Science of Flight The Aerospace Environment Model Rocketry

Science of Flight The Aerospace Environment Model Rocketry 1

Model Rocketry • Goals: – Understand how a rocket works – To demonstrate Newton’s Laws of Motion by launching model rockets • Purpose: Apply aerodynamic and aerospace propulsion concepts in practical application • How: Building and launching Alpha Model Rocket Kits 2

Grading Criteria • To receive the Rocketry Badge you must: – 1. Pass the written safety test – 2. Correctly build the Alpha Model Rocket Kit according to the written instructions provided – 3. Successfully launch and recover your rocket at least twice – 4. Correctly determine altitude of rocket at apogee within 10 feet using altitude tracker and table of tangents 3

Rocket Science What do we use rockets for? • Rockets and Launch vehicles – Get spacecraft into space – Move them around after they get there – Change their attitude (the direction they’re pointing) Rocket Functions 4

How a Rocket Works • A rocket is a system that takes mass plus energy and converts them into a force to move a vehicle. – The mass a rocket uses is up usually is called propellant. – The force a rocket produces is called thrust. The Simplest Version of a Rocket System

Thrust • Thrust is the force a rocket produces. – A rocket ejects mass at high speed in one direction so a vehicle can go in the other.

Thrust (cont’d) • The simplest example of this is a balloon. – Blow up a toy balloon and let go the stem to watch it fly wildly around the room. What makes the balloon go? – When you blow into a balloon, you force air into it, making the rubber skin tighten, increasing the internal air pressure, and storing energy like a spring. – When you let go of the stem, the air pressure has an escape route, so the skin releases, forcing the air out under pressure. An Inflatable Rocket

Newton’s First Law • First Law: (Law of Inertia) A body at rest tends to remain at rest and a body in motion tends to remain in motion, unless an outside force acts on the body – such as gravity 8

Newton’s Second Law • Second Law: The acceleration of a body is directly proportional to the force exerted on the body, and is in the same direction as the force • In other words: Force = Mass x Acceleration 9

Newton’s Third Law • Third Law: Whenever one body exerts a force upon a second body, the second exerts an equal and opposite force upon the first body In other words: For every action there is an opposite and equal reaction 10

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Model Rocket Parts 13

Model Rocket Pre-Flight 14

Model Rocket Launch Safety 15

1. Tracker 1 2. Tracker 2 3. Range Safety Officer 4. Data Recording Table 5. Preparation Table 6. Recovery Team 7. Launch Control Officer 8. National or Club Flag 9. Range-In-Operation Pennant (optional) 10. Student-Observers 11. Parking Area (optional) 12. Launching Pad

Model Rocket Engine Performance 17

Model Rocket Engine Specifications 18

Model Rocket Propulsion Parts • Controller: provides electrical current to ignite propellant • Engine: A 8 -3, B 6 -4 • Igniter: provides electrical current to rocket motor • Plug: holds igniter in place 19

Safety Code 1. 2. 3. 4. Launch Site - launch model rockets outdoors in a cleared area, free of tall trees, power lines, building and dry brush and grass. Launch site will be at recommended size for applicable engine. Launcher - launch model rocket from a stable launch device that provides rigid guidance until the model rocket has reached a speed adequate to ensure a safe flight path. To prevent accidental eye injury, always place the launcher so the end of the rod is above eye level or cap the end of the rod when approaching it. Cap or disassemble launch rod when not in use, never store it in an upright position. If cap is lost an empty plastic soda bottle will be placed over rod whenever not in use. Launcher - will have a jet deflector device to prevent the engine exhaust from hitting the ground directly. Always clear the area around launch device of brown grass, dry weeds, or other easy-to-burn materials

Safety Code 5. 6. 7. 8. 9. 10. Ignition System - The system will be remotely controlled, electrically operated and will contain a launching switch that will return to off when released. The system will contain removable safety interlock in series with the launch switch. All persons will remain at least 15 feet (5 meters) from the model rocket. Launch Safety - Ensure that people in the launch area are aware of the pending model rocket launch and can see the model rocket’s liftoff before beginning an audible five-second countdown. If rocket suffers a misfire, do not approach it or the launcher until the safety interlock has been removed or that the battery has been disconnected from the ignition system. Wait one minute after a misfire before approaching the launcher. Flying Conditions - Launch rockets only when the wind is less than 20 miles (30 kilometers) an hour. Do not launch rockets into clouds, near aircraft in flight, or in a manner that is hazardous to people or property. Launching Angle - Launch device will be pointed within 30 degrees of vertical. Recovery Hazards - If a model rocket becomes entangled in a power line or other dangerous place, do not attempt to retrieve it. Follow instructions!