During World War II, the city of Annapolis somewhat reluctantly became the cradle of American rocketry. The days, and sometimes the nights, were interrupted by stabbing flames and thunderous roars issuing from concrete emplacements across the Severn River at the Engineering Experiment Station. Wartime secrecy requirements made it impossible at the time to explain the rather mysterious and irritating goings-on. Early in 1943, however, a PBY airplane took off from the Severn River with these same flames issuing from cylindrical objects suspended beneath either wing. It then became obvious to one and all, and in particular to the patrons of the Chesapeake Bay ferries which used to ply in and out of Annapolis, that the Navy was developing rockets to assist the take-off of heavily loaded seaplanes. The rocket development work continued at the Engineering Experiment Station throughout the War and covered not only solid-propellant and liquid- propellant JATO units for aircraft rocket assisted take-offs, but also some of the earliest developments in the United States of rocket propulsion systems for guided missiles. For its development work in this period, the U. S. Navy brought to Annapolis the most famous of all rocket pioneers—Dr. Robert Hutchings Goddard, generally acknowledged these days as the wellspring of the modern-day renaissance of rocketry.
The story of how Annapolis became a center of rocket development goes back a number of years prior to the beginning of the War when I was a midshipman at the Naval Academy—and in a sense, a good deal farther back than that. I was, in fact, bitten by the rocket bug at a rather tender age, and had, prior to coming to the Naval Academy, built and flown several rockets of the more-or-less common gunpowder variety. It was in my third class year at Annapolis when the rocket bug really clamped its teeth down hard, and I began the design and actual construction of a liquid-propellant rocket originally designed as an altitude probe. I quickly discovered that the fabrication of propellant tankage was completely beyond my financial or personal capabilities, but it also became obvious that the first item of business was to develop the thrust chamber and its associated valves and controls.
The Naval Academy was not noted for the amount of free time it gave to midshipmen, and my rocketeering had to be sandwiched in between the termination of classes and evening formation. As a matter of fact, it developed that my time for building rocketeering devices was even more restricted because electric power in the shop was turned off at 5 p.m.
After I had completed the design of a rather sophisticated, cooled, liquid-propellant combustion chamber in my room in Bancroft Hall, I went over to Isherwood Hall to the machine shop to get on with the job of fabrication. Mr. Harold Lucas, the machinist in charge, listened sympathetically as I explained my requirements for materials and then asked me whether I had the proper requisitions. Of course I had none, and after a somewhat crestfallen silence on my part, Mr. Lucas offered a way out. He led me down to the scrap box and said, “If you can find anything in there that can be used for your rocket, go ahead and take it.” I selected as the main body of the thrust chamber a nickel-steel pinion gear. The hub of this gear appeared to be of proper thickness and quality to withstand almost any pressures which might be generated. I took the gear back to Mr. Lucas and asked him if I might use one of the machine-shop lathes. He asked me whether I had ever used a lathe before. When I replied that I had only that instruction given all midshipmen in shop work, he led me down the long line of lathes to the smaller and older ones. He finally stopped in front of a ten-inch South Bend lathe, of about 1917 vintage, and told me that I was free to use that one.
In spite of the age and decrepit condition of the lathe, I am sure that Mr. Lucas’ machinist’s soul winced each time the lathe went clank, clank, clank with the cutter hitting the case-hardened teeth as I proceeded to machine them off the pinion gear. I am not sure whether I lost more teeth off the driving gears of the lathe or off the work in the chuck. At length, however, this task was completed. I remember being so frustrated by the fact that the power was cut off at 5 p.m. that many times I would set up to take a cut, lose the power, and then pull the lathe through by hand. Under such circumstances, it is not surprising that it took about eight months to complete the first test combustion chamber.
When my masterpiece was completed, I took it to the head of the Marine Engineering Department and requested permission to set it up in the foundry and fire it. In perhap justifiable concern over the future of Isherwood Hall, permission was denied. I found much more receptive climate, however, across the Severn River at the Experiment Station. After a third-degree interrogation by several heads of departments, concerning in particular the safety of my proposed operations, it was decided to let me have a go at it. Not only was I given permission to work at the Experiment Station, but some assistance was provided in the form of materials.
