Robert Hutchings Goddard (October 5, 1882 – August 10, 1945) was an American professor, physicist and inventor who is credited with creating and building the world's first liquid-fueled rocket, which he successfully launched on March 16, 1926. Goddard and his team launched 34 rockets between 1926 and 1941, achieving altitudes as high as 2.6 km (1.62 miles) and speeds as high as 885 km/h (550 mph).
As both theorist and engineer, Goddard's work anticipated many of the developments that made spaceflight possible. Two of Goddard's 214 patents — one for a multi-stage rocket design (1915), and another for a liquid-fuel rocket design (1915) — are regarded as important milestones toward spaceflight. His 1919 monograph, A Method of Reaching Extreme Altitudes, is considered one of the classic texts of 20th century rocket science. Goddard successfully applied three-axis control, gyroscopes and steerable thrust to rockets, all of which allow rockets to be controlled effectively in flight.
Goddard received little public support for his research during his lifetime. Though his work in the field was revolutionary, he was sometimes ridiculed in the press for his theories concerning spaceflight. As a result, he became protective of his privacy and his work. Years after his death, at the dawn of the Space Age, he came to be recognized as one of the founding fathers of modern rocketry. He was the first not only to recognize the scientific potential of missiles and space travel but also to bring about the design and construction of the rockets needed to implement those ideas.
Early life and inspiration
Goddard was born in 1882 in Worcester, Massachusetts, to Nahum Danford Goddard (1859–1928) and Fannie Louise Hoyt (1864–1920). Robert was their only child to survive; a younger son, Richard Henry, was born with a spinal deformity, and died before his first birthday.Childhood experiments
With the introduction of electric power in American cities in the 1880s, the young Goddard became interested in science. When his father showed him how to generate static electricity on the family's carpet, the five-year-old's imagination was inspired. Robert experimented, believing he could jump higher if the zinc in batteries could somehow be charged with static electricity. Goddard halted the experiments after a warning from his mother that if he succeeded, he could "go sailing away and might not be able to come back."Goddard's father further encouraged Robert's scientific interest by providing him with a telescope, a microscope, and a subscription to Scientific American. Robert developed a fascination with flight, first with kites and then with balloons. He became a thorough diarist and documenter of his work, a skill that would greatly benefit his later career. These interests merged at age 16, when Goddard attempted to construct a balloon out of aluminum, shaping the raw metal in his home workshop. After nearly five weeks of methodical, documented efforts, he finally abandoned the project, remarking, "Failior [sic] crowns enterprise." However, the lesson of this failure did not restrain Goddard's growing determination and confidence in his work.
The cherry tree dream
He became interested in space when he read H.G. Wells' science fiction classic The War of the Worlds when he was 16 years old. His dedication to pursuing rocketry became fixed on October 19, 1899. The 17-year-old Goddard climbed a cherry tree to cut off dead limbs. He was transfixed by the sky, and his imagination grew. He later wrote:- On this day I climbed a tall cherry tree at the back of the barn . . . and as I looked toward the fields at the east, I imagined how wonderful it would be to make some device which had even the possibility of ascending to Mars, and how it would look on a small scale, if sent up from the meadow at my feet. I have several photographs of the tree, taken since, with the little ladder I made to climb it, leaning against it.
- It seemed to me then that a weight whirling around a horizontal shaft, moving more rapidly above than below, could furnish lift by virtue of the greater centrifugal force at the top of the path.
- I was a different boy when I descended the tree from when I ascended. Existence at last seemed very purposive.
Education and early studies
The young Goddard was a thin and frail boy, almost always in fragile health. He suffered from stomach problems, colds and bronchitis, and fell two years behind his classmates. He became a voracious reader, regularly visiting the local public library to borrow books on the physical sciences.
