Making rocket fuel out of Mars' thin air: New breakthrough could make it happen

Astronauts could travel back to Earth from Mars using rocket fuel converted directly from the carbon dioxide in the Red Planet's atmosphere, using a technique known as electrochemical reduction, a recent study reports.It's an old method involving electrolysis, which is the application of an electrical current to drive a chemical reaction, but the new trick produces methane pure enough to be used as liquid propellant. (A number of rocket engines these days burn liquid oxygen and liquid methane &m