Dave Nordling, Secretary, Reaction Research Society
The pioneering theoretical and experimental work that formed the basis for the modern practical liquid rocket was published 100 years ago today.
A Method of Reaching Extreme Altitudes, by Robert Hutchings Goddard (1882-1945), was published by the Smithsonian Institution, on May 26, 1919. Considered the father of American rocketry, Goddard developed the theory of his work while at Princeton University in 1912-1913 with experiments undertaken during 1915-1916 at Clark University.
This 79-page paper described a series of practical experiments using nitrocellulose “smokeless” powder combusted within an enclosed chamber through a de Laval nozzle both in the ambient environment and under vacuum conditions. This paper also included mathematical derivations to develop a theory of rocket action taking in account air resistance and gravity with the goal of determining the minimum initial mass necessary for an ideal rocket to deliver a final mass of one pound to any desired altitude.
In his research, Goddard sought to devise a practical means to send instruments above the range of sounding balloons (about 20 miles) to explore the upper atmosphere. What makes this work fascinating is how much was known at the time of his paper’s publication versus how much was yet to be learned and become common knowledge in our time. Very little was known about the nature of the upper atmosphere in 1919. Yet, the basic concept of a rocket with a restrictive nozzle was known for centuries in the Chinese civilization and later in Europe with the 19th century British Congreve rockets.
In this scientific work, Goddard meticulously lays out his plan of research and the incremental progress he made to verify each of his claims. Most significant is his first conclusion on page 34 that his experiments in air and in vacuum prove that the propulsive force from a rocket is really based on a jet of gas having an extremely high exhaust velocity and is NOT merely an affect of reaction against the air.
Goddard’s work did not receive much funding during his lifetime. His work in rocketry even invited the ignorant criticism of the New York Times and others in the public which had a profound affect on Goddard in his lack of willingness to collaborate even until his death in 1945. In all fairness, it should be noted that the New York Times did see fit to offer an apology to Goddard 24 years after his death and only 50 years ago (in 1969) in the weeks before the Apollo 11 flight that landed the first two men on the moon by a multi-stage rocket operating quite well in the vacuum of space without a media for the vehicle to react against.
Air & Space Magazine, The Misunderstood Professor
by Frank H. Winter, May 2008
Goddard was awarded two patents in 1914, one for a multi-stage rocket and one for a liquid-fuel rocket. Considered an iconic work of 20th century science, all rocketry enthusiasts, students and professionals owe themselves the privilege of reading Dr. Goddard’s 1919 monograph which would lead to the first successful test of a liquid rocket flight in 1923 and the first successful liquid rocket flight on March 16, 1926 in Auburn, Massachusetts.
Goddard’s early discoveries included the determination that fins on a rocket by themselves were not sufficient to stabilize a rocket in flight. Goddard’s inventions included movable vanes to vector the rocket exhaust stream in flight and a gyroscope-based control system to effectively guide a rocket in flight.
Although relatively unappreciated in his home country, Goddard’s work was noticed by the Germans and in years later leading to their own rocket development program leading to the V-2 ballistic missile used to terrifying effect during the latter portion of the Second World War. During the Cold War, the V-2 was the heritage of the first rockets by the first space-faring nations.