Around this time, Goddard read Newton's Principia Mathematica, and found that Newton's Third Law of Motion applied to motion in space. He wrote later about his own tests of the Law:
Aerodynamics and motion
Goddard's interest in aerodynamics led him to study some of Samuel Langley's scientific papers in the periodical Smithsonian. In these papers, Langley wrote that birds flap their wings with different force on each side to turn in the air. Inspired by these articles, the teenage Goddard watched swallows and chimney swifts from the porch of his home, noting how subtly the birds moved their wings to control their flight. He noted how remarkably the birds controlled their flight with their tail feathers — Goddard called these the birds' equivalent of 'ailerons.' He took exception to some of Langley's conclusions, and in 1901 wrote a letter to St. Nicholas magazine with his own ideas. The editor of St. Nicholas declined to publish Goddard's letter, remarking that birds fly with a certain amount of intelligence and that "machines will not act with such intelligence." Goddard disagreed, believing that a man could control a flying machine with his own intelligence.Around this time, Goddard read Newton's Principia Mathematica, and found that Newton's Third Law of Motion applied to motion in space. He wrote later about his own tests of the Law:
I began to realize that there might be something after all to Newton's Laws. The Third Law was accordingly tested, both with devices suspended by rubber bands and by devices on floats, in the little brook back of the barn, and the said law was verified conclusively. It made me realize that if a way to navigate space were to be discovered, or invented, it would be the result of a knowledge of physics and mathematics."
Academics
As his health improved, Goddard continued his formal schooling as an 18-year-old sophomore at South High School in Worcester in 1901. He excelled in his coursework, and his peers twice elected him class president. At his graduation ceremony in 1904, he gave his class oration as valedictorian. In his speech, titled On Taking Things for Granted, Goddard included a section that would become emblematic of his life:[J]ust as in the sciences we have learned that we are too ignorant safely to pronounce anything impossible, so for the individual, since we cannot know just what are his limitations, we can hardly say with certainty that anything is necessarily within or beyond his grasp. Each must remember that no one can predict to what heights of wealth, fame, or usefulness he may rise until he has honestly endeavored, and he should derive courage from the fact that all sciences have been, at some time, in the same condition as he, and that it has often proved true that the dream of yesterday is the hope of today and the reality of tomorrow.Goddard enrolled at Worcester Polytechnic Institute in 1904. He quickly impressed the head of the physics department, A. Wilmer Duff, with his thirst for knowledge, and Professor Duff took him on as a laboratory assistant and tutor. At WPI, Goddard joined the Sigma Alpha Epsilon fraternity, and began a long courtship with high school classmate Miriam Olmstead, an honor student who had graduated with Goddard as salutatorian. Eventually, she and Goddard were engaged, but they drifted apart and ended the engagement around 1909.
Goddard received his B.S. degree in physics from Worcester Polytechnic in 1908, and after serving there for a year as an instructor in physics, he began his graduate studies at Clark University in Worcester in the fall of 1909. Goddard received his M.A. degree in physics from Clark University in 1910, and then stayed at Clark to complete his Ph.D. degree in physics in 1911. He spent another year at Clark as an honorary fellow in physics, and in 1912, he accepted a research fellowship at Princeton University's Palmer Physical Laboratory.
First scientific writings
While still an undergraduate, Goddard wrote a paper proposing a method for "balancing aeroplanes." He submitted the idea to Scientific American, which published the paper in 1907. Goddard later wrote in his diaries that he believed his paper was the first proposal of a way to automatically stabilize aircraft in flight. His proposal came around the same time as other scientists were making breakthroughs in developing functional gyroscopes.His first writing on the possibility of a liquid-fueled rocket came on February 2, 1909. Goddard had begun to study ways of increasing a rocket's efficiency using methods differing from conventional, powder rockets. He wrote in his journal about using liquid hydrogen as a fuel with liquid oxygen as the oxidizer. He believed a 50 percent efficiency could be achieved with liquid fuel.
