THE ORDCIT PROJECT OF THE JET PROPULSION LABORATORY, 1943-1946
By Dr. Frank J. Malina
Although the German group at Peenumünde has been credited with making large advances in rocket technology which led to the age of space exploration , the role played by American rocket pioneers of the California Institute of Technology in the " Forties " was also extremely significant in spurring the development of propulsion systems and step-rocket techniques. In this memoir a leading member of this group gives a personal account of the researches which set the stage in America for the practical development of artificial satellites and interplanetary probes. Readers will be interested to know a few highpoints in the subsequent careers of persons who played key roles in this world.
Theodore von Karman (1881-1963) left the California Institute of Technology in 1944 to establish the Science Advisory Group of the US Air Force ; in 1951, he took steps to bring into being the NATO Advisory Group for Aeronautical Research and Development (AGARD) ; in 1959, he was asked by the International Astronautical Federation to be Chairman of the Founding Committee of the International Academy of Astronautics of which he became its first President in 1960.
Frank J. Malina left the Jet Propulsion Laboratory in 1946 to become a member of the secretariat of Unesco in Paris ; in 1953, he became a professional artist ; in 1959 he was a member of the Founding Committee of the International Academy of Astronautics and is now a Trustee-Past President ; in 1968 he launched the international journal of the art and science, Leonardo, of which he is the Editor.
Hsueh-Shen Tsien (now Chien Hsueh-sen) became Goddard Professor of Jet Propulsion at the California Institute of Technology in 1948. He returned to China in 1955 and is a member of the Academy of Sciences of the Peoples Republic of China. Report suggest that he has played a leading role in developing China's long-range rockets.
Martin Summerfield is a Professor in the Department of Aerospace and Mechanical Engineering Sciences at Princeton University ; editor of Astronautica Acta and of a series of books on Progress in Astronautics and Aeronautics.
Homer J. Stewart is Professor of Aeronautics at the California Institute of Technology and Special Assistant to the Director of the Jet Propulsion Laboratory, NASA ;
Louis G. Dunn became Director of the Jet Propulsion Laboratory in 1947. He left JPL in 1954 for Space Technology Laboratories, Ramo- Wooldridge Corporation of which he became President.
William H. Pickering is Professor of Electrical Engineering at the California Institute of Technology and Director of the Jet Propulsion Laboratory, NASA, at Caltech.
(Kenneth W. GATLAND)
The years covered by this memoir were extremely hectic compared to those discussed in my first two memoirs (Fig.1) It is very difficult for me even now to draw anything like a clear and coherent picture of them. Nevertheless, I hope that what I have to say will be of use to historians of astronautics by drawing attention to unpublished material available in the archives of the Jet Propulsion Laboratory. The Biweekly Research Conference Minutes especially give a vivid account of the evolution of the developments I shall discuss.
Between 1943 and 1947, I became more and more an administrator of research. The Air Corps Jet Propulsion Research Project GALCIT (The acronym stands for Guggenheim Aeronautical Laboratory, California Institute of Technology) which numbered around 85 persons in 1943 grew by 1946 to about 400 and the amount of money to worry about increased from hundreds of thousands to millions of dollars annually. Whereas I was directly acquainted with all that was taking place on the Project up to 1944, both as regards ideas and their execution, by 1946 I was aware of more and more research activities but in less and less details , and little of my time was free for carrying out research of my own - a situation not pleasing to one of my temperament.
Fig. 1 The author beside the WAC CORPORAL, the world's first successful sounding rocket,
White Sands Proving Ground, New Mexico
USA, October 1945
[ Insérer image JPEG]
Theodore von Karman's connection with the California Institute of Technology (Caltech) became increasingly tenuous in 1942 and in 1944 he became absorbed by activities centered in Washington D.C , where he took up residence. As a result, in 1944, I had to take over contract negotiations from both technical and management points of view, which required trips to Wright Field at Dayton, Ohio, to Washington D.C. and to other places. Life became a
" between trips " kind of existence.
By 1944, it was fairly evident that World War II would end in the defeat of the evil forces of fascism in Germany, Italy and Japan. But what then ? The harnessing of atomic energy for destructive purposes was demonstrated at Alamogordo, New Mexico and then at Hiroshima and Nagasaki, Japan, in 1945. As I was drawn into the councils of those with military responsibilities, I participated more and more in discussions of what should be done in the next war with long-range rocket missiles. Obviously, if atom bombs could be made light enough, they would be used as warheads on missiles. Such deliberations became more and more distasteful to me as the months went by. Since I had long been convinced that war between or by advanced technology nations was a form of national insanity, even before a way to release nuclear energy had been found, it seemed to me that ideas and effort were really needed now to find ways for " sovereign " nations to function in peace together rather than to develop better means of destroying themselves.
I was mentally and physically exhausted by 1946. General Eisenhower is said to have remarked when the war ended that all he wanted to do was to go fishing ; I felt the same way, except that I do not care much for fishing. I had had ten years of experience with research involving rocket problems on the fringes of basic and engineering science knowledge ; of devices requiring the use of explosives and toxic chemicals, of concern for the safety of our staff and of aircraft test pilots ; of frustrations resulting from dealings with administrators who had no grasp of the nature of research, and of travel by train and by air to meetings that frequently were not really necessary. This experience forced me, at the age of 34, to make a serious appraisal of myself and of my hopes for the future.
When we had begun rocket research at Caltech in 1936, most of our original group of 6 was dedicated to the peaceful uses of rocket propulsion .The design of a sounding rocket was our first goal. But world developments by 1938 dictated our participation in the military application of rocket propulsion, though I never lost sight of our first goal. When in 1945 the WAC Corporal became the first successful sounding rocket to exceed heights attainable by any other means, I felt a sense of personal fulfillment. I understood that this was but the first probe into extraterrestrial space and that voyages to the Moon and planets would follow but I also knew that there were now many others who would carry on the work necessary to reach these more distant goals. In 1936, the number of engineers in the worl seriously interested in astronautics was probably less than 50 ; by 1946, there were several hundreds.
What troubled me most in parting from JPL was the separation from the members of the staff, many of whom were my closest friends and with whom I had shared many good and many trying times. I have never again worked with a group that was as cooperative and enthusiastic.
My new goal became international cooperation. Although I left Caltech with a two-year leave of absence, which was renewed in 1949, I then allowed it to lapse and, in one way or another, I have devoted myself to this goal during the past 25 years. The night before I departed from Texas for Unesco in Paris, a last effort was made to dissuade me from leaving the Jet Propulsion Laboratory. A general officer of the Ordnance Department telephoned me from Washington D.C. and urged me to reconsider my decision. When I had asked von Karman for his advice, he told me that if he were younger he would follow a similar path to the one I was considering ; therefore, it was unlikely that anyone else would get me to change my mind.
I made a tour of the East Coast to discuss Unesco with many persons before going to Paris. Albert Einstein thought that major points of the Unesco programme were worthwhile. He said we must have courage to fight for real issues and not allow Unesco to become impotent like the Commission for International Intellectual Cooperation of the League of Nations. Vannevar Bush said scientists must get together to work on stopping wars for good. He did not know very much about Unesco but was all for it. Lyndon B. Johnson , who was then Congressman >from the district of my home in Texas, said he was not acquainted with Unesco intentions and that the United Nations was just a baby.
