Ephemerides describe the position and velocity of a celestial object as a function of time. The ephemerides data are obtained by solving the fundamental equations of motion of the body, which is obtained by applying the fundamental laws of motion postulated by Keppler and Newton. The objective of this project is to build a software package that manages JPL ephemerides. With this software, we will can select planets or natural satellites contained in the ephemerides file and we will can work with them on different ways. Also, we are going to do several programs to make changes of coordinates and some vector fields. Finally, we are going to explain an application of this software, such as the parallel shooting, and we are going to show different simulations.. En aquest projecte es desenvoluparan models gravitacionals a partir d'efemerides JPL dels planetes del Sistema Solar i els seus satel.lits més importants. S'haurà de desenvolupar un paquet de software que pugui ser usat per a fer diferents calculs en problemes de mecànica celest i astrodinàmica.