theoretically predicated, do we have the practical engineering know-how to implement such a venture?

The tentative answer to this question is yes. As a result of war-instigated research we have V2 rockets and microwave radio techniques. Even in 1945 a satellite vehicle could have been built in a "quick and dirty" fashion by staging, and by such crude expedients as clustering existing rocket motors together to form a single power plant. Since then power plants with improved fuel combinations and of a larger size, better materials for certain applications such as titanium metal, and exploratory research in the near upper atmosphere have tended to guarantee even greater success for such a program.

[485] The fact that a satellite has not been practical in a strict military sense has retarded its development in favor of guided missiles. On the other hand, the continual improvements of techniques in propulsion, aerodynamics, structures, and electronics have been brought about by missile programs.

It is on the subject of electronics that we shall dwell for the moment. Approximately half of the effort in the V2 development was expended in the simple radio control that established this vehicle on its relatively short-range ballistic trajectory. With this in mind, it is not hard to extrapolate to the difficulties involved in guiding a long-range missile over a complicated trajectory or in placing a satellite in its orbit. As was mentioned previously, this was one of the considerations in favor of having a pilot in a rocket plane for supersonic flight research. Ever-increasing needs for more complex control equipment call for better electronics. This, in turn, requires special consideration of the electron tubes themselves, which, for a particular application, went through the following interesting stages of evolu

tion.

Initial forms of radio-detection devices included the crystal detector and the triode. Subsequent tube development resulted in more and more complex elements within the tube and in multipurpose tubes. With the recent upsurge of electronic application in microwave radio and in digital computers (or electronic brains) it has become apparent that many simple and reliable diodes and triodes are to be preferred for such circuits. Further exploitation in this direction has centered interest on the semiconductor or transistor, and the equivalents to both diodes and triodes have been made in this form. What is a transistor? It is just an improvement of the old cat-whisker-crystal affair used in the early radio sets. This cycle aptly illustrates an underlying precept of development. As Boss Kettering says, "the ultimate solution to a problem is usually the simplest." Another way of stating this is, "If it's complicated, it's wrong."

The transistor consists of a simple blob of material the size of a lead-pencil eraser (or smaller) with several wires leading to it. Its power requirements may be as small as onehundredth that of an equivalent electron tube. The reliability of the transistor also probably will be considerably better. In short, it has been heralded as the forerunner of the coming electronic age, where many of man's more menial tasks will be replaced by computer controls.

In the actual construction of an upper-atmosphere vehicle many unforseen problems undoubtedly will arise. Usually, if a wide gap [486] exists between the physical and engineering limits on a device, then a large number of possible solutions exist. In the early days of aircraft, for example, many weird configurations evolved. As research in pistonengine types progressed it became apparent that monoplanes with thin wings were needed. Eventually a physical limit of 500 mph was approached since the additional power required resulted in a larger engine-cooling drag that offset the benefits of increased engine size. Thus, considerable work and careful design were required to reach this limiting speed.

By analogy, it may be said that we are still in the Curtiss biplane stage of rocketry, and such considerations as accessibility of instruments for ground testing frequently predominate. A good example of such freedom may be found in a recent news release, "Newsmen who recently attended the firing of a rocket asked why the rocket was exactly 32 inches in diameter. After a long technical explanation involving the ratio of length to diameter and

effects of air drag on a large projectile, the engineer concluded, “Besides, it so happened that the metal plate we were able to obtain made a cylinder exactly 32 inches across."

Summary

Past experience has shown that most advances in the field of human endeavor are not made as a result of some completely new and different concept, but rather by skillful day-to-day improvement of existing technology. This does not mean that intelligence is not required. On the contrary, the human mind is quite capable of solving multiparameter problems, an operation which is usually termed ingenuity. Very often a design created on the back of an old envelope is perfectly suitable (it can also be completely wrong). The continuing development of computing machinery has resulted in powerful tools for rapid, simultaneous solution of problems of many variables. However, it should be emphasized that the machines themselves do not possess intelligence. It is quite embarrassing, for example, to find that solutions are insensitive to a given parameter and upon subsequent investigation find that this factor did not belong in the problem in the first place.