Upon my arrival in Paris, the first task I was given by Joseph Needham, Head of the Natural Science Section of Unesco, was to study ways of breaking down the barriers to the free movement of scientists and engineers between nations ! It certainly was not true that I became a member of the Unesco secretariat as a rocket expert , as was stated in an article hostile to the organization in the Saturday Evening Post, entitled " Julian Huxley"s Zoo ". Unesco did not come within a smell of rockets before the International Geophysical Year (IGY) in 1957.
Nevertheless, my interest in astronautics continued and while at Unesco , outside my official duties, I wrote in 1950 a popular article entitled " Unmanned Rockets towards Space " upon the invitation of Kenneth W. Gatland, who was to be the editor of a collection of articles for a book called " Rockets into Space ". The venture was given up by the publisher in 1954.
In that year, I also wrote " A Short History of Rocket Propulsion up to 1945 " for the Princeton University series of volumes on Jet Propulsion and High Speed Aerodynamics of which at that time Martin Summerfield was General Editor. The article was finally published in the volume " Jet Propulsion Engines " in 1959 .
I terminated my Unesco appointment in February 1953 to pursue, as a painter, my long-held fascination with the relationships between art, science and technology . I did not enter astronautics until after the launching of the Sputnik by the Soviet Union in 1957, which made more evident than ever the need for international cooperation in this field. Andrew G. Haley, one of the founders with us of the Aerojet General Corporation and then President of the international Astronautical Federation, and von Karman who had become active in Federation affairs, told me that it was all very well for me to work quietly as an artist in a Paris studio but that my experience with astronautics and with the problems of international cooperation was wasted. They urged me to participate in the work of the Federation . After much debate, my wife and I decided , I would accept an appointment as representative of the Federation to Unesco. By 1959, I was again devoting most of my time to astronautics in the Federation, especially in connection with the establishment and direction of the International Academy of Astronautics.
But to return to the main subject of this memoir...
The Situation in 1943
The Air Corps Project at the beginning of 1943 was consolidating the successful development of solid and storable liquid propellent engines for aircraft superperformance applications, with research directed to improving the propellents and to trying new ones, to raising engine performance and to increasing their thrust and duration. Cooperation on matters of development and production was maintained with the Aerojet Engineering Corporation for those programmes sponsored by the US Air Corps and the Navy .
The Project had placed solid and storable liquid propellent rocket engine design on a sound scientific foundation. Practical information had been provided to engineers to permit the design of uncooled motors to meet desired specifications for thrusts up to around 2 tons for durations of up to around 75 seconds. By the end of World War II, information was available on the design of cooled liquid propellent engines and pump design was well advanced.
Albert A. Christman in his history of the Naval Weapons Center, China Lake, California, " Sailors, Scientists and Rockets " writes : " A suggestion by a Navy captain that it would be desirable to have a cooperative effort between Goddard and Malina brought out Goddard"s view that the work in Pasadena was about the stage in 1940 that his had been in 1952. He referred to the Caltech programme as the " The Student Work " . Goddard evidently did not subscribe to von Karman"s outlook : " It is always wise to remember that someone else might be just as clever as oneself ".
Goddard's opinion of our efforts does not surprise me but he must have been surprised when within two years after he made his remarks we had successfully developed and put into production for the Air Forces and the Navy service-type solid and storable liquid propellent engines. These became respectively , the progenitors of the engines in, for example, the Sergeant, Polaris, Minuteman and Titan missiles and the Apollo Command Module and Apollo Lunar Excursion module.
This raises an interesting question as regards what happened in Britain, U.S.A. and U.S.S.R. after the end of the war that should be probed by historians of rocketry and astronautics. I believe a good case can be made to show that the obsession of the military services in these countries for continuation of certain developments of German rocket technology caused a vast waste of funds by giving priority to rocket engines using liquid oxygen (LOX) , as in the case of the V-2. In America though the development of engines using a composite solid propellent and a storable liquid propellent combinations was not dropped, it was certainly given a lower priority. Today, not a single American military operational missile uses a LOX engine ; instead they are propelled by descendants of solid and liquid propellent engines developed at JPL, before the end of World War II.
The investment in LOX engines turned out to be an overall technological gain, for they were needed for extraterrestrial space activities but these were not then and are not now of primary interest in the military services in America .What is more, solid an storable liquid propellents also have an important role to play in the propulsion of spacecraft at this phase of " the space age ".
Popular opinion, even the opinion of some who should know better, has been that American rocket developments lagged far behind that of Nazi Germany. This belief is false but myths die hard.
Origins of the ORDCIT Project
At the Air Corps Project in 1943, we were following directives of 1939 that limited us to rocket engines to be used in connection with aircraft .This situation was radically transformed in the summer of 1943.
Von Karman received in early July 1945 a request from the Commanding General of AAF Material Center, Wright Field, to study and comment on three British intelligence reports on reaction propulsion devices for projectiles and aircraft supposedly being developed in Germany .Comments on the reports, based on an investigation that he, Hseueh-Shen Tsien (Chien Hsueh-sen) and I made, were sent by him to Wright Field on 2 August. Although much of the data from German prisoners in the reports was wrong, inexact and exaggerated, it was possible to arrive at some interesting conclusions. The fact that the conclusions bore little resemblance to actual German missile and aircraft developments, as was learned later, is irrelevant to their impact on the American military scene in 1943. Fascinating background material on these intelligence reports, to be read with circumspection, can be found in the book The Mare's Nest by David Irving .
The AAF Liaison Officer at Caltech at this time was Col. W.H. Joiner, a most congenial and cooperative officer. He immediately appreciated the significance of our comments on the reports and suggested to me that a study should be made of the possibility of propelling missiles using the rocket engines we had developed or that were available at Aerojet. I turned to Tsien for help and the two of us completed our study in November 1943 . Our results showed that although ranges in excess of 100 miles could not be reached with engines then available, rocket missiles could be constructed that had a greater range and a much larger explosive load than rocket projectiles then being used by the Armed Forces. Von Karman, after discussing the analysis with us, decided to attach a memorandum to our report proposing that a development programme be initiated along the lines we had indicated .
These documents for the first time carried the name 'Jet Propulsion Laboratory " .The memorandum and analysis were sent by Joiner to the Commanding General of AAF Material Center. In an adjoining office at Caltech was Captain R.B. Staver,who was liaison Officer at Caltech for the Ordnance Department. Staver forwarded the same documents to Colonel G.W. Trichel, Chief of Rocket Development Branch of the Ordnance Department .
Von Karman, Tsien and I at this point concentrated our thoughts on the technical problem of long-range missiles and on what appeared to us to be the most reasonable steps to be taken to develop them on the basis of current American experience with solid and liquid propellent rocket engines. Staver has recently drawn my attention to quite a different thought process that occupied his and Joiner's minds. They were concerned with assuring continued support of the development of rocket and other types of jet engines and of their applications by the military services after World War II, fearing the historic tendency of American governments to drop potentially important research for military purposes when a war ended. Furthermore, they felt that our Project should not only be continued but expanded to become the center of jet propulsion and of missile research and development .
The response of the military services to the above two documents on the development of long-range missiles planted one of the seeds for the bitter inter-service military rivalry that took place in America in the 1950's. I recall discussions with officers in the Air Force and in the Ordnance Department on the appropriate " botanical " classification of a rocket missile.
Those concerned with army ordnance said that, since long-range guided missiles followed a ballistic trajectory like a gun projectile, such missiles were clearly a responsibility of the Ordnance Department. Those responsible for long-range bomber aircraft said that, since a long-range guided missile needed acrodynamic control during the first phase of flight in the atmosphere, it was the Air Forces that should be responsible for their development and they called the missiles "pilotless aircraft".
