Accession Number : AD0292628

Title :   CONSIDERATION OF LUNAR OBLATENESS ON THE NUMERICAL INTEGRATION OF CIRCUMLUNAR TRAJECTORIES

Corporate Author : SPACE SYSTEMS DIV LOS ANGELES AIR FORCE STATION CALIF

Personal Author(s) : TURNER,PHYLLIS

Report Date : 12 NOV 1962

Pagination or Media Count : 1

Abstract : The effect of a non-symmetric lunar gravitational potential when included in the numerical integration of tight circumlunar trajectories is examined. The label of tight trajectories is applied here because in the lunar phase the vehicle is turned through the greatest possible angle, which is accomplished by very near approaches to the moon. Such trajectories would be affected the greatest by a non-symmetric lunar gravitation potential. The particular trajectories described have distances of closest approach to the moon's surface varying from 100 to 15,000 nautical miles and all impact the earth upon return, the return to earth being retrograde to the earth's rotation. The maximum deviation, due to inclusion of a lunar oblateness term, on return conditions at earth was in the order of 15 miles from a nominal impact position and 0.1 ft/sec in impact velocity, which is beyond the accuracy of n-body programs in use today. Thus it was determined that, for the numerical integration of circumlunar trajectories, the moon may be considered a sphere of uniform density. (Author)

Descriptors :   *LUNAR PROBES, DESCENT TRAJECTORIES, ERRORS, GEOMETRY, GRAVITY, LANDING, LUNAR TRAJECTORIES, MATHEMATICAL ANALYSIS, MOON, NUMERICAL ANALYSIS

Distribution Statement : APPROVED FOR PUBLIC RELEASE