Number One Rocket Man (May, 1938)
Number One Rocket Man
A Silhouette of the Shy Massachusetts Physicist Who Pioneered in Rocket Research . . . Much to His Distress He Broke into the Noisier Newspapers
By G. EDWARD PENDRAY
Past President, the American Rocket Society
Editor of Astronautics
ON a flat, dry plain, 18 miles north of Roswell, New Mexico, rises a 60-foot tower of steel that has roused more curiosity, and has probably had a greater influence on the future of the world, than any other feature of all New Mexico’s arresting landscape.
From this tower, at irregular intervals, a Massachusetts physicist and his assistants send roaring into the skies certain gleaming, cigar-shaped projectiles of metal, powered by gasoline and liquid oxygen, and landed by parachutes.
The physicist is Dr. Robert Hutchings Goddard, a bald, spare, pleasant man who will be 56 years old next October 5 (1938). Rocket experimenters the world over recognize him as their Number One man. Not only has he made more contributions to the new field of rocket engineering than any other one individual, but it was Dr. Goddard who launched modern rocket research with his clear presentation of the possibilities of rockets, both their limitations and advantages, 19 years ago. His publication, modestly entitled “A Method of Reaching Extreme Altitudes,” was published by the Smithsonian Institution in 1919.
DR. GODDARD at that time had already been a rocket experimenter for nearly ten years. His first trials were made during some studies of the upper atmosphere while he was an instructor at the Worcester Polytechnic Institute, in 1909. Baffled by the uncertainty and limitations of sounding balloons, he imagined that by building some kind of huge skyrocket he could shoot self-recording instruments high into the stratosphere and bring back information of value to science.
This idea of reaching high altitudes with rockets was by no means new with Dr. Goddard. In fact, we are told that a certain Chinese mandarin in the 13th Century sought to lift himself to the moon by fastening rockets to the legs of his chair. Cyrano de Bergerac, the novelist, wrote a story 300 years ago in which the hero transported himself by rocket power. Warmen saw in rockets a potential carrier of explosives centuries ago, and in the Napoleonic wars rocket brigades blossomed in Europe. In the siege of Boulogne, the English succeeded in setting the town afire with rockets designed by Sir William Congreve.
But those early efforts were rule-of-thumb procedures, and really came to little. What Dr. Goddard proposed, 29 years ago, was to apply the methods of modern engineering to the construction of rockets. He perceived that several diverse and complicated problems would have to be tackled, seriatim: (1) the fuel, (2) the materials, (3) the methods of feeding the fuels, (4) the aerodynamic design, (5) control in flight, (6) the further unknowns.
For the rocket, though a seemingly simple device, is really very complicated. It works by recoil—by application of the ancient principle that every action has an equal and opposite reaction. The action is produced by rapid combustion and simultaneous ejection of gas at high velocity. The reaction occurs in the body of the rocket, which flies at an accelerated rate in the direction opposite that of the ejected gases.
Had Dr. Goddard been a less practical man he would have been content to write an article about the idea, or give a lecture on it, and sit back to await the development at someone else’s hands.
But it happened that he was of the sort who undertake to test their notions before they talk about them. The only successful examples of rockets in his day were skyrockets and life-saving rockets— both powered by modified gunpowder. Beginning at this point, Dr. Goddard tested powder fuel rockets. As new teaching appointments took him to Princeton, and then to Clark University, the idea went with him.
Talk of rockets is so commonplace today—such success has attended the efforts of experimenters—that rocketry is almost respectable. But in the old days of 1914 and earlier, few sane engineers spoke of them except humorously, and physicists who entertained the idea of rocket transportation must have been as rare as one-armed flute players. Nevertheless, Dr. Goddard succeeded, one by one, in convincing his colleagues. In 1914, plugging away on his own, he took out two basic patents on rockets, pertaining to combustion chambers and nozzles. A short time later he talked the problem of rocketry through with Dr. Charles G. Abbot, Secretary of the Smithsonian Institution. So convincing was his argument that the conservative old Institution agreed to grant him modest funds for a series of experiments. In the tests that followed, Dr. Goddard demonstrated that rockets really need no air to push against, and that they are capable of development. He also proved that gunpowder-like fuels must be abandoned in favor of more powerful, more easily controlled kinds, probably liquefied gases.
Thus started what rocket engineers now refer to as the era of “liquid-fuel” rockets—the real beginning of scientific rocketry. Simple calculations show that the most powerful release of energy, pound for pound, occurs during the combustion of carbon or hydrogen with oxy- gen. The problem was to produce this combustion at the right time, in the right place, and under the right conditions.
After some preliminary trials, Dr. Goddard decided that the best fuel would be a chemical combination of hydrogen and carbon, as in gasoline, and that oxygen could most conveniently be supplied in the pure form, liquefied. These early tests were carried on very secretly near Auburn, Massachusetts, and apparently were the first “proving-stand”‘ experiments with liquid-fuel rocket motors —primitive, to be sure, but they set the foundation upon which a great deal of experimental work has since been built. Dr. Goddard tried out liquid oxygen and various members of the hydro-carbon series, including gasoline, kerosene, liquid propane, also ether. He finally discarded the others and settled on gasoline and oxygen. Virtually all of his experiments since have been made with these.