First patents
In the decades around 1910, radio was a new technology, a fertile field for innovation. In 1911, while working at Clark University, Goddard investigated the effects of radio waves on insulators. In order to generate radio-frequency power, he invented a vacuum tube that operated like a cathode-ray tube. U.S. Patent 1,159,209 was issued on November 2, 1915. This was the first use of a vacuum tube to amplify a signal, preceding even Lee de Forest's claim.By 1913 he had in his spare time, using calculus, developed the mathematics which allowed him to calculate the position and velocity of a rocket in vertical flight, given the weight of the rocket and weight of the propellant and the velocity of the exhaust gases. His first goal was to build a sounding rocket with which to study the atmosphere. He was afraid to admit that his ultimate goal was space flight, since scientists, in America especially, did not consider such a pursuit to be real science, and the public was not ready to
seriously accept it.
Unfortunately, in early 1913, Goddard became seriously ill with tuberculosis and was forced to leave his position at Princeton. He returned to Worcester, where he began a prolonged recovery.
It was during this period of recuperation that Goddard began to produce his most important work. As his symptoms subsided, he allowed himself to work an hour per day with his notes. He saw the importance of his ideas as intellectual property, and began working to secure those ideas. In May 1913, he wrote his first rocket applications. His father brought them to a patent firm in Worcester, who helped Robert refine his ideas for patent consideration. His first patent application was submitted in October 1913.
In 1914, his first two landmark patents were accepted and registered. The first, U.S. Patent 1,102,653, described a multi-stage rocket. The second, U.S. Patent 1,103,503, described a rocket fueled with gasoline and liquid nitrous oxide. The two patents would become important milestones in the history of rocketry.
In the fall of 1914, Goddard's health had improved, and he accepted a part-time position as an instructor and research fellow at Clark University.
His position at Clark allowed him to increase his research activities. He made orders of many different rocket supplies, and spent much of 1915 preparing for his first rocket tests.
Goddard's first test launch of a powder rocket came on an early evening in 1915 following his classes at Clark. The launch was bright and loud enough to arouse the alarm of the campus janitor, and Goddard had to reassure the man that his experiments were serious and harmless. After this incident, Goddard took his experiments inside the physics lab to limit any disturbance.
At the Clark physics lab, Goddard conducted static tests of powder rockets to measure their thrust efficiency. He found his estimates were verified; powder rockets were only converting about 2 percent of their fuel into thrust. At this point he applied de Laval nozzles, which were typically used with steam turbine engines. The de Laval nozzles greatly improved thrust efficiency. By mid summer of 1915, Goddard had obtained an average thrust efficiency of 40 percent with nozzle velocities up to 6,730 feet per second.
Later that year, Goddard designed an elaborate experiment at the Clark physics lab to prove that a rocket would perform in a vacuum such as space. He believed it would, but he had to show other scientists who did not. He demonstrated that a rocket's performance actually decreases under atmospheric pressure.
From 1916-1917, Goddard built and experimented with ion thrusters, which he imagined could be used for propulsion at near-vacuum conditions at very high altitudes. The small glass engines he built were tested at atmospheric pressure, where they generated a stream of ionized air.
In his letter to the Smithsonian in September 1916, Goddard claimed he had achieved a 63 percent thrust efficiency and a nozzle velocity of almost 8,000 feet per second. With these performance standards, he believed a rocket could lift a weight of one pound (0.45 kg) to a height of 232 miles (373.37 km) with an initial launch weight of only 89.6 pounds (40.64 kg).
The Smithsonian was interested, and asked Goddard to elaborate on his inquiry. Goddard responded with a detailed manuscript he had already prepared, titled A Method of Reaching Extreme Altitudes.
In January 1917, the Smithsonian agreed to provide Goddard with a five-year grant totaling $5,000. Afterward, Clark was able to contribute $3,500 and the use of their physics lab to the project. Worcester Polytechnic Institute allowed him to use its abandoned Magnetics Laboratory on the edge of campus during this time as a safe place for testing.
It wasn't until two years later, at the insistence of Arthur G. Webster, head of Clark's physics department, that Goddard arranged for the Smithsonian to publish his work.
While at Clark University, Goddard did research into solar power using a dish to concentrate the sun's rays on a machined piece of quartz that was sprayed with mercury which then heated water and drove a generator at the dish. Goddard believed his invention had over come all the obstacles that had previously defeated other scientists and inventors and had his findings published in the November 1929 issue of Popular Science.
