AN INVESTIGATION OF THE EFFECT OF LAUNCH SITE LOCATION AND VARIATION OF LAUNCH PARAMETERS ON LUNAR-EARTH TRAJECTORIES.
Abstract
Lunar-earth trajectories are examined to determine the sensitivities of earth re-entry angle and velocity to changes in both static and dynamic lunar launch parameters. These trajectories are classified as free return single pass trajectories with no guidance or delta capability considered. The equations of motion for the trajectories are derived from the restricted problem of three bodies in a rotating coordinate system. The earth and moon are considered to rotate about their barycenter in a circular orbit at a constant rate of rotation. The equations of motion do not permit closed form solutions and are programmed for solution on the IBM 7094 Digital Computer in Fortran IV language using Runge-Kutta-Gill numerical integration methods. Two lunar longitude launch locations with five latitude locations for each longitude were investigated. At each location launch angles and velocities were introduced which would result in an earth re-entry angle of approximately five degrees with the local horizontal. For these initial conditions, sensitivities to change of launch velocity, launch azimuth angle and launch elevation were determined. The results showed that an increase in launch velocity caused an increase in all sensitivity coefficients; that re-entry angle was most sensitive to change in launch azimuth angle, and that re-entry velocity is solely a function of launch velocity. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1965
- Accession Number
- AD0625394
Entities
People
- Paul Stuart Skartvedt
Organizations
- Air Force Institute of Technology