Rocketry has done incredible good for the world; however, it has also been used for immoral reasons. The Chinese invented the first true rocket in A.D. 1232. Modern rocketry is used for discovering the vast outer space, for war, and entertainment. Rockets are able to fly by relying on Isaac Newton's laws three laws of motion. The third law is the most important for rockets. This law states that for every action there is an equal and opposite reaction. When the chemicals react within the rocket, they explode out of the solid rocket boosters forcing the rocket to lift off the earth and fly. Thousands of chemicals are used in the process of making these extremely strong projectiles. The cost of fuel to propel a rocket is huge, yet the amount used compared to cars in minute. There is little pollution from rockets because the kind of fuel that is used and how it is burned; nevertheless, scientists and engineers are working on ways to prevent more pollution. Rocketry has been a great tool for increasing knowledge of the rest of the universe and helpful to earth, yet the potential of its usage has not nearly been reached.
History of Rocketry
The idea of rocketry started around 400 B.C. Archytas of Tarentum invented a wooden bird that could fly short distances by using steam as its propellant. For centuries, there were many more attempts to create a device with the ability to fly as a rocket. Some inventors were successful to a degree, and others failed miserably. In 1232, the Chinese were the first to create a true rocket. They did this by injecting gunpowder made from sulfur, saltpeter, and charcoal dust into a bamboo chute and attached it to an arrow to be shot. These were first used in the Battle of Kai-Keng against the Mongols. Rocketry spread to Europe where the industry spread to not only warfare uses but also for entertainment. Once it had gone to Europe, experimentations began. Many advances happened and uses for rockets came and went. Finally, after centuries of work, rocketry became huge in the twentieth century.
Much experimentation went on and eventually a man named Wernher von Brahn directed the making of the first major liquid propelled rocket, the V-2, which was made from liquid oxygen and alcohol. On October 4, 1957, a satellite called Sputnik I was launched into space, and less than a month later, another satellite was launched with a dog named Laika on board who survived seven days in outer space. A few months following Sputnik I, America launched there own satellite called Explorer I to space and created a space program called National Aeronautics and Space Administration (NASA). The Soviets and Americans were in a constant battle for the next step in space-exploration. On April 12, 1961, the Soviets were the first to humanity in space by sending Yuri Gagarin in the Vostok I; however, America responded a few years later by sending Neil Armstrong in the Eagle where he landed on the moon on July 21, 1969. Rocketry has an incredible history, and the materials that are used in it are just as interesting.
Raw Materials to Propel a Rocket
There are hundreds of materials that are used to make a rocket fly. Basically, for it to fly, it needs a fuel and an oxidizer to mix. These react together causing huge amounts of energy to be burned. The reaction is set up for the burned propellant to flow out of the Solid Rocket Boosters (SRB), which apply Newton's third law to make it fly. There are many fuels that are used for a propellant.
Liquid hydrogen, kerosene, and ethanol are three main fuels that are used. Liquid hydrogen comes from its gaseous form that has been pressurized and cooled to an extremely low temperature. Liquid hydrogen has a duel purpose as a coolant for the engine and a fuel. Kerosene is another fuel, which is a liquid form of hydrocarbons. It is produced by fractional distillation of petroleum. Kerosene was used predominantly as a fuel in earlier rockets. A third main fuel is ethanol, which is also used in drinking alcohol. It is produced from the hydration of ethylene. For an alcohol to work in a propellant, it has to be completely pure as ethanol is. Basically, a bottle of Jack Daniels is not going to make a rocket fly. The fuel is then mixed with an oxidizer to start the chemical reaction.
A few kinds of oxidizers are liquid oxygen, nitric acid, and aniline. Liquid oxygen is great since its expansion ratio to its gaseous form is 860:1 (Harvard). It is produced by fractional distillation from oxygen in the air. A second oxidizer is nitric acid. It is produced from the mixture of nitrogen dioxide and water in the presence of oxygen or air. One other main oxidizer is aniline. It is made by a two-step process: 1) It is nitrated using a concentrated mixture of nitric acid and sulfuric acid to make nitrobenzene. 2) The nitrobenzene that was just made is hydrogenated, typically at 600C, while in the presence of a nickel catalyst. The rocket holds its fuel and oxidizer in separate containers it is ready to be launched, then they are mixed for a chemical reaction that makes it fly. Just as there are many fuels and oxidizers for propellants, there are many other chemicals used to produce a rocket.
