Investigation of the LEO Transfer Orbit to GEO Using Lagrangian Points of the Earth-Sun System in the Presence of Perturbations

In this paper, a LEO to GEO transfer orbit is presented using the invariant dynamics of the Restricted Three Body Problem (RTBP) and the Lagrangian equilibrium points of the Earth-Sun system in the presence of disturbances. After launching the spacecraft to the LEO, its incidence angle is at least equal to the latitude of the launch site, so to transfer it to the GEO, it should be able to bring the spacecraft circle to zero with a large amount of energy. Here, with the help of the dynamics of the Lagrangian points, a method is proposed that minimizes the energy generated by the change in the incidence angle. For that purpose, the problem is divided into three parts. In the first stage, the appropriate initial conditions are obtained in GEO, which reaches the L1 point after the set time. The second phase is similar to the first one, with the difference that the initial conditions in the LEO are obtained in the form of forward transfer from L1. Finally, the Hallo orbit around L1 is used to connect two trajectories to achieve the integrated transfer orbit. In the following, the disturbances model is also added to the motion equations of the problem of three finite objects, in order to evaluate its effect on the results. The simulation results show that the impulse required by this method for inclination orbit greater than 29 degrees, even in the presence of disturbances, is better than the Hohmann transfer method.