"An investigation has been made of some of the problems associated with abort from landing and return to an orbiting vehicle in a 50-mile lunar orbit. For this study the landing module was considered capable of direct return to the orbiting vehicle from a hovering position at the lunar surface. The investigation was divided into two parts, an analytical study and a simulation study. The results of the analytical study indicate that, for an economical return to the orbiting vehicle, the landing maneuver should be chosen such that the orbiting vehicle is almost directly above the landing module at the touchdown point. This requirement places limitations on the angular travel of the landing vehicle around the moon prior to touchdown. Results of the simulation study indicate that a pilot can control the abort maneuver by using visual information."--Summary.