Specific Chemicals Among Rockets
There are thousands of chemicals used in the industry of rockets. Four of them are methyl hydrazine, diisocyanate, iron (III) oxide, and dinitrogen tetroxide. Methyl hydrazine's molecular formula is CH6N2. It's density is 0.88 g/mL, it's melting point is -52C and boiling point is 87C. Methyl hydrazine has been found in an edible mushroom called Gyramitia Esculenta. The majority of it is used as a fuel in rocket propellant. Diisocyanate comes from a grouping of two isocyanates, which are made of one nitrogen, one carbon, and one oxygen. It reacts with polyols to form polyurethanes. The polyurethanes are used for insulation within a rocket. They are used are throughout the rocket, primarily in the nozzle to protect the shuttle from heat. Iron (III) oxide's chemical formula is Fe2O3. It's density is 5.24 g/mL and it's melting point is at 1565C. Iron (III) oxide, also known as ferric oxide, is used as a catalyst in solid rocket propellants. A last chemical associated with rockets is dinitrogen tetroxide. Its chemical formula is N2O3. It is produced by the catalytic oxidation of ammonia, NH3. Because there are many chemicals used, there are also many equations for converting raw materials into chemicals.
Dinitrogen tetroxide reacts with water to form a nitric acid. It's chemical equation is N2H4 + H2O HNO2 + HNO3. A common propellant is liquid hydrogen as a fuel and liquid oxygen as an oxidizer. When hydrogen and oxygen react, twice as many hydrogen are needed; therefore, the chemical equation for this propellant is 2 H2 + O2 2 H2O (Parks). One other equation comes from a solid rocket propellant containing ammonium perchlorate, aluminum powder, and iron (III) oxide. There are two steps of equations for this propellant: 1) Al10 + 6 NH4ClO4 4 Al2O3 + 2 AlCl3 + 12 H2O + 3 N2, 2) Fe2O3 + 2 Al Al2O3 + 2 Fe (captainsherlock.com). Once these two mixtures are put together, the only step needed to ignite it, is to add some source of heat.
Rockets provide science with amazing amounts of information on the universe, but they also can take away much that is precious to it. In just a few minutes, literally tons of fuel is burned to get the rocket out of earth's atmosphere. Rockets use a huge amount of energy getting the fuel into the external tank. There are turbo pumps that inject the fuel into the rocket at over 30,000 rpm. It sends about 150 lbs. of liquid hydrogen and about 900 lbs. of liquid oxygen per second (NASA). Rockets require tons of fuel and much electricity to run; however, the amount is small compared to the amount used by cars and airplanes. The pollution from rockets depends on the kind of propellant being used. One that contains liquid oxygen and liquid hydrogen will not harm the atmosphere since it is like burning water. There are some liquid fuels that cause pollution but a lot of it comes from solid-fuel propellants. Some can produce hydrogen chloride, along with other toxic chemicals when ignited (Barry). The majority of uses in rocketry will not pollute the earth, although there are times when it will. From all of the information there is to know about this incredible industry, it is not an easy job for scientists and engineers.
Career and Education in Rocketry
Within the rocket industry, there are many positions to have, thus there are many fields of education to learn. Some fields of study that are used are engineering, biology, physics, chemistry, and mathematics. An article from NASA states that, to go into rocketry, an early preparation, good SAT/ACT scores, and internships are very helpful (Bray). With all of the fields of education for rocketry, there are many positions for careers. A few of these are engineers, chemists, and astronauts. Rocketry is a wonderful industry filled with so much knowledge and so much to learn, but it requires a great amount of time and effort to have a career in it.
Barry, Patrick L. Candlestick Rocket Ship. Ed. Tony Phillips
Bray, Becky, John Jaap, and Patrick Meyer.
Park, John L.
Wessling, Francis, and Samuel McManus.