does have a very special application in the power spectrum shown to you by Dr. Bisplinghoff. Mr. KARTH. Is the hydrogen used as a gas? Mr. SLOOP. Stored as a liquid, and can be gasified before going into the engine. We can use other reactants. Mr. KARTH. What about the normal boiloff. It is hard to store, isn't it? Mr. SLOOP. Yes. One of the ideas considered as to use the boiloff of the tanks to drive this engine, or if the spacecraft carries a different fuel and oxidizer, an engine could be built for them. For example, there is a NASA contract for an engine of this kind that runs on nigrogen tetroxide and a hydrazine mixture. Mr. KARTH. What are the possible consumer applications of those various sources of power we have been discussing today, if any? Mr. SLOOP. I think the thermionic system coupled with a nuclear reactor is of interest and I think that Mr. Finger will mention it. Solar cells, thin-film solar cells in large surfaces might be used in certain remote or arid parts of the earth; and you are all familiar with sun-powered radios, and things of that sort. Fuel cells, I think, will have an application for other purposes; as you know, and as you mentioned the other day, the Navy is working on fuel cells, and so is the Army, for terrestrial applications. I think fuel cells will have the greatest application on earth of those I mentioned. Mr. KARTH. Thank you. Mr. SLOOP. The last slide (fig. 231) is one that touches on the same area that Dr. Kelly mentioned in his testimony; namely, microminia turization. In this case we are working on utilizing the miniaturization techniques coming out of the research laboratories to reduce the sizes of circuitry that is associated with a power system. All this is meant to show is the great comparison between an experimental molecular power supply synchronizer, used in a three-phase synchronization circuit for power supply aboard spacecraft, compared with conventional components shown to the left and the right of it. There is a dime also pictured for comparison, so you can see there is quite a possibility of sizes reduction and, of course, increased reliability. This concludes the summary of what I wanted to say. Mr. KARTH. Thank you very much, Mr. Sloop. Are there any further questions? Unless the members decide later on they would like to have you back, I think we can adjourn today and meet at 10 o'clock on Monday for the purpose of hearing Dr. Konecci. Dr. BISPLINGHOFF. Yes, sir. Mr. KARTH. If there are no questions at this point, the meeting is adjourned. (Whereupon, at 12 noon, the committee was adjourned.) 1964 NASA AUTHORIZATION MONDAY, APRIL 8, 1963 HOUSE OF REPRESENTATIVES, SUBCOMMITTEE ON SPACE SCIENCES AND ADVANCED RESEARCH AND TECHNOLOGY, Washington, D.C. The subcommittee met, pursuant to adjournment, at 10 a.m., in room 304, Old House Office Building, Hon. Joseph E. Karth (chairman of the subcommittee) presiding. Mr. KARTH. The committee will be in order. Mr. Ames, I understand that you will be our first witness this morning. I see you have a prepared statement. I wonder if you could summarize the statement, and give us the benefit of whatever slides or other visual aids you might have. Mr. AMES. Thank you, sir. I appreciate the opportunity to appear before the subcommittee, Mr. Chairman, and would like to have my prepared statement in the record as you have indicated. STATEMENT OF MILTON B. AMES, JR., DIRECTOR, SPACE VEHICLES, OFFICE OF ADVANCED RESEARCH AND TECHNOLOGY, NASA (The prepared statement of Milton B. Ames, Jr., is as follows:) Mr. Chairman and members of the subcommittee, the objective of the space vehicle systems advanced research and technology program is to identify and solve critical technical problems bearing on present-generation space vehicles, as well as to advance the frontiers of knowledge that will enable the development of more advanced space vehicles for future space missions. The increased complexities of the advanced space vehicle systems that will be required to accomplish our national space objectives for the next two decades attest to the need for a broad, yet thorough and timely research program, to establish the technology required to insure the continued superiority of our country's space flight capability. PROGRAM AREAS The space vehicle research and technology program covers a broad range, as indicated by the areas of activity shown on figure 1. They are Vehicle technology flight experiments. Such a program has many facets. It begins with conceptual studies of missions and related launch vehicles and spacecraft, in order to evaluate their feasibility, to identify major problems, and to provide guidance and perspective for ongoing research and technology programs. Manned missions to the planets, manned orbital space stations, and nuclear Earth-Moon ferries are but a few examples of such studies. 96-504 0-63-pt. 3b-18 In the space vehicle aerothermodynamics area, our objectives are to devise better systems for entry into the atmosphere and for recovery of spacecraft, as well as economical and reliable methods for recovering and reusing large and expensive launch vehicles. Aerodynamic characteristics of new and unusual spacevehicle configurations_must_be studied to establish stability, control, and performance characteristics. Extreme heating conditions at the base of large multiengined launch vehicles, as well as effects of aerodynamic heating on spacecraft during entry into various atmospheres, such as those of the Earth or the planets, must also be investigated. Next, in the environmental factors and technology area, knowledge is required of the environments of the atmosphere and space, and their effects on vehicle design. Winds and atmosphereic turbulence create many control and structures problems. The harsh space environment with its many hazards to the spacecraft must also be thoroughly understood. The effects on space vehicles of high-energy radiation, meteoroid impacts, thermal radiation from the Sun, weightlessness, and hard vacuum must be defined and studied. Space-vehicle structures will become larger and heavier, and they will be re*quired to operate for longer periods of time to perform the advanced missions that will follow present programs. Aggressive research activities are required to maintain the weights of these structures at reasonable levels and, at the same time, to insure reliability under the severe environments and complex loading conditions which they will experience. Information resulting from research and technology programs must be formulated into space-vehicle design criteria to insure prompt and proper application ta vehicle design in an acceptable and uniform manner. We are undertaking the compilation, correlation, and assessment of the state of the art of space-vehicle research and technology, and the preparation, documentation, and updating of general design criteria standards. The effort encompasses the establishment of standard models of the environment within which space vehicles operate, and of criteria for the design of structures, propulsion systems, and guidance and control systems. The demands for rapid technological progress are such that at times neither theoretical analyses nor