Ignition!: An Informal History of Liquid Rocket Propellants

Ignition!

Figure 1. Engraving on plastic by Inga Pratt Clark, presented to Bob Border, Engineering Officer, NARTS, by the Propellant Division, 1959

Figure 2. This is what a test firing should look like. Note the mach diamonds in the exhaust stream. U.S. Navy photo

Figure 3. And this is what it may look like if something goes wrong. The same test cell, or its remains, is shown. U.S. Navy photo

Ignition!

An Informal History of Liquid Rocket Propellants

by John D. Clark

Those who cannot remember the past are condemned to repeat it.

George Santayana

Rutgers University Press

New Brunswick, Newark, and Camden, New Jersey, and London

Library of Congress Cataloging-in-Publication Data

Names: Clark, John D. (John Drury), 1907–1988, author.

Title: Ignition! : an informal history of liquid rocket propellants / by John D. Clark.

Description: New Brunswick, New Jersey : Rutgers University Press, [2017] | Orignally published: New Brunswick, N.J. : Rutgers University Press, 1972. | Includes index.

Identifiers: LCCN 2017033845| ISBN 9780813507255 (cloth : alk. paper) | ISBN 9780813595832 (pbk. : alk. paper)

Subjects: LCSH: Liquid propellants. | Liquid propellants—History. | Rockets (Aeronautics)—Fuel—History.

Classification: LCC TL785 .C53 2017 | DDC 629.47/522—dc23

LC record available at https://lccn.loc.gov/2017033845

Copyright © 2017 by Rutgers, the State University

All rights reserved

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www.rutgersuniversitypress.org

This book is dedicated to my wife Inga, who heckled me into writing it with such wifely remarks as, You talk a hell of a fine history. Now set yourself down in front of the typewriter—and write the damned thing!

Contents

In Re John D. Clark

Preface

Chapter 1. How It Started

Chapter 2. Peenemunde and JPL

Chapter 3. The Hunting of the Hypergol . . .

Chapter 4. . . . and Its Mate

Chapter 5. Peroxide—Always a Bridesmaid

Chapter 6. Halogens and Politics and Deep Space

Chapter 7. Performance

Chapter 8. Lox and Flox and Cryogenics in General

Chapter 9. What Ivan Was Doing

Chapter 10. Exotics

Chapter 11. The Hopeful Monoprops

Chapter 12. High Density and the Higher Foolishness

Chapter 13. What Happens Next

Glossary

Index

About the Author

In Re John D. Clark

by Isaac Asimov

I first met John in 1942 when I came to Philadelphia to live. Oh, I had known of him before. Back in 1937, he had published a pair of science fiction shorts, Minus Planet and Space Blister, which had hit me right between the eyes. The first one, in particular, was the earliest science fiction story I know of which dealt with anti-matter in realistic fashion.

Apparently, John was satisfied with that pair and didn’t write any more s.f., kindly leaving room for lesser lights like myself.

In 1942, therefore, when I met him, I was ready to be awed. John, however, was not ready to awe. He was exactly what he has always been, completely friendly, completely self-unconscious, completely himself.

He was my friend when I needed friendship badly. America had just entered the war and I had come to Philadelphia to work for the Navy as a chemist. It was my first time away from home, ever, and I was barely twenty-two. I was utterly alone and his door was always open to me. I was frightened and he consoled me. I was sad and he cheered me.

For all his kindness, however, he could not always resist the impulse to take advantage of a greenhorn.

Every wall of his apartment was lined with books, floor to ceiling, and he loved displaying them to me. He explained that one wall was devoted to fiction, one to histories, one to books on military affairs and so on.

Here, he said, is the Bible. Then, with a solemn look on his face, he added, I have it in the fiction section, you’ll notice, under J.

Why J? I asked.

And John, delighted at the straight line, said, J for Jehovah!

But the years passed and our paths separated. The war ended and I returned to Columbia to go after my PhD (which John had already earned by the time I first met him) while he went into the happy business of designing rocket fuels.

Now it is clear that anyone working with rocket fuels is outstandingly mad. I don’t mean garden-variety crazy or a merely raving lunatic. I mean a record-shattering exponent of far-out insanity.

