Motion of Satellite under the Effect of Oblateness of Earth and   Atmospheric Drag
  The equations governing motion of the satellite under the effect of oblateness of Earth and atmospheric drag have been simulated, for a fixed initial position and three different initial velocities, till satellite collapses on Earth. Simulation of motion of artificial Earth satellite subject to the combined effects of oblate Earth and atmospheric drag is presented. The atmospheric model considered here takes in to account of exponential variation of the density with initial distance of Satellite from Earth's surface, scale height and radial distance. The minimum and maximum values of orbital elements and their variation over a time for different initial velocities have been reported. 
Jaita Sharma, B. S. Ratanpal, U. M. Pirzada, Vishant Shah
physics.space-ph