In addition, a little welder named Sugar Evans was assigned to give me a hand in the construction of the rocket test stand.
In order to complete the test that I had programmed, I had to forego my September leave, and I was most annoyed to find that construction of an item as prosaic as a test stand required nearly half of my leave period. Nowadays, of course, construction of a rocket stand requires upwards of 18 months and many millions of dollars. Sugar Evans and I took a very practical approach, although not a very elegant one. In making the propellant tanks, we went out to the stock rack, selected some steel pipe of approximately the right size, and pulled it out to what appeared to be about the right length. Sugar, whiz that he was with the cutting torch, then cut the pipe off at the proper length without even removing it from the stock rack. We then made closures for the tanks by burning circles out of boiler plates, welding them in, and providing them with gussets which appeared to both of us to be about adequate in thickness and strength. There was a tank for fuel, a tank for the liquid oxygen, and, since the thrust-chamber design utilized a nozzle cooled in part by an injection of water, there was also a tank for cooling water.
Instrumentation was characteristically simple and direct, involving the use of Bourdon tube pressure gauges, an Eastman Kodak timer, and best of all, a stock-room scale on which the thrust chamber was mounted in a nozzle-up position. In operation, the beam rider on the scale was set to the thrust desired, and the valves were opened until that thrust was obtained. The instruments were then photographed with a Boy Scout camera at intervals determined primarily by the time required to wind the film on the camera. The fuel consumption was measured by means of a boiler gauge glass.
Although such flow measurements were undoubtedly highly inaccurate, they were no more inaccurate than the measurement of the thrust itself. And at any rate, it was not accuracy, but the principle of the thing that counted at this stage of the game.
Before completion of the test stand, I went to the Industrial Superintendent, Mr. John K. Amos, and announced that I was ready for my tests and would need an adequate supply of liquid oxygen and gasoline. I might as well have asked for an atomic bomb. Mr. Amos replied that the U. S. Naval Welding Regulations specifically forbade the use of oils or hydrocarbons in conjunction with oxygen of any kind, and there was no supply of liquid oxygen at the Experiment Station or any place else in the vicinity. Mr. Amos volunteered, however, that there was an adequate supply of compressed air at very high pressure available from some torpedo air compressors, and that I would be allowed to use this compressed air as the oxidizer for the gasoline. This fact probably proved to be a very favorable turn of fate, since the compressed air supply allowed me to run my thrust chamber for relatively long periods of time. It also avoided the difficulties which undoubtedly would have been encountered in the use of liquid oxygen.
With the first combustion chamber we made a considerable number of more-or-less successful tests, running the apparatus for periods as long as several minutes at a time. I would frequently run the tests during the lunch hour when the workmen from the shop would come out, gather around the rocket, and amuse themselves by throwing stones into the jet to see how high they would be hurled. I remember once two of the men got a large board and attempted to force it into the jet. Although the thrust of the rocket was only about 25 pounds, they found it difficult to hold the board in position against this force. The measurements made during these runs were reported in the Journal of the American Rocket Society, and constitute some of the very earliest measurements on rockets ever described.
The following months saw successive modifications, not only in the rocket combustion chamber, but in the test apparatus. A ceramic nozzle, made by casting Thermit slag in a metal mold, permitted long-duration runs without the use of water cooling. A second motor used fuel for cooling.
Noting the success of the tests as they were being conducted, Mr. Amos finally agreed to allow me to use gaseous oxygen in place of the compressed air. Because the welding regulations so dictated, however, he specified that a welding regulator be used in conjunction with the oxygen bottles. The welding regulators available to me at the Experiment Station were far too small to permit passage of enough oxygen to give significant thrust, and I protested this restriction as strenuously as I could. Mr. Amos, however, felt that he had stuck his neck out far enough, and he insisted on the welding regulator. I found a way around the difficult by the simple expedient of interchanging the high-pressure gauge commonly found on welding regulators with the outlet connection. In this fashion I was able to completely bypass the regulator, conforming to the letter, if not the spirit, of the rule book.
