Rockets Educators' Guide pdf - ER - NASA

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Applying Newton’s Laws The next step in becoming a rocket scientist is to apply rocket science and mathematics to the design and construction of actual rockets. There are many tricks of the trade for maximizing thrust and reducing rocket mass. Each of these tricks is an application of one or more of Newton’s laws. Although there are many different kinds of rockets, the same laws apply to all. <strong>Rockets</strong> are generally classified as either solid or liquid. They produce thrust by burning propellants and expelling the combustion products out of the engine. Propellants are simply a combination of fuel and oxidizer. The oxidizer for solid propellants is a chemical containing oxygen. For example, gunpowder, used in the engines of model rockets, contains potassium nitrate (KNO 3 ). Potassium nitrate provides the oxygen needed for the other gunpowder chemicals to burn rapidly. The oxidizer for liquid rockets is usually pure oxygen chilled to 90 K (-183 o C or -297.3 o F) so that it condenses into liquid oxygen (LOX). The propellants for rockets are held in tanks or within cases. This is both an advantage and a disadvantage. Because they carry their propellants (oxygen onboard), rockets can work in space. No other presently available vehicle can do that. A jet engine cannot function in space because it is an “air-breather.” Although jets and rockets both employ Newton’s law of action and reaction, the jet needs to draw in air from the atmosphere to burn its fuel. This limits the altitude of a jet plane. Solid Propellant <strong>Rockets</strong> The first true rockets, “fire arrows” invented by the Chinese, employed solid propellants. An early form of gunpowder was packed into a cylinder closed off at one end. On the other end was an opening. When the gunpowder was ignited, it burned very quickly and created great quantities of gas and other combustion products that rushed out of the hole. This produced thrust. Flight control was accomplished by attaching a long stick to the rocket to create drag as the rocket sailed 24
Four-stage, solid propellant Scout rocket. through the air. This wasn’t a very accurate system, but the rocket usually flew in the intended direction. More than 1,000 years later, solid propellant rockets are not appreciably different from the Chinese fire arrows. The solid rocket boosters (SRBs) for the space shuttle are very large tubes packed with propellants that are closed off at one end and have a hole at the other. The SRBs do have many other sophisticated innovations, but, in principle, they are no different from their primitive ancestors. Solid propellant rockets have a simple design. They consist of a case or tube in which the propellants are packed. Early rockets used cases made of paper, leather, and iron. Modern rockets use a thin and lightweight metal such as aluminum. Making the case from thin metal reduces the overall weight of the structure and increases flight performance. However, the heat from the burning propellants could easily melt through the metal. To prevent this, the inner walls of the case have to be insulated. The upper end of the rocket is closed off and capped with a payload section or recovery parachutes. The lower end of the rocket is constricted with a narrow opening called the throat, above a larger cone-shaped structure, called the nozzle. By constricting the opening, the throat causes the combustion products to accelerate greatly as they race to the outside (second law). The nozzle aims the exhaust straight downward so that the rocket travels straight upward (third law). To appreciate how the throat of the rocket accelerates the combustion products, turn on the water for a garden hose. Open the nozzle to the widest setting. Water slowly flows out. Next, reduce the opening of the nozzle. Water quickly shoots out in a long stream (second law) and the hose pushes back on you (third law). The propellant in solid rockets is packed inside the insulated case. It can be packed as a solid mass or it may have a hollow core. When packed as a solid mass, the propellant burns from the lower end to the upper end. Depending upon the size of the rocket, this could take a while. With a hollow core, the propellants burn much more rapidly because the entire face of the core is ignited at one time. Case Core Flight Control Nozzle Payload Igniter Propellant Throat Solid propellant rocket. End-burning and hollow core rockets. 25
Page 1 and 2: National Aeronautics and Space Admi
Page 3 and 4: National Aeronautics and Space Admi
Page 5 and 6: Dear Educators: NASA has embarked o
Page 7 and 8: A Pictorial History of Rockets The
Page 9 and 10: Wan Hu, Sixteenth Century According
Page 11 and 12: Robert H. Goddard, 1882 to 1945 Ame
Page 13 and 14: X-15 Between 1959 and 1968, the X-1
Page 15 and 16: “One Small Step...” At 10:56 p.
Page 17 and 18: The Space Shuttle and International
Page 19 and 20: What Comes Next An entire generatio
Page 21 and 22: .On top of the second stage will be
Page 23 and 24: The EDS propels Orion and the Altai
Page 25 and 26: How Rockets Work Whether flying a s
Page 27 and 28: Balanced Force Unbalanced Force the
Page 29: A Taste of Real Rocket Science Natu
Page 33 and 34: module and the ascent stage of the
Page 35 and 36: propellant accounts for 91% of its
Page 37 and 38: National Curriculum Standards The r
Page 39 and 40: Suggested Grade Levels The matrix b
Page 41 and 42: Tip Ask students to bring undented
Page 43 and 44: Assessment • Ask teams to state t
Page 45 and 46: Pop Can Hero Engine Design and buil
Page 47 and 48: endezvousing with the International
Page 49 and 50: Procedure Second Activity 1. Give s
Page 51 and 52: Fold 1 Fold 1 Fold 1 Fold 1 Fold 2
Page 53 and 54: Explain how the straw is used for g
Page 55 and 56: Assessment • Have each team descr
Page 57 and 58: Rocket Activity Newton Car Objectiv
Page 59 and 60: Procedure The Experiment 1. Provide
Page 61 and 62: Test 1 Newton Car Experiment Report
Page 63 and 64: for trimming. It is much easier to
Page 65 and 66: How to Build a Rocket Racer 1. Lay
Page 67 and 68: Name: __________________ TOP VIEW R
Page 69 and 70: Pop! Rocket Activity Pop! Rocket La
Page 71 and 72: the launch tube in the desired dire
Page 73 and 74: The basic pattern is found on page
Page 75 and 76: 6. Fold the triangles inward to for
Page 77 and 78: One-Piece Pop! Rocket Cut on solid
Page 79 and 80: page for details. Before conducting
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90 Cut slots the same width as the
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Cut four slits 8 cm long. 1 Build a
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Rocket Range Experiment Team Member
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tracker and consistent in measuring
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Water Level Marking Diagram 50 60 7
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Altitude Tracking Data Sheet Tracke
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High-Power Air Rocket Launcher Asse
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emoving cemented pieces will damage
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Rocket Activity High-Power Paper Ro
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Assessment • Review student missi
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Air Rocket Mission Report Test Flig
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Rocket Activity Rocket Wind Tunnel
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Constructing the Wind Tunnel: 1. Us
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Wind Tunnel Data Sheet Name: ______
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Rocket Activity Advanced High- Powe
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the fold line as the leading or upp
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Rocket Scientist Names: Mission Pro
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Rocket Activity Water Rocket Launch
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of each plate serve as fulcrums. Th
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1 - Wooden Base (Circle 16” diame
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Management Begin collecting 2-liter
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9. When the rockets have been compl
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They will then have to test the roc
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Request for Proposal The United Spa
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Project X-51 Checklist Project Grad
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State of: Certificate of Assumed Na
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Company Name: Project X-51 Purchase
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Keep this stub for your records Che
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Rocket Measurements for Scale Drawi
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Rocket Stability Determination (Swi
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Project X-51 Company Name: Pre-Laun
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Project X-51 Score Sheet Total Scor
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Print this page on the back of the
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How High? Using Mathematics to Esti
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A rough estimate of rocket altitude
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However improbable and dopey some o
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Students should first decide where
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NASA Resources The National Aeronau
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ROCKETS Educator’s Guide with Act
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