There are, after all, some chemicals that explode shatteringly, some that flame ravenously, some that corrode hellishly, some that poison sneakily, and some that stink stenchily. As far as I know, though, only liquid rocket fuels have all these delightful properties combined into one delectable whole.

Well, John Clark worked with these miserable concoctions and survived all in one piece. What’s more he ran a laboratory for seventeen years that played footsie with these liquids from Hell and never had a time-lost accident.

My own theory is that he made a deal with the Almighty. In return for Divine protection, John agreed to take the Bible out of the fiction section.

So read this book. You’ll find out plenty about John and all the other sky-high crackpots who were in the field with him and you may even get (as I did) a glimpse of the heroic excitement that seemed to make it reasonable to cuddle with death every waking moment—to say nothing of learning a heck of a lot about the way in which the business of science is really conducted.

It is a story only John can tell so caustically well from the depths within.

Preface

Millions of words have been written about rocketry and space travel, and almost as many about the history and development of the rocket. But if anyone is curious about the parallel history and development of rocket propellants—the fuels and the oxidizers that make them go–he will find that there is no book which will tell him what he wants to know. There are a few texts which describe the propellants currently in use, but nowhere can he learn why these and not something else fuel Saturn V or Titan II, or SS-9. In this book I have tried to make that information available, and to tell the story of the development of liquid rocket propellants: the who, and when, and where and how and why of their development. The story of solid propellants will have to be told by somebody else.

This is, in many ways, an auspicious moment for such a book. Liquid propellant research, active during the late 40’s, the 50’s, and the first half of the 60’s, has tapered off to a trickle, and the time seems ripe for a summing up, while the people who did the work are still around to answer questions. Everyone whom I have asked for information has been more than cooperative, practically climbing into my lap and licking my face. I have been given reams of unofficial and quite priceless information, which would otherwise have perished with the memories of the givers. As one of them wrote to me, What an opportunity to bring out repressed hostilities! I agree.

My sources were many and various. Contractor and government agency progress (sometimes!) reports, published collections of papers presented at various meetings, the memories of participants in the story, intelligence reports; all have contributed. Since this is not a formal history, but an informal attempt by an active participant to tell the story as it happened, I haven’t attempted formal documentation. Particularly as in many cases such documentation would be embarrassing—not to say hazardous! It’s not only newsmen who have to protect their sources.

And, of course, I have drawn on my own records and recollections. For something more than twenty years, from 1 November 1949, when I joined the U.S. Naval Air Rocket Test Station, until 2 January 1970, when I retired from its successor, the Liquid Rocket Propulsion Laboratory of Picatinny Arsenal, I was a member of the unofficial, but very real, liquid propellant community, and was acutely aware of what was going on in the field, in this country and in England. (It wasn’t until the late 50’s that it was possible to learn much about the work in the Soviet Union, and propellant work outside these three countries has been negligible.)

The book is written not only for the interested layman—and for him I have tried to make things as simple as possible—but also for the professional engineer in the rocket business. For I have discovered that he is frequently abysmally ignorant of the history of his own profession, and, unless forcibly restrained, is almost certain to do something which, as we learned fifteen years ago, is not only stupid but is likely to result in catastrophe. Santayana knew exactly what he was talking about.

So I have described not only the brilliantly conceived programs of research and development, but have given equal time to those which, to put it mildly, were not so well advised. And I have told the stories of the triumphs of propellant research; and I have described the numerous blind alleys up which, from time to time, the propellant community unanimously charged, yapping as they went.

This book is opinionated. I have not hesitated to give my own opinion of a program, or of the intelligence—or lack of it—of the proposals made by various individuals. I make no apology for this, and can assure the reader that such criticism was not made with the advantage of 20–20 hindsight. At one point, in writing this book, when I had subjected one particular person’s proposals to some rather caustic criticism, I wondered whether or not I had felt that way at the time they were made. Delving into my (very private) logbook, I found that I had described them then, simply as Brainstorms and bullbleep! So my opinion had not changed—at least, not noticeably.

I make no claim to completeness, but I have tried to give an accurate account of the main lines of research. If anyone thinks that I have unreasonably neglected his work, or doesn’t remember things as I do, let him write to me, and the matter will be set right in the next (d.v.) edition. And if I seem to have placed undue emphasis on what happened in my own laboratory, it is not because my laboratory was unusual (although more nutty things seem to have happened there than in most labs) but that it was not, so that an account of what happened there is a good sample of the sort of things which were happening, simultaneously, in a dozen other laboratories around the country.