The AAF did not respond to our proposals, much to our amazement. Instead, von Karman received a letter dated 15 January 1944 from Trichel of Army Ordnance expressing not only interest in the proposed programme but a desire that Caltech undertake a more intensive programme than was outlined .
Trichel urged that a revised and more inclusive programme be commenced at the earliest possible date. He further stipulated that the Ordnance Department was prepared to furnish the necessary funds to cover such a project, providing the Institute, in turn, was willing to give the necessary emphasis to the undertaking in the assignment of personnel and facilities. Also recommended was that a proposal be submitted that would include a chronological schedule of the studies to be made, models, built, etc..; further, if such a project was decided upon, it would be advisable to make a contract with Caltech on a cost-plus-a-fixed-fee-basis. The plan of operations should initially cover not more than one year and the expenditures should not be more than $3,000,000 for the one-year programme.
The scale of operations envisaged threw us into a proper dither! We prepared a new proposal incorporating Trichel's suggestions, and von Karman, with the support of Robert A. Millikan, Chairman of Caltech' Executive Council (father of Clark B. Millikan) obtained the approval of the Caltech Trustees to put forward the proposal to the Ordnance Department.
On 28 February, von Karman submitted on behalf of Caltech the new proposal, based on Trichel's suggestions, to Major General G.M. Barnes, Chief of the Technical Division, Ordnance Department, in Washington D.C. This proposal was accepted practically intact .
A Letter of Intent for the Army Ordnance programme was placed with Caltech on 22 June 1944 : "for services consisting of research, investigation and engineering in connection with the development of a long-range rocket missile and launching equipment and for complete reports, drawings and specifications describing all work done in connection there with". An expenditure not exceeding $1;600,000 was authorized. This was followed by a definitive contract, which entered into force on 16 Janurary 1945, with the following objectives :
a) Missile was to have a minimum weight of highly explosive payload of 1000 lb.
b) Maximum weight of missile was not to exceed weight consistent with good design and maximum payload.
c) Range of missile up to 150 miles.
d) Dispersion at maximum range not in excess of 2% on a missile suitable for direction by remote control.
e) Velocity sufficient to afford protection from fighter aircraft.
The termination date of this contact was 22 December 1945; however , it was amended to extend through 30 June 1946; the total funds provided amounted to $3,600,000.
This expanded programme led to re-organization of the Air Corps Jet Propulsion Research Project, GALCIT into the Jet Propulsion Laboratory, GALCIT. The programme was given the designation ORDCIT Project (ORDCIT is an acronym for Ordnance California Institute of Technology).
Reorganization of the Air Corps Project into the Jet Propulsion Laboratory , GALCIT
The ORDCIT Project required a rapid expansion of the staff and facilities of what I shall from now on refer to as the Jet Propulsion Laboratory ( GALCIT) or, for short, JPL. During the period into consideration, JPL was attached to the Guggenheim Aeronautical Laboratory (GALCIT) of which von Karman was director. He remained titular director until 1949 when he became Professor Emeritus and Clark B. Millikan became his successor. By this time, JPL had been separated from GALCIT and came directly under the overall administration of Caltech.
While we were in the midst of preparing plans for carrying out the programme of the ORDCIT Project, von Karman underwent serious abdominal surgery at the end of May, 1944, in New York City, which prevented his return to Pasadena until September. It was while he was recuperating in New York that General H.H. Arnold, Commanding General of the AAF, approached him to undertake the creation of the Scientific Advisory Board to the Chief of Staff of the AAF to investigate all possibilities and desirabilities for postwar and future war's development as respects the AAF. Von Karman left for Washington D.C., in December, not to return to Caltech except for short period of time.
The scope of the ORDCIT Project posed to the administrators of Caltech novel problems as regards the range of activities, the size of staff and the amount of money involved. It was decided to establish a JPL Executive Board, responsible to the Caltech's Administration, whose task would be to oversee the general policies of JPL administration and to take cognizance of the implications of any new technical developments that took place. When von Karman took leave of Caltech, the question of who would be responsible for directing JPL had to be resolved. C.B. Millikan was asked to become Chairman of the JPL Executive Board and I took over direction of JPL .
In 1944, Col. L.A. Skinner was designated Liaison Officer for the Ordnance Department. Those of us concerned with solid propellent rocket engines were acquainted with his studies in the 1930s of nitroglycerine-nitrocellulose as a propellent. I also had met him when he was working with the "Indian Head Group" at Indian Head, Maryland, in the early 1940s . Joiner was succeeded by Col. E.H. Eddy as Liaison Officer for the AAF and Lt. Col. J.W. Newman was designated Liaison Officer by the Army Ground Forces.
Research at JPL was carried out beginning in 1944, on four major projects l JPL-1 (Project MX 121 of Aircraft Laboratory of AAF Materiel Command, was a continuation of aspects of the programme previously carried out for the Aircraft Laboratory) ; JPL-2 (Project MX 163 of the Armament Laboratory of AAF Material Command, begun in 1943 , was on hydrobomb research); JPL-3 (Project MX 527 of the Power Plant Laboratory of AAF Materiel Command , begun in 1944, was primarily on ramjet engine research and JPL-4 (The ORDCIT Project).
The ORDCIT Project involved not only fundamental engineering research on thermal jet propulsion engines, propellents and the design of guided missiles but also the construction of missiles and of launching devices for firing tests. The firing tests were to be made in cooperation with the Ordnance Department. This required us to become accustomed to thinking in terms of design and construction of a very different kind and on a much larger scale than before. We were greatly helped in confronting this situation by Romeo R. Marte, Professor of Civil Engineering at Caltech and member of the JPL Executive Board, and by Aladar Hollander of the Byron Jackson Company of Los Angeles, a manufacturer of pumps. The design of large constructions required for the development and launching of missiles was guided by William A. Sandberg of the Consolidated Steel Company of Los Angeles. Mark Serrurier of Caltech supervised the design of installations for ramjet engine studies. E.M. Pierce, Sr. an architect who had been my personal assistant since 1943, and W. Hertenstein, head of maintenance and buildings at Caltech, bore the brunt of designing and contracting for new buildings to be constructed as quickly as possible. The construction programme was aided in every way by the Ordnance Liaison Officers by Skinner up to August 1945 and thereafter, by Colonel Benjamin S. Mesick, V.C. Larsen, Jr. who in 1946 took charge of Laboratory administration, was in charge of materiel procurement. William R. Stott, Assistant/Controller at Caltech, and I spent many days on contract negotiations.
The chiefs of Technical Sections were the following :
H.J. Stewart, Section 1, Research Analysis; J.V. Charyk, Section 2, Underwater Propulsion; H.S. Seifert, Section 3, Liquid Propellent Rocket Engiones; C. Bartley, Section 4, Solid Propellent Rocket Engines; P. Duwey, Section 5, Materials; S.A. Johnson, Section 6, Propellents, W.B. Barry, Section 7, Engineering Design; J. Ammeus, Section 8, Research Design; W.H. Pickering, Section 9, Remote Control; W.D. Rannie, Section 10, Ramjet Engines; and S.J. Goldberg, Section 11, Field Testing.
Tsien, who had been the first chief of the Research Analysis Section, left Caltech for the Massachussets Institute of Technology in 1946. He returned in 1948 to set up the Jet Propulsion Center established at Caltech by the Daniel and Florent Guggenheim Foundation. Martin Summerfield returned to JPL >from the Aerojet Engineering Corporation in the autumn of 1945 to take part in planning and research analysis of possible applications of rocket propulsion to extraterrestrial space flight.