Through the co-operation of the Experiment Station, I was able to have the Experimental Shop build several new thrust chambers. These were ready for test along with the new oxygen gasoline apparatus in December 1938. The tests continued through Christmas vacation and on until graduation, in such time as I could spare. These tests were also reported in the Journal of the American Rocket Society. They included experiments with ceramic nozzles of almost every description, including such materials as silicon dioxide, aluminum oxide, silicon carbide and tungsten carbide. The chambers themselves in this period were cooled with water circulating through a jacket.
In the late spring of 1939, I prepared an article for the Naval Academy Log on the subject of rockets and their future application to aircraft and guided projectiles. This article came to the attention of Commander A. B. Vosseller, then Head of the Plans Division of the Bureau of Aeronautics. Upon graduation, I received a note from Commander Vosseller asking me to come to Washington to pay him a visit before proceeding to my ship. I thought I knew what he had in mind, and when he asked me whether I thought that rockets could be used to assist the take-off of heavily loaded seaplanes, I replied with the classic, “I’m glad you asked that question.” I had prepared an analysis of rocket-assisted takeoff as applied to the PBY airplane. The PBY was the airplane in which Commander Vosseller was interested. Apparently, the Bureau of Aeronautics had purchased a number of these airplanes which turned out to be so underpowered they would not carry a satisfactory payload, and the Bureau had the option of putting new engines in them or finding some other means of improving their take-off characteristics under load.
Commander Vosseller agreed to attempt to have me ordered back to duty to the Bureau of Aeronautics as soon as possible to head up a program to develop rockets for assisted takeoff use. In the meantime, it was agreed that I would apply for letters patent on my design for such a rocket. This request for a patent would be processed through the Bureau of Aeronautics and used as a medium for obtaining my assignment to duty there. The application was duly made, but Commander Vosseller had not taken into account the inflexible attitude of my commanding officer with respect to the assignment of young ensigns to shore duty. Captain C. A. Pownall, the commanding officer of the USS Enterprise (CV-6), felt it mandatory that young ensigns complete two years continuous sea duty before being assigned to duty ashore. It was, therefore, two years before I was finally ordered to the Bureau of Aeronautics. In the meantime, however, I had succeeded in collecting a number of parts, including regulators from torpedoes, and had constructed a new test stand adequate for a continuation of my work.
On reporting to the Bureau of Aeronautics, I was assigned to duty with the Ship Installations Division, since rocket take-off was visualized as a sort of a catapult. My skipper in the Ship Installations Division was Commander C. A. Bolster who had showed considerable interest in the project and who became my valuable friend and a firm ally in times of adversity.
My job at the Bureau of Aeronautics was to set up a permanent jet propulsion desk and to draw up a program for the Bureau of Aeronautics to pursue in the field of rocket development. Since at the time “rocket” was a science-fiction term associated only with crackpots, the term “jet propulsion” was always used. My program included the setting up of an in-house Navy project at the Engineering Experiment Station to develop liquid propellant JATOs (jet assisted take-off) for the PBY airplane as well as rocket propulsion for guided missiles, sounding rockets, and manned aircraft. When my planning for the program was completed, I took it to Commander Bolster to obtain his blessing. He thought the plans were excellent, but deemed my $65,000 estimated cost to be far more than the Bureau of Aeronautics was ready to put in the program. Since all of the funds were controlled by the Experiments and Developments Branch headed by Commander L. C. Stevens, however, Commander Bolster suggested that I go down and try at least to obtain the needed funds.
Commander Stevens turned out to be a very forward looking officer, and when I told him I did not think that an adequate program could be carried out for less than $65,000, he very quickly told me to write up a Project Order for that amount. I walked back down the hall toward Ship Installations kicking myself for not having asked for $165,000. With the paperwork approved, I could hardly wait to get back to the Experiment Station and start getting my hands dirty once more with actual development work. I turned my jet propulsion desk over to Lieutenant C. F. Fisher and departed for the Engineering Experiment Station in July 1941.
