TITLE: SATELLITE TRAJECTORY MODELLING WITH MISSION TO HALO ORBIT AROUND LAGRANGE POINT 1 (L1) IN THE SUN-EARTH SYSTEM

• Main Author: Luqmanul Hakim, Yudi
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/50051
• Institution: Institut Teknologi Bandung

Since a few decades ago, the Lagrange point had been proposed to be utilized by satellites in carrying out its mission. Missions that utilize the Lagrange point will use the three-body problem where there are two primary objects and one secondary object (satellite). This thesis uses a Circular Restricted Three-Body (CRTBP) which considers the effects of two gravitational forces from a primary object acting on a secondary object (satellite). CRTBP has assumptions; first, secondary objects have a much smaller mass compared to primary objects so in this case the mass of secondary objects can be ignored. Second, the orbit of two primary objects in a circle around the center of its mass. To be able to carry out missions at the Lagrange point, there are several orbits that can be used, one of which is the Halo Orbit. Satellites that use this orbit will surround the Lagrange point periodically. Although it is periodic, Halo orbit still requires regular station-keeping to maintain its orbit. This orbit is suitable for missions such as solar observations (L1), space telescopes (L2), and relay satellites. In this thesis, the chosen Lagrange point is the Sun-Earth Lagrange point L1. To design a Halo orbit, the initial Halo orbit determination algorithm consists of two phases, namely the determination of the initial guess of the Halo orbit and the differential correction. The initial guess is obtained from the analytic solution described by Richardson (1980). The solution is not entirely periodic because there are still slight deviation that causes the orbit to lose stability before the orbit has been completed (Geipel, 2019). Therefore a differential correction is performed to obtain a periodic Halo orbit. After the periodic Halo orbit is obtained, then a backward integration method is performed to determine the trajectory from Low Earth Orbit (LEO) to the Halo orbit that has been made. The results obtained from this thesis is a Halo orbit model around the Lagrange point L1 of the Sun-Earth along with its route from LEO. In choosing a trajectory from LEO to Halo orbit, the magnitude of ?v becomes the main consideration where the trajectory that has the smallest ?v will be selected.