[47] This paper attempts to recapitulate some of the problem areas pertinent to manned space flight that have been discussed in the preceding papers and indicates some of the phasing problems which must be faced in incorporating information resulting from research investigations into an active program for the procurement of hardware. In this regard, the time table that is currently being used in planning the work and the manner in which we propose to coordinate activities will also be discussed.

The problems that have been discussed by the previous speakers have covered a wide range of subjects. For the purposes of discussion, figure 1 is a chart that groups these problems of multimanned space flight into three categories the mission, the vehicle and the operation. Appendices II and III list other problem areas in slightly greater detail. It is not the intention to single out or define the problem areas best suited for study by any particular Research Center. Matters of this kind, of course, are best determined by the Centers themselves. It is anticipated, however, that the Research Centers, in orienting their thinking toward the objectives outlined in this presentation, will develop a comprehensive problem list that would serve themselves and the Space Task Group as a guide to activity in this area. This list of problem areas, of course, is not complete, but it contains many items of problem areas that Mercury experience has shown must be considered and thoroughly evaluated before one would be able to prepare specifications for a mission such as this. Once the extent of the NASA in house effort on these problems is known, we will be in a position to issue complementary study contracts with industry and other groups to cover specialty areas not otherwise provided for.

In the mission area, considerable study is needed relative to the mission itself. For example, what part should the pilot really play? Should he be an active element in the system? What use can be made of the existing ground networks available in the time period? It may well turn out that emergency conditions dictate much of the essential elements of the design in the same manner that the escape and abort considerations for Project Mercury had a great influence on the design of that vehicle. The vehicle itself will have many of the problems reminiscent of those encountered in the Mercury program. But these will be more difficult to solve than in the case of Mercury. The problem of heating will, of course, be a serious one although it is one about which more is known perhaps than some of the other problems. Even in Project Mercury, we [48] find that we are pushing the technology of materials to the limit. The radiation hazard and the required protection will involve a tremendous research effort if, indeed, flights of the kind envisioned can be con sidered at all. In the other areas listed in the vehicle column, one will recognize regions requiring extensive investigations before the completion of any design can take place.

The items under operations reflect Mercury experience. Booster reliability and safety problems become an order of magnitude greater in difficulty because of the superorbital flight regime. We know from Mercury experience that the abort sensing problems and the launching techniques must be carefully programed. We are facing, perhaps for the first time, the problem of training people for real space flight. Mercury, we hope, will supply us with some insight to fit these training requirements. This is a whole new area of operations for NASA and some plans must be forthcoming for providing answers to human factors problems.

A proposed timetable of events for initiating the procurement of hardware is outlined on figure 2. Following the disclosure of plans to Research Centers, it is expected to disclose in a similar way the plans to industry representatives. After studying the guidelines, it is hoped the Centers will be able to outline what problem areas they will undertake, thus permitting us to initiate industry studies for problem areas not otherwise covered. Some procedure for the exchange of information will be required. The Space Task Group will have a team or group following these programs continually. However, we see no substitute here for a direct and frequent communication between Research Center personnel and Space Task Group people. Frequent communication between working groups is essential. Also, there are times when progress as a whole should be reviewed. For this reason, we have indicated the desirability of two briefings for the exchange of technical information to allow for such an overall assessment of progress. One such briefing is suggested for November 1960, at which time a preliminary research progress report would be arranged. Such a meeting would assist in focusing attention to the pertinent problem areas and might well reveal additional problem areas that have not yet come to light. It is believed desirable also, perhaps in the Fall of 1961, to arrange for a NASA Industry conference similar to the one recently held at Langley relative to Dyna Soar problems. The purpose of this conference would be to lay the foundation for the preparation of final specifications for the multimanned vehicle prior to extending an invitation for industry to bid on such a vehicle. The presence of industry at such a conference would also assure having them incorporate the latest thinking of NASA in their proposals which we would hope to be in a position to evaluate by July 1962. Contractor go ahead under this plan may be feasible as early as August 1962.

