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 PLATEAUS AND GROSS MISSION DESCRIPTION

This section of the Symposium will describe the first Apollo lunar landing mission in its entirety—from lift off to recovery. It is intended to provide the general framework for a proper understanding of the subsequent presentations which will explore particular aspects of the mission in c ons iderably greater detail.

It is useful to think of the lunar landing mission as being planned in a series of steps (or decision points) separated by mission "plateaus" ( Figure 1). The decision to continue to the next plateau is made only after an assessment of the spacecraft's present status and it's ability to function pro­perly on the next plateau. If, after such as asse sment, it is determined that the space craft will not be able to function properly, then the decision may be made to proceed with an alternate mission. Alternate missions, therefore, will be planned essentially for each plateau. Similarly, on certain of the plateaus, including lunar stay, the decision may be made to delay proceeding in the mission for a period of time. In this respect, the mission is open-ended and considerable flexibility exists. This flexibility will be discussed in detail throughout the symposium.

It will be convenient, for purposes of overall mission description, to quickly go through the mission plateaus and decision points. Following this gross description, the operations for each plateau will be examined in greater detail.

The end points of these plateaus representing major "commit" points in the lunar landing mission are characterized by propulsive maneuvers resulting in major changes in the space­craft energy. These commit points and mission plateaus can both be represented schematically on a single chart as shown in Figure 2.

Figure 2 illustrates the major maneuvers during the lunar landing mission in terms of both delta V (on the left) and pounds of propellant (on the right). These maneuvers repre­sent the "commit" points, and the space in between represents the plateaus. A pictorial representation of the mission is illustrated in Figure 3, in which the Earth, the Moon, and their relative movement throughout the mission are shown to scale in an earth centered coordinate system. The spacecraft's orbit's about the earth and moon are, of course, not to scale.