History of Rocketry Chapter 3
By Cliff Lethbridge
The Rocket Pioneers
It was, of course, the 20th century that witnessed an explosion in the field of rocketry. By the end of the 19th century, the three men considered to be the primary pioneers of modern rocketry had been born and begun their studies. These were Russian Konstantin Eduardovitch Tsiolkovsky, American Robert Hutchings Goddard and German Hermann Oberth.
Konstantin Eduardovitch Tsiolkovsky
Konstantin Eduardovitch Tsiolkovsky was born in September, 1857 in the town of Izhevskoye, Spassk District, Ryazan Gubernia. He became a “people’s school teacher” at Borovsk, Kulaga Province, in 1878.
On the merits of some of his early research and related writings, Tsiolkovsky was elected to the Society of Physics and Chemistry at St. Petersburg, Russia.
On March 28, 1883 Tsiolkovsky demonstrated the reaction principle through experimenting with opening a cask filled with compressed gas. He discovered that movement of the cask could be regulated by alternating the pressure of the gas released from it.
Tsiolkovsky completed a draft of his first design of a reaction thrust motor on August 25, 1898. The following year, he received a grant of 470 rubles from the Academy of Science’s Physics and Mathematics Department to engage in research. This work was dedicated to the establishment of scientific principles, so no actual motors were developed.
In 1903, his first article on rocketry appeared in the “Naootchnoye Obozreniye” (Scientific Review). The article was entitled “Issledovanie Mirovykh Prostransty Reaktivnymi Priborami” (Exploration Of Space With Rocket Devices).
In the article, Tsiolkovsky clearly outlined in scientific terms exactly how a reaction thrust motor could demonstrate Newton’s Third Law to allow men to escape the bounds of Earth.
Also in 1903, Tsiolkovsky drafted the design of his first rocket. It was to be powered by a combination of liquid oxygen and liquid hydrogen, which would create an explosive mixture at the narrow end of a tube. Burning of the fuels would produce condensed and heated gases.
The gases would then be quickly cooled and rarefied at the wider end of the tube, located at the tail of the rocket. The resulting exhaust, escaping from a nozzle, would provide liftoff thrust at a relatively high velocity.
This design was indeed prophetic, especially when consideration is given to the fact that liquid oxygen and liquid hydrogen have traditionally been combined as a fuel for various rocket components, not the least of which are the three main engines of the Space Shuttle.
In subsequent writings, Tsiolkovsky speculated on a multi-stage approach to spaceflight. He envisioned a fantastic “passenger rocket train of 2017” which employed 20 single-engine rocket stages, each of which carried its own fuel.
This rocket was to be about 300 feet long and 12 feet wide, just a bit smaller than the actual Saturn V rockets used to carry men to the Moon. It would be built from three layers of metal incorporating quartz windows and an outer skin made of refractory material to protect the spacecraft from the intense heat of moving through the atmosphere.
As each individual rocket stage consumed its fuel, it would be discarded to keep the overall weight of the vehicle as light as possible. Tsiolkovsky recognized that although this design was fanciful, it would actually require a tremendous amount of fuel for a rocket to reach escape velocity, and multiple stages would likely be needed.
He had calculated that a single-stage rocket would have to carry four times its own weight in fuel to reach escape velocity, and that a multi-stage approach would be more efficient. Even at the turn of the 20th century, Tsiolkovsky was absolutely confident that the reaction principle would someday carry men into space.
In 1919, Tsiolkovsky was elected to the Socialist Academy, which later became the U.S.S.R. Academy of Science. Between 1925 and 1932 he wrote about 60 works on astronautics, astronomy, mechanics, physics and philosophy. He died on September 19, 1935.
His book “Na Lune” (On The Moon) was published in 1935. It contained prophetic speculation on spaceflight, as well as offered descriptions on the types of rockets and vehicles necessary for the task.
Although practical strides in rocketry were being made at this time in other parts of the world, Tsiolkovsky never saw his designs materialize. His rocket motors were neither built nor tested, primarily due to Russian political instability, lack of resources and inadequate technical personnel.
Still, his writings endured and served to stimulate a thriving Russian rocket and space program that emerged years later.
Robert Hutchings Goddard
Robert Hutchings Goddard was born on October 5, 1882 in Worcester, Massachusetts. Early in his life, Goddard was inspired by works of science fiction, primarily “War Of The Worlds” by H.G. Wells and “From The Earth To The Moon” by Jules Verne.
In 1902, while a student at South High School in Worcester, Goddard submitted an article entitled “The Navigation Of Space” to “Popular Science News”. The article speculated on the possibility of rocketry and space travel.
A second submission to the magazine included speculation on multi-stage spacecraft along the same lines as those envisioned by Tsiolkovsky. Completely independent of Tsiolkovsky, Goddard realized that the reaction principle would provide a foundation for space travel.
But rather than focus entirely on theory, Goddard set out at an early age to become equipped to build and test the hardware he believed was necessary to best demonstrate the reaction principle.
Goddard graduated from Worcester Polytechnic Institute in 1908, then went on to study at Clark University in Worcester. He received a doctorate of physics at Clark University in 1911 and immediately began teaching physics there.
During his studies at Clark University in 1909, Goddard began to make detailed calculations regarding liquid-fueled rocket engines. Again independent of Tsiolkovsky, he too theorized that a combination of liquid hydrogen and liquid oxygen would make an ideal propellant.
These theories were refined by Goddard during a year of research and teaching at Princeton University between 1912 and 1913. Unlike many of his contemporaries, Goddard kept detailed records on his research, most of which survive today.
As early as 1914, Goddard received patents for now common rocket components like combustion chambers, exhaust nozzles, propellant feed systems and multi-stage rockets. At about the same period, Goddard began flight tests using gunpowder propelled rockets near Worcester. Some of these rockets reached maximum altitudes of 500 feet.
He requested financial support for rocket tests from the Smithsonian Institution in 1916, and received a $5,000 grant from the organization in January, 1917. High-altitude rocket research was put on hold, however, when the United States entered World War I later that year.
Considered a staunch patriot until his death, Goddard went to work for the Army in 1917 with the goal of designing rockets that would aid in the war effort. The work was conducted in California, and yielded the development of a small, hand-held rocket launcher similar to what was later called the bazooka.
By September, 1918 Goddard had presented the Army Signal Corps with several options for rockets and launchers, the most simple of which could be fired from trenches. The largest version could carry an eight-pound payload a distance of about one mile.
Many of these rockets were successfully demonstrated at the Aberdeen Proving Ground, Maryland on November 7, 1918. Goddard presented solid-fueled 5, 7.5 and 50-pound rockets capable of being launched from a 5.5-foot long by 2-inch or 3-inch wide tube.