During this time, Goddard was also contacted by a civilian industrialist in Worcester about the possibility of manufacturing rockets for the military. However, as the businessman's enthusiasm grew, so did Goddard's suspicion. Talks eventually broke down as Goddard began to fear his work might be appropriated by the business.
Goddard proposed to the Army an idea for a tube rocket launcher as a light infantry weapon. The launcher concept became the precursor to the bazooka. The Rocket-Powered Recoil-free Weapon was the brainchild of Dr. Goddard as a side project (under Army contract) of his work on rocket propulsion. Goddard, during his tenuyre at Clark University, and working at Mount Wilson Observatory for security reasons, designed a tube-fired rocket for military use during World War I. He and his co-worker, Dr. Clarence Hickman, successfully demonstrated his rocket to the U.S. Army Signal Crps at Aberdeen Proving Ground,m Maryland, on November 6, 1918 using a music rack for a launch platform, but the Compiegne Armistance was signed only five days later, further development was discontinued as World War I ended.
The delay in the development of the bazooka was as a result of Goddard's serious bout with tuberculosis. Goddard continued to be a part-time consultant to the U.S. Government at Indian Head, Maryland, until 1923, but soon turned his focus to other projects involving rocket propulsion.
Later, a former Clark University researcher, Dr. C. N. Hickman, continued Goddard's work on the bazooka, leading to the weapon used in World War II.
Goddard described extensive experiments with solid-fuel rocket engines burning high grade nitrocellulose smokeless powder. A critical breakthrough was the use of the steam turbine nozzle invented by the Swedish inventor Gustaf de Laval. The de Laval Nozzle allows the most efficient (“isentropic”) conversion of the energy of hot gases into forward motion. vBy means of this nozzle, Goddard increased the efficiency of his rocket engines from 2 percent to 64 percent and obtained supersonic exhaust speeds of over Mach 7.
Though most of this work dealt with the theoretical and experimental relations between propellant, rocket mass, thrust and velocity, a final section titled Calculation of minimum mass required to raise one pound to an "infinite" altitude discussed the possible uses of rockets, not only to reach the upper atmosphere, but to escape from Earth's gravitation altogether. Included as a thought experiment was the idea of launching a rocket to the moon and igniting a mass of flash powder on its surface, so as to be visible through a telescope. He discussed the matter seriously, down to an estimate of the amount of powder required; Goddard's conclusion was that a rocket with starting mass of 3.21 tons could produce a flash "just visible" from Earth. Forty years later, Goddard's concept was vindicated when the Soviet space probe Luna 2 crash-landed on the Moon on September 14, 1959, though radio tracking did away with the need for flash powder.
Goddard eschewed publicity, because he did not have time to reply to criticism of his work, and his imaginative ideas about space travel were shared only with private groups he trusted. He did, though, publish and talk about the rocket principle and sounding rockets, since these subjects were not too "far out." In a letter to the Smithsonian dated March 1920, he discussed: photographing the Moon and planets from rocket powered flyby probes, sending messages to distant civilizations on inscribed metal plates, the use of solar energy in space, and the idea of high-velocity ion propulsion. In that same letter, Goddard clearly describes the concept of the ablative heat shield, suggesting the landing apparatus be covered with "layers of a very infusible hard substance with layers of a poor heat conductor between" designed to erode in the same way as the surface of a meteor.
His position at Clark allowed him to increase his research activities. He made orders of many different rocket supplies, and spent much of 1915 preparing for his first rocket tests.
Goddard's first test launch of a powder rocket came on an early evening in 1915 following his classes at Clark. The launch was bright and loud enough to arouse the alarm of the campus janitor, and Goddard had to reassure the man that his experiments were serious and harmless. After this incident, Goddard took his experiments inside the physics lab to limit any disturbance.
At the Clark physics lab, Goddard conducted static tests of powder rockets to measure their thrust efficiency. He found his estimates were verified; powder rockets were only converting about 2 percent of their fuel into thrust. At this point he applied de Laval nozzles, which were typically used with steam turbine engines. The de Laval nozzles greatly improved thrust efficiency. By mid summer of 1915, Goddard had obtained an average thrust efficiency of 40 percent with nozzle velocities up to 6,730 feet per second.
