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Lift Control During Atmosphere Entry from Supercircular VelocityThis paper presents an analysis of a guidance method which uses a reference trajectory. The four state variables needed to prescribe the trajectory are used as follows : Velocity is made the independent variable, and the errors in the rate-of-climb,
acceleration, and range variables away from the reference are used to govern the lift. A linearized form of the motion equations is used to show that this represents a third-order control system. First- and second- order control terms (rate of climb and acceleration inputs) are shown to determine the entry corridor depth by stabilizing the trajectory so that the vehicle does not skip back out of the atmosphere or does not exceed a specified acceleration limit. The destabilizing effect that range input (the third-order control term) can have is illustrated and the results indicate that a low value of range input gain must be used at the high supercircular velocities while larger values of range input gain can be used at lower velocities. The usable corridor depth and range capability with this guidance system are demonstrated for a lifting capsule (L/D = 0.5). The practical applications of this system are illustrated with a fixed trim configuration wherein roll angle is used to command the desired lift. The results show that the guidance system requires only one reference trajectory for abort entry conditions as well as for entry conditions near the design values.
Document ID
19620002529
Document Type
Conference Paper
Authors
Rodney C Wingrove (Ames Research Center Mountain View, California, United States)
Robert E Coate (Ames Research Center Mountain View, California, United States)
Date Acquired
August 1, 2013
Publication Date
January 1, 1962
Publication Information
Publication: Proceedings of the National Meeting on Manned Space Flight (Unclassified Portion)
Subject Category
Space Communications, Spacecraft Communications, Command and Tracking
Meeting Information
National Meeting on Manned Space Flight(St. Louis, MO)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Keywords
Atmosphere
Velocity
Reentry
Lifetime
Lift

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IDRelationTitle19620004468Analytic PrimaryProceedings of the National Meeting on Manned Space Flight (Unclassified Portion)
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