My 1944 Mission to Europe
JPL was visited in the summer of 1944 by Colonel F.F. Reed, called by his friends "Froggy". He was Assistant Military Attache, Ordnance Department, in London. It was decided that I should return his visit by going to Britain to study rocket and ramjet engine research underway, to obtain first-hand experience of being in the target area of the V-1s and V-2s, and to inspect at Farnborough, England, the parts of the V-2 that had been obtained from the one that had strayed off course and landed in Sweden in early 1944.
Since my trip included an inspection of German V-1 launching sites and other kinds of installations in northern France (Pas de Calais region), which had been liberated in August 1944, I was given the rank of Colonel (assimilated rank, in case of capture). Upon the urging of Reed, I designed and had a tailor make a shoulder patch with a rocket on it -perhaps the first US military insignia signifying rocket missiles.
There are 82 names of engineers and scientists in the UK on the list of those with whom I discussed various aspects of my mission. Among them were Sir Alwyn D. Crow, Controller of Projectile Development, London; W. Blackman, Chief Superintendent, Projectile Development Center, Aberporth Wales; J.E. Lennard-Jones, Chief Superintendent , Armament Research Department, Fort Halstead; R.F. Fraser, Imperial College of Science and Technology, London; S. Goldstein, Cambridge University; Thomas Petroleum Warfare Department, Langhurst; Hankins and Ralph, respectively Superintendent of the Engineering Divison and Superintendent of the Aerodynamics Division of the National Physical Laboratory, Teddington; Perring, Roayl Aeronautical Establishment, Farnborouhg, Capt. A. Richards Superintendent of Torpedo Exp. and Dev. , Geenoch, Scotland; I. Lubbock, Asiatic Petroleum Co. B. Lockspeiser, Director of Scientific Research, Ministry of Aircraft Productions; Air Commodore F. Whittle, Power Jets, Ltd. Whetstone; Smith, Metropolitan-Vickers Ltd., Manchester.
These discussions were quite open on both sides, although I knew that some information was held back, just as I held back on some of our plans and developments. Compared to American research practice, the extent of theoretical analysis and the length of debate on pros and cons before a decision was made to build something particularly struck me. This difference in approach was in large part due to the much more limited financial and manpower resources available in wartime Britain. I realize that our PRIVATE F fiasco (to be described later) might well have been avoided if a more thorough theoretical analysis had been made of an unguided winged missile.
The main interest in Britain in 1944 was centered on the improvement, under the dominating personality of Sir Alwyn Crow, of an anti-aircraft rocket missile. Under his leadership, unguided anti-aircraft ballistite UP rockets (UP for Unrotated Projectile) were developed and used in the Battle of Britain in 1941. Some said that UPs should have been called "misguided missiles", for, as Charles C. Lauritson, who watched them perform in London that year is quoted to have said: "I dont think they ever shot down a bomber" (p. 108). They did make a lot of noise, which perhaps gave a psychological lift to the people; By the time I arrived in London in October 1944, only a few V-1s were still arriving during the night, launched from aircraft over the North Sea because land launching sites on the other side of the English Channel had been captured by the Allies. V-2s bombarded London from bases off the coast of Holland. One shook up a conference I was attending at Fort Halstead, near London. My first experience of this sort left me rather disturbed but not my colleagues , who continued the meeting as though nothing had happened.
Information was available on the V-2 and on German engines using LOX and hydrogen peroxide (H2O2). The British were of the view that the nitric-acid-aniline family of propellents was less suitable than hydrogen peroxide and, hopefully, nitromethane. We did not go overboard on either of these latter chemicals as they did. (By 1944, we had good reasons to doubt the great expectations of John W. Parsons and Fritz Zwicky for nitromethane as a monopropellent; It was tested extensively both at JPL and at Aerojet and, as far as I know, nitromethane was finally given up as a rocket propellent because it is sensitive to shock and it is difficult to use a s a rocket motor coolant). Test facilities for liquid propellent engines were still in a very primitive state in Britain and work was just getting underway on composite solid propellents and on long duration engines using them. There was much interest in the possibilities of the ramjet engine, mainly because of claims made for it in Germany, especially by Eugen Sänger. The British knew considerably more that we did at JPL of the problems to be solved to make a ramjet a practical device . Ramjet studies were being carried out in England at Power Jets, Ltd. Under Lloyd and Constant; Here , also, Air Comodore Frank Whittle was continuing his development of turbojet engines and he and I compared experiences on the vicissitudes of those who try to get unorthodox ideas accepted.
I inspected the parts of the V-2 brought from Sweden at the Royal Aircraft Establishment at Farnborough. Design elements of the engine and the guidance system were than still not completely understood The latter was especially of interest to us at JPL, where we were just beginning to confront the problems of missile guidance and control.
Between 16 and 26 November 1944 I visited France with Captain C.E. Martinson, who had been assigned by Reed to look after me during my mission. We inspected V-1 launching sites at Wizerne, Montreuil and Siracourt. Bombing from aircraft had produced only minor damage to the sites, whereas nearby villages were in shambles. At Mimoyecques and Watten were very large constructions whose purpose up that time no experts could make out.
While crossing the Atlantic on my return journey, during the second week of December, the many hours gave me a chance to think over the implications of all I had observed on my tour. When I had departed from JPL in October, plans were far advanced for testing the first ORDCIT solid propellent missile, the PRIVATE A, for the design of a winged version, the PRIVATE F, and for the liquid propellent CORPORAL. Turning over the many bits of information stored in my mind, I clearly realized that the first objective our rocket research group had set for itself in 1936 was within reach a sounding rocket . We now had reliable solid and liquid propellent engines around which to build it. The next step was to sell the idea to the Ordnance Department.
I visited Trichel and his staff during a stop-over in Washington D.C. to report on my mission, before proceeding on to Pasadena. When I completed my report, I presented my wish to have JPL design, construct and test a sounding rocket. I explained that it should be possible to carry out the program rapidly; that modest requirements should be set (to lift a 25 lb. payload of 100,000ft.); that the rocket with a liquid-propellent engine could be considered as a small-scale test version of the CORPORAL; that experience would be gained with launching techniques and that it might be considered as a first step in the development of a guided anti-aircraft missile. The proposal immediately raised a favorable response. The Signal Corps was contacted to establish meteorological payload requirements for the rocket that would meet its needs . By 16 January 1945, the study of the proposed sounding rocket requested from JPL, by the Ordnance Department was completed by Homer J. Stewart and me .
The first missile to be tested used a solid propellent rocket engine that could be quickly provided, as proposed by Tsien and me in 1943 . It was called PRIVATE A, with the intention to name subsequent missiles in hierarchical order of army ranks. The JPL missiles series ended in 1954 with the SERGEANT, a solid propellent surface-to-surface missile with an inertial guidance system.
The PRIVATE A (also designed XF 10S1000-A) was designed to provide experimental data on the effect of sustained rocket thrust on a missile stabilized with fixed fins and on the use of booster rockets for missile launching . It had a length of 92 in., a maximum diameter of 10 π in. And 4 tail fins extending 12 in. from the body. The gross weight was 500-550 lb. including a payload of 60 lb. The solid propellent motor, manufactured by the Aerojet Engineering Corp. (now Aerojet General Corp.) delivered a thrust of 1,000lb. for about 30 sec. The specific impulse of the GALCIT 61 C asphalt-base castable propellent was 186 sec.
