Rocketry Basics

created for 5th grade science classroom

1. Rocketry Basics
A Basic Introduction to
Rocketry

2. What is a rocket?
•A rocket in its simplest form is just a chamber
with a gas under pressure.
•A small opening at one end of the chamber allows
the gas to escape, and when it does, it propels
the chamber foward.
–A good example of this is a balloon. Air inside a
balloon is compressed by the balloon’s rubber
walls which causes air pressure. When the end
of the balloon is released, air escapes through
it and the balloon goes in the opposite
direction.

3. Rockets are balloons?
•When we think of rockets, we don’t really think
of balloons.
•Instead, we think of the giant vehicles that carry
satellites and spacecraft into space, but they
have a lot in common.
•The only major difference is the way the
pressurized gas is made.
–In balloons, the rubber walls compact the gas,
making pressure
–In space rockets, the gas is made by burning
propellants that can be solid or liquid in form
or a combination of the two.

4. Types of Rockets
•There are several types of rockets. These
include:
–Missiles (for military use)
–Space Vehicles (both manned and unmanned)
–Sounding Rockets (suborbital, research, and
weather)
–Amateur (model rockets)

5. Stages of Rocket Flight
•Preparation
•Ignition and
Liftoff
•Powered Ascent
•Coast
•Recovery System
Deployment
•Descent
•Recovery

6. Movement of the Rocket
•What causes a rocket to move?
–Newton’s Third Law of Motion: For every action there
is an equal and opposite reaction
•Rocket motor = energy conversion device
–Gases are stored in the combustion chamber until
enough pressure builds up to force some gasses out of
a nozzle.
•Thrust is made by how much pressure is built up
and how much gas shoots out of the nozzle
•The shape of the combustion chamber, the shape
of the nozzle

7. Movement of Rockets Cont’d
•Chinese fire arrows were not very reliable.
–Most of the time, they blew up when launched.
–The ones that did launch went on crazy paths
and most of the time did not land where they
were supposed to.
•Modern rockets have propellants that are more
reliable.
•Propellants are not just the fuel. They are the fuel
and the oxidizer.
–The fuel is the substance that burns but for
burning to take place, there must be an oxidizer
(oxygen)

8. Movement of Rockets cont’d
•No matter which type of rocket, a nozzle is used
for the escaping matter.
•The more weight (mass) that the rocket has, the
more thrust (force) is needed to lift it off the
ground.
–Liquid rockets are easier to control the thrust.
–They use computers in the rocket’s guidance
system. The computers control the amount of
propellant that goes into the combustion
chamber (and out of the rocket).

10. Payloads are anything that the rocket is
carrying. This can be people, satellites,
fireworks, warheads, or anything else.

11. Solid Propellant Rockets
•Solid propellants are solid and dry.
•They contain both the fuel and oxidizer
combined together in the chemical itself.
•Usually the fuel is a mixture of hydrogen and
carbon and the oxidizer is oxygen compounds

12. Solid Propellant Rockets cont’d
•The parts of a solid propelled rocket are simple.
–nozzle: where the gases escape
–case: usually a relatively thin metal that is lined
with insulation to keep the propellant from
burning through
–insulation: the propellant itself is packed inside
the insulation layer
–propellant: solid mixture of hydrogen, carbon,
and oxygen.
–igniter: what is lit to cause the burning of the
propellant.

14. Liquid Propellant Rockets
•The other type of rocket is a liquid
propellant rocket.
–The fuel and the oxidizer are kept in
separate tanks until they are ready to be
launched.
–They are forced into the combustion
chamber.
–There, they ignite and liftoff occurs.

15. Liquid Propellant Rockets cont’d
•Liquid propellant rockets have a few more
parts than solid rockets.
–oxidizer and fuel tanks: hold the materials until
they are ready to be mixed.
–pumps: pump the oxidizer and fuel into the
combustion chamber.
–combustion chamber: where the fuel and
oxidizer are mixed.