Although the rockets were available for immediate production, the Army never ordered any since World War I came to a close just a few days after Goddard was able to successfully demonstrate them. Goddard returned to Clark University upon the conclusion of the war.
In 1919, Goddard published a work entitled “A Method Of Reaching Extreme Altitudes”, which contained a detailed compilation of much of the research he had completed to date. It also included speculation on the possibilities of spaceflight.
This is still considered to be his most scholarly work, but it was at the time barely understood and largely ignored by the scientific community. Members of the popular media ridiculed the work, and dubbed Goddard “the Moon man” due to his speculation on journeys to the Moon.
These reviews had a profound impact on Goddard, who vowed to carry on the bulk of his high-altitude rocket research in a secluded environment to avoid negative publicity. He did, however, accept invitations to carry on rocket research for the military.
From 1920 through 1923, Goddard worked for the U.S. Navy Bureau of Ordnance Indian Head Powder Factory in Maryland where he aided in the development and testing of rocket propelled depth charges and armor piercing rockets.
During this period, Goddard concluded that a combination of liquid oxygen and gasoline were the only practical fuels that could be used in his continuing research in the development of liquid-fueled rocket motors.
After completing his work for the Navy, Goddard returned to Worcester, where he began focusing exclusively on the refinement of both solid and liquid fuels for rocketry. He also began the design and testing of rocket stabilization and guidance systems.
By 1924, Goddard had developed and tested a liquid oxygen pump and engine that functioned. The unit, however, was too small to actually be employed on a working rocket. But, with a working design, he began to plan more elaborate research.
Goddard successfully test fired a pressure-fed liquid oxygen engine inside the Clark University physics laboratory on December 6, 1925. The engine was attached to a small test rocket housed inside a fixed stand. The engine was fired for about 24 seconds and lifted the rocket for about 12 seconds within its stand.
After additional laboratory tests were completed, Goddard began outdoor tests with a flight-ready rocket. The work was conducted at an Auburn, Massachusetts farm owned by his Aunt Effie. Static engine tests on a fixed stand were begun on March 8, 1926.
On March 16, 1926 Goddard launched a 10-foot long rocket from a 7-foot long frame. The rocket reached a maximum altitude of 41 feet at an average velocity of 60 m.p.h. The rocket remained in the air for 2.5 seconds and flew a distance of 184 feet.
While this flight did not even come close to matching the performance of gunpowder propelled rockets of years past, it remains one of the most significant events in the history of rocketry. Powered by a combination of liquid oxygen and gasoline, the rocket launched by Goddard on March 16, 1926 was the first to ever be launched using liquid fuel.
The second flight of a liquid-fueled rocket occurred on April 3, 1926. Goddard launched a rocket similar to the first one in a flight that covered a distance of 50 feet in 4.2 seconds.
Following this flight, Goddard realized that his rocket was too small to be refined. He decided to develop larger rockets for further tests. Work was also begun on the development of a more elaborate launch tower.
The new rockets incorporated innovative technology like flow regulators, multiple liquid injection, measurement of pressure and lifting force and an electrically fired igniter to replace a gunpowder fired igniter used previously. A turntable was also designed to produce spin stabilization.
On January 18, 1927 a new larger rocket was placed on a test stand. Although it had the potential of carrying 20 times as much fuel as its predecessors, this rocket was used for static tests only. The next flight tests employed rockets that had about four times the fuel capability as the first two.
Construction of the new flight-ready rockets began on September 3, 1927. These featured interchangeable parts and an improved fuel injection system. The first four attempts at launching these rockets failed when the rockets tipped over after they were ignited and caught the tower.
However, the third launch of a liquid-fueled rocket occurred on December 26, 1928. The rocket flew a distance of 204.5 feet at a maximum velocity of about 60 m.p.h. This launch was followed by a series of tests to develop mechanisms to improve combustion chamber cooling and in-flight stability.
The fourth launch of a liquid-fueled rocket occurred on July 17, 1929. Considered much more elaborate than the first three, Goddard equipped the rocket with a barometer, thermometer and a camera to record their readings during flight. The rocket achieved a maximum altitude of 90 feet in an 18.5-second flight covering a distance of 171 feet.
The scientific payload was recovered safely via parachute. However, the launch was so noisy and bright that it captured much public attention. Many eyewitnesses believed an aircraft had crashed in the area. Local fire officials quickly forced Goddard to discontinue his launch operations at the Auburn site.
Aviation hero Charles A. Lindbergh paid his first visit to Goddard on November 23, 1929. Lindbergh had become fascinated by accounts of the work of Goddard he had read, and believed strongly that rocketry had vast and significant potential.
Lindbergh arranged financial support for Goddard, which included a $50,000 grant from the Daniel Guggenheim Fund for the Promotion of Aeronautics, paid to Clark University to fund research activities of Goddard. In addition, a smaller grant from the Carnegie Institution was received for the construction of test facilities.
In December, 1929 Goddard established a rocket test facility at Camp Devens, an artillery range located about 25 miles from Worcester. A total of 16 static engine test firings were conducted there, but no actual rocket launches.
Goddard then made a large move after deciding to embark on his first full-time effort at constructing and testing rockets. He set up shop at the Mescalero Ranch near Roswell, New Mexico in July, 1930. The relocation was initially financed through the Guggenheim grant.
Static engine tests conducted at Roswell yielded a maximum thrust of 289 pounds for about 20 seconds, with exhaust velocity of about 5,000 feet per second. These tests paved the way for a number of test launches.
The first Roswell launch occurred on December 30, 1930 using a rocket 11 feet long by 12 inches wide and weighing 33.5 pounds empty. The test was impressive as the rocket reached a maximum altitude of 2,000 feet and maximum speed of 500 m.p.h. The rocket employed a new gas pressure tank to force the liquid oxygen and gasoline into the combustion chamber.
This was followed by four more successful rocket flights from Roswell. On September 29, 1931 a rocket with a streamline casing and remote control igniter reached a maximum altitude of 180 feet in a 9.6-second flight. This rocket was 9 feet, 11 inches long by 12 inches wide.
A rocket with a simplified combustion chamber was launched on October 13, 1931. It was 7.75 feet long by 12 inches wide, reached a maximum altitude of 1,700 feet and was successfully recovered by parachute.
On October 27, 1931 a rocket employing a new gasoline shutoff valve reached a maximum altitude of 1,330 feet and covered a distance of 930 feet in an 8.3-second flight.
The final in this first series of rocket launches from Roswell occurred on April 19, 1932. This was by far the most sophisticated rocket launched by Goddard to date. Liquid oxygen and gasoline were fed into the combustion chamber by pressurized liquid nitrogen, and the rocket was stabilized in flight by gyroscope-controlled steering vanes.