experimental investigations conducted in ground-based facilities can be relied upon to provide timely answers to all of the important problems. Consequently, as a complement to these ground-based programs, carefully selected flight experiments have been planned to provide urgently needed data. In some cases, the answers to important problems can be obtained only by flight experiments. The determination of the nature and extent of the meteoroid hazard is a specific example of such a research problem. While most of the activities in the space-vehicle research and technology program are general in nature, the results of these activities are applicable to all NASA space vehicles and missions, and in many cases, to military space vehicles as well. In order to give you some further concept of the nature and scope of our programs, I will discuss examples of a few technical problems and some results of our research activities in each of the areas shown on figure 232 (p. 2346). ADVANCED SPACE-VEHICLE CONCEPTS NASA research programs have always been strongly guided by studies of future performance possibilities and mission requirements. Vehicles and missions such as the X 15 and Mercury were created as the results of in-house advanced conceptual studies. Today, the cost and complexity of space missions and vehicles make it vital that the advance planning which precedes them be based on the soundest research programs possible. In addition to in-house activities, an increased use of contractual studies with industry is required to provide depth and breadth representative of the industrial designer's veiwpoint. Figure 233 (p. 2347) identifies our three main areas of study activity. They areEarth orbital operations; Advanced lunar missions; and Exploratory missions to the planets. Each of these three areas poses special problems in design of space vehicles. For example, manned exploration of the planets confronts us with quite different technical problems than those of manned orbital missions or missions to the Moon. Obviously vehicles for planetary missions will be much heavier, and must operate effectively for much longer periods of time. The date on which any planetary mission is undertaken is of great importance with respect to vehicle size and mission time. Advanced conceptual studies currently underway include: Earth-orbiting space laboratories; recoverable boosters; Earth-lunar transfer vehicles or ferries; and large advanced launch-vehicle systems with spacecraft capable of entering planetary atmospheres and returning to the Earth at velocities of 35,000 miles per hour, or greater. These studies have defined a number of important longrange problems in research and technology, and have indicated that some future missions may require radically new vehicle configurations and systems. All advanced conceptual vehicle design studies result from asking the question, "What do we need to further our ability to operate in a given space regime?" Vehicle sizes and forms are the result of the complex interplay of all the technologies from structures to life support systems. And, "How do these studies help the research worker?" First, the studies point out that if we are to conduct future space operations using conventional missile and space vehicle technology, missions will become more costly and launch vehicles must get bigger-so much so that research must supply, for example, the technology for the construction of huge cryogenic tanks 60 by 200 feet, and rocket engines 20 times the thrust of the F-1, our largest to date. Such results lead to speculation on the need for reusable launch vehicles, and this subject is a good example of the close and continuing relationship between advanced vehicle study effort and research programs. Present state-of-the-art technology suggested the use of parachutes or paragliders to bring back Saturn-5 launch vehicles, or perhaps adding wings and jet engines. On the other hand advanced conceptual studies indicated that such developments would be only marginally justified operationally or economically, and that much better techniques were needed. This has led to increased research and study effort on radically new launch vehicles-designed along radically new lines. Initial results indicate that we must be able to design a launch vehicle structure which will operate again and again with little rework, at temperatures which reach between 2,000° and 3,000° F., and through flight regimes from orbital speed to landing. To such technical requirements the studies add the dimension of time-"When is it reasonable to expect a requirement for such an advanced vehicle system, and when could we be capable of producing one?" Such estimates, of course, are part of a circular or closed-loop process, and it is the research timetable which will determine when we will be capable of achieving the goals indicated by the studies. Thus, there is and must be a close and continuing relationship between research activities and advanced mission and vehicle studies. Since such a relationship should start early if its full value in research planning is to be obtained, the Office of Advanced Research and Technology has concentrated its initia ĺ efforts on the mission area furthest in the future-manned planetary exploration. Initial results have already identified a number of important research problems requiring a long leadtime if solutions are to be available when needed. SPACE VEHICLE AEROTHERMODYNAMICS The major areas of activity in space vehicle aerothermodynamics are indicated on the left side of figure 234 (p. 2354). Our program encompasses the problems of atmospheric entry heating of manned and unmanned spacecraft at speeds ranging from near-Earth satellite speed upward to those characteristic of interplanetary flight on which we are not able at present to set an upper bound. The program also encompasses the aerodynamic performance, motion, and flight characteristics of spacecraft, to evolve advanced configurations for future missions. The landing and recovery item covers essentially the low-speed end of our activity, and includes research and advanced development on techniques for final letdown and landing such as paragliders and rotors, as well as lifting reentry vehicles capable of horizontal landing without auxiliary means. The area of launch vehicle aerothermodynamics covers the specialized aerodynamic and heating problems of our present families of launch vehicles and, with guidance from the advanced conceptual studies, the aerothermodynamic problems of advanced reusable launch vehicle configurations for future space flight missions. Finally, we are concerned with the problems associated with the generation, propagation, and possible alleviation of acoustic noise primarily the intense low-frequency noise generated by large rockets and the noise generated in aerodynamic boundary layers. I would like to treat two subjects in a little more detail: (1) Advanced manned vehicles for future missions; and (2) One facet of the spacecraft landing and recovery research program. Advanced manned vehicles for future missions. With regard now to advanced manned entry vehicles-"What can we say about the shape of things to come?" |