Although rockets had been around for several centuries before Newton no one understood how they actually worked. Galileo began the work towards changing this but it was Newton who truly provided the foundation for the science of rocketry. His three laws of motion finally provided the science to understand how they worked, although it would not be realised until the late 19th century, when these laws would be applied to rockets. In particular the reaction principle (Newton's third law of motion) was to be crucial.
Newton's understanding of gravity also allowed a more scientific approach to be taken in solving the problems of breaking the Earth's gravitational field and thus be able to actually reach space.

So why have I decided to put a brief synopsis of modern science fiction here at the start of a webpage entitled 'The Approach of Modern Rocketry'?
The answer is a simple one, after Newton's work there was very little substantial work done that contributed to us reaching space and it took nearly 200 years for anyone to really approach the issue from a scientific point of view. Then suddenly three men, seeming working independently, made massive contributions to the science of rocketry and soon we had rockets actually taking off. So what was the catalyst that suddenly sparked all of this activity? Science Fiction.

The three founding fathers of modern rocketry, as they are known, were all inspired in their work by science fiction writers.
Science fiction also began to capture the general public's imagination, and this inspired great interest as to whether we could reach the stars. This public interest eventually led to financing and political support.

The first major account of science fiction was Jonathan Swift's publication of 'Gulliver's Travels' in the eighteenth century. It was not, however, until the nineteenth century that the great influential works were written. The first truly inspirational writer was Jules Verne (1828-1905) and he is often referred to as the founding father of modern science fiction. His most influential book was 'From the Earth to the Moon'.

The other great science fiction writer was H.G. Wells (1866-1946) and his most famous work now is probably 'The Time Machine' but at the time of the founding fathers his greatest work was 'The War of the Worlds'.
This work produced the most amazing reaction when the story was aired on the radio. Orsen Wells announced that the Earth was under attack from Martians and people actually believed it, there was widespread panic with the thought that war against extraterrestrials had broken out.
Just as with Jules Verne, history would tell of H.G. Wells' great influence that was to inspire the birth of modern rocketry.

Kanstantin Tsiolkovsky (1857-1935)

Kanstantin Tsiolkovsky became known in USSR as the Father of 'cosmonautics', though this was not until after his death. He was inspired by Jules Verne's writings.

The brilliance of his work in rocketry and interplanetary travel is clear when it is considered that a large bulk of his theories of space travel were produced years before Orville Wright, together with his brother Wilbur Wright, made the first powered, sustained and controlled flight on 17 Dec 1903, in an aeroplane that few just a few yards. As simple as it seems to us now, his most important idea was in the formation of the first step of his theory, the fact to reach and travel in space man was going to have to use rockets.
At this time no one believed that a rocket would be able to reach space and even if it did, by some miracle, it was believed that a rocket could not function in the vacuum of space.
Tsiolkovsky realised that these beliefs were in error and he was sure that a rocket could produce enough power to achieve escape velocity and that a rocket would work in a vacuum.

There is no question Tsiolkovsky was a true visionary, he theorised many aspects of space travel, and laid out the theoretical foundations for rocket propulsion, including the use of liquid fuel propellant.
His first significant article was published in 1883 and was entitled 'Free Space', in this work he demonstrated Newton's reaction principle (Third Law) for the first time, and then related this work to rockets. Tsiolkovsky was convinced that the reaction principle could, and indeed would, take man into space, and the science of rocketry was born.

Tsiolkovsky rocket designs	Model of Tsiolkovsky's rocket
Courtesy: MSFC	© Mark Wade

By 1898 he had completed several important articles but none were published until 1903, when in a series of articles he discussed his principles for space travel, these were the first articles ever published on the principles of using rocket propulsion to explore space. Of particular importance was Exploration of Space by Rocket Devices.
In this work Tsiolkovsky proved mathematically that Newton's reaction principle could propel a rocket into space. The final mathematical equation became (and still is!) known as the Tsiolkovsky equation. He also realised, in accordance with Newton, the thrust of the rocket would be determined by the escaping velocity of the exhaust gas.
1903 was also the year that saw him start designing rockets, which used liquid hydrogen and liquid oxygen for fuel (of course today's rockets use a mixture of these two).
Of his many other important works, his plan for space exploration, written in 1926, really demonstrates just what a visionary he was. In it he detailed a plan for space colonisation that is incredibly close to how we have progressed so far. Will future history continue to vindicate his ideas? Click here to take a detailed look at his plans.

