Technology have developed a concept that would make Martian rocket fuel, on Mars, that could be used to launch future astronauts back to Earth. The bioproduction process w