The Gravitational Slingshot Essay

Have you ever wanted to soar? Fly? Glide through the skies of the earth or even the great unknown called the universe? Well thanks to todays’ technology and the company founded on July 29 1958, NASA (National Advisory Committee for Aeronautics), we can now undertake that dream; you can finally take to the air.

When the Germans showed the world that reaching the stars was not a far-fetched idea, it was possible to do an unbelievable feat of science and engineering. Although the German rocket project was terminated, they had started the basis of modern day rocketry. The dream was growing to enormous proportions. Various nations were interested in this technology, especially the U.S.S.R. and later the United States of America (Snedden 9).

Johannes Kepler (1571-1630) was a German astronomer who believed in the heliocentric theory. Kepler is a clear example of the narrow line that separated science and religion. Nonetheless, his ideas would show that things could be solved through reason alone. He believed that the harmony of the human soul could be found through numerical relationships that existed between planets. He found that the planets: Mercury, Venus, Earth, Mars, Uranus, Jupiter, and Saturn all revolved at different times. For example, the earth revolved around the sun in a year while Saturn revolved around the sun in fifty years. From this, Kepler found a mathematical ratio, nine to the two-thirds power, to explain this phenomenon. This was revolutionary to humanity’s place in the universe. People were shocked that the universe could be explained by math alone rather than religion. This went strongly

Among these people were Copernicus who believed the sun was at the center of the world and the earth, stars and planets revolved around it. Danish astronomer Brahe helped contribute to this idea by contributing a large mass of data about the universe that he was able to discover. His student Kepler kept his ideas going, as he formulated many laws of planetary motion. He said the orbits around the sun were elliptical, planets don’t move in a uniform speed and the time a planet completes its orbit is related to its distance from the sun. Meanwhile, Florentine Galileo decided to use experiments to find out what happened and not what should happen, and discovered that a uniform force makes a uniform acceleration as well as inertia laws, that an object will be in motion forever unless stopped by another force.

the heliocentric solar system. Johannes Kepler further modified the heliocentric system, by mathematically showing that the planets’ orbits are elliptical. With his invention of the telescope, Galileo made new observations about the solar system and found mathematical laws that described the movement of the planets. Later, Isaac Newton established a universal law of gravity. With the new scientific discoveries, the gap between religion and science increased. Science revolutionized the human though and its understanding of the universe.

The Law of ellipses, which means that each planet travels around the sun in an ellipses.

Johannes Kepler was a man who made a surplus of achievements and discovery. What he is most known for is discovering that planets don’t go in a circular motion around the

In this time period the Greeks emperors believed and paid lot of money to have astronomers make new discoveries of the planets and stars. Astronomy was a big mixture of knowing how the planets worked and mathematics. As more and more theories began coming to picture, each of them were built off of eachother. These theories also allowed inventions to come to life, some that we even use still today such as the telescope. Even though these theories and inventions are old, they have influenced today's technologies and space science. Just how Newton's theory of gravity was influenced on other great greek astronomers and their studies.

Before Newton talked about gravitation the main knowledge of scientists was a elementary knowledge of optics, mechanics and astronomy.Copernicus Kepler and Galileo provided the background knowledge of the stars and planets, but Newton used their data to discover the whole gravitational system.10Newton reasoned that the planets and all other physical objects in the universe moved through mutual attraction of gravity.Newton said that every other object in the universe affected every other object through gravity.This explained why the planets move in an orderly fashion. Newton found that “the force of gravity towards the whole planet did arise from and was compounded of the forces of gravity towards all it’s parts, and towards every one part was in the inverse proportion of the squares of the distances from this part.”Newton proves all of this mathematically. This was known to be the single most important contribution to physics that ever has been made.11

Johannes Kepler had several theories and laws, including some that shape our world today, including his 3 laws which are, the path of the planets about the sun is elliptical in shape, with the center of the sun being located at one focus, which is called The Law of Ellipses. An imaginary line drawn from the center of the sun to the center of the planet will sweep out equal areas in equal intervals of time, this law was named The Law of Equal Areas. Finally, his third law stated that the ratio of the squares or rectangles of the periods of any two planets would be equal to the ratio of the cubes of their average distances from the sun (The Law of Harmonies). Several people and companies indeed did like his laws, including NASA, Johannes Kepler and NASA where close with their work and so close, NASA even named a mission (the K2 mission) and spacecraft (The Kepler spacecraft) after

Robert H. Goddard, the American scientist who built the first liquid-fueled rocket—which he successfully launched on March 16, 1926—became fascinated with spaceflight after reading an 1898 newspaper serialization of H.G. Wells’ classic novel about a Martian invasion, War of the Worlds. As Goddard would recall later, the concept of interplanetary flight “gripped my imagination tremendously.”

When Kepler first began his work on the orbit of Mars he was under the assumption, as many scientists were, that the planetary orbits were circular, and that the Sun was at the center of the orbits. This type of system is called a heliocentric system. Also at this time only six planets were known. When Kepler obtained Brahe's data he discovered that the orbits were not perfect circles, but instead were ellipses that were only slightly flattened. The reason nobody else realized this was because the orbits were so slightly elliptical that extensive investigation and data would be needed to show this. It also turned out that the reason the orbit of Mars was very difficult to understand was because its orbit was more eccentric than the other planets that Kepler and Brahe had data about. To understand a lot of Kepler's work you must first

gravitational pull and all of the asteroids in it revolve around the Sun. Although the majority of

Johannes Kepler was a German astronomer and mathematician who lived between 1671-1630. Kepler was a Copernican and initially believed that planets should follow perfectly circular orbits (“Johan Kepler” 1). During this time period, Ptolemy’s geocentric theory of the solar system was accepted. Ptolemy’s theory stated that Earth is at the center of the universe and stationary; closest to Earth is the Moon, and beyond it, expanding towards the outside, are Mercury, Venus, and the Sun in a straight line, followed by Mars, Jupiter, Saturn, and the “fixed stars”. The Ptolemaic system explained the numerous observed motions of the planets as having small spherical orbits called epicycles (“Astronomy” 2). Kepler is best known for introducing three

After Tycho’s death, his assistant, young mathematician Johannes Kepler used Tycho’s observations and came up with his First Law that orbits of the planets are elliptical instead of round like Copernicus believed. With his Second Law, Kepler stated that the speed of the planets depends on their distance from the sun which helped English astronomer and physicist Isaac Newton, to come up with his Law of Universal Gravitation.