- Science as Inquiry
- Physical Science - Position and motion of objects
- Science and Technology - Abilities of technological design
Science Process Skills:
- Collecting Data
- Making Models
- Defining Operationally
- Problem Solving
- To problem solve ways to lift a load using a balloon rocket.
Students construct a rocket out of a balloon and use it to carry a
paper clip payload.
This activity works best with students working in teams of three or
four. It will take approximately one hour to complete. The activity
focuses on the scientific processes of experimentation.
The mass of a rocket can make the difference between a successful
flight and a rocket that just sits on the launch pad. As a basic principle
of rocket flight, a rocket will leave the ground when the engine produces
a thrust that is greater than the total mass of the vehicle.
Large rockets, able to carry a spacecraft into space, have serious
weight problems. To reach space and proper orbital velocities, a
great deal of propellant is needed; therefore, the tanks, engines,
and associated hardware become larger. Up to a point, bigger rockets
fly farther than smaller rockets, but when they become too large
their structures weigh them down too much.
A solution to the problem of giant rockets weighing too much can
be credited to the 16th-century fireworks maker John Schmidlap.
Schmidlap attached small rockets to the top of big ones. When the
large rockets exhausted their fuel supply the rocket casing dropped
behind and the remaining rocket fired. Much higher altitudes can
be achieved this way.
This technique of building a rocket is called staging. Thanks
to staging, we can not only reach outer space in the Space Shuttle,
but also the Moon and other planets using various spacecraft.
Materials and Tools:
- Large long balloons (Several per group)
- Fishing line
- Small paper cups
- Paper clips
- Clothes pins
- Attach a fishing line to the ceiling or as high on the wall
as possible. Try attaching a paper clip to a fishing line and
hooking it on to the light or ceiling tile braces. Make one drop
with the fishing line to the floor or table top per group. Note:
The line may be marked off in metric units with a marker to aid
students in determining the height traveled.
- Blow up the balloon and hold it shut with a clothes pin. You
will remove the clip before launch.
- Use the paper cup as a payload bay to carry the weights. Attach
the cup to the balloon using tape. Encourage students to think
of creative locations to attach the cup to the balloon.
- Attach the straw to the side of your rocket using the tape.
Be sure the straw runs lengthwise along the balloon. This will
be your guide and attachment to your fishing line.
- Thread the fishing line through the straws. Launch is now possible
simply by removing the clothes pin. Note: The fishing line should
be taut for the rocket to travel successfully up the line, and
the clipped balloon nozzle must be untwisted before release.
- After trying their rocket have students predict how much weight
they can lift to the ceiling. Allow students to change their design
in any way that might increase the rockets lifting ability between
each try (e.g. adding additional balloons, changing locations
of the payload bay, replacing the initial balloon as it loses
some of its elasticity enabling it to maintain the same thrust,
- Compare what you have learned about balloons and rockets.
- Why is the balloon forced along the string?
Compare results from student launches. Have students discuss design
elements that made their launch successful and ideas they think could
be used to create an even more successful heavy-lift launcher.
- Can you eliminate the paper cup from the rocket and have it
still carry paper clips?
- If each balloon costs one million dollars and you need to lift
100 paper clips, how much money would you need to spend? Can you
think of a way to cut this cost?
- Without attaching the paper cup as a pay-load carrier, have
the students measure the distance the balloon travels along the
string in a horizontal, vertical, and 45 degree angle using metric
units. Discuss the differences.