There is, and will be, no substitute for sound and thoughtful planning and direction of research. The middle road between the no-stone-left-unturned school and the advocates of the "brilliant hunch" type of investigation will afford the most fruitful course of action.

[487] Just how long before space travel is accomplished cannot be predicted accurately since a very large weighing factor must be assessed to man's own incentives and decisions. If it became necessary to our very existence to conduct interplanetary flights tomorrow, the development period required would be materially shortened-probably within our lifetime. Without such an impetus it may be many generations before such a program is attempted. Let us recall that 50 years ago most of the mechanics of a complete rocket vehicle were known.

To recapitulate, most of the components comprising an upper-atmosphere vehicle probably will be refinements of existing rocket devices. Rather than having an appreciable increase in rocket-plane altitude, the next step probably will be a satellite, with a returnable version used for manned flights. Considerable improvement in electronics from the standpoint of reliability, weight, and power consumption is indicated. The transistor may pave the way toward this end. Many of the more complex operations in the development of rocket vehicles, as well as within the vehicle itself, will be implemented by self-sustaining computers. In the final analysis, though, man himself, with his ability to use judgment and his physical limitations, will provide the key to space flight.

Document II-5

Document title: A.V. Grosse, The Research Institute of Temple University, to Donald A. Quarles, Assistant Secretary of Defense for Research and Development, "Report on the Present Status of the Satellite Problem," August 25, 1953, pp. 2-7.

Source: NASA Historical Reference Collection, NASA History Office, NASA Headquarters, Washington, D.C.

In 1952, President Truman requested Aristid V. Grosse, a physicist at Temple University who had worked on the Manhattan Project, to study the "satellite problem." Major General Kenneth D. Nichols, formerly deputy for Lieutenant General Leslie R. Groves on the Manhattan Project, arranged Grosse's meetings with space scientists at Huntsville, particularly Wernher von Braun. The report was finished after Truman left office; it was delivered to Donald Quarles, the new Assistant Secretary of Defense for R&D under President Eisenhower, on September 24, 1953. Quarles later became a major advocate of the use of space for military purposes. Another copy of the report was sent to Dr. John R. Dunning,

dean of the School of Engineering, Columbia University. Dunning discussed it with President Eisenhower, and the report contributed to the initiation of Project Vanguard. Grosse's report represents the first time that the potential propaganda consequences of a Soviet first launch of a satellite were reported directly to top levels of the government.

[2] The Present Status of the Satellite Problem

A satellite is a man-made or artificial moon which will rotate around the earth beyond the furthermost extent of its atmosphere, for many years or indefinitely. After it has once reached its orbital velocity the centrifugal force of its motion is held in exact balance by the gravitational attraction of the earth; thus the satellite once on its orbit around the earth does not require any additional power to keep it there. Usually altitudes of 300 to 1000 miles above the earth's surface are considered.

As an example, at an altitude of 346 miles above sea level the time necessary for the satellite to travel once around the earth, i.e. its period of revolution, will be exactly 96 minutes or 15 revolutions per day. Its orbital velocity will then be 4.71 miles per second. Similarly, a satellite at an altitude of 1037 miles above sea level will have a period of revolution of exactly 120 minutes or 12 revolutions per day and a velocity of 4.37 miles per second.

The satellite could be made to travel over the surface of the earth in a wavy line so that in the course of a few successive days most of the North American continent, Europe, Africa and Asia, could be observed from it.

It could be made visible to the naked eye, under clear atmospheric conditions, at dawn and at dusk as a bright fast moving star.

The technical problem of creating a satellite should logically be divided into the two following steps:

1, The unmanned satellite and

2. The manned satellite.

[3] The accomplishment of the first step, in the opinion of even the most skeptical engineers, is possible with the present know-how and engineering knowledge. Since it is not manned by human beings it would not require any essentially new research and development.