The launcher was a 36 ft. long rectangular steel boom of the truss type, with four guide rails inside the truss. It was mounted on a steel base and both the lateral and vertical angles could be varied.
The missile was boosted by 4 modified Ordnance Department aircraft armament rockets in a cluster, which delivered a total thrust of 22,000 lb. for 0,18 sec. They completed their burning and disconnected from the missile before it left the launcher. Full details on the design of the PRIVATE A, its booster and launcher can be found in Refs .
Firing tests were made in the Mojave Desert at Leach Spring, Camp Irwin, near Barstow, California, between 1-16 December 1944 while I was in England. Twenty-four rounds were fired, with an average range of approximately 18,000 yd. The maximum range was 20,000 yd. or 11,3 miles. The missile reached an estimated peak height of 14,500 ft/ and an estimated peak height of 1,300 ft/sec. A view of the smoke trail of a PRIVATE A in flight is shown in Fig. 5 Trajectory analyses were carried out by W.Z. Chien and C.C. Lin . The firing tests were completely successful, meeting all of the objectives specified for the programme. The PRIVATE A became the direct precursor of American composite propellent rocket engine missiles, the SERGEANT, POLARIS, MINUTEMAN, and POSEIDON and of anti-missile missiles.
Tsien and I in the memorandum of 1943 also proposed the addition of wings to a missile having the characteristics of the PRIVATE A, estimating that the range would be increased by around 50% but with a reduced payload. We pointed out that the problems of stability and control of such an unguided missile were very complicated.
The winged PRIVATE A was designated PRIVATE F (also FX 10S1000-B). The same Aerojet solid propellent engine was used. The missile was provided with fixed wings having a span of 5 ft., stubby wings of 3 ft. span at the forward end for trimming the aerodynamic forces and, at the rear, horizontal stabilizers and a vertical fin. The same PRIVATE A booster cluster was used. A new launcher was constructed with two rails, in order to clear the wings and tail surfaces. Design details can be found in Ref .
Firing tests were made at Hueco Range, Fort Bliss, Texas between 1-13 April 1945. The tests began on April Fools Day and turned out to be quite appropriate to the day. All of the PRIVATE F rounds were successfully launched but each one, after a short flight, went into a tailspin. A striking corkscrew smoke trail was drawn in the sky by the rocket jet ! It was concluded after a post mortem of the tests that better performance might have been obtained if the missile had been constructed with greater precision and if the lifting surfaces have been more readily adjustable .
In calmer times, when the use of funds is more carefully scrutinized , programmes, such as the PRIVATE F, would have been undertaken only after more theoretical studies of such a complex device had been made and more care would have been taken in its construction.
While tests of the PRIVATE FW were underway at Fort Bliss, Texas, we visited the nearby missile test range being newly prepared for the Ordnance Department at White Stands, New Mexico. Here facilities were being constructed for the tests of the WAC CORPORAL, which the following September inaugurated the White Sands Proving Ground, then under the command of Col. H.R. Turner.
The first long-range missile proposed by Tsien and me in 1943 was to be boosted and then propelled by a storable liquid propellent rocket engine of the type already developed at JPL Our proposal contained the basic design ideas that were used in the WAC CORPORAL sounding rocket , although we did not contemplate the design of a sounding rocket at the time we made the original analysis. One immediate result of our proposed third missile was the initiation in 1944 of the design and construction of a guided long-range missile called the CORPORAL, which I shall discuss later.
Since in 1943 there was not available a guidance and control system for ground-to-ground missiles , we proposed that a liquid propellent missile be boosted by an unrestricted burning solid propellent rocket out of a launcher. If launched at sufficient speed, the tail fins would provide the necessary restoring force when the missile was disturbed into yaw by a cross-wind.
The possibility of employing rocket propulsion for lifting a vehicle to great heights was realized at the beginning of this century . In America, Robert H. Goddard first gave serious consideration to this possibility in about 1914. At first he studied the feasibility of using constant-volume process, short-duration smokeless powder rocket engines . A more rigorous analysis that Goddards of the flight performance of a rocket propelled by successive impulses was made by Tsien and me in 1939 . A historical summary of sounding rockets is contained in a book recently released by NASA , which in my opinion, should be used with caution by historians, as there are a number of errors in those parts which relate to the history with which I am familiar.
Black powder rockets were capable of reaching several thousand feet before the 20th century and balloons in the 1930s could reach altitudes of about 100,000 ft. A successful sounding rocket, therefore, was considered to be one that surpassed the altitudes achieved balloons. Furthermore, it should be designed to minimize costs of production and of servicing and maintenance.
Goddard in the 1920s had decided that a liquid propellent rocket engine offered better possibilities for constructing such a sounding rocket and he obtained very limited financial support for developing one from the Smithsonian Institution . The Daniel Guggenheim Fund for the Promotion of Aeronautics, upon the urging of Charles A. Lindbergh, began to support this work in the 1930s at the station Goddard established near Roswell, New Mexico . In 1936;Goddard published a very general report on the progress of his work at Roswell . Our group at Caltech in 1936 arrived at the conclusion that the reason Goddard had not succeeded in constructing a successful sounding rocket was because he had underestimated the difficulties involved; there were too many problems for an isolated inventor to solve . Even so, success for anyone in the 1920and 1930s was not likely because rocket technology was not sufficiently advanced; there were no high-thrust, short-duration booster rocket engines and no suitable guidance systems. Goddards LOX-gasoline rocket engines, moreover did not provide a high enouh specific impulse for the tasks.
Similar difficulties confronted experimenters in Germany and in the Soviet Union where a group headed by M.K. Tikhonravov first launched a liquid propellent rocket called "Rocket 09" in vertical flight on 17 August 1933 . In Germany, the V-2 (A-24) was launched as a ground-to-ground missile , it was used as a sounding rocket for a period in the USA beginning in April 1946 .
The situation in 1944 was radically different from the one that faced Goddard 10 years earlier. Solid propellent rocket engines for boosters could be taken from armament rockets being used in the war to circumvent the necessity of a guidance system within a sounding rocket. Both solid and storable liquid propellent rocket engines with a thrust of sufficient magnitude and duration, and with adequate specific impulse had been developed at JPL.
We considered the advantages of using various types of rocket engines to propel the WAC, in particular : (a) a high-thrust , short-duration ballistite engine used in armament rockets; (b) a long-duration asphalt-base GALCIT 61-C solid propellent engine of the type used in the PRIVATE A and PRIVATE F; and (c) a nitric acid-aniline liquid propellent engine with a cooled motor and a gas-pressure propellent supply system. Armament rocket engines would have produced excessive acceleration of the WAC, which was not desirable from the point of view of mechanical design and of the high drag resulting from high flight speeds in the dense lower levels of the atmosphere.
The second alternative, the GALCIT 61-C solid propellent engine, was dropped because its weight as then designed, was excessive. For the WAC to reach an altitude in excess of 100,000 ft. , it was estimated that an overall impulse-weight ratio of at least 95 sec. was necessary and not more than around 77 sec. Could be obtained with the available GALCIT-61-C engine.
It was decided that the most feasible engine to meet WAC objectives would be the nitric-acid-aniline of the type mentioned above. The motor to be used was a modified version of one designed by Aerojet to deliver 1,500 lb. thrust for around 45 sec.