Later that year, Goddard designed an elaborate experiment at the Clark physics lab to prove that a rocket would perform in a vacuum such as space. He believed it would, but he had to show other scientists who did not. He demonstrated that a rocket's performance actually decreases under atmospheric pressure.
From 1916-1917, Goddard built and experimented with ion thrusters, which he imagined could be used for propulsion at near-vacuum conditions at very high altitudes. The small glass engines he built were tested at atmospheric pressure, where they generated a stream of ionized air.
Smithsonian Institution sponsorship
By 1916, the cost of Goddard's rocket research had become too much for his modest teaching salary to bear. He began to solicit potential sponsors for financial assistance, beginning with the Smithsonian Institution, the National Geographic Society, and the Aero Club of America.In his letter to the Smithsonian in September 1916, Goddard claimed he had achieved a 63 percent thrust efficiency and a nozzle velocity of almost 8,000 feet per second. With these performance standards, he believed a rocket could lift a weight of one pound (0.45 kg) to a height of 232 miles (373.37 km) with an initial launch weight of only 89.6 pounds (40.64 kg).
The Smithsonian was interested, and asked Goddard to elaborate on his inquiry. Goddard responded with a detailed manuscript he had already prepared, titled A Method of Reaching Extreme Altitudes.
In January 1917, the Smithsonian agreed to provide Goddard with a five-year grant totaling $5,000. Afterward, Clark was able to contribute $3,500 and the use of their physics lab to the project. Worcester Polytechnic Institute allowed him to use its abandoned Magnetics Laboratory on the edge of campus during this time as a safe place for testing.
It wasn't until two years later, at the insistence of Arthur G. Webster, head of Clark's physics department, that Goddard arranged for the Smithsonian to publish his work.
While at Clark University, Goddard did research into solar power using a dish to concentrate the sun's rays on a machined piece of quartz that was sprayed with mercury which then heated water and drove a generator at the dish. Goddard believed his invention had over come all the obstacles that had previously defeated other scientists and inventors and had his findings published in the November 1929 issue of Popular Science.
The 'Goddard rocket'
Not all of Goddard's early work was geared towards space travel. As the United States entered World War I in 1917, the country's universities began to lend their services to the war effort. Goddard believed his rocket research could be applied to many different military applications, including mobile artillery, field weapons and naval torpedoes. He made proposals to the Navy and Army. No record exists of any interest by the Navy to Goddard's inquiry. However, Army Ordnance was quite interested, and Goddard met several times with Army personnel.During this time, Goddard was also contacted by a civilian industrialist in Worcester about the possibility of manufacturing rockets for the military. However, as the businessman's enthusiasm grew, so did Goddard's suspicion. Talks eventually broke down as Goddard began to fear his work might be appropriated by the business.
Goddard proposed to the Army an idea for a tube rocket launcher as a light infantry weapon. The launcher concept became the precursor to the bazooka. The Rocket-Powered Recoil-free Weapon was the brainchild of Dr. Goddard as a side project (under Army contract) of his work on rocket propulsion. Goddard, during his tenuyre at Clark University, and working at Mount Wilson Observatory for security reasons, designed a tube-fired rocket for military use during World War I. He and his co-worker, Dr. Clarence Hickman, successfully demonstrated his rocket to the U.S. Army Signal Crps at Aberdeen Proving Ground,m Maryland, on November 6, 1918 using a music rack for a launch platform, but the Compiegne Armistance was signed only five days later, further development was discontinued as World War I ended.
The delay in the development of the bazooka was as a result of Goddard's serious bout with tuberculosis. Goddard continued to be a part-time consultant to the U.S. Government at Indian Head, Maryland, until 1923, but soon turned his focus to other projects involving rocket propulsion.
Later, a former Clark University researcher, Dr. C. N. Hickman, continued Goddard's work on the bazooka, leading to the weapon used in World War II.