By 1923 he felt ready to try an actual liquid-fuel rocket. On November 1 of that year he completed and tried out a small one on his proving-stand, tying it down so it couldn’t fly. It seemed promising, but wasn’t good enough. For one thing, there was the problem of getting the fuels from the tanks into the combustion chamber fast enough. He had used small pumps on the rocket, but pumps are slow, heavy, and troublesome.
IT took two more years to overcome that problem. In December, 1925, he completed and tested a second liquid-fuel rocket in which the fuels were forced into the chamber by the pressure of an inert gas, nitrogen. This method worked well, but still the experimenter cautiously denied himself the experience of turning it loose to see it fly.
That pleasure was reserved until three months later, when on March 16, 1926, at Auburn, he put an improved liquid-fuel rocket into his improvised launching rack and let her go. So far as I have been able to find evidence, this was the first actual flight of a liquid-fuel rocket in this country or anywhere in the world. It was in no sense a public shot. The only witnesses were Dr. Goddard and a couple of helpers. The experimenter timed it with a stop watch and later reported that it fired for two and a half seconds, during which time it flew 184 feet, “making the speed along the trajectory about 60 miles an hour.”
A queer-looking rocket it was, too, compared with the sleek projectiles Dr. Goddard’s shop in New Mexico now turns out. The fuel tanks were slender tubes, placed one behind the other. The motor, consisting of the combustion chamber and its exhaust nozzle, was well ahead, supported on spidery arms which also carried the fuel lines. The whole contrivance was about ten feet long, but only about half of this length was actual rocket; the rest was the harness that joined the motor to the tanks. Pressure to force the fuels into the combustion chamber was furnished by an outside pressure tank and, after launching, by an alcohol heater carried on the rocket.
The idea of putting the motor ahead of the tanks was the mistaken one that this method of “pulling” the rocket, instead of pushing it, would make it fly better. In practice it did nothing of the kind; it only added to the difficulties of construction. Dr. Goddard abandoned the design at once in favor of rockets with the motor at the rear. Between 1926 and 1929 he shot a number of these, with varying success.
And then, quite unexpectedly, Dr. Goddard broke into the newspapers— much to his distress. Naturally reserved and somewhat uncommunicative, he had early discovered what most rocket experimenters find out sooner or later— that next to an injurious explosion, publicity is the worst possible disaster. (Most newspaper writers still seem to believe that every rocket is aimed at the moon.) It was his shot of July 17, 1929, at Auburn, that brought Dr. Goddard this great and unexpected burst of notoriety. The rocket was a fairly large one, carrying a small barometer and a camera. Being large enough to carry instruments, it also made a great deal of noise. Neighbors telephoned the police that an airplane had crashed in flames. A few ex- cited Auburnites were certain a meteor had fallen. When fire and police departments arrived, they found only a rocket experimenter, examining the remains of his rocket, pleased at the notable fact that his instrument, shot several hundred feet heavenward, had parachuted gently back from the flight and landed intact.
But the simple facts were by no means enough for the newspapers. Some, of course, had sensible stories, but they were in the minority. It was widely reported that he had shot a rocket to the moon, but had failed, that his rocket had exploded, that it had contained tons of explosive, that his intentions were to fly to Mars.
Fortunately the flurry was short-lived. Also, it had some good results, for it is said that as a result of the publicity Col. Charles A. Lindbergh first became interested in Dr. Goddard and his rockets. At any rate, it was in 1929 that the flyer brought rocketry to the attention of the late Daniel Guggenheim. The result was a grant that made possible the present establishment in New Mexico, under conditions that many experimenters consider ideal for rocket research.
About three miles north of Roswell, a shop 30 by 55 feet was erected, and near it a 20-foot tower built for proving-stand tests of motors and rockets. Fifteen miles farther north, on the plains, stands the 60-foot launching tower from which actual rocket shots are made. The region thereabout lias an altitude of about 3500 feet—enough to reduce noticeably the resistance of the air to rapid flight, as compared with the denser air at sea level. The country is level and open. There is space for high experimental flights without much danger of the rocket landing on an indignant bystander.
Gasoline and liquid oxygen, mixed, form a peculiarly violent detonator, yielding about five times as much energy pound for pound as TNT. Dr. Goddard has taken what may seem like extreme precautions against accident and injury. At the launching tower, all experiments are managed by remote control. The operator and observers are stationed 1000 feet away, in a shelter protected by sand bags on the roof. The observer whose task it is to clock the rocket flight, and who therefore cannot conveniently work from a shelter, is stationed 3000 feet from the tower. For close observations, to watch the firing, launching, and so on, there is a concrete dugout 50 feet from the launching tower. The observer looks through four-inch peepholes in a tilted slab of concrete three inches thick.
