Design of flight safety display and decision rule for launch op-eration considering time derivative of instantaneous impact point and real time impact point dispersion

Abstract

This study proposes a new flight termination decision rule and a flight safety display related with range safety. The proposed rule and display uses information on both of the time derivatives of instantaneous impact point (IIP) of a launch vehicle and dispersion of the impact point calculated in real time. The time de-rivative of the IIP is defined as the impact point’s movement on the Earth’s surface, and the method makes it possible to know the IIP derivative and the IIP considering time delay of the operation of a fight terminate system can be found at the same time. Furthermore, this paper proposes the impact point dispersion that is calculated in real-time by dividing impacted velocity caused by fragments of a launch vehicle into three or-thogonal directions and defining a sensitive function on each direction. If the proposed analytic method of the time derivative of IIP and the real time impact point dispersion are to be applied in a flight safety infor-mation system (FSIS), a flight safety officer (FSO) would be able to make more accurate and reasonable deci-sions making.