The treatment of individuals’ names is, I know, inconsistent. The fact that the family name of somebody mentioned in the text is preceded by his given name rather than by his initials signifies only that I know him very well. Titles and degrees are generally ignored. Advanced degrees were a dime a dozen in the business. And the fact that an individual is identified in one chapter with one organization, and with another in the next, should be no cause for confusion. People in the business were always changing jobs. I think I set some sort of a record by staying with the same organization for twenty years.

One thing that is worth mentioning here is that this book is about a very few people. The propellant community—comprising those directing or engaged in liquid propellant research and development—was never large. It included, at the most, perhaps two hundred people, three-quarters of whom were serving merely as hands, and doing what the other quarter told them to do. That one quarter was a remarkably interesting and amusing group of people, including a surprisingly small number (compared to most other groups of the same size) of dopes or phoneys. We all knew each other, of course, which made for the informal dissemination of information at a velocity approaching that of light. I benefited particularly from this, since, as I was working for Uncle, and not for a rival contractor, nobody hesitated to give me proprietory information. If I wanted the straight dope from somebody, I knew I could get it at the bar at the next propellant meeting. (Many of the big propellant meetings were held in hotels, whose management, intelligently, would always set up a bar just outside the meeting hall. If the meeting wasn’t in a hotel, I’d just look around for the nearest cocktail lounge; my man would probably be there.) I would sit down beside him, and, when my drink had arrived, ask, "Joe, what did happen on that last test firing you made? Sure, I’ve read your report, but I’ve written reports myself. What really happened?" Instant and accurate communication, without pain.

Conformists were hard to find in the group. Almost to a man, they were howling individualists. Sometimes they got along together—sometimes they didn’t, and management had to take that into account. When Charlie Tait left Wyandotte, and Lou Rapp left Reaction Motors, and they both came to Aerojet, the management of the latter, with surprising intelligence, stationed one of them in Sacramento and one in Azusa, separated by most of the length of the state of California. Lou had been in the habit, when Charlie was giving a paper at a meeting, of slipping a nude or two into Charlie’s collection of slides, and Charlie was no longer amused.

But friends or not, or feuding or not, everything we did was done with one eye on the rest of the group. Not only were we all intellectual rivals—anything you can do I can do better—but each of us knew that the others were the only people around competent to judge his work. Management seldom had the technical expertise, and since most of our work was classified, we couldn’t publish it to the larger scientific community. So praise from the in-group was valued accordingly. (When Irv Glassman, presenting a paper, mentioned Clark’s classical work on explosive sensitivity, it put me on cloud nine for a week. Classical, yet!) The result was a sort of group Narcissism which was probably undesirable—but it made us work like Hell.

We did that anyway. We were in a new and exciting field, possibilities were unlimited, and the world was our oyster just waiting to be opened. We knew that we didn’t have the answers to the problems in front of us, but we were sublimely confident of our ability to find them in a hurry, and set about the search with a gusto—the only word for it—that I have never seen before or since. I wouldn’t have missed the experience for the world. So, to my dear friends and once deadly rivals, I say, Gentlemen, I’m glad to have known you!

John D. Clark

Newfoundland, N.J.

January 1971

1

How It Started

The dear Queen had finally gone to her reward, and King Edward VII was enjoying himself immensely as he reigned over the Empire upon which the sun never set. Kaiser Wilhelm II in Germany was building battleships and making indiscreet remarks, and in the United States President Theodore Roosevelt was making indiscreet remarks and building battleships. The year was 1903, and before its end the Wright brothers’ first airplane was to stagger briefly into the air. And in his city of St. Petersburg, in the realm of the Czar of All the Russias, a journal whose name can be translated as Scientific Review published an article which attracted no attention whatsoever from anybody.

Its impressive but not very informative title was Exploration of Space with Reactive Devices, and its author was one Konstantin Eduardovitch Tsiolkovsky, an obscure schoolteacher in the equally obscure town of Borovsk in Kaluga Province.

The substance of the article can be summarized in five simple statements.

1. Space travel is possible.

2. This can be accomplished by means of, and only by means of, rocket propulsion, since a rocket is the only known propulsive device which will work in empty space.