A Method of Reaching Extreme Altitudes
In 1919, the Smithsonian Institution published Goddard's groundbreaking work, A Method of Reaching Extreme Altitudes. The report describes Goddard's mathematical theories of rocket flight, his experiments with solid-fuel rockets, and the possibilities he saw of exploring the earth's atmosphere and beyond. Along with Konstantin Tsiolkovsky's earlier work, The Exploration of Cosmic Space by Means of Reaction Devices (1903), Goddard's little book is regarded as one of the pioneering works of the science of rocketry. It was distributed worldwide.Goddard described extensive experiments with solid-fuel rocket engines burning high grade nitrocellulose smokeless powder. A critical breakthrough was the use of the steam turbine nozzle invented by the Swedish inventor Gustaf de Laval. The de Laval Nozzle allows the most efficient (“isentropic”) conversion of the energy of hot gases into forward motion. vBy means of this nozzle, Goddard increased the efficiency of his rocket engines from 2 percent to 64 percent and obtained supersonic exhaust speeds of over Mach 7.
Though most of this work dealt with the theoretical and experimental relations between propellant, rocket mass, thrust and velocity, a final section titled Calculation of minimum mass required to raise one pound to an "infinite" altitude discussed the possible uses of rockets, not only to reach the upper atmosphere, but to escape from Earth's gravitation altogether. Included as a thought experiment was the idea of launching a rocket to the moon and igniting a mass of flash powder on its surface, so as to be visible through a telescope. He discussed the matter seriously, down to an estimate of the amount of powder required; Goddard's conclusion was that a rocket with starting mass of 3.21 tons could produce a flash "just visible" from Earth. Forty years later, Goddard's concept was vindicated when the Soviet space probe Luna 2 crash-landed on the Moon on September 14, 1959, though radio tracking did away with the need for flash powder.
Goddard eschewed publicity, because he did not have time to reply to criticism of his work, and his imaginative ideas about space travel were shared only with private groups he trusted. He did, though, publish and talk about the rocket principle and sounding rockets, since these subjects were not too "far out." In a letter to the Smithsonian dated March 1920, he discussed: photographing the Moon and planets from rocket powered flyby probes, sending messages to distant civilizations on inscribed metal plates, the use of solar energy in space, and the idea of high-velocity ion propulsion. In that same letter, Goddard clearly describes the concept of the ablative heat shield, suggesting the landing apparatus be covered with "layers of a very infusible hard substance with layers of a poor heat conductor between" designed to erode in the same way as the surface of a meteor.
Publicity and criticism
The publication of Goddard's document gained him national attention from U.S. newspapers, most of it negative. Although Goddard's discussion of targeting the moon was only a small part of the work as a whole and was intended as an illustration of the possibilities rather than a declaration of Goddard's intent, the papers sensationalized his ideas to the point of misrepresentation and ridicule. Even the Smithsonian had to abstain from publicity because of the amount of ridiculous correspondence they received from the general public.On January 12, 1920 a front-page story in The New York Times, "Believes Rocket Can Reach Moon", reported a Smithsonian press release about a "multiple charge high efficiency rocket." The chief application seen was "the possibility of sending recording apparatus to moderate and extreme altitudes within the earth's atmosphere", the advantage over balloon-carried instruments being ease of recovery since "the new rocket apparatus would go straight up and come straight down." But it also mentioned a proposal "to [send] to the dark part of the new moon a sufficiently large amount of the most brilliant flash powder which, in being ignited on impact, would be plainly visible in a powerful telescope. This would be the only way of proving that the rocket had really left the attraction of the earth as the apparatus would never come back."
First Liquid Fueled Flight
Goddard began experimenting with liquid oxygen nd liquid-fueled rockets in September 1921, and tested the first liquid-fueled engine in November 1923. It had a cylindrical combustion chamber, using impinging jets to mix and atomize liquid oxygen and gasoline.
In 1924–25, Goddard had problems developing a high-pressure piston pump to send fuel to the combustion chamber. He wanted to scale up the experiments, but his funding would not allow such growth. He decided to forgo the pumps and use a system applying backk pressure from an inert gas.
