Method for re-entry prediction of uncontrolled artificial space object

A method for re-entry prediction of an uncontrolled artificial space object, the method comprising:

• calculating an average semi-major axis and an argument of latitude by inputting two-line elements (TLE) or osculating elements of the artificial space object at two different time points;
• calculating an average semi-major axis, an argument of latitude, and an atmospheric drag at a second time point of the two different time points by performing orbital propagation with a Cowell's high-precision orbital propagator using numerical integration up to the second time point, the orbital propagation being performed by applying an initial drag scale factor, which is an arbitrary constant, to orbit information at the first time point;
• estimating an optimum drag scale factor while changing the drag scale factor until error becomes smaller than a random convergence value by comparing the predicted average semi-major axis or the argument of latitude with a preset average semi-major axis or a preset argument of latitude at the second time point;
• and
• predicting time and place of re-entry of the artificial space object into the atmosphere by performing orbit prediction with the Cowell's high-precision orbital propagator using numerical integration from the second time point to a re-entry time point and being applied with the estimated drag scale factor.