3. Gunpowder rockets cannot be used, since gunpowder (or smokeless powder either, for that matter) simply does not have enough energy to do the job.

4. Certain liquids do possess the necessary energy.

5. Liquid hydrogen would be a good fuel and liquid oxygen a good oxidizer, and the pair would make a nearly ideal propellant combination.

The first four of these statements might have been expected to raise a few eyebrows if anybody had been listening, but nobody was, and they were received with a deafening silence. The fifth statement was of another sort entirely, and a few years earlier would have been not merely surprising, but utterly meaningless. For liquid hydrogen and liquid oxygen were new things in the world.

Starting with Michael Faraday in 1823, scientists all over Europe had been trying to convert the various common gases to liquids—cooling them, compressing them, and combining the two processes. Chlorine was the first to succumb, followed by ammonia, carbon dioxide, and many others, and by the seventies only a few recalcitrants still stubbornly resisted liquefaction. These included oxygen, hydrogen and nitrogen (fluorine had not yet been isolated and the rare gases hadn’t even been discovered), and the holdouts were pessimistically called the permanent gases.

Until 1883. In April of that year, Z. F. Wroblewski, of the University of Krakow, in Austrian Poland, announced to the French Academy that he and his colleague K. S. Olszewski had succeeded in their efforts to liquefy oxygen. Liquid nitrogen came a few days later, and liquid air within two years. By 1891 liquid oxygen was available in experimental quantities, and by 1895 Linde had developed a practical, large-scale process for making liquid air, from which liquid oxygen (and liquid nitrogen) could be obtained, simply by fractional distillation.

James Dewar (later Sir James, and the inventor of the Dewar flask and hence of the thermos bottle), of the Royal Institute in London, in 1897 liquefied fluorine, which had been isolated by Moisson only eleven years before, and reported that the density of the liquid was 1.108. This wildly (and inexplicably) erroneous value (the actual density is 1.50) was duly embalmed in the literature, and remained there, unquestioned, for almost sixty years, to the confusion of practically everybody.

The last major holdout—hydrogen—finally succumbed to his efforts, and was liquefied in May of 1898. And, as he triumphantly reported, on the thirteenth of June, 1901, five liters of it (liquid hydrogen) were successfully conveyed through the streets of London from the laboratory of the Royal Institution to the chambers of the Royal Society!

And only then could Tsiolkovsky write of space travel in a rocket propelled by liquid hydrogen and liquid oxygen. Without Wroblewski and Dewar, Tsiolkovsky would have had nothing to talk about.

In later articles, Tsiolkovsky discussed other possible rocket fuels—methane, ethylene, benzene, methyl and ethyl alcohols, turpentine, gasoline, kerosene—practically everything that would pour and burn, but he apparently never considered any oxidizer other than liquid oxygen. And although he wrote incessantly until the day of his death (1935) his rockets remained on paper. He never did anything about them. The man who did was Robert H. Goddard.

As early as 1909 Dr. Goddard was thinking of liquid rockets, and came to the same conclusions as had his Russian predecessor (of whom he had never heard); that liquid hydrogen and liquid oxygen would be a near-ideal combination. In 1922, when he was Professor of Physics at Clark University, he started actual experimental work on liquid rockets and their components. Liquid hydrogen at that time was practically impossible to come by, so he worked with gasoline and liquid oxygen, a combination which he used in all of his subsequent experimental work. By November 1923 he had fired a rocket motor on the test stand, and on March 16, 1926, he achieved the first flight of a liquid-propelled rocket. It flew 184 feet in 2.5 seconds. (Exactly forty years later, to the day, Armstrong and Scott were struggling desperately to bring the wildly rolling Gemini 8 under control.)

One odd aspect of Goddard’s early work with gasoline and oxygen is the very low oxidizer-to-fuel ratio that he employed. For every pound of gasoline he burned, he burned about 1.3 or 1.4 pounds of oxygen, when three pounds of oxygen would have been closer to the optimum. As a result, his motors performed very poorly, and seldom achieved a specific impulse of more than 170 seconds. (The specific impulse is a measure of performance of a rocket and its propellants. It is obtained by dividing the thrust of the rocket in pounds, say, by the consumption of propellants in pounds per second. For instance, if the thrust is 200 pounds and the propellant consumption is one pound per second, the specific impulse is 200 seconds.) It seems probable that he worked off-ratio to reduce the combustion temperature and prolong the life of his hardware—that is, simply to keep his motor from burning up.

