Research on Attack Angle Design Method for Sub-Orbital Vehicle Re-Entry to Reduce the Normal Acceleration Peak Value

An attack angle design method for solveing large overload problem for sub-orbital vehicle re-entry is proposed in this paper.Based on the normal acceleration dynamic equilibrium,this method is designed to reduce the normal acceleration peak value.In order to accommodate the angular rate of attack angle to the desired equilibrium value of normal acceleration,characteristics of the overload are analyzed first.Autonomous segmentations,feedback forecasting and iterative correction are used to design re-entry attack angle with an aim to minimize the normal overload peak.Numerical results demonstrate that the proposed method can reduce the vertical overload peak value effectively.It is found that the attack-angle strategy designed by the method can be used for sub-orbital spacecraft re-entry mission planning,re-entry trajectory and guidance law design.