Study on a Lunar Approach Strategy Tolerant of a Lunar Orbit Injection Failure

Abstract

Discussed in this paper is a lunar approach strategy tolerant of a lunar orbit injection (LOI) failure. LOI is one of the most critical events for a lunar orbiting mission. If LOI is not performed, the spacecraft flies by the moon, and in the worst case, it escapes not only from the moon but also from the earth, which leads to mission failure. The proposed strategy is to design a trajectory so as to re-encounter the moon even when LOI is not performed. It provides an opportunity for mission recovery even in the case of an unexpected fly-by. A trajectory design procedure is introduced and an example of the designed trajectory is shown.