Unified guidance analysis in design of space trajectories

Based on the fact that all of the ballistic space trajectories can be piecewise approximated by conic sections, certain geometric and dynamic similarities of these trajectories permit a systematic and unified guidance investigation. This paper develops analytical expressions for a set of dimensionless differential corrections and a “proper” coordinate system suitable for generalized preflight guidance analysis. Numerical results in graphic form characterizing interplanetary and lunar trajectories are presented which are applicable to the calculation of target dispersions caused by random injection and maneuver execution errors and the determination of required midcourse corrective maneuvers.