This rocket measured 10 feet, 9.5 inches long by 12 inches wide. Although it did successfully test innovative technological elements, the rocket only reached a maximum altitude of 135 feet and flew for five seconds.
The Guggenheim grant was unexpectedly canceled in June, 1932 due to effects of the Great Depression. This forced Goddard to return to Clark University by September, 1932. A grant from the Smithsonian Institution allowed Goddard to continue laboratory testing, but not flight testing, while he was again a professor at Clark University.
In September, 1933 Goddard obtained additional funding from the newly established Daniel and Florence Guggenheim Foundation. This supported more detailed research on insulators, welding techniques for lighter metals, gyroscope balancers, reciprocating and centrifugal fuel pumps, jet pumps and improved combustion chambers.
The new source of funding also allowed the continuation of rocket tests at Roswell, which resumed in September, 1934. A series of tests called the “A-Series” were conducted from September, 1934 through October, 1935.
The “A-Series” tests employed rockets ranging in size from 13.5 feet to 15 feet, 3.25 inches long and weighing between 58 and 85 pounds empty. The rockets employed pressure-fed combustion chambers and were steered by gyroscopic-controlled blast vanes.
During the “A-Series” tests, one static engine test and 14 launch attempts were conducted. During the 14 launch attempts, seven rockets actually left the tower. Some results of these seven launches are as follows:
February 16, 1935 – Rocket was launched without automatic guidance; rocket crashed quickly; crash was deadened by parachute deployment.
March 8, 1935 – An equalizer was installed to keep the liquid oxygen pressure from exceeding the gasoline pressure; a pendulum stabilizer was employed; the engine fired for 12 seconds; unplanned horizontal tilt diminished altitude; maximum velocity 700 m.p.h.; recovered via 10-foot parachute 9,000 feet from launch tower.
March 28, 1935 – Rocket employed improved gyroscopic stabilizer; reached a maximum altitude of 4,800 feet; flew a distance of 13,000 feet; corrected its flight path several times; reached an average speed of 550 m.p.h.; flight lasted 20 seconds.
May 31, 1935 – Rocket employed a new lift indicator; reached a maximum altitude of 7,500 feet; flew a distance of 5,500 feet; created a 10-inch hole upon impact.
June 25, 1935 – Rocket employed a new timing device for parachute deployment; employed a new cushioned gyroscopic stabilizer; flight was cut short by high winds; flew for 10 seconds; reached a maximum altitude of 120 feet.
July 12, 1935 – Rocket employed stronger and thicker steering vanes; engine fired for 14 seconds; reached a maximum altitude of 6,600 feet; flight path correction noted at altitude of 3,000 feet; rocket crashed when parachute was torn loose.
October 29, 1935 – Rocket employed new gasoline orifices; engine fired for 12 seconds; reached maximum altitude of 4,000 feet; a “water wave” was noted in the sand when the rocket crashed.
The “A-Series” tests were followed by “K-Series” tests, which were conducted from November, 1935 through February, 1936. The “K-Series” tests consisted of ten static engine tests only, and no rockets were actually launched.
The goal of the “K-Series” tests were to refine an improved 10-inch diameter engine. The rocket used for “K-Series” tests weighed 225 pounds empty and could carry 31 pounds of liquid oxygen and 24 pounds of gasoline. During this series, a maximum thrust of 623.5 pounds and maximum exhaust velocity of 4,470 feet per second were achieved.
Rocket launches resumed during the “L-Series” tests, which were conducted from May, 1936 through August, 1938. The “L-Series” tests were divided into “Section A”, “Section B” and “Section C” experiments.
The “Section A” tests in the “L-Series” were conducted from May, 1936 through November, 1936. The rockets employed the improved engines that were static tested during the “K-Series”. The rockets ranged in size from 10 feet, 11 inches long to 13 feet, 6.5 inches long by 18 inches wide. Each weighed 120 to 202 pounds empty to 295 to 360 pounds full.
During the “Section A” tests in the “L-Series” a total of four static engine tests and three rocket launches were conducted. All three of the rockets left the tower, and some of the results of these three launches are as follows:
July 31, 1936 – Rocket reached a maximum altitude of 280 feet; flight lasted five seconds; achieved a distance of 300 feet.
October 3, 1936 – Rocket reached a maximum altitude of 200 feet; flight lasted five seconds; combustion chamber was completely burned through.
November 7, 1936 – Rocket employed a new combustion chamber made up of four clustered chambers each 5.75 inches wide; rocket reached a maximum altitude of 200 feet and fell near the tower.
The “Section B” tests in the “L-Series” were conducted from May, 1936 through May, 1937. The rockets employed a combustion chamber made up of four clustered chambers each 5.75 inches wide, a new tilting cap parachute release, various exposed moveable air vanes, retractable air vanes and improved parachutes with heavy shroud lines.
Rockets used were either 16 feet, 7.63 inches long by nine inches wide or 17.75 feet long by nine inches wide. During the “Section B” tests in the “L-Series”, a total of two static engine tests and six rocket launches were conducted, with all six rockets leaving the tower. Some results of these six launches are as follows:
December 18, 1936 – Rocket employed a pressure storage tank; achieved a range of 2,000 feet; landed horizontally; engine noise was heard as many as eight miles away.
February 1, 1937 – Engine was fired for 20.5 seconds; rocket achieved a maximum altitude of 1,870 feet; ground behind the flame deflector turned green after being glazed by the exhaust.
February 27, 1937 – A new parachute release system was controlled by gyroscope; rocket achieved a maximum altitude of 1,500 feet and range of 3,000 feet; flight lasted 20 seconds.
March 26, 1937 – Rocket employed larger moveable air vanes; achieved a maximum altitude of between 8,000 and 9,000 feet; successfully corrected its path during flight; flight lasted 22.3 seconds.
April 22, 1937 – Rocket employed larger moveable air vanes and reinforced parachute; altitude could not be measured as the rocket flew almost straight upward; flight lasted 21.5 seconds; rocket was recovered one mile from the tower.
May 19, 1937 – Rocket employed streamlined, retractable air vanes and a wire-wound pressure storage tank to save weight; achieved a maximum altitude of 3,250 feet; stabilization was reported to be vastly improved; flight lasted 29.5 seconds.
The “Section C” tests in the “L-Series” were conducted from July, 1937 through August, 1938. Rockets used during the “Section C” tests employed light tank construction, moveable (or gimbaled) tailpiece steering, catapult assist launching and improved liquid nitrogen pressurization.
