This study attempts to address the lifetime and reentry of the space debris in low earth orbit LEO which extends from 200 to 1200 km. In this study a new Computer programs were designed to simulate the orbit dynamics of space debris lifetime and reentry under atmospheric drag force using Runge-Kutta Method to solve the differential equations of drag force. This model was adapted with the Drag Thermosphere Model (DTM78, 94), the Aluminum 2024 space debris in certain size (1&10 cm) were used in this study, which is frequently employed in the structure of spacecraft and aerospace designs. The selected atmospheric model for this investigation was the drag thermospheric models DTM78 and DTM94, because of this dependence on solar and geomagnetic activities. It was found that the lifetime of the space debris increases with increasing perigee altitudes. It was also found that the elliptical shape of the debris orbit would change gradually into a circular shape, then its kinetic energy would be transformed into heat and hence the debris might be destroyed in the dense atmosphere.

This research studies the orbital dynamics of space debris in near earth orbit. The orbital dynamics of space debris is closely examined in near earth orbit whereby (apogee altitude ha=1200 km and perigee altitude hp=200 km). In addition, the lifetime of the space debris is calculated using the influence of the friction force exerted on the atmospheric particles with debris dimensions measuring between (1 and 10 cm). In this study, the Drag Thermospheric Models (DTM78 and DTM94) are used because of their dependence on solar and geomagnetic activities, and pulsed lasers are utilized to interact with Aluminum 2024 particles which are frequently employed in the structure of spacecraft and aerospace designs. A numerical analysis program (NaP1) was built to calculate the lifetime of space debris and its time of return to the atmosphere. It is then integrated with a second numerical analysis program (NaP2) developed using the Lax-Wendroff finite difference method to simulate the laser material interaction model. A high power Nd:YAG laser was applied to produce shock wave pressure in target. The results show that the maximum peak pressure occurs at 50 µm depth then slowly decays, the peak pressure increases with the increase of the laser intensity, and the optimum value of the momentum coupling coefficient (Cm) for the aluminum debris of size range (1and10 cm) is 6.5 dyn.s/j.