In the meantime, I had succeeded in obtaining the services of Robertson Youngquist, a graduate of the Massachusetts Institute of Technology, whom I had met at one of the field firing activities of the American Rocket Society. Bob Youngquist was as much of a nut about rockets as I was, and together we began our very challenging task. Soon to join the staff were Ensigns William Schubert, James R. Patton, and Ray C. Stiff, whom I selected from the card files, in the Bureau of Aeronautics, of reserve ensigns who were being ordered to active duty.
Initial test work was done with gaseous oxygen and gasoline using the same test stand which I had built on board the Enterprise. We began construction immediately, however, of a much larger test stand capable of handling rocket engines with thrusts up to 1,500 pounds, a very sizable increase over the 25 to 30 pounds thrust that I had used while a midshipman. It was recognized early that liquid oxygen would be a rather impractical oxidizer to use on a service JATO unit because of the logistic problems involved in handling a cryogenic liquid. The propellants which were selected for the PBY JATO unit (which came to be know as the DU-1 since it was designed to be dropped and recovered, hence droppable unit number one) were nitric acid and gasoline. The small test stand was soon modified for these propellants.
We knew from chemical considerations that nitric acid should furnish adequate quantities of free oxygen to burn the gasoline one it had been decomposed in a hot thrust chamber. But we knew little or nothing of the problem of igniting this combination. Our initial approach was to burn the propellent in the open air and to test different kinds of fuel atomizers, or injectors as they were called, until we found one which would produce the smallest flame. We were most chagrined at our initial results. We were unable to get any combustion whatsoever of the nitric acid with the gasoline! In fact, all attempts to burn these two propellents in the open air were unsuccessful. It was only when we decided to take the bull by the horns and risk running the injectors in an enclosed thrust chamber that we succeeded in getting combustion. As a matter of fact, except for an occasional explosion, there was relative little difficulty with the small-size rocket. After a few months, we were obtaining excellent performance and were adequately cooling the rocket thrust chambers with the incoming propellents--the so called regenerative system.
Will still in the Bureau of Aeronautics, I had received a visit from Dr. Robert H. Goodard who told me that, upon the suggestion of the Guggenheim Foundation, he was offering his services to the Government. We discussed the various possibilities for rocket development. I suggested to Dr. Goddard that he draw up a specific proposal covering what should be done and exactly how he would like to see the work carried out, and that he then present this proposal to the Bureau for further action. After my departure, Lieutenant C. F. Fisher continued negotiations with Dr. Goddard, placing him under contract in approximately December 1941, and he was moved to the Experiment Station in the same general area as the Navy Project which I was heading.
Dr. Goddard arrived with his crew from Roswell, New Mexico, and began work on a JATO unit for the PBY using liquid oxygen and gasoline. These were the propellants which he had been using on his free-flying rockets at Roswell. Dr. Goddard’s team and the all-Navy crew continued working along side one another in a pleasant association that lasted for the duration of the War.
Completion of the large test stand coincided approximately with solution of the various problems that confronted us with the small-scale engines. Design and manufacture of a full-size engine, that is, one of 1,500 pounds thrust, followed shortly on the heels of the solution of the problems of combustion and cooling on the 25-pounds-thrust engines. The first firing of the 1,500 pounds engine was scheduled to occur on a Monday, and a host of representatives from the Bureau of Aeronautics, including Commander Bolster, was to be on hand. On the preceding Friday we had the first check-out run of the 1,500 pounds engine. This engine was designed using a number of injectors essentially the same size and design as those used on the small-thrust chambers. These injectors were designed to be cut in one at a time by a special valve.
The proper kind of nitric acid could be obtained in those days only in seven-pound bottles. Procuring and filling the tanks was a difficult and time-consuming job. As a result, it was decided to check out the engine by cutting in only one injector. This was done, and the engine ignited and functioned perfectly at a very low thrust level. The apparatus was then shut down, and we waited for the great day which was to come. Monday arrived and so did the visitors from the Bureau of Aeronautics. This time, when the valve was actuated, instead of hesitating at each thrust level and increasing only when the operator yanked the cord again calling for another injector to be cut in, the valve slammed all the way open. There was a short pause followed by a thunderous explosion. I pulled the water deluge lever, and we all waited. A few seconds later we looked out the door and saw no signs of fumes or fire, so we ventured to inspect the damage. The test stand was all but demolished. All of the equipment not protected by concrete or steel was nicked with flying fragments, and the concrete on the inside of the test stand was spalled in many places. This was the first of a long line of difficulties associated with the problem of igniting and obtaining stable combustion with the nitric acid/gasoline combination—a problem which has never been adequately solved.