The next problem studied was stability of the WAC in vertical flight. A missile in vertical flight is obviously unstable in the sense that, if there is some small disturbance, gravity causes the trajectory to depart more and more from the vertical. There were two ways to assure vertical flight. The first and most direct method was to employ a gyro-stabilization system together with movable aerodynamic surfaces. For the desirable relatively small dimensions of a sounding rocket, however, the weight of such a system with its gyroscopes servo-mechanisms and other auxiliary equipment was at the time so high as to make it a rather dubious method of solving the problem. The second approach was to launch the WAC at a sufficiently high speed so that deviation from the vertical was not of any great importance . This speed could be accomplished by using a second rocket to boost the WAC quickly to a velocity of about 400 ft. per sec. before it left a launching tower. It was estimated that the WAC needed to be guided in a tower for around 60 ft. and that launching acceleration should not exceed about 50 g.
The WAC was to be capable of carrying an instrument payload of 25 lb. which was to be lowered to the ground by parachute.
The above recommendations were accepted by the Ordnance Department , and design of the WAC with supporting equipment was immediately initiated. Plans were also made for testing the WAC at White Sands Proving Ground.
The WAC , as finally constructed and tested (Fig.1), had the following specifications:
Overall length : 194 in.
Max. diameter of body : 12,2 in.
Three tail fins of 24 in. half span
Gross weight : 665 lb.
Empty weight : 297 lb.
Red fuming nitric acid 286 lb.
Aniline-furfuryl alcohol mixture : 114 lb.
Air at 1900 p.s.i. : 19 lb.
Motor thrust : 1,500 lb.
Thrust duration : 45 sec.
Impulse weight ratio : 102 sec.
It was assembled by the Douglas Aircraft Co., Santa Monica, California, from components supplied by JPL’s ORDCIT Project.
The sounding rocket was boosted from the launcher by means of a modified ballistite solid propellent rocket engine from an armament projectile called the TINY TIM which had the following specifications :
Overall length : 96 in.
Max. diameter of body : 11,75 in.
Three tail fins of 24 in. half span : 26 in.
Gross weight : 759 lb.
Weight of propellent : 149 lb.
Ave. Thrust (sea level) : 50,000 lb.
Nominal duration of thrust : 0,6 sec.
Impulse-weight ratio : 40 sec.
The launcher at White Sands Proving Ground consisted of a 77 ft. triangular structural steel tower, 6 ft. on a side, resting on a tripod 25 ft. high with a 26 ft. base, giving an overall height of 102 ft. The tower contained three launching rails set 120 ° apart to guide the WAC and its booster. The effective length of the rails was 82 ft. Details of the design of the launcher are given in Reference . It was built for the ORDCIT Project. A bombproof control house was constructed by the Ordnance Department 465 ft. from the launcher.
To check the flight characteristics of the WAC-booster combination, tests were made with a 1/5 scale model, called the BABY WAC. These were launched from a scaled-down launching tower at Camp Irwin, California, beginning 4 July 1945 . One of the interesting aspects of these tests was the verification of the suitability of employing three instead of the traditional four tail fins. For some reason, rockets in the past and aerial bombs were equipped with four fins. Stewart, to save weight, proposed we use three but Ordnance "experts" told us the WAC would then not be stable in flight. When he pointed out that arrows for ages had three fins and had performed very nicely, he was still doubted. The tests of the BABY WAC settled all arguments; the model behaved very well, as later did the three-finned full-scale WAC. The BABY WAC reached an altitude of around 3,000 ft.
Since the WAC was expected to be used as a meteorological sounding rocket in locations that would be near populated areas, we decided to provide a 10 ft. parachute in the nose of the WAC to lower it to the ground at a velocity of around 70 ft. per sec. . The parachute was to be released at the zenith of vertical flight. It was attached to the top of the propellent tanks and housed in the nose cone; The nose cone was attached to the WAC by means of three explosive pins inserted through the skirt of the nose cone into lugs welded on the taken head. The skirt was seated on a rubber ring seal-strip so that, at launching atmospheric pressure was sealed in the nose and provided a force to push the nose away at the zenith of flight, where the outside pressure was practically zero.
Two schemes were to be tried to fire the explosive pins at zenith. The first used a gyroscope, the frame of which when the WAC turned through 90° was to close an electric circuit to the pins. The second scheme used a mechanical timing device to close the circuit at the predicted time of flight to zenith .
To check the flight characteristics of the WAC-booster combination, tests were made with a 1/5 scale model, called the BABY WAC. These were launched from a scaled down the Signal Corps provided radio sonde equipment with its own parachute to be installed in the nose cone, to be released at the same time as the parachute of the WAC . It also provided weather information, including data obtained from balloons rising up to about 100,000 ft.
The WAC was tested at the White Sands Proving Ground, New Mexico, during the period 26 September to 25 October 1945, only nine months after I proposed the sounding rocket to Trichel in Washington D.C. Details of the test programme can be found in References.
In 1936, I had placed on my office wall at Caltech a chart showing the aspects of a successful sounding rocket requiring attention . The dream had now become a reality, with an engineer in charge of each of these aspects . Key members of my WAC team were : M.M. Mills (Booster), P.J. Meeks (Sounding Rocket), W.A. Sandberg and W.B. Barry (Launcher and WAC nose), S.J. Goldberg (WAC Field Tests), H.J. Stewart (External Ballistics) and G. Emmerson (Photography).
A group photograph of most of the ORDCIT Project Personnel who participated in the test programme at White Sands is shown in Fig. 6. In all, 37 persons were involved, not including those concerned with preparations for the tests at JPL. The number of people in this programme indicated why the dreams of individuals and small groups of rocket enthusiasts in the 1920s and 1930s to design, construct and test a high altitude sounding rocket had little chance of success; Fortunately, most pioneers do not foresee all of the practical implications of their dreams. No doubt if they were able to do so, few new ideas would ever be tried.
The test programme proceeded step by step until we were confident that basic components were satisfactory. First four rounds of the weight-adjusted TINY TIM booster alone were fired to check the booster, launcher and firing controls, and to give practice to radar and camera crews. Next, two dummy rounds of the WAC and the operation of the nose cone release mechanism. Up to this point , all systems were "go" except for the nose cone release mechanism, which failed both times. The partial charge WAC reached an altitude of around 28,000 ft. and difficulties were only encountered in tracking it with radar .
Radar tracking at this time was still in a rudimentary state of development. The troubles of the radar group from the Ballistic Research Laboratory at Aberdeen Proving Ground, Maryland, headed by L.A. Delsasso, did not interfere with his prowess as a poker player in games we played in the evenings when we did not go across the Rio Grande River to Juarez in Mexico or work on the WAC.
Our great day for the first flight of the WAC (round 5) fully charged with propellent was 11 October 1945. It was a clear day. We craned our necks to watch the WACs smoke trail until the engine stopped at around 80,000 ft. On the basis of radar tracking data for the 6th round of the WAC, it was estimated that the maximum altitude reached was between 230,000 and 240,000 ft. The total time of flight was about 450 sec. or 7,5 minutes. The velocity of the WAC at the end of burning was about 3,100 ft/sec. and the impact point of the first round was about 3,500 ft. from the launcher, which meant that the WAC had maintained a very satisfactory vertical path. Success!
I was the sole member of the original GALCIT Rocket Research Group of 1936 to experience the culmination of its hopes after many zig-zaggings in rocket development over the ensuing period of 10 years. It is difficult to describe my feelings as I watched the sounding rocket soar upward. One can think of many things in a few minutes and one of my thoughts was that I could now turn my mind to other goals in a world full of both fascinating technological possibilities and of desperate social problems.
