Exploring abort of manned lunar module from powered descent phase

Sections 1, 2 and 3 explain the exploration mentioned in the title. Tables 2, 4 and 5, and Figs. 1 and 4, present the results of our exploration, utilizing the published parameters of the Apollo 17; in addition, we analyzed the results. The core of sections 1, 2 and 3 consists of: "We mainly focus on the orbit design of the manned lunar module abort from powered descent phase. Firstly, in order to meet the requirements of the manned spacecraft aborting, an improved co-elliptic technique was proposed. Secondly, the expression of the explicit guidance law for ascent phase in abort was deduced. Then, with the help of Simulink tools this guidance law was proved to be precise enough when used in ascent phase, for the error in the height could be neglected and the error in the velocity was within a few meters per second. Finally, the height of apolune of the ellipse transfer orbit was designed based on the result of the ascent phase, which effectively shortened the waiting time of lunar module. Only abort from the pre-phase of powered descent needs this technique. " Section 4 presents our preliminary main conclusions, which may be useful for the manned lunar project.