On December 6, 1925, he tested the simpler back-pressure system. Goddard conducted a static test on the firing stand at the Clark University physics laboratory. The engine successfully lifted its own weight in a 27 second test in the static rack. It was a major success for Goddard, proving that a liquid fuel rocket was possible. The test moved Goddard an important step closer to launching a rocket with liquid fuel.
Goddard conducted an additional test in December, and two more in January 1926. After that, Goddard began preparing for a possible launch of the rocket system.
First flight
Goddard launched the first liquid-fueled (gasoline and liquid oxygen) rocket on March 16, 1926, in Auburn, Massahusetts. Present at the launch were Goddard's crew chief Henry Sachs, Esther Goddard, and Percy Roope, who was Clark's assistant professor in the physics department. Goddard's diary entry of the event was notable for its understatement:
March 16. Went to Auburn with S[achs] in am. E[sther] and Mr. Roope came out at 1 p.m. Tried rocket at 2.30. It rose 41 feet & went 184 feet, in 2.5 secs., after the lower half of the nozzle burned off. Brought materials to lab. . . .
His diary entry the next day elaborated:
March 17, 1926. The first flight with a rocket using liquid propellants was made yesterday at Aunt Effie's farm in Auburn. . . .
Even though the release was pulled, the rocket did not rise at first, but the flame came out, and there was a steady roar. After a number of seconds it rose, slowly until it cleared the frame, and then at express train speed, curving over to the left, and striking the ice and snow, still going at a rapid rate.
The rocket, which was dubbed "Nell", rose just 41 feet during a 2.5-second flight that ended 184 feet away in a cabbage field, but it was an important demonstration that liquid propellants were possible. The launch site is now a National Historic Landmark, the Goddard Rocket Launching Site.
Viewers familiar with more modern rocket designs may find it difficult to distinguish the rocket from its launching apparatus in the well-known picture of "Nell". The complete rocket is significantly taller than Goddard, but does not include the pyramidal support structure which he is grasping. The rocket's combustion chamber is the small cylinder at the top; the nozzle is visible beneath it. The fuel tank, which is also part of the rocket, is the larger cylinder opposite Goddard's torso. The fuel tank is directly beneath the nozzle, and is protected from the motor's exhaust by an asbestos cone. Asbestos-wrapped aluminum tubes connect the motor to the tanks, providing both support and fuel transport. This layout is no longer used, since the experiment showed that this was no more stable than placing the rocket engine at the base. By May, after a series of modifications to simplify the plumbing, the engine was placed in the now classic position, at the lower end of the rocket.
Robert Goddard
With new financial backing, Goddard eventually relocated to Roswell, New Mexico in 1930, where he worked with his team of technicians in near isolation and secrecy for a dozen years. Here they would not endanger anyone, would not be bothered by the curious, and experienced a more moderate climate (which was also better for Goddard's health).
By September 1931, his rockets had the now familiar appearance of a smooth casing and tail fins. He began experimenting with gyroscopic guidance and made an unsuccessful flight test of such a system in April 1932. A gyroscope mounted on gimbals electrically controlled steering vanes in the exhaust, similar to the system used by the German V-2 over 10 years later.
A temporary loss of funding from the Guggenheims forced Goddard to return to Clark University until 1934, when funding resumed. Upon his return to Roswell, he began work on his A series of rockets 4 to 4.5 meters long, powered by gasoline and liquid oxygen pressurized with nitrogen. The gyroscopic control system was housed in the middle of the rocket, between the propellant tanks. On March 28, 1935, the A-5 successfully flew to an altitude of 1.46 kilometres (0.91 mi; 4,800 ft) using his guidance system. This rocket also achieved supersonic velocity.
In 1936-1939, Goddard began work on the K and L series rockets, which were much more massive and designed to reach very high altitude. This work was plagued by trouble with engine burn-through. Goddard had built a regeneratively cooled engine, which circulated liquid oxygen around the outside of the combustion chamber, in 1923 but deemed the idea too complicated. He was therefore using fuel curtain cooling, spraying excess gasoline on the inside wall of the combustion chamber, but this was not working well, and the larger rockets failed. Returning to a smaller design again, the L-13 reached an altitude of 2.7 kilometres (1.7 mi; 8,900 ft), the highest of any of Goddard's rockets. Weight was reduced by using thin-walled fuel tanks wound with high tensile strength wire.