Another of his works that was significant enough to merit a mention was entitled 'The Space Rocket Trains' and was published in 1929. Here he gave a detailed account of how it would be essential to find the best balance possible between mass and fuel in the rocket in order to reach space.
In other words he identified the key problem, a certain amount of fuel would be required to propel the rocket into space, however this fuel itself would have considerable mass, so more fuel would be required to lift the mass of the fuel already present, of course this extra fuel also has mass and the same problem cycles over and over again.
Tsiolkovsky proposed the use of multi-stage rockets to achieve an optimum balance.

Tsiolkovsky was very much a theorist, he did not construct a single rocket, though he designed hundreds, it has been suggested that this situation was forced upon him by a lack of resources. This could well have been the case as his work was ignored and his achievements unrecognised in the USSR until after his death.
His inspiration to the USSR space program is obvious and it is noticeable that within the US his work was not really looked at until the late 1950's after the USSR had gained a surprise victory in the race to space.

Robert Goddard (1882-1945)

Robert Goddard drew his inspiration from H.G. Wells.
There was one key difference between Goddard and Tsiolkovsky in that Goddard was a practical man, he did not just theorise about rockets, he built and tested his designs, using experimental investigation to advance his knowledge.
It has been said that Goddard was to astronautics what the Wright brothers were to aeronautics.

There is absolutely no evidence of Goddard having any knowledge of Tsiolkovsky's work and as no one in the US it seems had even heard of Tsiolkovsky until the late 1950's it is a fair assumption that Goddard was working independently of Tsiolkovsky.
This is a remarkable situation because Goddard was to come, just a few years later, to exactly the same conclusions as Tsiolkovsky.

Goddard's experiments began with solid fuel and by 1914 he had already received patents for a combustion chamber design and a design for a multi-stage rocket, and soon after he experimentally proved that a rocket would work in a vacuum.
Just as Tsiolkovsky, Goddard also realised the importance of the escape velocity of the exhaust gas and in 1915 while testing solid fuels, to find the optimum fuel it was his turn to develop the idea of using a liquid fuel rocket. Being of a more practical nature though he quickly analysed the addition problems that such a system could bring, for example the need for fuel and oxygen tanks as well as turbines and combustion chambers.

In 1919 Goddard had his first major article published, it was entitled 'A Method of Reaching Extreme Altitude', which included a suggestion of flying a demonstration rocket to the Moon. He was widely criticised for this work, in particular his assertion that a rocket could function in space was rubbished because there was no air for the rocket to push against. He had already proved to himself that this was not the case but this criticism made him very uneasy about publishing future work, and much was kept in secrecy while he continued his experiments.
His end conclusions in this paper were striking similar to Tsiolkovsky's conclusions:

1. A rocket would work in a vacuum (he correctly identified that the requirement for something to push against (from Newton's third law) could be satisfied by the push being against the expelled propellant mass).
2. That it was indeed possible to achieve escape velocity with a rocket (almost certainly requiring a liquid fuel rocket).
3. A multi-stage rocket would produce the optimum efficiency of the rocket to achieve escape velocity.

Courtesy: NASA

Possibly Goddard's greatest breakthrough, and undoubtedly his most famous, was the achievement of the world's first flight of a liquid propelled rocket. This occurred on 16 March 1926, at Worcester, Massachuttes, and this event has, unsurprisingly, been called the Kittykawk of modern rocketry (Kittyhawk was the location of the Wright brothers first aeroplane flight).
The flight only lasted 2.5 seconds but this was the beginning of the future of space exploration. Goddard continued to develop his rockets from here. In July 1929 he built another, larger rocket that became the first rocket to carry instruments, and in 1932 he used basic guidance systems for the first time which included gyroscopes for stabilisation.

