NASA - National Aeronautics and Space Administration

Event Focus Your class is doing a unit on the Space Program and you are assigned to make a report on rockets and how they work. What will you say? How will you describe what makes a rocket go up into space and go where it is pointed? Does it take a Rocket Scientist to explain rockets? Description

This module is appropriate for video conference AND web conference presentation.

Rocket Science draws on math and science principles to explain to students how rockets operate. Emphasis is placed on Newton's Laws of Motion and the forces on a rocket as well as such ideas as center of gravity, thrust, stability, and combustion, to demonstrate and explain how we put satellites and astronauts into space. Demonstrations of different kinds of rockets as well as models of NASA rockets will be used to help students understand the application of these principles.

RocketModeler, a computer simulation program that allows students to design and "fly" a variety of model rockets on their classroom or home computers, is demonstrated.

Presentations can be prepared in collaboration with the requesting teacher to re-enforce topics being taught in the classroom. Previous topics have included:

• Rocket parts and motion - four forces on a rocket
• Rocket stability and flight trajectory
• Rocket thrust - principles of combustion
• Gases - properties - equation of state - atmospheric models
• Forces on model rockets.
• Bottle rocket design and flight

Instructional Objectives

 

Engage	The learners will discuss where they have ever seen a rocket fly.
Explore	The learners will investigate the history of rocket development from the Chinese through the V-2.
Explain	The learners will discuss the application of Newton's three laws to motion of rockets.
Elaborate	The learners will apply these ideas to both solid and liquid fuels rockets and discuss their applications and limitations.
Evaluate	The learners will demonstrate their understanding of how rockets work by answering questions during a demonstration of either pump rockets or alcohol whoosh rockets.

Sequence of Events

Pre-Conference Activities Participants should become familiar with the RocketModeler simulation program and with the information available at the Beginner's Guide to Rockets and the specific group of web pages related to the requestor's chosen topic, as described in the Rocket Index and the Guided Tours of the Beginner's Guide. Grades 5-12: Complete the pre-conference assessment and activity created by Chris Marks and Brian Mears, University of Akron, Akron, Ohio. Click here to access the introduction and to link to the materials.

VOCABULARY

Center of Gravity: the single point within a body through which all gravitational forces act. All rockets will rotate about their center of gravity.

Center of Pressure: the single point within a body through which all aerodynamic forces act. Rockets are stable if the Center of Pressure is below the Center of Gravity.

Energy: the capacity to do work. Rockets require large amounts of energy to leave Earth's Gravity.

Fin: A fixed or movable airfoil used to stabilize a rocket in flight. Fins are generally placed near the bottom of the rocket to lower the Center of Pressure.

Force: a push or a pull. The rocket's mass is accelerated upward by the force of gases leaving the rocket nozzle.

Impulse: the product of the average force acting upon a body and the time during which it acts. Rockets generally have a large impulse.

Oxidizer: a substance, generally oxygen, which combines with a fuel to produce combustion. Rockets must carry oxidizers because there is no oxygen in space.

Newton's Third Law: For every action there is an equal and opposite reaction. This is how rockets generate force.

Nose: the forward end of the rocket, generally pointed in shape.

Nozzle: a projecting spout from which hot gases are discharged, producing thrust for the rocket.

Power: work done or energy transferred per unit of time. Rockets usually do a huge amount of work in a short time.

Propellant: a substance, usually a mixture of fuel and oxidizer, for propelling a rocket.

Rocket: any of various simple or complex tube like devices containing combustibles that on being ignited liberate gases whose action propels the tube through the air. Rockets are a good example of Newton's Third Law.

Stability: The ability of an object, such as a rocket, to maintain equilibrium or resume its original, upright position after displacement. Fins add stability to rockets.

Stage: a section of a rocket containing a rocket engine or engines that separates when its propellant is exhausted. Stages allow rockets to fly higher and faster.

Trajectory: the curved path described by a rocket in its flight.

Work: force times the distance through which it acts.

Videoconference Activities

In this event the presenter will focus on the key concepts of Newton's laws of motion as they apply to rockets, stability of rockets in flight, center of gravity and center of pressure, types of rocket engines, and weight versus strength considerations. He will begin with questions like "What causes a rocket to go up into the air?" and "How do rockets keep pointed in the right direction?". He will use diagrams, models, and demonstrations of alcohol "whoosh" rockets and air pump rockets to illustrate action and reaction, acceleration, center of gravity, and stability. Models of the Saturn V rocket and the SST will show how staging is used to get rockets into space. Misconceptions such as the idea that rockets push against the earth and that rockets need fins to be stable will be discussed.

Some key concepts that will be presented are that math predicts how a rocket will operate, rockets operate under Newton's Laws of Motion (especially the Third Law), rockets have either solid fuel or liquid fuel engines, solid engines cannot be turned off, hot gasses escaping the nozzle create the action that causes the rocket to move as a reaction, rockets must carry oxygen into space to burn fuel, center of gravity, and center of pressure.

Some of the questions that the presenter may ask are:

1. Why do rockets have fins? (they lower the center of pressure and add stability)

2. How do rocket engines work? (hot gases propel out the nozzle to move the rocket forward)

3. Why do rockets carry their own oxygen? (there is no oxygen in space to burn the fuel)

4. What is a force? (a push or a pull)

5. Why do you think rockets have streamlined shapes? (to help overcome drag when moving through the air)

6. What is the advantage of making a rocket in stages? (you don't have to lift empty fuel tanks into space)

7. How are the Space Shuttle and the Saturn V different? (the Shuttle only goes into low Earth orbit and is reusable)

Meet Tom Benson, creator and author of RocketModeler and The Beginner's Guide to Rockets.

Advanced consultation with the presenter is required in order to tailor the event to your specific needs.

Post-Conference Activities

Complete the grades 5-12 post-conference activity created by Chris Marks and Brian Mears, University of Akron, Akron, Ohio.

Standards

NSTA Science Content Standards: 5-8

PHYSICAL SCIENCE CONTENT STANDARD B

MOTIONS AND FORCES

• An object that is not being subjected to a force will continue to move at a constant speed and in a straight line. If more than one force acts on an object along a straight line, then the forces will reinforce or cancel one another, depending on their direction and magnitude. Unbalanced forces will cause changes in the speed or direction of an object's motion. The motion of a rocket is a balance of the forces of thrust, weight, and drag.

TRANSFER OF ENERGY

• Energy is a property of many substances and is associated with heat, light, electricity, mechanical motion, sound, nuclei, and the nature of a chemical. Energy is transferred in many ways. Rockets transfer chemical energy into heat energy.

NSTA Science Content Standards: 9-12

PHYSICAL SCIENCE CONTENT STANDARD B

MOTIONS AND FORCES

• Objects change their motion only when a net force is applied. Rockets move by exhausting hot gases. Laws of motion are used to calculate precisely the effects of forces on the motion of objects. The magnitude of the change in motion can be calculated using the relationship F = ma, which is independent of the nature of the force. Rockets have advanced due to improvements in engines to develop more thrust. Whenever one object exerts force on another, a force equal in magnitude and opposite in direction is exerted on the first object.This is how rockets get into the air and beyond.