Six charged rounds were fired during this 1945 programme. In round 7, the nose cone release mechanism functioned prematurely shortly after the WAC left the launcher but it continued in vertical flight. The parachute did not lower the WAC to the ground successfully in any of these flights , for it was either not released, released prematurely or torn off during descent. This did not surprise use as there was very little prior experience of the behavior of parachutes opened at high altitude. Even after the parachute failed the first time, many of us remained standing in the impact area because Stewart assured us that the probability of being struck was very small. Even so, we were startled to see one impact take place about 200 yards from where we were standing.
When the center of gravity of the WAC was too far forward, it went into a flap spin during its fall to the ground and, as a result, it struck the ground at greatly reduced speed. Radar tracking gave a minimum of data to permit the height reached by the WAC to be calculated. On most rounds, it failed completely. That radar can now be used to map the surface of a distant planet seems incredible.
The tests of the WAC CORPORAL showed that the design features we chose for a practical sounding rocket of reasonable cost were correct. The use of a booster rocket and an adequate launching tower circumvented the need of a guiding system. The use of storable liquid propellent engine simplified launching procedures compared to the use of LOX engines .
It is a tradition at JPL, to be conservative and unsensational in making proposals when dealing with problems involving many unknowns. Thus, we set the altitude to be reached by the WAC to be above 100,000 ft. In view of the fact that no liquid propellent engine sounding rocket before had reached more than a few thousand feet that seemed quite ambitious; The fact that the WAC so far exceeded our first theoretical estimates was primarily due to a reduction of the empty weight and to the increased amount of propellent carried by the WAC.
In March 1946, plans were initiated for the design and construction of the WAC CORPORAL B, with Meeks as Project Co-ordinator. The modified sounding rocket was to incorporate recommendations resulting from the tests of October 1945 and from those scheduled for May 1946, and a lighter weight redesigned engine and propellent tanks to increase the propellent-to-gross weight of the first design. A report on the tests of the WAC B at White Sands Proving Ground in December 1946 and in February-March 1947 can be found in Ref.
The results and know-how obtained with the WAC CORPORAL were incorporated in its successor the AEROBEE, which was designed and constructed by Aerojet and assembled by the Douglas Aircraft Company. The project, sponsored by the Navy Bureau of Ordnance, was carried out under the technical direction of the Applied Physics Laboratory of John Hopkins University, with James A. Van Allen as supervisor. The contract to Aerojet was awarded on 17 May 1946 and the first full-scale AEROBEE was launched at White Sands on 24 November 1947 .
Numerous variations of the basic WAC design have been constructed in the USA and in other countries and have been used for high-altitude research since 1948 .
A major objective of the ORDCIT Project , as described earlier, was the development of a remotely controlled missile to carry an explosive load of 1,000 lb. for a distance of up to 150 miles, with a dispersion not in excess of 2% and at a velocity sufficient to afford protection from fighter aircraft. Tsien outlined on 14 August 1944 a programme for an experimental missile (with the designation XF36L 20,000) that had the following tentative specifications :
Gross weight : 5 tons
Diameter: 36 in.
Rocket thrust : 20,000 lb.
Thrust duration : 60 sec/
Sp. Propellent cons.: 0.005 sec.
Stabilization : fins
Range : 30 to 40 miles
At that time, only a storable liquid propellent engine of the type developed by JPL could meet these specifications and the thrust required was much higher than any motor constructed in America up to that time. The largest uncooled motor that had been tested at JPL delivered about 6,000 lb. thrust.
We were now also confronted for the first time with the idea of launching a large rocket vertically without a booster rocket and a guiding launcher; I do not believe that we knew in early 1944 that the V-2 was launched in this way. There was considerable scepticism voiced over the possibility of keeping a missile in a vertical position solely by means of tail fins and control surfaces as it slowly lifted off the ground. On the other hand, it was evidently not feasible to boost at high accelerations a lightly constructed vehicle of the dimensions required.
Detailed analysis of the various components and of the flight characteristics of the missile was immediately started. The design and testing of the 20,000 lb. thrust nitric acid-aniline type engine was initiated under the supervision of Seifert. It was decided to develop simultaneously two engines, an engine with a gas-pressure propellent supply system, with which much experience had already been gained, for installation in a missile designated the CORPORAL E; and an engine with a turbine-driven pump propellent supply system (turborocket) for installation in the CORPORAL F. The development of a turborocket engine, which had been underway for some time under N. van de Verg, was speeded up .
Facilities for testing the complete CORPORAL engines were constructed at the Muroc Flight Test Base, California of the Air Technical Service Command. They were completed in June 1945 and operated under the direction of W.B. Powell .
When Duncan became Assistant Director in 1944, he devoted much of his effort to the CORPORAL programme. In the summer of 1945, Summerfield returned from Aerojet and assumed the role of co-ordinator. Fabrication of components of the missiles was sub-contracted to machine shops in the Southern California area. The construction of components became the main bottle neck in the programme because the ORDCIT Project at this time could not compete with priorities assigned to other production orders of the Armed Forces for the final year in the Pacific Theatre of Operations . Information on work carried out by the end of 19465 on the aerodynamics and mechanical design of the CORPORALS can be found in the archives of JPL.
The problems of remotely guiding and controlling a missile were entirely new to JPL and, furthermore, no work had been carried out on aircraft autopilot systems at the Caltech Guggenheim Aeronautical Laboratory. Upon the suggestion of Skinner, consideration was given to making contractual arrangements on CORPORAL guidance development with either C. Stark Drapers group at the Massachussetts Institute of Technology (M.I.T.) or the Sperry Gyroscope Company . The evolution of aerospace guidance technology at MIT between 1935 and 1951 was discussed by Draper in the paper presented at this Symposium .
Meetings of von Karman and Trichel on 29 July 1944 and of Martel and me on 24 August with Sperry personnel led to a contract between JPL and Sperry for the co-operative development of the CORPORAL guidance system . I especiallyenjoyed making the acquaintance of Gifford E. White of Sperry, who with Pickering laid the basis for the guidance system . C.B. Millikan , who had wide experience in aerodynamics, devoted much time to getting this programme underway. Primarily through his efforts Pickering joined the staff of JPL in August 1944 to establish the Remote Control Section with Frank Lehan as his principal assistant. Information on the work carried out under this Section up to the end of 1946 can be found in the archives of JPL.
Solid Propellent Research and Applications
Sponsorship of solid propellent research was taken over by the ORDCIT Project from the Air Force Materiel Command on 1 July 1944 . By this time, JPL had made the following fundamental contributions to the design and construction of long-duration solid propellent engines :
(a) Theory .
1. Von Karman-Malina theory of constant-thrust long-duration engines ( 1940).
(b) Propellent development
1. Parson’s break-away from ballistite and use of an amine black powder (1940)
2. Parson’s introduction of perchlorates an oxidizer (1942)
3. Parson’s introduction of asphalt as a fuel-binder with perchlorates. Invention of a castable case-bonded composite propellent charge (1942)
(c) Engine component design.
1. Parson’s design of a restricted burning (case-bonded) propellent charge with amine black powder (1940).
2. Design by Malina and Mills of a safety pressure-relief valve (1942)
3. Mill’s review of various types of burning surfaces of a charge and theoretical confirmation that the surface of a cigarette type burning charge was stable (1943).