From 1940–1941, work was done on the P series of rockets, which used propellant turbopumps (also powered by gasoline and liquid oxygen). Higher fuel pressure permitted a more powerful engine, but two launches both ended in crashes after reaching an altitude of only a few hundred feet. The turbopumps worked well, however.
Goddard was able to flight test many of his rockets; but many resulted in what the uninitiated would call failures because of engine malfunction or loss of control. Goddard did not consider them failures because he felt that he always learned something from a test. Most of his work involved static tests, which are a standard procedure today, before a flight test. Between 1930 and 1945...31 rockets were launched.
By September 1931, his rockets had the now familiar appearance of a smooth casing and tail fins. He began experimenting with gyroscopic guidance and made an unsuccessful flight test of such a system in April 1932. A gyroscope mounted on gimbals electrically controlled steering vanes in the exhaust, similar to the system used by the German V-2 over 10 years later.
A temporary loss of funding from the Guggenheims forced Goddard to return to Clark University until 1934, when funding resumed. Upon his return to Roswell, he began work on his A series of rockets 4 to 4.5 meters long, powered by gasoline and liquid oxygen pressurized with nitrogen. The gyroscopic control system was housed in the middle of the rocket, between the propellant tanks. On March 28, 1935, the A-5 successfully flew to an altitude of 1.46 kilometres (0.91 mi; 4,800 ft) using his guidance system. This rocket also achieved supersonic velocity.
In 1936-1939, Goddard began work on the K and L series rockets, which were much more massive and designed to reach very high altitude. This work was plagued by trouble with engine burn-through. Goddard had built a regeneratively cooled engine, which circulated liquid oxygen around the outside of the combustion chamber, in 1923 but deemed the idea too complicated. He was therefore using fuel curtain cooling, spraying excess gasoline on the inside wall of the combustion chamber, but this was not working well, and the larger rockets failed. Returning to a smaller design again, the L-13 reached an altitude of 2.7 kilometres (1.7 mi; 8,900 ft), the highest of any of Goddard's rockets. Weight was reduced by using thin-walled fuel tanks wound with high tensile strength wire.
From 1940–1941, work was done on the P series of rockets, which used propellant turbopumps (also powered by gasoline and liquid oxygen). Higher fuel pressure permitted a more powerful engine, but two launches both ended in crashes after reaching an altitude of only a few hundred feet. The turbopumps worked well, however.
Goddard was able to flight test many of his rockets; but many resulted in what the uninitiated would call failures because of engine malfunction or loss of control. Goddard did not consider them failures because he felt that he always learned something from a test. Most of his work involved static tests, which are a standard procedure today, before a flight test. Between 1930 and 1945...31 rockets were launched.
- "It is difficult to say what is impossible, for the dream of yesterday is the hope of today and the reality of tomorrow." (From his high school graduation oration, "On Taking Things for Granted", June 1904)
- "On the afternoon of October 19, 1899, I climbed a tall cherry tree and, armed with a saw which I still have, and a hatchet, started to trim the dead limbs from the cherry tree. It was one of the quiet, colorful afternoons of sheer beauty which we have in October in New England, and as I looked towards the fields at the east, I imagined how wonderful it would be to make some device which had even the possibility of ascending to Mars. I was a different boy when I descended the tree from when I ascended for existence at last seemed very purposive." (Written later, in an autobiographical sketch)
- "Every vision is a joke until the first man accomplishes it; once realized, it becomes commonplace." (His response to a reporter's question following criticism in The New York Times, 1920)
- "It is not a simple matter to differentiate unsuccessful from successful experiments. . . .[Most] work that is finally successful is the result of a series of unsuccessful tests in which difficulties are gradually eliminated." (Written to a correspondent, early 1940s)
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