Accession Number : AD0686327

Title :   AN ASSESSMENT OF LIFT-DRAG MODULATION TECHNIQUES FOR ATMOSPHERIC ENTRY,

Corporate Author : POLYTECHNIC INST OF BROOKLYN N Y DEPT OF AEROSPACE ENGINEERING AND APPLIED MECHANICS

Personal Author(s) : Crisp,John D. C.

Report Date : JAN 1961

Pagination or Media Count : 82

Abstract : The plane dynamics of lifting entry into a planetary atmosphere is studied in detail to arrive at generalizations of the behavior previously reported for nonlifting entry. Constant lift is first assumed and its effect on the variations of the instantaneous orbital elements established by numerical analysis of the exact equations of motion. Entry conditions necessary for instantaneous circularization and the attainment of inflective trajectories are determined as functions of entry angle and lift-drag ratio. A technique of constrained circularization is developed analytically which requires a simple coupled drag-lift modulation. Effective braking is achieved at low decelerations and considerable flexibility shown to exist in the choice of impact range. Characteristics of exit orbits and the multiple peak decelerations are given for multiple-pass impact with constant lift. (Author)

Descriptors :   (*LIFTING REENTRY VEHICLES, *ATMOSPHERE ENTRY), LIFT, DRAG, AERODYNAMIC LOADING, VECTOR SPACES, PERIGEE, DESCENT TRAJECTORIES, AERODYNAMIC HEATING, ABLATION, EQUATIONS OF MOTION

Subject Categories : Atmospheric Physics
      Spacecraft Trajectories and Reentry

Distribution Statement : APPROVED FOR PUBLIC RELEASE