A satellite of about 30 feet in length would require the stepping up of the German V-2 rocket by a take-off weight factor of 6-7. This would require essentially the addition of a third large stage to the present well known two stage rockets such as the WAC Corporal mounted on a V-2, which reached an altitude of 250 miles at the White Sands Proving Grounds in February 1949. A design for such a large stage was already on the drawing boards of Dr. von Braun and his associates in Peenemünde, Germany, in 1945. This German project "A-9+ A-10" was designed for transatlantic bombing of the United States. The A-9 stage was a slightly enlarged V-2 (take-off weight 16.3 metric tons vs. 12.8 tons of the V-2) whereas the A-10 stage had a take-off weight of 69 metric tons. Such a three stage rocket would use conventional fuels giving a specific thrust of 220-240 seconds (for example, liquid oxygen + ethyl alcohol 75%, water 25% = 239 seconds, red fuming nitric acid + aniline = 221 seconds). Conventional combustion chambers, pumps, tanks, ignition devices, etc., could be used.

Research scientists have recently demonstrated that much larger specific thrusts can be realized. For example, a liquid fluorine-liquid hydrogen rocket motor can generate a thrust of about 380 seconds. This would permit the use of a much smaller rocket to achieve satellite velocity. However, the engineers feel that this advantage is offset by the necessity of doing a lot of additional research and development in order to bring the high thrust rocket motors and their accessories to [4] the same stage of reliability and smoothness of operation as the conventional rockets. All of this new development would thus cause a loss in time. This would be unwise because it is felt by all engineers that the present rocket fuels and motors will be able to do the satellite job.

The second step or a satellite manned by human beings is decidedly a much more difficult problem. Ultimately, if solved, it would mean the beginning of man's conquest of

interstellar space and would have infinite possibilities for the human race. The solution of this problem, however, involves overcoming all the obstacles in the way of man's existence in the vacuum of outer space. It means the overcoming of the absence of a gravitational field on the functions of the human body and the effects of cosmic radiation on it. Although all of these problems have a possibility of ultimate solution, it would require at least a 20-fold expense of human effort, money and time, as compared to Step 1, coupled with an inestimable amount of human ingenuity and invention.

It is felt that the accomplishment of the first step would help solve many of the problems of the second. This writer feels that probably after the successful launching of the first unmanned satellite, a number of such unmanned satellites will be in existence at various altitudes above the surface of the earth, for various purposes. It is thus felt that at this time the main effort should be directed toward solving the unmanned satellite problem. The value of an unmanned satellite would fall into the following categories.

a) Scientific — with proper electronic and telemetering equipment and devices it would enable us to obtain valuable scientific information regarding the various physical conditions existing in outer space. [5] The satellite would need a concentrated source of energy, which should be light in weight and should produce power for a number of years. It is considered that such a power plant could be produced by using alpha-active radioactive substances of an average life of a few years in concentrated form, if the appropriate resources of the Atomic Energy Commission could be mobilized.

b) Military again, with the equipment referred to above coupled with televising devices, a satellite station could be a valuable observation post.

c) Psychological - with appropriate signaling or broadcasting devices such a satellite could develop into a highly effective sky messenger of the free world.

In the opinion of this writer the last item, i.e., the psychological effect, would be considered of utmost value by the members of the Soviet Politbureau. They would recognize that in the case of atomic and hydrogen bombs the people of the belligerent countries would be subjected to their effects only after the die of World War III is already cast. On the other hand, the satellite would have the enormous advantage of influencing the minds of millions of people the world over during the so-called period of "cold war" or during the peace years preceding a possible World War III. In the countries of Asia, where the star gazer since time immemorial has been influencing his countrymen, the spectacle of a man-made satellite would make a profound impression on the minds of the people. The Soviet Union has demonstrated that it has been able to develop the atomic bomb and recently to follow that up with the accomplishment of a thermonuclear reaction on August 12, 1953, [6] as confirmed by the Chairman of the U.S. Atomic Energy Commission, Admiral L. Strauss, much faster than had been generally expected by our scientists and engineers. The building of an unmanned satellite would be a feat of much smaller magnitude than the construction of an atomic bomb since all the basic information was available to the Germans at the end of World War II and is since known both to this country and to the Soviet Union. Furthermore, the industrial plant necessary for the construction of a satellite is much simpler and is now being developed for the guided missiles programs in both countries.