Goddard needed financing to continue his work and with the local population becoming increasing adverse to him firing rockets over their town the need was urgent. It was a certain Charles Lindbergh, the first man to cross Atlantic Ocean in an aeroplane (20-21 May 1927) that became interested in his work and helped to set up the Guggenheim grant for Goddard. This new impetus of money allowed Goddard to move his testing facilities to Roswell, New Mexico, from where he worked from 1934 to 1942. While working here he produce many more advances, particularly in the area of combustion chamber design.

As with Tsiolkovsky, Goddard's government paid little attention to his work, and by 1942, during World War 2, they had employed him, not to build a rocket to go to space, but to design small rockets for the Navy.

Goddard with his first liquid propelled rocket in 1926	Goddard had much larger rockets by the time he moved to Roswell
Courtesy: NASA	Courtesy: JPL

Hermann Oberth (1894-1989)

Hermann Oberth was inspired, just as Tsiolkovsky, by Jules Verne's 'From the Earth to the Moon'. He was born in Rumania, but was living in Germany when he produced his great work.
In 1923 he published 'The Rocket into Interplantetary Space' (Die Rakete zu den Planetenraumen), this was originally submitted as his thesis for his Doctorate in 1922, but was refused due to its unrealism!
This had angered Oberth and he was never again to try for his doctorate, instead campaigning against the establishment and its lack of foresight. In the work itself he suggested the possibility that a rocket could be built that could take man into space and allow him to explore the new environment.

Again there is no evidence, or indeed likelihood, that he knew of the work that had been produced by Tsiolkovsky or Goddard, but unbelievably his conclusions were again almost identical.
His ideas included the use of liquid fuel propellant, he also analysed the relationship between mass, fuel and thrust and it is believed that he had the idea for a multi-stage rocket at this time. He did not have the resources to test such ideas by experimentation so he contented himself with his theorising during these early years.
As early as 1917 he had proposed to the German War Department that development of a long range, liquid fuelled rocket would have great military power. This was 9 years before Goddard made the world's first liquid fuelled flight, and would have put Oberth a long way in front of Goddard. The German department, however, was not only to reject the proposal, but all but laughed it out!

By 1929 Oberth released 'Ways to Travel in Space', this comprised of a much longer version of his 1923 paper, with much greater analysis and understanding.
The work contained theories on rocketry similar to the two before him, including that a rocket could operate in space (which as detailed above was widely held not to be the case) and he also suggested that a rocket could travel faster than its exhaust gas velocity. Unlike Goddard, Oberth added to this work a more visionary nature, he spoke of the possible effects on the human body of space flight and of zero-g environments (it is believed he even conducted some experiments on himself to test the potential problems). He also analysed possibilities of artificial satellites being placed into space.
In the same year Oberth was to launch his first liquid fuel rocket however, certainly compared to Goddard , his experimentation in rocketry was very limited. His theorising was, of course, important, but it is the influence that this man possessed and how many people that his theories reached that really makes him a giant in the arrival of modern rocketry.

His work inspired many rocket organisations across the world to test liquid propelled rockets (e.g. The Verein Fur Raumschiffahrt in Germany, GIRD in USSR, the American Interplanetary Society (a few years later became the American Rocket Society) and the British Interplanetary society).
With his work becoming so well known it is not surprising that it influenced a great many individuals, without question the most significant of these people was Wernher von Braun (see TheSpaceSite.com page on The Space Race), who Oberth took on as his assistant in the early 1930's.

Almost all of the theories that these three men produced that were rubbished in their time have gone on to be proved absolutely correct in the future when technology allowed definitive proof to be found.

Check out How a Rocket Works (then we shall continue onto The Space Race)
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