The trouble with exploring the solar system is that there just aren't any rocket fueling stations out there. That won't be the case if future planet-hopping astronauts are equipped with a new kind of rocket engine which burns two gases that are already in good supply on several other planets: methane and oxygen.Methane doesn't exactly have high-tech, Trekkie credentials, being better known for its association with flatulent cows and natural gas. But the latest tests of a prototype supersonic methane rocket engine by XCOR Aerospace show that the good old swamp gas has interplanetary potential.
