ROCKETS

1. ROCKETS

2. CARLOS MACIEL PRINCIPAL OF TECHNOLOGY JANUARY 2006

3. TABLE OF CONTENTS PRACTICE ROCKETRY INTRODUCTION MODERN USES HISTORY NASA LAUNCHES TIMELINE POSITIVES & NEGATIVE PRINCIPAL CONCLUSION INDEX HOW ROCKETS WORK SCIENTIFIC METHOD GLOSSARY NATURE OF SCIENCE RESOURCES PROBLEM SOLVING

4. INTRODUCTION TO ROCKETS • The evolution of the rocket has made it an indispensable tool in the exploration of space. For centuries, rockets have provided ceremonial and warfare uses starting with the ancient Chinese, the first to create rockets. The rocket apparently made its debut on the pages of history as a fire arrow used by the Chin Tartars in 1232 AD for fighting off a Mongol assault on Kai-feng-fu. The lineage to the immensely larger rockets now used as space launch vehicles is unmistakable. But for centuries rockets were in the main rather small, and their use was confined principally to weaponry, the projection of lifelines in sea rescue, signaling, and fireworks displays. Not until the 20th century did a clear understanding of the principles of rockets emerge, and only then did the technology of large rockets begin to evolve. Thus, as far as spaceflight and space science are concerned, the story of rockets up to the beginning of the 20th century was largely prologue.

5. INTRODUCTION TO ROCKETS 2 All through the 13th to the 18th Century there were reports of many rocket experiments. For example, Joanes de Fontana of Italy designed a surface-running rocket-powered torpedo for setting enemy ships on fire. In 1650, a Polish artillery expert, Kazimierz Siemienowicz, published a series of drawings for a staged rocket. In 1696, Robert Anderson, an Englishman, published a two-part treatise on how to make rocket molds, prepare the propellants, and perform the calculations.

6. HISTORICAL ACCOUNT The evolution of the rocket has made it an indispensable tool in the exploration of space. For centuries, rockets have provided ceremonial and warfare uses starting with the ancient Chinese, the first to create rockets. • ©The History of Rockets

7. HISTORICAL ACCOUNT 2 The rocket apparently made its debut on the pages of history as a fire arrow used by the Chin Tartars in 1232 AD for fighting off a Mongol assault on Kai-feng-fu. The lineage to the immensely larger rockets now used as space launch vehicles is unmistakable. But for centuries rockets were in the main rather small, and their use was confined principally to weaponry, the projection of lifelines in sea rescue, signaling, and fireworks displays. Not until the 20th century did a clear understanding of the principles of rockets emerge, and only then did the technology of large rockets begin to evolve. Thus, as far as spaceflight and space science are concerned, the story of rockets up to the beginning of the 20th century was largely prologue. ©The History of Rockets

8. ROCKETRY TIMELINE Congreve Rockets 19th Chinese Fired Arrows 13th century Step Rocket 16th century Invention of Gunpowder 1st 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 century 1900 Liquid Propellant Rockets - 1926 2000+ V2 Rocket - 1944 X ROCKETS- 20?? Jupiter C Launch of Explorer 1 - 1958 Delta Clippers- 1995 Pegasus - 1900 Mercury Redstone - 1961 Delta, Scout - 1960 Atlas - 1963 Apollo Saturn 1b - 1968 Space Shuttle - 1981 Skylab Saturn v - 1973 Apollo Saturn v - 1968 Gemini Titan - 1965

9. PRINCIPLE • Rockets have a built-in guidance and control system so they are capable of determining their own position and attitude, but once a satellite has separated, its position and attitude are controlled from terrestrial or solar sensors so it is not possible to release a satellite from a rocket during night time of the Earth. • Launch times are dependent on factors such as the season and orbital insertion, and require delicate calculations, leaving only some 30 minutes to two hours during a day when launch conditions are ideal

10. HOW ROCKETS WORK • A rocket engine is generally throwing mass in the form of a high-pressure gas. The engine throws the mass of gas out in one direction in order to get a reaction in the opposite direction. The mass comes from the fuel that the rocket engine burns. • The power of a rocket engine is called its thrust. Thrust is measured in "pounds of thrust". A pound of thrust is the amount of power it would take to keep a 1-pound object stationary against the force of gravity on Earth. So on Earth, the acceleration of gravity is 32 feet per second per second (21 mph per second).

11. SCIENTIFIC PROCESS • The evolution of the space science program furnished a good example of the scientific process in operation. Out of advancing technology came rockets and spacecraft which, even before they were developed, were envisioned as powerful scientific tools. As soon as large enough rockets were available, they were put to work in high-altitude research. When the space program was formally established, researchers working on problems of the atmosphere and space naturally gravitated to the new tools. The phrase space science came to mean scientific research made possible or significantly aided by rockets and spacecraft.