[49] The bar chart in figure 3 is intended to give a general idea of how we anticipate the various programs following Mercury to fit into the overall planning. Mercury itself will probably continue through 1962. The phasing out of the dark areas of the chart are intended to indicate the successful completion of the basic Mercury mission. If we can skip for the moment the lifting Mercury bar and focus our attention on the third line identified as the multimanned vehicle, we will observe that the research and development activity extends from the present time to approximately the next 5 years. The ticks for the bidder's conference correspond to those previously discussed. If everything goes according to schedule, however, it may be possible to receive some delivery on initial hardware for the multimanned vehicle as early as the beginning of 1965. We are of the opinion at this time that earth orbit qualifications for multimanned vehicle is essential. The period of this activity, of course, will be dependent upon the problems we encounter; but in full recognition of the fact that the radiation hazard may prohibit early completion of the lunar mission, we have allowed for the possibility of rather extensive earth orbiting flights to supply the experience and information that may well be essential to the formulation of more definite plans for the lunar mission. About all one can say at this time, is that the reentry vehicle or component of the multimanned system should be designed with the full capability of reentering with the hypervelocity required for the lunar mission.

In the time period between the phasing out of the Mercury and the introduction of flight tests of a multimanned vehicle, it is attractive to consider the possibility of a flight test program involving the reentry unit of the multimanned vehicle which at times we have thought of as a lifting Mercury. We, frankly, do not know what form this reentry vehicle should have. Only further studies will crystallize concepts in this regard. We feel rather certain it should be a vehicle capable of some lift in order to make use of the maneuvering capabilities that lift affords. We have envisioned the use of a Mercury capsule designed to provide lift capability as a full scale flight vehicle allowing us to gain considerable experience in guidance problems in this interim time period. The adoption of an interim program of this type, however, is a major undertaking for NASA, and we feel that we are not yet ready to finally determine whether we should attempt this step until more information is available upon which to base a decision.

The general concept of the lifting reentry vehicle, be it a Mercury capsule or a basically new reentry module of the multimanned vehicle, is to equip the capsule with the reentry control navigation system that would permit the vehicle to maneuver at least 500 miles from the impact point that would correspond to a ballistic trajectory. As noted in figure 4, two or three ground stations would provide command inputs to update the guidance system. The capsule would receive intelligence just [50] before the retrofiring period and at least in the experimental stage prior to the onset of high acceleration forces during the reentry plus some terminal guidance during the subsonic portion of the flight. At the present time, there is some hope that this kind of experiment could be performed with a Mercury capsule modified in such a manner as to provide the capability of providing a trimmed L/D other than zero. However, none of the problems have really been investigated to the degree required for a rational decision. We have proposed, therefore, that the problems presented by the lifting Mercury be studied in the wind tunnels in order to provide information on the problem areas described in figure 5.

The type of flap suitable for a lifting reentry vehicle is in itself something that will be established only from research programs. The type of flap shown in figure 5 is for illustrative purposes only and does not represent any preconceived notion as to the ultimate geometry that a lifting flap might assume. Whatever flap develops, however, must operate over a substantial Mach number range, and careful coordination of the interesting flap arrangements must be made in order to assure adequate coverage. The method of control is still under study but could very well be aerodynamic in nature. On figure 6, there are indicated some of the NASA facilities that could well be utilized in investigating the adequacy of a controlled flap for a lifting Mercury or a lifting reentry vehicle for the multimanned lunar program. Most of the basic wind tunnel models required for the tests that are shown in figure 6 are available from the Mercury program except for the incorporation of an aerodynamic flap. Many of the models are at the Space Task Group and can be made available at any time.

Having described our thoughts on the multimanned vehicular mission, we earnestly solicit your suggestions and proposals as to how best this effort can be carried out in the best interest of the NASA organization with its many centers and somewhat overlapping interests. We would hope in the immediate future to obtain your views as to the problems that each Center may concentrate on so that the whole NASA effort can be integrated as soon as possible.