Accession Number : AD0768355

Title :   Power Lunar Rendezvous Guidance.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO SCHOOL OF ENGINEERING

Personal Author(s) : Baughn,Lawrence E. , Jr. ; Leach,James Edward

Report Date : JUN 1973

Pagination or Media Count : 86

Abstract : A computer program was developed to simulate the rendezvous of an ascending lunar shuttle on a bielliptic transfer orbit with an earth shuttle on a free-return circumlunar trajectory. The effects of the gravitational perturbations due to the earth and sun on the transfer trajectory were corrected by an equation which predicted these perturbations. Finite burn periods were used for the transfers into the unguided coasting timing semi-ellipses. A previously proposed timing system was developed and refined. Two controllers were investigated for the terminal guidance portion of the rendezvous trajectory. A linearized suboptimal method was developed using a set of Riccati equations and was applied successfully. A 'reduced-memory' optimization scheme was also developed, but could not be successfully implemented. Since the optimal control was not achieved by the attempted method, results are presented only for the linearized scheme. (Author)

Descriptors :   (*TRANSFER TRAJECTORIES, RENDEZVOUS SPACECRAFT), (*RENDEZVOUS TRAJECTORIES, COMPUTER PROGRAMMING), MATHEMATICAL MODELS, OPTIMIZATION, TERMINAL GUIDANCE, THESES, LUNAR CRAFT, LUNAR TRAJECTORIES

Subject Categories : Spacecraft Trajectories and Reentry

Distribution Statement : APPROVED FOR PUBLIC RELEASE