After the successful JATO development with the asphalt-perchlorate propellent in 1942, effort was primarily directed, under the supervision of Mills, to finding a fuel-binder for the perchlorate superior to asphalt. In 1944. Charles Bartley joined Mills group and in 1945 introduced as a replacement for asphalt a castable elastomeric material, polysulfide rubber, produced by the Thiokol Chemical Corporation. A report on the development of this propellent can be found in Ref. . The polysulfide rubber compared to asphalt produced a propellent much better both as regards storage temperature limits and hardness at high atmospheric temperatures. The latter property was especially important in the design of high thrust engines requiring an internal burning surface rather than a cigarette-burning surface charge. Since at this time only Aerojet in America was producing composite solid propellent engines, I drew the companys attention to the asphalt replacement but it was already interested in a similar material made by the General Tire and rubber Co. I believe it was at the urging of the Ordnance Department that the Thiokol Chemical Corporation entered the field of composite solid propellents with the new fuel-binder found at JPL.
After obtaining the experience with the composite solid propellent missiles PRIVATES A and F, studies were initiated at JPL in 1946 on larger missiles using in particular the polysulfide rubber-perchlorate type of propellent. The results of these studies led eventually to the design of the guided missile called the SERGEANT.
The Laboratory followed closely developments with other types of solid propellents, especially ballistite, used in high-thrust short-duration engines suitable for boosters. Available engines were modified to meet special requirements for boosting the PRIVATES and the WAC CORPORALS.
Considerable research was also conducted by the Solid Propellent Rocket Section under Bartley, and the Propellent Section, under N. Kaplan and later under S.A. Johnston, on gas generation systems to replace stored gas for feeding liquid propellents to rocket motors. Our optimism that such a system could be developed quickly proved to be unfounded.
Applications of Rocket Propulsion for Extraterrestrial Space Exploration
I have described the background to the initiation of rocket research at Caltech in my first memoir on the GALCIT Rocket Research Project, 1936-38 . Space travel, which was the goal of this Project, was not stressed after we realized that existing rocket technology was a long way from providing the means for accomplishing such a goal. It is true that journalists published stories interpreting our studies of sounding rocket performance and preliminary rocket engine experiments as heralding a planned landing on the Moon by Caltech. It was not until after work on the CORPORAL was initiated in early 1945 that studies were resumed that had been put aside in 1938 in order to develop rocket engines for aircraft applications.
The WAC could be considered as a two-step rocket vehicle; Summerfield and I began, I believe in the summer of 1945, a more detailed analysis of such vehicles, with a re-evaluation of the feasibility of a rocket payload being launched at sufficient velocity to escape the gravitational field of the Earth. The analysis was based on the state of rocket technology at that time and included a discussion of the possible use of a nuclear energy rocket engine . The analysis led to the Malina-Summerfield criterion for step-rockets, which states that the optimum step-rocket will be one in which the ratio of the mass of payload for each step to the mass of the step propelling the payload is the same (the payload for step one is the mass of all succeeding propulsion steps plus the mass of the final useful payload).
We calculated as an example a step-rocket to launch to escape velocity a useful payload consisting of an instrument for measuring cosmic ray intensity with a radio beacon transmitter for sending the data back to Earth. Obviously, if a useful payload could be launched to escape velocity, it could also be placed in orbit around the Earth, at least as regards rocket propulsion. Americas first satellite , EXPLORER 1, on 31 January 1958, carried a cosmic ray instrument and the payload weight was about the same as we had chosen.
I presented on 3 January 1946 in Washington D.C. the results of our study as well as the high points of achievements at JPL, to the War Equipment Board of the Army, which was headed by General Joseph W. Stilwell. As I recall, the Board made little comment on the implications of the possibility of launching a man-made object away from the Earth. Stilwell is quoted in Ref. as having written the following in his diary in regard to his assignment to the Board: "I am eminently suited to do something else and would as lief sit on a tack".
We had made conservative assumptions in our "escape" analysis, especially as regards propellent specific impulse and structural weights of vehicle components. An example we gave of 5-step rocket to launch a 10 lb. Payload to escape velocity was estimated to weigh 3,000,000 lb. for the nitric acid-aniline propellent combination and 450,000 lb. for oxygen and ethanol. It was difficult for almost anyone in 1946 to imagine meeting the engineering problems and cost of construction such rockets.
The analysis we made was correct, as was pointed out in 1959 by J.E. Froehlich . However, between 1946 and 1959, improvements in engine and structural design permitted the gross weight required to launch a payload to escape velocity to be reduced by a factor of over 400. This is certainly an amazing demonstration of the possibilities of technological research and development when there is a will to support them.
The following summer I returned to London to undertake, starting on 7 July 1946, a second mission in Europe for the Army Ordnance Department in the office of Colonel Reed, Assistant Military Attache. My mission was much broader than it had been in 1944, for I also was asked to report on matters related to science and technology outside the domains of rocket propulsion and missile design. I remained in Europe until December 1946 and during this time I saw von Karman several times and discussed with him aspects of the post-war situation, especially as they would affect his and my plans for the future.
I discussed our "escape" study at a a meeting of the British Interplanetary Society (BIS) in London and presented a paper on it at the Sixth International Congress for Applied Mechanics in Paris . The members of the BIS who were at the meeting were not very happy when I said that at this time it should be possible to land a man on the Moon, provided that he was sent up in two halves in separate rockets, without the offer of a return trip to Earth.
One of the results of our study was Summerfields suggestions that a programme be initiated to launch a two-step rocket vehicle consisting of the WAC CORPORAL, boosted by the V-2. Initiation of this programme at JPL was authorized by the Ordnance Department in October 1946 and the vehicle was designated as the BUMPER WAC
A photograph of the rocket vehicle is shown in Fig.8. It was successfully launched at White Sands Proving Ground on 24 February 1949 and the WAC reached an altitude of 244 miles . Thus the WAC became the first positively recorded man-made object to enter extra-terrestrial space and the " space-age " could be said to have been opened in America in 1949. On 24 July 1950, a BUMPER WAC was launched as part of the first missile launching programme from Cape Canaveral (now called Cape Kennedy).
While Summerfield and I were concluding our "escape" study, the Navy Bureau of Aeronautics on 12 December 1945 made a contract with JPL for studies of a rocket vehicle for launching and Earth satellite. The work of the Navy and of JPL on this programme can be found in a detailed historical paper by R. Cargill Hall . Unfortunately, for the reasons he puts forward, the Navy dropped the programme in 1947.
A summary of the basic aspects fo the physics of space flight as understood at JPL in 1946 can be found in a paper by Seifert, Mills and Summefield . A Guided Missile and Upper Atmosphere Symposium was held at JPL from 13 to 16 March 1946, in which leaders of research on relevant subjects from all parts of the USA participated .
There are many areas of research conducted under the ORDCIT Project that I have not gone into in any detail, for example, work on materials, chemistry of propellents, ramjet design, telemetering of data from missiles in flight and remote control of missiles. The main reason is that my role in these domains was mainly of an administrative character and, therefore, those that led the actual work would be able to shed light on them that cannot be gleaned from formal technical reports.
The preparation of my three memoirs on the origins and work of JPL between 1936-1946 has heightened my appreciation of the difficulties confronting those who write on the history of technology. Not only are demands made on authors to understand the technical matters of a development but interpretations are expected of them that require a historical perspective on a world-wide scale, which cannot be obtained only from chronologies and formal, technical, published and unpublished reports. If in addition, authors wish to attract the attention of the lay public, then , if the greatest care is not taken, approximations to the truth recede further and further into space to be replaced by myths.