In the Soviet Union the construction of a satellite would amount to only a fraction of the cost in this country, a) because of the use of cheap or slave labor; b) no necessity for great safety precautions, and c) no need for tracking the satellite in the early stages of its flight.

Since the Soviet Union has been following us in the atomic and hydrogen bomb developments, it should not be excluded that the Politbureau might like to take the lead in the development of a satellite. They may also decide to dispense with a lot of the complicated instrumentation that we would consider necessary to put into our satellite to accomplish the main purpose, namely, of putting a visible satellite into the heavens first. If the Soviet Union should accomplish this ahead of us it would be a serious blow to the technical and engineering prestige of America the world over. It would be used by Soviet propaganda for all it is worth. Of course, the probable reaction of the American people to a

Soviet satellite circling about 300 miles above Washington, New York, Chicago and Los Angeles, would have to be considered.

At the present time our engineering efforts in this field are limited in scope and distributed over various government agencies. It [7] is recommended as a first step in solving the satellite problem that a small but effective committee be set up composed of our top engineers and scientists in the rocket field, with representatives of the Defense and State Departments. This Committee should report to the top levels of our government and should have for its use and evaluation, all data available to our government and industry on this subject. It should report in detail as to what steps should be taken to launch a satellite successfully into outer space and to estimate the cost and time required for such a development. It is felt that if such a committee were in existence and a definite decision taken by our government regarding the construction of a satellite, that it would fire the enthusiasm and imagination of our engineers and scientists and effectively increase our success in the whole field of rockets and guided missiles.

Document II-6

Document title: J.E. Lipp and R.M. Salter, "Project Feed Back Summary Report," The Rand Corporation, R-262, Volume II, March, 1954, pp. 50-60. The figures have been omitted from this document.

Source: Archives, The Rand Corporation, Santa Monica, California.

In November 1950, Rand recommended to Air Force headquarters that it pursue further advanced research on satellite reconnaissance. Two Rand reports, including "The Utility of a Satellite Vehicle for Reconnaissance" [II-3], were completed in April 1951 and were enthusiastically received by the Air Force. Some members of the Air Force recognized the valuable role that satellites could play in providing strategic reconnaissance of areas not reachable by other means. As a result, the Air Research and Development Command authorized Rand to make specific recommendations on a satellite reconnaissance system. Project Feed Back involved hundreds of scientists and engineers from Rand and a host of subcontractors. Its results were presented to the Air Force on March 1, 1954, and became the basis for the first military satellite program. Many of its specific proposals, such as the use of television transmission of reconnaissance images, were not adopted until many years later. The section of the report dealing with "television payload equipment" is still classified. Volume I of this report has not been cleared for public release. In this excerpt from Volume II, the report discusses the scanning technique that was the basis for obtaining useful data from Earth orbit. The figures have been omitted.

The scanning problem arises for an obvious reason. The limited size and resolving power of the Image Orthicon result in each picture's being able to contain only a finite number of bits of information. Elsewhere in this report it is shown that in order to keep the time between successive views of a particular ground area to a reasonable value, the television optical system must cover a strip extending for 200 mi on each side of the flight line. If this area were to be covered by a single picture, about 1 in. on a side, the scale would then be 1:25,000,000; if the spot size of the scanning beam in the camera tube could be kept down to 0.001 in, the image projected on the ground by the optical system would be 2100 ft in diameter. Anything much smaller than a mile in its principal dimension would be difficult to detect.

At the scale of 1:500,000, one picture is about 8 mi on a side. A strip 400 mi wide will require fifty pictures to cover it. This number of pictures must be transmitted in the time it