A semi-analytical solution for the motion of a low altitude Earth satellite under J2-gravity and air drag perturbations

This paper is dealt with the zonal harmonics up to J4 and atmospheric drag effects on the orbital elements of low satellite. There are many techniques to treat this problem as analytical and numerical techniques. The solution can be obtained by using two methods which are Cowell's Method and Average Method. We used average method as analytical method and applied Lagrange planetary equation to obtain the variation on the orbital elements. Cowell’s method was applied to estimating the perturbation because it is the most straight advancing method and correct. The atmospheric model drives in reckoning change of the density scale height with altitude. This study used the data of TLE of the International Space Station (ISS) to compare analytical method (average method) and numerical method Cowell’s method. A program code MATHEMATICA Language is constructing to treat the solutions (ISS). We find the good comparing between final TLE and Cowell’s Method more acceptable.