SS433, the first known object of a population recently termed 'Galactic micro quasars' provides an ideal laboratory for studying cosmic jet sources as most of the physical parameters of its jets are known to better than about an order of magnitude. Future X-ray missions win be sensitive enough to discriminate second-order effects in the jet flows, currently not accounted for in the interpretation of the observational data. Some of these effects and their relevance for the interpretation of the measurements are discussed. Further, numerical simulations of the terminal fate of the jet, disposing its energy into the interstellar medium are presented.