The rockets ranged in size from 17 feet, 4.25 inches long to 18 feet, 5.75 inches long by 9 inches wide. The rockets weighed from 80 to 109 pounds empty and a minimum of 170 pounds full. Static engine thrusts ranged from 228 to 477 pounds with exhaust velocities ranging from 3,960 to 5,340 feet per second.
Extremely hot exhaust temperatures were observed during the “Section C” tests. In some cases, pebbles in the cement used to construct exhaust deflectors fused and separated during flight, causing fires up to 50 feet away from the launch tower.
During the “Section C” tests in the “L-Series”, a total of seven static engine tests and eight rocket launches were conducted, during which all eight rockets left the tower. Some results of these eight launches are as follows:
July 28, 1937 – Rocket employed moveable tailpiece steering, wire-wound pressure storage tanks and carried a barograph; achieved maximum altitude of 2,055 feet; parachute did not open until the rocket neared the ground; flight lasted 28 seconds; rocket was recovered 1,000 feet from the tower.
August 26, 1937 – Catapult assist launching was employed; achieved a maximum altitude of 2,000 feet; rocket corrected its flight path seven times during the flight.
November 24, 1937 – Rocket leaned after leaving the tower and crashed about 100 feet away.
March 6, 1938 – Rocket reached a maximum altitude of 500 feet before the engine shut down prematurely, causing an uncontrolled coasting.
March 17, 1938 – Rocket achieved a maximum altitude of 2,170 feet; flight lasted 15 seconds; rocket was recovered 3,000 feet from the tower.
April 20, 1938 – Rocket carried a barograph; engine was fired for 25.3 seconds; achieved maximum altitude of 4,215 feet; rocket was recovered 6,960 feet from the tower.
May 26, 1938 – Rocket veered after leaving tower; achieved a maximum altitude of 140 feet; rocket was recovered 600 feet from the tower.
August 9, 1938 – Maximum altitude of 4,920 feet was estimated via telescope; on-board barograph recorded a maximum altitude of 3,294 feet; flight path corrected well during the flight; parachute opened at the top of the trajectory.
At the conclusion of the “L-Series” tests, Goddard began a focused study on the development of improved fuel pumps. He believed that the proper fuel pumps were critical if rockets were to achieve effective and enduring high-altitude performance.
From October, 1938 through November, 1938 Goddard made a thorough study of five small, high-speed centrifugal fuel pumps. From January, 1939 through February, 1939 he conducted proving stand tests on two of these pumps, which were called A and D.
These tests indicated that a small chamber or gas generator producing warm oxygen gas should be used to operate turbines in the fuel pumps. From March, 1939 through August, 1939 more static engine tests were conducted to test a new gas generator employing drive pump turbines.
From November, 1939 through October, 1941 Goddard conducted his final and most sophisticated series of rocket tests at Roswell. This series of tests was not identified by letter or number as previous tests had been.
Rockets used during this series of tests incorporated engines, pumps and turbines that had been previously refined. The rockets were all about 22 feet long by 18 inches wide and weighed 190 to 240 pounds empty. Each could carry 140 pounds of liquid oxygen and 112 pounds of gasoline.
During this series of tests, a total of 15 static engine tests and nine rocket launches were conducted. Of the rockets launched, just two left the tower. The maximum thrust achieved during static engine tests was 985 pounds, which was achieved on January 6, 1941. Some of the results of the two successful launches are as follows:
August 9, 1940 – Rocket employed improved fuel pumps; achieved a maximum altitude of 300 feet at a speed of just 10 to 15 m.p.h.
May 8, 1941 – Rocket employed improved fuel pumps; achieved a maximum altitude of 250 feet before veering off course.
Robert Hutchings Goddard conducted his last rocket launch on May 8, 1941. As war loomed on the horizon, he again offered his expertise to the United States military.
In the years approaching World War II, Goddard had agreed to allow military officials to review his research. On May 28, 1940 Goddard and Harry F. Guggenheim had met with a joint committee of Army and Navy officials in Washington, D.C.
A complete report was given to these officials by Goddard which outlined his advances in both solid-fueled and liquid-fueled rockets. The Army rejected the prospect of long-range rockets altogether. The Navy expressed a minor interest in liquid-fueled rockets. Goddard later characterized these responses as negative.
Neither branch of service was interested in an innovative rocket aircraft that had been patented by Goddard on June 9, 1931. The lack of military interest in rocketry had confounded Goddard for years, since he understood that only the government had adequate resources to fund proper research.
By the dawn of World War II, Goddard realized he was running out of time in his effort to achieve any meaningful advances in rocketry. Goddard had, however, stimulated some interest from Brigadier General George H. Brett of the Air Corps Materiel Division, with whom he and Guggenheim had met on July 27, 1940.
At the meeting, a proposal had been made to apply advances Goddard had made in liquid-fueled rockets to the problem of providing assisted take-off for heavy bombers and other aircraft. Although the Army was interested, they refused funding until such time as Goddard could produce his own working model of a take-off assist rocket.
However, military attitudes changed as it became clear that United States entry into the war was not a matter of if, but when. The concept of rocket assisted take-off became known as “Jet-Assisted-Take-Off”, or “JATO”.
In September, 1941 a team headed by Goddard began working under a contract with the Navy Bureau of Aeronautics and the Army Air Corps. In July, 1942 Goddard set up shop at the Naval Engineering Experiment Station at Annapolis, Maryland. He remained there on a full-time basis through July, 1945.
During this period, Goddard supervised the development of a working liquid-fueled JATO unit for flying boats. He was also able to fulfill a long-time goal of making a large number of tests of variable thrust rocket engines, a process which had become vital in JATO development.
Goddard died in Baltimore, Maryland on August 10, 1945. After all he had managed to accomplish in the field of rocketry, Goddard never witnessed the fruits of his labor. His work remained relatively overlooked until years later, when it was recognized that many of his principles were being used in modern rocketry.
His research did receive some attention in 1948 when his book, “Rocket Development: Liquid-Fuel Rocket Research, 1929-1941” was published posthumously. This was a follow-up to a previous book by Goddard, “Liquid-Propellant Rocket Development” which was published in 1936 and chronicled his research from 1919 to 1935.
In 1959, Goddard was honored by the United States Congress and posthumously received the first Louis W. Hill Space Transportation Award of the now defunct Institute of Aeronautical Sciences.
On May 1, 1959 NASA named the Goddard Space Flight Center in Greenbelt, Maryland after Goddard. In 1960, Goddard posthumously received the Langley Medal from the Smithsonian Institution.
Another great tribute was paid to Goddard literally in 1960 when the United States government agreed to pay his widow, Esther C. Goddard and the Guggenheim Foundation a $1 million settlement. It had been determined that over 200 patents granted to Goddard and held by his heirs had been applied to United States missile and rocket programs.
