The work presented here is mainly based on the paper: Discrete velocity model for an escaping singlecomponent atmosphere by William J. Merryfield and Bernie D. Shizgal [3]. We have reproduced their model in order to contrast it with Direct Simulation Monte Carlo models as well as to apply it to different planetary bodies’ atmospheres. Also, we wish to show advantages of using discrete velocity method, such as computation time gain, numerical error reduction and scientific relevance regarding planetary atmospheres.