Book Description
Onboard procedures requiring only simple calculations have been developed for midcourse and approach guidance for translunar trajectories. For midcourse guidance the procedure relies solely on an optical range measurement. The approach-guidance procedure requires a star-to-body measurement and may require a range measurement, depending on the distance to the moon. For both procedures the velocity-correction vector is applied in a fixed inertial direction. In the approach-guidance procedure either one or two guidance maneuvers are applied, depending on the accuracy desired and tile distance to the moon. An error analysis showed that perilune radius can be controlled to a onesigma accuracy of about 30 km.