The impetus for the next generation of experimenters came in 1923, from a book by a completely unknown Transylvanian German, one Herman Oberth. The title was Die Rakete zu den Planetenraumen, or The Rocket into Planetary Space, and it became, surprisingly, something of a minor best seller. People started thinking about rockets—practically nobody had heard of Goddard, who worked in exaggerated and unnecessary secrecy—and some of the people who thought about rockets decided to do something about them. First, they organized societies. The Verein fur Raumschiffart, or Society for Space Travel, generally known as the VfR, was the first, in June 1927. The American Interplanetary Society was founded early in 1930, the British Interplanetary Society in 1933, and two Russian groups, one in Leningrad and one in Moscow, in 1929. Then, they lectured and wrote books about rockets and interplanetary travel. Probably the most important of these was Robert Esnault-Pelterie’s immensely detailed L’Astronautique, in 1930. And Fritz Lang made a movie about space travel—Frau in Mond, or The Woman on the Moon, and hired Oberth as technical adviser. And it was agreed that Lang and the film company (UFA) would put up the money necessary for Oberth to design and build a liquid-fueled rocket which would be fired, as a publicity stunt, on the day of the premiere of the movie.

The adventures of Oberth with the movie industry—and vice versa—are a notable contribution to the theater of the absurd (they have been described elsewhere, in hilarious detail), but they led to one interesting, if abortive, contribution to propellant technology. Foiled in his efforts to get a gasoline-oxygen rocket flying in time for the premiere of the movie (the time available was ridiculously short) Oberth designed a rocket which, he hoped, could be developed in a hurry. It consisted of a long vertical aluminum tube with several rods of carbon in the center, surrounded by liquid oxygen. The idea was that the carbon rods were to burn down from the top at the same rate as the oxygen was to be consumed, while the combustion gases were ejected through a set of nozzles at the top (forward) end of the rocket. He was never able to get it going, which was probably just as well, as it would infallibly have exploded. But—it was the first recorded design of a hybrid rocket—one with a solid fuel and a liquid oxidizer. (A reverse hybrid uses a solid oxidizer and a liquid fuel.)

At any rate, the premiere came off on October 15, 1929 (without rocket ascent), and the VfR (after paying a few bills) fell heir to Oberth’s equipment, and could start work on their own in early 1930.

But here the story starts to get complicated. Unknown to the VfR—or to anybody else—at least three other groups were hard at work. F. A. Tsander, in Moscow, headed one of these. He was an aeronautical engineer who had written extensively—and imaginatively—on rockets and space travel, and in one of his publications had suggested that an astronaut might stretch his fuel supply by imitating Phileas Fogg. When a fuel tank was emptied, the astronaut could simply grind it up and add the powdered aluminum thus obtaining to the remaining fuel, whose heating value would be correspondingly enhanced! This updated emulation of the hero of Around the World in Eighty Days, who, when he ran out of coal, burned up part of his ship in order to keep the rest of it moving, not unnaturally remained on paper, and Tsander’s experimental work was in a less imaginative vein. He started work in 1929, first with gasoline and gaseous air, and then, in 1931, with gasoline and liquid oxygen.

Another group was in Italy, headed by Luigi Crocco, and financed, reluctantly, by the Italian General Staff.¹

Crocco started to work on liquid rockets in 1929, and by the early part of 1930 was ready for test firings. His work is notable not only for the surprising sophistication of his motor design, but above all for his propellants. He used gasoline for his fuel, which is not surprising, but for his oxidizer he broke away from oxygen, and used nitrogen tetroxide, N2O4. This was a big step—nitrogen tetroxide, unlike oxygen, can be stored indefinitely at room temperature—but nobody outside of his own small group heard of the work for twenty-four years!²

V. P. Glushko, another aeronautical engineer, headed the rocket group in Leningrad. He had suggested suspensions of powdered beryllium in oil or gasoline as fuels, but in his first firings in 1930, he used straight toluene. And he took the same step—independently—as had Crocco. He used nitrogen tetroxide for