  The project consists to determine, mathematically, the trajectory that will
take an artificial satellite to fight against the air resistance. During our
work, we had to consider that our satellite will crash to the surface of our
planet. We started our study by understanding the system of forces that are
acting between our satellite and the earth. In this work, we had to study the
second law of Newton by taking knowledge of the air friction, the speed of the
satellite which helped us to find the equation that relates the trajectory of
the satellite itself, its speed and the density of the air depending on the
altitude. Finally, we had to find a mathematic relation that links the density
with the altitude and then we had to put it into our movement equation. In
order to verify our model, we'll see what happens if we give a zero velocity to
the satellite.