Hermann Oberth was born on June 25, 1894 in Hermannstadt, Transylvania, Romania. Since he was born to German speaking parents and became a German citizen later in life, Oberth is traditionally considered German even though he was born in Romania.
Like Robert Goddard, Oberth became fascinated with the possibility of spaceflight at an early age by reading science fiction works by authors such as Jules Verne. He was brought up in an academic environment, and eventually became a teacher in Transylvania.
Early in his career, Oberth expressed fanciful views on rocketry and spaceflight, but later began a scientific analysis on the reaction principle. It was just prior to World War I that he became interested in war rocketry.
In 1917, Oberth proposed to the German War Department the development of liquid-fueled long-range bombardment missiles. The idea, which could have placed Oberth years ahead of Robert Goddard in the launching of a liquid-fueled rocket, was rejected by the German military out of hand.
Several years later, Oberth learned of the existence of a 1919 book by Robert Goddard entitled “A Method Of Reaching Extreme Altitudes” but was unable to locate a copy in Germany. In 1922, Oberth wrote to Goddard and suggested that the development of liquid-fueled rockets should be an international endeavor.
A year later, Oberth published the book “Die Rakete Zu Den Planetenraumen” (The Rocket Into Planetary Space) in Munich. The book included a disclaimer which stated that any similarities between his theories and the 1919 book by Robert Goddard were purely by coincidence.
The book contained theories on rocketry similar to those of Goddard, but also included speculation on the effects of spaceflight on the human body. Oberth also put forth later proven theories that a rocket could travel faster than its own exhaust and could operate in a vacuum. He also theorized on the possibility of placing satellites in space.
Oberth never admitted borrowing any of his ideas from Goddard, and claimed to have engaged in extensive research of his own. Whether or not this was true, Oberth was able to gain the necessary momentum to stimulate German experiments in liquid-fueled rocketry.
Operating under the Newtonian premise that a rocket could carry a payload into Earth-orbit if it could fly fast enough and high enough, Oberth began to experiment with a number of propellants.
He designed a basic rocket, called “Modell B” which could be used in high-altitude research. Oberth also considered the merits of using a mixture of alcohol and hydrogen as rocket fuels.
An expanded and updated version of his previous book was released in 1929 as “Wege Zur Raumschiffahrt” (The Road To Space Travel). This, coupled with distribution of his earlier work, did much to stimulate interest in rocketry throughout Germany and Europe.
Also in 1929, Oberth joined Verein Fur Raumschiffahrt (Society for Space Travel) and became its president.
Unlike Robert Goddard, Oberth made every practical effort to publicize his work. He became technical advisor to the Ufa Film Company and director Fritz Lang, who was filming a movie entitled “Frau Im Mond” (Girl In The Moon). Oberth was commissioned to construct a rocket which would be launched in a publicity stunt for the movie.
Aided by a young and eager scientist named Wernher von Braun, Oberth was able to construct and static test a small rocket engine on July 23, 1930. But it quickly became apparent that a rocket would not be available in time for the release of the movie, and the project was abandoned.
After this project fizzled, Oberth returned to teaching in Transylvania. In the years following World War II, Oberth came to the United States to work with his former student Wernher von Braun at the Army Ballistic Missile Agency.
When it became clear that he would lose his German pension if he stayed in the United States too long, Oberth returned to Germany where he continued to author books on rocketry and space travel.
While his practical experiments in rocketry were few, he remains credited with encouraging many talented scientists to enter the field of rocketry.
Rocketry Enters The 20th Century
Although the pioneering works of Tsiolkovsky, Goddard and Oberth represent the most significant strides in pre-World War II rocketry, other noteworthy developments did take place in the early 20th century.
Some of these, however, were of novelty interest only, such as the occasion in the very early 1900’s when scientists tried launching rockets into the clouds then exploding them in an effort to prevent hailstorms. The rockets exploded, but so did the hailstorms.
In 1906, a German named Alfred Maul successfully took aerial photographs of the ground by attaching cameras to solid-fueled rockets. This method, while somewhat hopeful, was completely discontinued upon the advent of airplanes.
Rockets See Limited Use During World War I
Although rockets were used during World War I, they were of limited value. As was the case during the U.S. Civil War, rockets were simply not as effective as artillery weapons of the day. Rockets sometimes were employed both on land and at sea to lay smoke screens. Allied forces also used rockets as a method of illuminating battlefields.
Rockets were exploded in a brilliant flash that could illuminate a battlefield for several seconds. Some rockets carried a parachute with a flare attached. As the parachute and flare dropped toward the ground, a battlefield could be illuminated for about 30 seconds.
Offensive use of rockets did occur during World War I in France, where French forces introduced La Prieur rockets, named after their inventor Naval Lt. Y.P.G. La Prieur. These small solid-fueled rockets were designed to be fired from French or British bi-planes against German captive observation balloons.
The First Guided Missiles Are Introduced
Although they were never used offensively during the war, World War I spurred the demonstration of what are considered to be the first guided missiles, the British A.T. and the U.S. Kettering Bug.
British guided missile studies began in 1914 under the direction of professor A.M. Low. The British guided missile project was called A.T. for “Aerial Target” so that enemy spies would believe the vehicles were simply drones flown to test the effectiveness of anti-aircraft weapons.
However, A.T. concept vehicles were really intended to determine the feasibility of using radio signals to guide a flying bomb to its target. Radio guidance equipment was developed, tested and installed on small mono-planes which were powered by a 35-horsepower Granville Bradshaw engine.
Two A.T. test flights were conducted in March, 1917 at the Royal Flying Corps training school field at Upavon. Although both vehicles crashed due to engine failure, it was determined that radio guidance was feasible. Nevertheless, the A.T. program was scrapped due to its perceived limited wartime value.
Under the direction of Charles Kettering, development of the Kettering Bug began at the Delco and Sperry companies in 1917. The Kettering Bug was a pilotless bi-plane bomber made of wood and weighing just 600 pounds, including a 300-pound bomb as payload. It was powered by a 40-horsepower Ford engine.
Engineers employed an ingenious method of guiding the Kettering Bug to its target. Once wind speed, wind direction and target distance were determined, the number of revolutions of the engine needed to take the missile to its target were calculated.
A cam was then set to automatically drop into position when the proper number of engine revolutions had occurred. The Kettering Bug took off using a four-wheel carriage that ran along a portable track. Once in the air, the Kettering Bug was controlled by a small gyroscope. Altitude was measured by an aneroid barometer.
