Pop Bottle Rockets

Challenge
With recent launches of rockets and a few more happening in July, it's time to blastoff this month with the STEM Challenge!  Check out the Events Calendar at Kennedy Space Center for upcoming launches to watch them live or previous launches to prepare for builidng your own rocket to launch. Your challenge is to create and design a rocket and launch pad for blastoff. Adjust the rocket fuel and rocket design to see which provides the best blastoff. What size rocket will work best? What if the rocket had fins or other designs? Does the ratio of fuel ingredients matter? What about the ratio of fuel to the rocket size? What should the rocket launch pad be? The goal is create the best rocket you can and to experiment with all those questions!

Design some sort of launch pad first. The goal of the launch pad is to hold the bottle upside down in an upright position. Next, decide on a plastic bottle to use as your rocket and design your rocket. Finally, experiment with the ratio of your rocket fuel or baking soda and vinegar. 

Your creation does have some criteria and constraints. Make sure safety is noted at all times. After the rocket is fueled, place it in the launch pad, and back away. Only launch rockets in a wide open spaces and from the designed launch pad. For launching, fill the bottle with the chosen vinegar ratio, pour the baking soda on a 4"x4" piece of paper towel, wrap up the baking soda with the paper towel, stuff it carefully into the spout of the bottle, cork the bottle, and turn it upside down into the launcher and move quickly out of the way. Prepare for blastoff!

Materials

• various plastic bottles
• corks or foam for bottle toppers
• vinegar
• baking soda
• paper towels
• measuring cups/spoons
• rocket decorations
• launch pad materials: Legos, craft sticks, glue, tape, blocks, etc.

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Hints and Tips for Success

1. Allow students planning and discussion time by having them decide which type of bottle to use so they can start building their launch pad.
2. Test to see if the launch pad is sturdy and will hold the bottle with liquid. Add water to the bottle with a cap to do this test. 
   
3. Plan out the ratio of baking soda and vinegar. As a guide, a 2 liter bottle does well with 1-2 cups of vinegar and a tablespoon of baking soda. Have students experiment with different amounts to see which they think is best. 
4. Always ensure safety when loading and launching the rockets. 
5. Record the launches in a constant spot so students can compare heights and launches if wanted. 
6. Connect to math by discussing ratios, measurement, conversions, etc. 
7. Connect to science by discussing engineering, properties of matter, solids, liquids, gases, pressure, chemical reactions, etc.