[1] The Space Task Group of the Goddard Space Flight Center has been assigned the task of implementing an advanced program of manned space flight. The tremendous amount of applied research required for such a program can only be done with the assistance of all of the NASA Centers. The following discussions were designed for use in enlisting the aid of the various centers in formulating the vehicle and mission design.

A very broad mission objective has been established; i.e., manned circumlunar flight and return to earth. It is implicit that the Saturn will be the primary propulsion system for this mission.

The following papers attempt to:

(a) Define the objective so as to achieve as much capability in the vehicle as possible.

(b) Draw on Mercury experience to provide broad guidelines for vehicle performance and safety.

(c) Provide flexibility in the vehicle capability in the event that the manned lunar mission is proved to be subject to unacceptable risk in the target time period.

(d) Indicate problem areas where work appears to be particularly needed.

The following papers outline and discuss guidelines for the mission. These guidelines are summarized in figures 1 and 2 and are presented more completely in Appendix I. Most of the guidelines are fairly obvious ones. A few of the guidelines may appear somewhat arbitrary and these require some introduction.

1. It is suggested that the vehicle be capable of lunar reconnaissance, i.e., it must pass close to the moon rather than simply make a broad lunar pass. This step is to insure that the problems of space navigation which ultimately must be solved for manned landings are attacked at an early date.

[2] 2. It is shown that, as in Mercury, the escape or abort maneuver will strongly influence the vehicle design, particularly for onboard propulsion. However, having provided sufficient onboard propulsion for aborts the vehicle should be quite versatile for mission-oriented space maneuvers - either in lunar or earth orbits.

3. In the human-factors area the crew size and environment will be discussed. However, it is felt that the greatest unknowns lie in this area, particularly in the field of radiation. It is this lack of certainty about radiation which raises questions about the feasibility of the lunar mission in the target time period. This is an area that is most difficult to explore and which will require the utmost support from the Life Sciences organization.

4. In the control and guidance phase of the mission guidelines, a definite stand is taken for onboard command of the mission. One major finding of the Mercury project to date is that great simplification is possible through the use of onboard command. This will be proven more important in this more ambitious space flight where the duration is relatively great, where communications with earth may become tenuous, and where unusual and unpredictable situations may require direct assessment and action.

The various papers make frequent reference to "modules" or the "modular concept." This design concept has emerged from studies made by several groups and may have considerable merit in the present program. In this concept, it is suggested that a reentry vehicle together with its escape package might be Part I of the system. This vehicle would have attached to it a lunar module or caboose which would complete the system. For orbital qualification of the lunar system, these two parts would be flown in earth orbits. The reentry vehicle, however, would also be compatible with a much larger and heavier module for specific earth-orbital missions. The reentry vehicle with only the onboard propulsion would form a multiman space taxi with a considerable rendezvous capability.

A brief discussion of weight allowances is in order - the use of the Saturn does not permit unlimited, or even generous, weight allowances for any part of the system. Figure 3 lists various components required for a lunar system along with early crude estimates of the weights that might be allowable for each. One point is clear - when the weight is parcelled out among the various components, the weight situation is fairly tight; since the total shown on figure 3 is 14,100 pounds and [3] the Saturn capability for a lunar mission is presently estimated to be 15,000 pounds. Another point worth particular notice is the rather large requirement of 6,000 pounds for the auxiliary propulsion. Much work will be required in this area; and, in fact, highly ingenious systems will have to be used across the board in order to stay within weight limits.

Figure 4 presents an approximate timetable for the NASA manned space flight program. The primary point to be made at this time is that the research and development phase of the advanced vehicle program is beginning now and must be vigorously pursued in order to achieve our mission within the target time period.

Editor's note: Because of the preliminary nature of these discussions the timetable shown may not be current at any given time and some of the terms used are subject to redefinition as the program develops. The term "Lifting Mercury" in figure 4, for instance, refers to some type of continuation of the Mercury flight-test program prior to the beginning of actual flights of the advanced vehicle. This is discussed more fully on pages 49 and 50 (paper by Mr. Donlan).