When the engine had completed the necessary number of revolutions, the cam dropped into position. As it did, the bolts that fastened the wings to the fuselage were pulled in. The wings then detached, and the bomb-carrying fuselage simply fell onto its target.
The Kettering Bug was successfully demonstrated in 1918 before Army Air Corps observers in Dayton, Ohio. However, World War I hostilities ended before the guided missile could be placed into production.
Russia Creates Official Rocketry Organizations
Russian rocketry research intended to follow up on the work of Tsiolkovsky was formally continued in 1924, when the Russian government created the Central Bureau for the Study of the Problems of Rockets and the All-Union Society for the Study of Interplanetary Flight.
Wernher von Braun Joins The VfR
In 1927, an eager 17-year-old scientist named Wernher von Braun joined the VfR, or Verein fur Raumschiffahrt (Society for Space Travel), which had been formed in June, 1927. This group of mainly young scientists immediately began designing and building a variety of rockets.
Membership in the VfR quickly soared to about 500, a sufficient member base to allow the publication of a periodic journal, “Die Rakete” (The Rocket). A number of VfR members, including Walter Hohmann, Willy Ley and Max Valier, had written, and continued to write, popular works on the field of rocketry.
Hohmann’s book “Die Erreichbarkeit der Himmelskorper” (The Attainability of Celestial Bodies) published in 1925 was so technically advanced that it was consulted years later by NASA. Valier would later seek to popularize rocketry by helping to organize tests of German rocket cars, gliders, train cars and snow sleds.
Other VfR members, including Hermann Oberth and von Braun, participated in the Ufa Film Company project in the late 1920’s through 1930, which also sought to popularize the field of rocketry.
The British Introduce Another Guided Missile
Also in 1927, British engineers at the Royal Aircraft Establishment introduced a missile called the Larynx. Larynx was a radio guided mono-plane flight tested from the HMS Stronghold at sea and from a testing ground in Egypt. It could carry a 250-pound bomb to a target up to 100 miles away at a maximum speed of 200 m.p.h.
Rocket Automobiles Are Tested
German automobile manufacturer Fritz von Opel tested his Opel-Rak I, the first rocket-powered automobile, in 1928. Opel-Rak I was an experimental modified racing car powered by a battery of Sander solid-propellant rockets used for life-line rescues at sea.
The final version of the Opel-Rak I employed 12 Sander rockets, after initial test runs using clusters of six and eight Sander rockets were completed. Although only seven of the 12 Sander rockets actually fired when the car was tested on April 12, 1928, the Opel-Rak I reached a maximum speed of 70 m.p.h.
This was followed by the Opel-Rak II, which was powered by a battery of 24 Sander rockets. The Opel-Rak II reached a maximum speed of 125 m.p.h. when it was tested on May 23, 1928.
Rocket Railway Cars Are Tested
The versatile Sander rockets were also used to support experiments on rocket-powered railway cars. The first railway test was conducted in June, 1928 on a track between Celle and Burgwedel, Germany. In this test, a cluster of 24 Sander rockets propelled a railway car to a maximum speed of 100 m.p.h.
Two follow-up rocket-powered railway car tests were conducted on a track between Blankenburg and Halberstadt, Germany. Specific results of these tests are unknown, with the exception that in the final run, a cluster of Sander rockets failed to move a heavier railway car.
Rocket Aircraft Are Tested
Germans also developed the first rocket-powered aircraft, the Ente (Duck), a sailplane powered by two Sander rockets. An Ente flew a distance of three-quarters of a mile in just under one minute during a test flight on June 11, 1928. The test was conducted by the German glider group Rhon-Rossitten Gesellschaft.
Not to be out-done, the publicity-seeking Fritz von Opel piloted a glider powered by 16 Sander rockets on September 30, 1928. The glider reached a maximum speed of 95 m.p.h.
Austrian Scientist Proposes Rocket Engines
Also in 1928, Austrian Dr. Franz von Hoefft of Vienna’s Gesellschaft fur Hohenforschung (Society for Altitude Research) proposed the development of a variety of rocket engines.
Rocket Sleds Are Tested
On January 22, 1929 Germans tested the first rocket-powered snow sled, called RS-1. Also powered by a cluster of Sander rockets, the sled glided along the snow on pontoons at a maximum speed of 65 m.p.h.
Italy Conducts Rocketry Tests
Limited rocketry research began in 1929 in Italy when scientists General G.A. Crocco and Riccardo M. Corelli determined that solid fuels were not effective for long-range rockets. Engines were designed that burned combinations of gasoline/nitrogen dioxide, trinitroglycerine/methyl alcohol and trinitroglycerine/nitromethane.
While the Italian rocketry tests had some promise, they centered around combustion chamber tests only and did not produce any rockets. The Italian tests were abandoned by 1935 due to a lack of funding.
Russian Rocketry Research Continues
In 1930, Russian government rocket design teams led by Fridrikh Arturovitch Tsander and Valentin Petrovitch Glushko began testing a number of liquid-fueled rocket engines. Tsander published “Problems of Flight by Means of Reactive Devices” in 1932 while Glushko published “Rockets, Their Construction and Utilization” in 1935.
These Russian rocket tests continued through 1937, and tested liquid-fueled rocket engine concepts burning such combinations as gasoline/gaseous air, toluene/nitrogen tetroxide, gasoline/liquid oxygen, kerosene/nitric acid and kerosene/tetranitromethane.
One of the Russian rocket designs emerging from these tests was called GIRD-X, which weighed 65 pounds, was 8.5 feet long and 6 inches wide. A GIRD-X rocket reached a maximum altitude of three miles during a test on November 25, 1933.
Another of the Russian rockets, called Aviavnito, weighed 213 pounds, was 10 feet long and 1 foot wide. An Aviavnito rocket reached an altitude of 3.5 miles in 1936.
The VfR Begins Rocket Tests
Also in 1930, the VfR set up permanent offices in Berlin and began testing rockets which would ultimately change the nature of warfare and propel the world into the space age.
These at first humble tests began at an abandoned German ammunition dump at Reinickendorf nicknamed Raketenflugplatz (Rocket Airfield). The true genius of the VfR team at this time was reportedly Klaus Riedel, although he had no formal training. Riedel was killed in an automobile accident prior to the close of World War II.
By August, 1930 tests began on the first of the VfR rockets, called Mirak-1 (Minimum Rocket-1). Powered by a combination of liquid oxygen and gasoline, Mirak-1 employed a 12-inch long liquid oxygen tank that shrouded a combustion chamber, thus cooling it. Gasoline was carried in a three-foot long tail stick.
Mirak-1 was successfully static test fired in August, 1930 at Bernstadt, Saxony. During a second static test firing in September, 1930 Mirak-1 exploded when its liquid oxygen tank burst.
