PIONEERS AND MODERN ROCKETS

21 do you are watching reaction engines work they burned kerosene and liquid oxygen great heat and pressure build the superheated gases raced through narrow exhaust nozzles the exhaust jet builds it rusts down with tremendous force the vehicle follows Newton's third law of motion [Music] [Applause] [Music] it reacts by moving up [Music] by moving away from the fiery blast beneath it [Music] this vehicle is a marvel of modern engineering but the idea for a rocket like this first appeared about 70 years ago the whole story of the modern rocket concerns a few men with a lot of imagination and a lot of knowledge about why it ought to be possible to build a space rocket they understood about gravity and the conditions in outer space they understood the physics of rocket flight what they needed to do was to create an actual design find the right fuels the right metals the right guidance system they had to be space scientists and they had to be rocket engineers Konstantin zeal speed suggested using a mixture of liquid fuels he suggested making a walls of a rocket as thin as paper and then stiffening them from inside very few people outside Russia knew about zeal kofsky startling ideas but on the other side of the world another scientist was studying the same problem a physics professor from Massachusetts robert h Goddard [Music] as a boy Goddard read all the science fiction he could find at 17 he wanted to build a machine that would go higher than anything else he didn't know about zeal Cosby's work but he worked out many of the same theories on his own first of all he understood why the rocket was the only machine that could work in space this is because a rocket carries both its oxygen and its fuel along with it in a liquid rocket these are carried in separate tanks now any engine needs both oxygen and fuel to burn together and in a rocket it takes place in a burning chamber and the gases come out the exhaust nozzle if you were to take the oxygen away the fire would go out the oxygen burns the fuel and is called the oxidizer now in a solid propellant rocket the oxidizer and fuel are mixed together in the propellant because a rocket doesn't need to take oxygen from the atmosphere it can go very high where the atmosphere is very thin in fact it can go into space where the atoms of oxygen are so far apart it's almost impossible to measure them with the most sensitive instruments and completely impossible to use them in our rocket Goddard build rockets that used a combination of two liquids he explained his design to the Smithsonian Institution and they published his plans for using rockets to carry research instruments into the upper atmosphere [Music] he told people these same principles apply to bigger rockets even ones that could reach the moon building rockets was an expensive business even in 1920 the Smithsonian Institution gave him five thousand dollars to help in his early research but that was soon used up we had no money for a large laboratory or a big step but he went on designing and building while he was professor of physics at Park University Goddard made more tests and finally in 1926 the world's first liquid fuel rocket rolls into the air from his aunt at his farm in Massachusetts other Rockets followed then one day one of his Rockets went so high the local residents thought it was a plane about to crash an angry fire marshal suggested that the testing should be done in a less populated place [Music] the famous flyer Charles Lindbergh heard of Goddard's work and helped him get research money from the Guggenheim family with his staff Goddard moved the test site to the wider skies of New Mexico here he had room to test the improvements on his basic rocket design [Applause] dr. Goddard's ideas were in many ways like theoretical scientist and mathematician dadar more than anything wanted to build a rocket that worked he was like Thomas Edison or the Wright brothers part scientist part engineer part inventor how did Goddard's rockets work if you opened up one end you would see a maze of wires and gadgets but they were really five basic parts there were two tanks one for liquid oxygen and gasoline was poured into another there was a pump to get the two fuel elements into the combustion chamber there was the combustion chamber itself where the fuel burned finally there is a narrowed exhaust nozzle at the face of the rocket this was where the superheated gases rushed out giving the rocket its upward movement even today's mighty Saturn moon rocket has these five basic elements Goddard felt he had just begun his work he was the kind of scientist who sets out to build a machine builds it and then spends his life making it bigger better and more efficient dr. Goddard launched the first rocket to fly faster than sound he added small fins behind the exhaust nozzle their movement corrected the path of the rocket if it seemed to be going off course his methods look primitive but his rockets were astonishingly advanced [Music] in America very few people were interested in Germany however many people wanted to build a space rocket they got their first inspiration from the work of a very brilliant man Hermann Oberth Oberth like veal koffsky made designs for rockets but both men were more interested in exploring space in over its designs for a space capsule the passengers would lie down to withstand the acceleration at launch just as the astronauts must when the Apollo is launched [Music] he knew that the crew would be weightless when the capsule was coasting and designed special hooks for them to hold while they work [Music] is designed for a space suit included a backpack of oxygen and also books and claws so his imaginary astronaut wouldn't float off into space from the laws of physics he knew the capsule itself would move when the crew moved inside he designed large lightweight space stations spinning to produce artificial gravity in some of his designs huge gyroscopes control the position of the space station he even dreamed of interplanetary space ships people mistook his diagrams for blueprints and complained he hadn't given detailed measurements but Oberth was not trying to make finish designs he was illustrating ideas he was interested in possibilities and theories he explained one important idea that many people didn't understand a rocket can go faster than the speed of the exhaust stream coming out the exhaust nozzle this is what happens a rocket goes steadily faster as it burns up its fuel now the exhaust gases are leaving the rocket always at the same speed compared to the rocket but the rocket is