12. NATURE OF SCIENCE • In order for a satellite to go into orbit it must accomplish two major tasks. First, the satellite must rise above the atmosphere which surrounds the Earth's surface. The atmosphere contains enough particles which slow the spacecraft preventing it from orbiting the planet. • A propulsion device must strain against gravity to rise above the atmosphere. Second, the satellite must also be provided with enough horizontal velocity above the atmosphere to at least equal the local circular speed upon orbital injection otherwise it will reenter the atmosphere and burn due to friction. Both of these jobs are done by rockets

13. PROBLEM SOLVING • In the early days of rocketry many aircraft features were adapted to the new vehicles. Dr. Robert Goddard placed vanes, similar to the tail surfaces of an airplane, on the nozzle section of his early rockets. • Turning these one way or the other deflected a portion of the exhaust gases, pushing the rocket’s tail in the opposite direction

14. PROBLEM SOLVING 2 • The mere presence of the vanes, however, reduces the efficiency of the rocket. Whatever amount of downward thrust pushes against the vanes cancels out an equal amount of the thrust’s upward push inside the rocket. • The solution developed for large rockets and space boosters was to “gimbal” the nozzle. A gimbal is a pivot device that allows the entire nozzle, and the flow of exhaust gases, to be swiveled in any desired direction. This is how the rocket’s course in the opposite direction is controlled. • Rockets can be guided by radio signals from the ground or by equipment and prerecorded instructions placed on board

15. PROCESS Rockets have a built-in guidance and control system so they are capable of determining their own position and attitude, but once a satellite has separated, its position and attitude are controlled from terrestrial or solar sensors so it is not possible to release a satellite from a rocket during night time of the Earth.Launch times are dependent on factors such as the season and orbital insertion, and require delicate calculations, leaving only some 30 minutes to two hours during a day when launch conditions are ideal. If these times are missed, there is no other option but to cancel a launch during that day. For example, the H-II Launch Vehicle No. 4 launched in Octobr 1996 started its countdown three days before the actual take-off, and work allocated for each day was steadily carried out. The final countdown started seven minutes before the lift-off.

16. PROCESS 2 Six seconds before take-off, the first-stage of rocket ignites. As the rocket takes off, its solid rocket boosters (SRB-A) ignite. With a roaring sound, immediately after the rocket's full propulsion comes into operation, the rocket separates from its launch tower.At 105 seconds, the SRB-A separates after having burned for 100 seconds. At 220 seconds, the satellite faring separates. The first-stage of rocket stops firing after 389 seconds and at 399 seconds separates. At 405 seconds, the second-stage fires for the first time, and at 1,421 seconds, for the second time. At 1,664 seconds, the satellite separates, and is inserted into a geostationary transfer orbit.

17. PRACTICAL ROCKETRY • The first rockets ever built, the fire-arrows of the Chinese, were not very reliable. Many just exploded on launching. Others flew on erratic courses and landed in the wrong place. Being a rocketeer in the days of the fire-arrows must have been an exciting, but also a highly dangerous activity. • Today, rockets are much more reliable. They fly on precise courses and are capable of going fast enough to escape the gravitational pull of Earth. Modern rockets are also more efficient today because we have an understanding of the scientific principles behind rocketry. Our understanding has led us to develop a wide variety of advanced rocket hardware and devise new propellants that can be used for longer trips and more powerful takeoffs http://www.allstar.fiu.edu/aerojava/rocket2.htm

18. MODERN USES • In 1898, a Russian schoolteacher, Konstantin Tsiolkovsky (1857-1935), proposed the idea of space exploration by rocket. In a report he published in 1903, Tsiolkovsky suggested the use of liquid propellants for rockets in order to achieve greater range. Tsiolkovsky stated that the speed and range of a rocket were limited only by the exhaust velocity of escaping gases. For his ideas, careful research, and great vision, Tsiolkovsky has been called the father of modern astronautics.

19. MODERN USES 2 Early in the 20th century, an American, Robert H. Goddard (1882-1945), conducted practical experiments in rocketry. He had become interested in a way of achieving higher altitudes than were possible for lighter-than-air balloons. He published a pamphlet in 1919 entitled A Method of Reaching Extreme Altitudes. It was a mathematical analysis of what is today called the meteorological sounding rocket.

20. NASA LAUNCHES • Many of NASA's most famous missions -- from those observing Earth such as EOS, Aura and Landsat, to interplanetary and deep space missions like the Mars Exploration Rovers and Deep Space 1 -- are launched on Expendable Launch Vehicles (ELVs). These missions are unpiloted and can accommodate all types of orbit inclinations and attitudes

21. GRAPH

22. NEGATIVE ASPECT • Pollutes the air, the water an earth . • Its dangerous, its expensive and you can die. • You can get left in the galaxy for ever.

23. POSITIVE ASPECT • They got the power to get through the atmosphere, it lets us go explore other planets. • If we didn’t have rockets we could not find out what goes on in the atmosphere .

24. CONCLUDING THOUGHTS • I think rockets are cool, because I learned good things about them. • I learned that if they id not made them we would not known every thing we know about those other planets

25. INDEX • acceleration • gimbal • astronautics • interplanetary • deflected • meteorological • determining • propellants • determining • satellite • exploration • significantly • geostationary • technology • gravitational • warfare uses