While Ensigns Schubert, Patton, and I, together with Robertson Youngquist, were struggling with the problems of combustion chamber design, Ensign Stiff was attempting to develop the tankage and pressurization system. In particular, one approach which we called chemical pressurization appeared attractive to us. This system involved injecting into the propellant tanks reactive chemicals which would create hot gases that would expel the propellents from the tanks into the combustion chamber. In the course of his work, Ensign Stiff had discovered a number of chemicals that would not only react with nitric acid, but which would inflame spontaneously upon contact. One of these materials was aniline. After our first explosion, we decided to substitute aniline as the primary propellent in place of the gasoline and eliminate the ignition problem entirely. The second large-thrust chamber, which used a single injector rather than the multiple injectors used on the first model, employed nitric acid and aniline as propellents. This chamber had no ignition, and proved to be ultimately a highly successful design. With various refinements, this thrust chamber was used on the flight test unit. The chemical pressurization system never did work; however, the accidental solution to the ignition problem which it offered has been used to this day.
After the first few tests of the large-thrust chamber, I was detached from the Experiment Station and took up my long deferred flight training at Pensacola.
The PBY project turned its attention to the construction of the complete JATO unit including tanks, valves, and pressurization system. Because of the difficulties with the chemical pressurization, we decided to use compressed nitrogen as the propellant expulsion medium, acting through a more or less conventional regulator valve. New personnel joined the project at intervals, including a Marine Master Sergeant, W. L. Gore, who became the project test pilot.
Dr. Goddard continued his efforts on the liquid oxygen gasoline rocket, and his apparatus was ready for test first. The equipment was installed in the hull of the PBY with only the thrust chamber projecting outside of the skin line. A number of successful taxi tests were conducted, but soon a malfunction occurred which resulted in a fire and extensive damage to the aircraft.
Early in 1943, the DU-1 was ready for flight test. With Sergeant Gore at the controls and Lieutenant Stiff as the JATO operator, the PBY lumbered off the waters of the Severn River for a historic first. Successively greater loads demonstrated the ability of the JATO units to give good take-off performance—even with loads so heavy that the aircraft would not stay in the air once the operation of the JATOs had terminated.
As the assisted take-off development program approached a successful conclusion, several events took place which were to lay the foundation for rocket-propelled guided missiles. Engineers at the Bureau of Standards had been working on a small glider called the Pelican which was to be used as a gliding guided bomb. In order to provide additional range for this device, some form of propulsion was desired. Ensign Schubert adapted to the propulsion of this guided bomb a small rocket engine that had been developed by the newly formed Reaction Motors, Incorporated. On its first trial, the Pelican was carried aloft over the Chesapeake Bay by an airplane and dropped. The engine ignited and fired perfectly, but the guidance system failed. The Pelican, true to its name, headed straight down and plunged into the waters of the Bay, its small rocket engine still firing.
Shortly after this event, the personnel of the Project were approached by people from the Naval Aircraft Factory who were beginning the development of an air-to-air guided missile known as the Gorgon. The original intent was to power the Gorgon with a small turbo jet engine--the first such engine developed in the United States. These engines, however, proved to be prohibitively expensive, and the engineers of the Naval Aircraft Factory were looking for a cheaper power plant. Ensign Schubert, in a short period of 45 days from the time the specifications were laid down, developed and delivered a small acid/aniline rocket engine which was capable of delivering 350 pounds of thrust for two minutes. A number of these engines were later manufactured by Reaction Motors, Incorporated, and powered by Gorgon IIA missiles in several flight tests. During one of these flight tests a world speed record in excess of 500 miles an hour was set. The Gorgon was the first air-to-air guided missile to be successfully flown in the United States.
