STATION KEEPING DESIGN FOR SATELLITES IN SUN-SYNCHRONOUS ORBIT USING ECCENTRICITY AND SEMI-MAJOR AXIS MANEUVER CORRECTION METHODS
Kiki Citra Wati*, Endang Soegiartini

Astronomy Study Program, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung.
Jalan Ganesha 10, Bandung 40132, Indonesia.
*10321040[at]mahasiswa.itb.ac.id

Abstract

Sun-synchronous orbit (SSO) is a low Earth polar orbit that enables satellites to observe the same region on Earth at a constant local solar time each day, making it ideal for environmental monitoring missions. The continuity of this orbit relies on maintaining a nodal precession rate of \(360^\circ/year\), which is primarily influenced by Earths gravitational harmonics, represented by the \(J_2\) coefficient.
However, SSO satellites are also subject to various external perturbations such as lunar and solar gravity, atmospheric drag, and solar radiation pressure, which induce variations in key orbital parameters such as inclination (i), eccentricity (e), and semi-major axis (a). These variations alter the nodal precession rate, disrupt the consistency of local solar time, and degrade the accuracy of observational data. To mitigate this, a robust station keeping strategy is essential to preserve orbital stability in alignment with mission objectives.
This study proposes a station keeping strategy for the LAPAN A4/NEO-1 satellite, an Indonesian microsatellite planned to be launched into SSO. The strategy focuses on correction maneuvers targeting the satellites eccentricity and semi-major axis. Orbital simulations over a five-year mission duration without any corrective maneuvers were conducted using the General Mission Analysis Tool (GMAT) to quantify changes in orbital parameters due to perturbations. The results show an accumulated nodal precession drift of \(11.539^\circ\) for 5 years. Several maneuver frequency scenarios (with intervals of 2, 4, 6, 12, and 24 months) were tested to evaluate the effectiveness of each in maintaining the target nodal precession rate of \(360^\circ/year\). The outcomes of this study will be compared with the station-keeping strategy using inclination maneuver methods that has previously studied for LAPAN A4 satellite to determine a more efficient approach.

Keywords: Sun-synchronous orbit, station keeping, maneuver correction

Topic: Planetary Science