Accession Number : AD0429017

Title :   ON THE PROBLEM OF OPTIMAL THRUST PROGRAMMING FOR A LUNAR SOFT LANDING,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF

Personal Author(s) : Meditch,J. S.

Report Date : 31 JUL 1963

Pagination or Media Count : 25

Abstract : The problem of minimal fuel thrust programming for the terminal phase of a lunar soft landing mission is shown to be equivalent to the minimal time problem for the mission. The existence of an optimal (minimal fuel) thrust program for the problem is then assured by appealing to existence theorems for time optimal controls, and the optimal thrust program is developed by application of the Pontryagin maximum principle. The optimal thrust program is shown to consist of either full thrust from the initiation of the mission until touchdown, or a period of zero thrust (free-fall) followed by full thrust until touchdown. An approximate switching function which is adequate for a large number of cases is derived, and a preliminary system design is presented. (Author)

Descriptors :   (*LUNAR CRAFT, LANDING), (*SOFT LANDINGS, ENERGY MANAGEMENT), THRUST, OPTIMIZATION, FUEL CONSUMPTION, FUNCTIONS(MATHEMATICS), TIME, EQUATIONS, MOTION

Distribution Statement : APPROVED FOR PUBLIC RELEASE