Description: The mathematical model of the rocket mortar start from the transport and starting container is developed. Movement in system "the rocket - the container" is partitioned on time for three sections. The first – a section of the rocket relative movement in the container. The second – a section of the rocket relative difficult movement in the container. The third – a section of the container movement after total loss of mechanical contact with the container by the rocket that represents the free oscillations. The model represents system of differential equations that describes the interdependent movements of components of system the flying device - the launcher concerning parameters which define these movements.
Keywords: mortar start, dynamics of start, system of differential equations