The British Introduce More Guided Missiles
The British introduced the Queen Bee in 1930, which was followed by the Queen Wasp. Both were radio-guided bi-planes launched by catapult from naval vessels or ground installations. Considered an advanced concept in their day, these missiles were able to drop an explosive weapons payload then return to the launch site for a pontoon landing.
Rocket Mail Service Begins
Beginning in February, 1931 Austrian Friedrich Schmiedl launched solid-fueled rockets carrying mail payloads, primarily intended to be launched between the cities of Schockel and Radegund or Schockel and Kumberg.
Schmiedl’s innovative method of launching rocket mail was successful for several years, so an Austrian inventor named Gerhard Zucker proposed a service that would carry rocket mail across the English Channel. Unfortunately for Zucker, all of his long-range solid-fueled rocket mail prototypes exploded at launch.
German Rocket Testing Continues
On March 13, 1931 Karl Poggensee launched an experimental solid-fueled rocket near Berlin. The rocket carried an altimeter, cameras and a velocity indicator. It reached an altitude of 1,500 feet and was successfully recovered by parachute.
The first European liquid-fueled rocket was launched on March 14, 1931 not by the VfR but rather by German scientist Johannes Winkler, supported in his research by Hugo A. Huckel. The pair launched a 2-foot long by 1-foot wide rocket called the Huckel-Winkler 1, powered by a combination of liquid oxygen and liquid methane.
The Huckel-Winkler 1 was launched near the city of Dessau and reached an altitude of 1,000 feet. This was followed by the launch of Huckel-Winkler 2 near Pillau in East Prussia on October 6, 1932. This rocket caught on fire and crashed after reaching an altitude of just ten feet.
In April, 1931 a German scientist named Reinhold Tiling launched four solid-fueled rockets at Osnabruck. One exploded at an altitude of 500 feet, two reached altitudes of between 1,500 and 2,000 feet and one reached an altitude of 6,600 feet at a maximum speed of 700 m.p.h.
Tiling later launched two more solid-fueled rockets, each more advanced than the first four. These rockets were launched from Wangerooge, one of the East Frisian Islands. Details of these tests are not certain, but one of the rockets is believed to have reached an altitude of 32,000 feet.
The VfR Makes Advances In Rocket Testing
Also in the spring of 1931, VfR tested the Mirak-2, which was similar in design to the Mirak-1, but incorporated an improved propulsion system. Like the Mirak-1, the Mirak-2 rocket was destroyed during a static test firing when its liquid oxygen tank burst.
VfR then moved on to tests of a new series of rockets called Repulsor, so named by VfR member Willy Ley. Repulsor rockets, like their Mirak ancestors, also burned a combination of liquid oxygen and gasoline. But the Repulsor combustion chamber was cooled by water stored inside a double-walled aluminum skin.
Repulsor-1 was successfully launched by VfR to an altitude of 200 feet on May 14, 1931 in the second European launch of a liquid-fueled rocket. Repulsor-2 reached an altitude of 200 feet and range of 2,000 feet on May 23, 1931.
VfR then introduced a series of rockets under the designation Repulsor-3, which were intended to be launched then recovered intact via parachute. The first Repulsor-3 reached an altitude of 2,000 feet and range of 2,000 feet, although its parachute was torn off and the rocket crashed. Several Repulsor-3 tests followed with mixed results.
These tests were followed by the Repulsor-4 series, which introduced a rocket incorporating a single tail stick for stability. In August, 1931 the first Repulsor-4 reached an altitude of 3,300 feet and was recovered by parachute. Subsequently tested Repulsor-4 rockets typically reached altitudes of about one mile.
Rocket Tests Commence In The U.S.
The American Interplanetary Society (AIS) completed the design of a liquid-fueled rocket in January, 1932. It was patterned after the VfR Repulsor series of rockets, and burned a combination of liquid oxygen and gasoline encased in an aluminum alloy frame.
Fabrication of AIS Rocket #1 began on a farm in Stockton, New Jersey in August, 1932. The first static test firing of the rocket occurred on November 12, 1932 at which time the 15-pound rocket produced a thrust of 60 pounds. A planned test launch of Rocket #1 was canceled on November 13, 1932 due to bad weather.
Rocket #1 was never launched, but was overhauled and renamed Rocket #2. Rocket #2 was launched from Great Kills, Staten Island, New York on May 14, 1933. Its oxygen tank burst at an altitude of 250 feet. AIS then planned tests using Rockets #3, #4 and #5, which ranged in length from 5.5 to 7.5 feet and in diameter from 3 to 8 inches.
Rocket #4 was launched from Great Kills, Staten Island, New York on September 9, 1934 and reached an altitude of 382 feet and range of 1,338 feet. Rocket #3 was never flown due to a faulty design, and Rocket #5 was never built. AIS performed liquid-fueled engine tests, but conducted no rocket launches, through 1939.
AIS was able to support the test launches of a number of solid-fueled rockets between 1937 and 1939. These rockets varied in size and employed dry-fuel cartridges. All AIS rocket testing ceased in 1939 upon the advent of World War II.
In the same general time frame as the AIS activities, the Cleveland Rocket Society tested a number of liquid-fueled rockets that burned a combination of liquid oxygen and gasoline. These tests were conducted at a test site outside the city of Cleveland.
In 1932, the U.S. Army Ordnance Department began a six-year program which involved the sporadic testing of powder rockets at the Aberdeen Proving Ground, Maryland. These tests were directed by Captain Leslie A. Skinner, and were intended to develop an effective air-to-air missile.
These U.S. Army tests employed modified 81 millimeter trench mortars reloaded with powder and fired from a pipe launcher. While the tests did not yield a weapon accurate enough to be fired from the air, the research was later successfully applied to both U.S. Navy rocket accelerated bombs and the U.S. Army bazooka.
German Army Considers Support Of VfR Rocket Tests
Membership within the VfR dropped dramatically in 1932 as German police began objecting to rocket tests within the Berlin city limits. This was coupled with a fear of Adolph Hitler, who began restricting the activities of organizations, like VfR, that had significant ties to the international community.
Facing total elimination, VfR made pleas to the German Army to aid in the continuation of rocket testing. In the summer of 1932, the German Army allowed VfR to launch a Repulsor-type rocket at an army proving ground at Kummersdorf.
The German Army then allowed Wernher von Braun to continue experiments while working on his doctoral thesis in rocket combustion phenomena using the facilities at Kummersdorf.
First Modern Manned Rocket Is Proposed
The first definite plans to construct a manned rocket emerged in 1933 as a part of the Magdeburg Project, headed by German scientists Rudolf Nebel and Herbert Schaefer. A test rocket was launched on June 9, 1933 at Wolmirstedt near Magdeburg. The rocket never left its 30-foot launching tower.