accelerating because it's steadily being pushed at the same time as it uses up its fuel it gets lighter and that makes it go faster still how fast will the rocket be going when it finally runs out of fuel well that depends on how much the empty weight is compared with the weight fully loaded the more fuel you can get into a rocket compared to its empty weight the faster we'll go all rockets like this modern one are really just flying fuel tanks if you could somehow keep a rocket engine burning indefinitely then it would go on getting faster and faster actually there's no theoretical limits to the speed of a rocket except the speed of light as far as we know that's the absolute top speed of anything in the universe dr. Oberth also explained what happens to Iraq it when its engines finally stop now many people believed it would simply turn over and come back to earth but actually that's not what happens at all a modern rocket is going so fast when its engines finally stop that it keeps on coasting up until gravity slows it down stops it and brings it back to earth if it has another engine to fire to make it go still faster then it will go still higher before it stops and comes back how high the rocket goes depends upon how fast it's going when its engines stop if it's going for example 10,000 miles per hour then it will go up another 700 miles before gravity stops it 700 miles above the point where its engine stopped Oberth explained this with mathematic equations people were fascinated by his ideas and wanted to try to build the rocket that he had written about in 1927 a group of these people got together to form a club known as the German rocket society the society members wanted to build liquid-fueled rockets they didn't know that Goddard had launched one the year before [Music] but they were successfully launching many solid fuel Rockets and we're trying to use them in practical ways one group built a postal rocket they hope they could speed mail delivery like Goddard they needed money for research some came from a few wealthy men interested in the idea of rockets and space travel industry donated spare parts like sheet metal and copper tubing their rockets were small but they dreamed of one day building a true space rocket they experimented with several rocket designs such as this one with wings that snapped out when the fuel is used up and they hoped it would glide like an airplane and all this time rocket societies were forming in many other countries [Music] people tried to use rocket motors to drive other vehicles student with some very interesting [Music] [Applause] [Music] [Applause] [Music] [Applause] [Music] [Applause] [Music] [Music] there was even a rocket torpedo that skips across the water most of these experiments were trial and error but young men were gaining experience like the student Wernher von Braun later in 1939 the rocket went to war dr. von Braun was leading the biggest experimental rocket program yet for the German army this group based their research on the principles worked out by Ziolkowski Goddard and Oberth and added a new element coordinated team effort they built several types of rockets tested the engine [Music] [Applause] observe the results rebuilt the rockets and tested them again for the first time a rocket research program had enough men material and support as they learn more they build bigger and more efficient rockets these were the giants of their day inside they looked a lot like a Goddard rocket but this one had an engine that produced 56 thousand pounds of thrust it weighed 14 tons and stood 46 feet tall von Braun and his colleagues had developed a rocket that could go at two thousand five hundred and fifty miles per hour more than three times the speed of sound it could travel about 200 miles it was steered by its own internal guidance this was the v2 the world's first true guided missile for months that blasted British cities it didn't change the outcome of the Second World War but no one would ever think of the rocket is a toy again after the war dr. von Braun and a group of German rocket experts came to white sands with 300 boxcars of V 2 parts white sands a strip of the New Mexico desert became the new center of American rocket testing we were impressed by how complex the v2 was of what it could do we studied its parts the basic elements were familiar but the details were new [Music] we reassemble the v2 part by part [Music] we used its parts and other research rockets and what we learned we applied to rockets of our own we tested new designs checked out different fuel combinations [Music] we learned to control rockets from the ground as we were sending more and more into the air to follow our rockets in flight we designed new tracking stations develop new radar techniques all this time the Rockets themselves were growing bigger in the 1950s there was a large military rocket program we were building the Rockets that would one day start our space program these would lift our first satellites and then our first men into space they were named after the great and terrifying figures of mythology there was Thor god of thunder taken the giant god of Greek mythology Atlas who held the heavens on your shoulders some of the features of these new Giants would be familiar to the early pioneers most of these big rockets are propelled by a mixture of liquid oxygen and kerosene fed from separate tanks the engines swivel for guidance control the walls of this rocket are paper thin metal stiffened by pressure inside their descendant is the mighty Saturn the moon rocket that the early rocket pioneers had dreamed about this is our biggest rocket engine today this is the f1 engine this engine and four others like it power the first stage of the Saturn five each engine weighs 22,000 pounds and each has a thrust of a million and a half pounds as we've seen this engine is the product of 70 years of pioneering effort zo coughs keys dreams and formulas helped lead the way to similar mighty engines in the Soviet Union oberth's vision the dedicated engineering of Goddard the brilliant leadership of Verner von Braun they're all part of the f1 we're now in a new era of space science the day of the individual scientists working away at his private dream are in the past modern space science is a team effort it has to be to keep the whole mighty operation going it has to be to cover all the complicated steps in testing a modern rocket launching a satellite and getting a man into space [Music] [Applause] [Applause] [Music] [Applause] [Music] [Applause] [Music] you [Applause] [Music] [Applause] [Applause] [Music]