School Project: Two Stage Rockets Made From Balloons

Rocket staging can be demonstrated wih a simple balloon experiment.

Rocket science is the butt of many jokes because of its notorious difficulty, but some aspects of this discipline are remarkably simple to understand. One of these aspects is rocket staging, a basic principle that makes rocket propulsion possible. Rocket staging can be fairly easily demonstrated with an experiment using two balloons.

Tools You'll Need

You will only need eight items for this project. First, you need two long party balloons like those used for balloon animals. You cannot use round balloons for this project; their shape limits the effectiveness of the experiment. Also, you need a roll of Nylon mono-filament fishing line of any weight, two stiff, wide plastic straws, one small Styrofoam cup, a roll of masking tape and scissors. This experiment is designed to be performed indoors.

Set-Up- Part 1

To set up this experiment, cut off a 16-foot length of fishing line (or cut the fishing line to the width of the room where the experiment will be performed). Insert one end of the nylon fishing line through both of the straws. Tape one end of the string to one wall in your room, then tape the other end to the wall on the opposite side of the room. Cut the cup in half and discard the bottom half (you only need the top Styrofoam ring).

Set-Up- Part 2

Inflate one balloon three-fourths full, and pull the nozzle end through the Styrofoam ring. Have a partner hold the ring and the first balloon, while you blow up the second balloon inside of the ring. The second balloon should be blown up halfway through the ring; the pressure of this balloon should hold the first balloon shut. Tape this balloon rocket to the straws - one balloon to each straw. Pull the balloon rocket carefully along the fishing line back to the first wall, holding the second balloon closed.

Execution and Explanation

Release the second balloon. The rapid release of air from the second balloon will propel the rocket halfway down the line, then the first balloon will be released and continue to propel the rocket the remainder of the way down the line. This is the basic principle behind rocket staging. The first balloon to be released (the second balloon blown up) acts as a rocket booster, then the second balloon to be released (the first one blown up) finishes propelling the rocket with a second burst of energy in mid flight.

References

• NASA: Two-Stage Balloon Rocket
• HomeTrainingTools: Balloon Jet
• NASA: Rocket Staging