THE rocket motor used by Dr. Goddard in his New Mexico shots is 5% inches in diameter and weighs five pounds. It usually fires about 20 seconds, and delivers a maximum thrust of 289 pounds. Such a motor can hoist a real projectile into the air, and such, indeed, have been the projectiles that Dr. Goddard has been attaching to them. His first New Mexico rocket was shot on December 30, 1930. It was 11 feet long and weighed 33.5 pounds without fuel. It reached an altitude of 2000 feet, and a maximum speed of 500 miles an hour.
This was only the beginning. Heavier, more powerful rockets were to come. In August, 1934, the experimenter shot a pendulum-controlled rocket that made an altitude of 1000 feet, then turned horizontally for 11,000 feet, landing a little over two miles from the launching tower. At one point its velocity touched 700 miles an hour.
In none of these shots was altitude or speed the chief object. The experimenter, having tentatively solved, in order, the problems of fuel, material, methods of feeding the fuel, and aerodynamic design, was by now working on the hardest knot of all—control. Specifically, he was trying to build a rocket that would be capable of sure, dependable upward flight. After 25 years of experiment his eyes were still on the stratosphere.
Now there may be some trick of aerodynamics or design that will guarantee vertical flight without special control mechanisms and the extra complications they entail. Many rocket experimenters hope so, but to date they haven’t discovered it. After his early experiences with cantankerous projectiles, whishing through the air at express speed but fol- lowing whimsical air-paths all their own, Dr. Goddard decided that a gyroscopically-operated control mechanism would have to be devised.
In the beginning he tried some other devices, notably the pendulum, but these depend on gravity and are affected by the course and acceleration of the rocket. The gyroscope, however, holds its position with relation to space, regard- less of the torque or acceleration of the projectile carrying it.
The main problem was to construct a sensitive servo-mechanism that would steer the rocket back on course without disturbing the gyro. Dr. Goddard’s idea was to have small vanes pushed into the path of the exhaust gases in such a manner as to deflect the flight. In his first trial the system didn’t work as well as expected. The performance led the physicist to suspect that the vanes were too small, and he resolved later to try again with larger ones.
The improved system worked better. The vanes, driven by gas pressure into the rocket exhaust stream, were set to apply controlling force when the axis of the projectile deviated as much as 10 degrees from the vertical. The finest shot so far reported with this system reached an altitude of 7500 feet. Rising slowly from the launching tower, the rocket undulated from side to side as the gyro-control continually corrected the course. “The first few hundred feet of the flight,” reported the experimenter, “reminded one of a fish swimming in a vertical direction.” After the rocket had gained more speed, the curves smoothed out.
Such a flight, of course, is not ideal. Much power is lost in useless undulations. But flight control had at least been started, and the physicist of Worcester could check off one more step in the series of conquests leading to the de- velopment of the rocket. Still before him are those problems classified as “the further unknowns.” One of them is the problem of reducing the weight of the rocket, for every extra ounce requires extra fuel to lift it, and extra fuel to lift the extra fuel, ad infinitum. There are no filling stations on the route to extreme altitudes. The rocket must start with a full tank, and one filling is all it can expect.
Other problems are those of improving the efficiency of the rocket motor, which is still far from that which is theoretically expected; improving the aerodynamic design for flight at super-sonic velocities; smoother control; and a surer technique for releasing the parachute or other landing apparatus at the exact top of the flight.
IN justice it should be said that Dr.
Goddard is no longer alone in the colossal task of mastering these difficulties. All over the world, since 1928. rocket societies and rocket experimenters have sprung up, some to make a few tests and drop the subject, others to plow on toward the goal as doggedly as does Dr. Goddard himself. In this country there are at least 20 other active experimenters, and a rocket society that numbers nearly 300 members. In England an experimental group has about 50 members. There are rocket experimenters in Austria, Russia, France, Japan, New Zealand, Canada. The American Rocket Society has an active affiliate at Yale University. Other American universities are considering the establishment of affiliate groups of experimenters among their engineering students and faculties. California experimenters cross the continent to report their work in New York before the Institute of Aeronautical Engineers.
Dr. Goddard’s work thus may have opened a new era in transportation, for rockets can do more than explore the upper atmosphere. They ultimately may carry mail and goods—and possibly even passengers—with speed rivaling that of the telegraph; usher in an epoch of swift communication more spectacular than that brought by the telephone and airplane; alter once more the complexion of civilization as only basic inventions can alter it.
It was Col. Lindbergh who, in a letter recently to the President of Clark University, put the matter most directly: “The rocket is now in that most interesting period of discovery where the shore lines are unplotted and the future limited only by imagination. We cannot state what speeds or ranges the rocket may attain, but it is not restricted by the rotation of an engine or by dependence on the atmosphere.
“As the airplane gave man freedom from the earth, the rocket offers him freedom from the air.”