About this time the Fleet was suffering extensive damage from the Japanes Kamikaze airplanes. Engineers of the Bureau of Aeronautics began a program for a surface-to-air guided missile capable of knocking down these Kamikazes. The Project at the Engineering Experiment Station undertook the development of a suitable rocket power plant for this missile which came to be known as the Lark. Two thrust chambers were required. The Gorgon thrust chamber was taken as the prototype for both. By raising the chamber pressure, the thrust of the Gorgon engine was increased from 350 pounds to 400 pounds of thrust. A new scaled-down thrust chamber was developed which would give approximately 220 pounds thrust. The smaller engine was designed to burn continuously, and the larger one turned on and off in response to a signal from a Mach meter. This pulsing action would control the speed at approximately .85 Mach number. The Lark was capable of climbing to 30,000 feet or more. Development of the engines was done at the Engineering Experiment Station, and the Lark rocket engine was then turned over to Reaction Motors, Incorporated, for manufacture.
Essentially the same engine was used in two versions of the Lark, one built by Consolidated Aircraft and the other by Fairchild Aircraft and Engine Company. A second version of the engine was planned for the Fairchild bird. This second engine was to use turbo pumps to feed the propellants into the chamber, thereby eliminating the requirement for a high-pressure gas bottle and making more space available for propellants. The initial development work on this engine was completed at the Engineering Experiment Station, and general feasibility was shown. The final engine was the result of a co-operative program involving both Reaction Motors and the Eclipse Pioneer Division of the Bendix Corporation.
The work of the Experiment Station Navy Project expanded to include flight tests of solid propellant JATOs developed by the Aerojet-General Corporation and liquid propellant JATO engines by both Aerojet-General and Reaction Motors. At least two of these JATOs were flight-tested on seaplanes operating out of the Naval Academy’s Aviation Unit. Many of the flight tests were conducted on the Severn River.
New personnel were added as time went on. The Project eventually grew until it had some 25 engineers, approximately 100 enlisted men, and 30 or 40 civilian employees, as well as the services of the various shops at the Engineering Experiment Station.
During this time, the work of Dr. Goddard was reoriented from JATO to guided-missile power plants using both liquid oxygen and gasoline and also the nitric acid/aniline propellant combination. Dr. Goddard’s work included the development of a pump-fed acid /aniline engine driven by two unique Pelton-wheel-type turbines. Dr. Goddard also did experimental work on a rotating combustion chamber which was designed to pump its own propellants by the centrifugal force created by rotating the chamber. Between Dr. Goddard and the Navy Project, hardly a day went by that did not see one or more firing tests on rockets of one kind or another. Numerous contributions to technology were made by both groups. But at no time did the scope of U.S. effort even approach that which was being carried on in Germany. Their all-rocket airplane, the ME-163 and the giant V-2 rocket came as a complete surprise to the personnel at the Experiment Station and also to the nation. Our effort was minuscule by comparison and heavily oriented toward assisted take-off of aircraft, deemed at that time to be the only mission for a rocket worthy of sizable expenditures of funds. After V-E Day the Navy Project was consolidated with a guided-bomb project; and both moved first to the Naval Air Station at Mojave, California, and then to the new Guided Missile Center which was set up at Point Mugu, California.
Dr. Goddard’s contract expired, and he contracted his services to the Curtiss-Wright Corporation. Dr. Goddard’s people went to Caldwell, New Jersey, and formed the nucleus for a rocket development group there with Curtiss-Wright. Dr. Goddard himself, however, who had been suffering for many years from tuberculosis, then developed cancer. Before he was able to move to New Jersey, he died of cancer of the throat in a Baltimore Hospital.
During the War, Dr. Goddard was not given the opportunity to work on the free-flying type of rockets, the development of which he hah begun so successfully in Roswell, New Mexico. No one in the United States in a position of authority was willing to admit at that time that such free-flying missiles would have any value in the art of warfare. It is interesting to note that when U.S. technical people were interrogating Dr. Wernher von Braun of Peenemunde relative to the development of the V-2 rocket, he said, "I don’t know why you ask these questions of me when it is you who have the teacher who first expounded the technology that has made the V-2 possible."