Several tests followed with mixed results. On June 29, 1933 a rocket left the launch tower, but flew horizontally at a low altitude for a distance of about 1,000 feet. This rocket was recovered undamaged and refashioned into a design more closely resembling the VfR Repulsors.
This rocket was eventually launched from Lindwerder Island in Tegeler Lake near Berlin and reached an altitude of 3,000 feet before crashing about 300 feet from the launching tower. Additional test launches were conducted from a boat on Schwielow Lake through August, 1933 at which time the Magdeburg Project was completely abandoned.
British Interplanetary Society Is Founded
The British Interplanetary Society was founded in 1933. Its member publications sought to greatly broaden an awareness of the need for experiments in rocketry. But as the history of the British Interplanetary Society was just beginning, the history of VfR was reaching an untimely end.
German Army Absorbs VfR Rocket Testing
The VfR was forced to disband in the winter of 1933/1934 because the organization could not meet its financial obligations. Rocketry experiments ceased at the Raketenflugplatz facility in January, 1934 and the area resumed operation as an ammunition dump. Upon the disbanding of VfR, all private rocket testing in Germany ceased.
Wernher von Braun, however, went to work officially for the German Army at Kummersdorf. There, the Heereswaffenamt-Prufwesen (Army Ordnance Research and Development Department) established the Versuchsstelle Kummersdorf-West as a static testing site for ballistic missile weapons.
Kummersdorf also became a site for the development and testing of a number of prototype jet-assisted take-off (JATO) units for aircraft. These tests were conducted by Wernher von Braun in association with Major von Richthofen and Ernst Heinkel.
Under the direction of Captain Walter Dornberger, the Kummersdorf team was quickly able to design and build the A-1 (Aggregate-1) rocket. The A-1 was powered by a combination of liquid oxygen and alcohol, and could develop a thrust of about 660 pounds.
A 70-pound flywheel gyroscope was carried in the nose of the rocket to provide stability during flight. The A-1 was ultimately unsuccessful because its small fiberglass liquid oxygen tank housed inside its alcohol tank was fire prone. In addition, the gyroscope was located too far from the center of the rocket to be effective.
The A-1 was soon followed by the A-2, which employed separate alcohol and liquid oxygen tanks. The A-2 gyroscope was located near the center of the rocket between the two fuel tanks. In December, 1934 two A-2 rockets, nicknamed Max and Moritz, were launched from the North Sea island of Borkum. Each reached an altitude of about 6,500 feet.
But the feasibility of effective military rockets remained speculative at best, exemplified by the fact that in 1935, Adolph Hitler rejected a proposal from Artillery General Karl Becker for a long-range bombardment rocket.
The British Engage In Limited Rocket Development
Although the Explosives Act of 1875 had severely restricted rocketry research in Great Britain, certain government rocketry tests were allowed. These included rocket tests begun in 1935 by the Research Department at Woolwich Arsenal.
The Woolwich Arsenal tests employed smokeless cordite as fuel, the use of which was not restricted by the government. The research work was permitted to expand with the goal of producing anti-aircraft rockets, long-range attack rockets, air-to-air rockets and assisted take-off rockets.
Small 2-inch or 3-inch charges of smokeless cordite became the basis for a number of solid rocket motor designs, some of which were used in clustered applications. The smokeless cordite rockets were tested through 1939 in England and Jamaica, and eventually made their way into British Army and Navy arsenals.
Rocket Aircraft Are Tested In The U.S.
In the United States, a limited test of rocket-assisted aircraft was conducted on February 23, 1936 when two 15-foot wingspan airplanes were launched from a frozen lake at Greenwood Lake, New York. Each airplane was powered by a single rocket engine that burned a combination of liquid oxygen and alcohol.
Each airplane carried a number of commemorative cachet envelope covers and postcards. One airplane crashed after a 15-second flight when its wings tore off. The other reached an altitude of 1,000 feet before its combustion chamber ran out of fuel. Flight operations were supervised by noted author and former VfR member Willy Ley.
U.S. Navy Supports Liquid-Fueled Rocket Tests
Navy Midshipman Robert C. Truax began experimenting with liquid-fueled rocket engines in 1936. With his work supported by the Navy at Annapolis, Truax was able to develop several small experimental rocket engines that burned a combination of compressed air and gasoline.
Lesser Known Rocket Tests Commence In Germany
Sanctioned German rocketry research was also conducted by engineer Eugen Sanger, whose work began in 1936 and eventually yielded experimental rocket engines which burned a combination of liquid oxygen and diesel fuel. These engines could produce a sustained thrust of 50 pounds for up to 30 minutes, but had no military value.
Rockets Carry Propaganda Leaflets In Spain
Solid-fueled sea-rescue rockets were used in a particularly interesting manner during the Spanish Civil War, which lasted from 1936 to 1939. These rockets were converted for the purpose of carrying propaganda leaflets behind enemy lines.
The sea-rescue rocket nose cones were modified to burst open at a predetermined time and altitude to release a payload of leaflets, which were printed on an especially thin paper to conserve weight.
German Rocket Tests Commence At Peenemunde
In April, 1937 all of the German rocket testing was relocated to a top-secret base at Peenemunde on the Baltic Coast. The first task of engineers at what was established as the Heeresversuchsstelle Peenemunde (Army Experimental Station Peenemunde) was to develop and test a new rocket called the A-3.
By the end of 1937, the Peenemunde team had developed and tested the 1,650-pound, 21-foot long A-3 rocket, which burned a combination of liquid oxygen and alcohol. Although the propulsion system of the A-3 functioned well, its experimental inertial guidance system did not. The guidance problems were solved, and larger rockets were planned.
By 1938, Germany had begun invading huge portions of Eastern Europe, and Adolph Hitler began recognizing the need for an effective ballistic missile weapon. The German Ordnance Department requested that the Peenemunde team develop a ballistic weapon that had a range of 150 to 200 miles and could carry a one-ton explosive warhead.
The size of the weapon would need to be compatible with existing railways in terms of tunnels and bends and would need to be transportable in the field by truck. These criteria led directly to the development of the A-4 rocket.
An interim test vehicle to bridge the gap between the A-3 and the A-4 was named the A-5. The A-5 was similar in design to the A-3, but employed a simpler, more reliable guidance system and stronger structure. The A-5 was fashioned with the exterior appearance of the proposed A-4 weapon.
A-5 tests were conducted from the fall of 1938 through 1939. The rockets were launched both horizontally and vertically, and were often recovered by parachute and launched again. The first A-5 launched vertically reached an altitude of 7.5 miles.