STUDY OF THE USE OF TERMINAL CONTROL TECHNIQUES FOR GUIDANCE DURING DIRECT AND SKIP ENTRIES FOR A CAPSULE TYPE VEHICLE AT PARABOLIC VELOCITY

摘要

This report describes a guidance system, based on terminal control tech¬niques, which was developed to control a capsule-type vehicle from parabolic entry conditions to desired terminal conditions. The guidance system makes use of three separate portions of a precomputed reference trajectory to obtain range control for the vehicle. A skip maneuver is utilized to obtain desired ranges greater than about 4,200 international nautical miles from the initial entry point.nResults of the study are presented which describe the operation of the system for a number of desired terminal conditions and a variety of off-nominal initial entry conditions. Results are also presented which illustrate the oper¬ation of the system in nonstandard atmospheres. Prom a range-error sensitivity standpoint, optimum skip-out conditions are indicated.