Methane is apparently the most easily available hydrocarbon. It is also a flammable, and highly combustible fuel; does burning methane provide sufficient power-weight to be used to launch artificial satellites and their ilk into Earth Orbit?
Probably possible, rockets have been built that used kerosene and even Hydrogen peroxide. Liquid natural gas stores a lot of energy per volume, but hydrogen is very light and so offers a huge amount of energy per kg. And in trying to accelerate your rocket vertically upward at several 'g' it's kg that matter.
Note: data from http://en.wikipedia.org/wiki/Energy_density