ECCENTRICITY MANEUVER IN EAST-WEST STATION KEEPING STRATEGY OF GEO SATELLITE (CASE STUDY: INDOSTAR II/SES-7)

• Main Author: Fitri, Elisa
• Format: Theses
• Language: Indonesia
• Subjects: Astronomi
• Online Access: https://digilib.itb.ac.id/gdl/view/57485
• Institution: Institut Teknologi Bandung

Geosynchronous Equatorial Orbit (GEO) drift from the nominal position caused by external forces, i.e. sun radiation pressure and earth's non-spherical potential. Sun radiation pressure changes satellite eccentricity, that is changes the orbit from a circle to an ellipse. Meanwhile, the earth's non-spherical potential caused longitude drift in the east-west direction. These two external forces caused a satellite out of the allocation dead band. Station keeping maneuver or orbit correction is required to correct satelli- te orbit due to external forces and to ensure the satellite remains within the allowed dead band. In this thesis, we performed the eccentricity maneuver to correct eccentricity at once longitude. This maneuver is done by keeping eccentricity within a control circle. The control circle is a circle that limits the changes in the eccentricity of the satellite. The research object is Indostar II/SES-7 satellite located at 108; 25 east longitude. We use General Mission Analysis Tool (GMAT) to perform station- keeping maneuvers. GMAT is a software for orbital design and analysis develo- ped by various international space agencies, one of which is NASA. Simulation is done for one year, the same strategy from the previous year can be used for the next years. There are three scenarios in this is simulation, i.e. scenario 1 (the control cirle, ec is the same as the eccentricity natural radii, Re), scenario 2 (ec = 0.5 Re), and scenario 3 (ec = 0.3Re). The various ec is required if the control station desired to control eccentricity into a very tightly magnitude and related to the collocation. V for each scenario from smallest are scenario 1, scenario 2, and scenario 3. If the three scenarios are compared, the most optimal is scenario 2.