An Error Analysis of Lunar Return Trajectories

摘要

The sensitivities of ballistic lunar return trajectories to errors in burnout flight path angle and velocity are examined. Only those trajectories which re-enter the atmosphere at a shallow flight path angle in the vicinity of the 're-entry corridor' have been included. The derivations included are based on a stationary earth-moon system and employ the sphere of influence concept. The calculations were done on an IBM 1620 Digital Computer. A listing of the computer programs is included. It was found that the shallower the re-entry angle the more sensitive the trajectory. The sensitivities to angular error increase with increasing burnout velocity while the sensitivities to velocity error decrease. A launch location was found at which the sensitivity to velocity error was essentially zero. This location was suspect because of the assumptions, but it was concluded that there were launch locations with minimum guidance requirements. (Author)