Inside: Film Canister Rockets are a fun and easy science activity to do with your kids this summer. Kids of all ages will love launching their own rocket.
Looking for a fun, hands-on science experiment that your kids will love? Try launching a film canister rocket using just Alka-Seltzer and water!
Disclosure: This post contains affiliate links, which means I earn a small commission off sales made through these links at no extra cost to you. Click here for details.
It’s the perfect outdoor STEM activity for kids this summer (your kids won’t even know they are learning).
Whether you’re a homeschool parent, teacher, or just looking for a backyard activity, this simple rocket science experiment is one your kids will love.
What You Need to Make a Film Canister Rocket
This experiment uses common household materials and takes just a few minutes to set up.
Supplies:
- 1 plastic film canister (with a tight-fitting lid)
- Water
- Alka-Seltzer (any flavor works I just buy the cheapest – if it’s flavored it will be colored instead of clear)
- Safety glasses (we didn’t use these, but it might be a good idea)
- Outdoor space (this gets messy!)
Tip: Make sure you’re using a film canister with a lid that snaps inside the rim—not over the top. This creates the pressure seal needed to launch!
How to Make a Film Canister Rocket
The rockets are so easy and fun to make and launch for kids of all ages. I did it with my kids and some neighbor kids ranging in age from 3 to 10.
Decorate Your Film Canister
The first thing we did was decorate the film canister (this is optional…but makes it more fun).
I let the kids use a bunch of permanent markers to decorate their canisters but stickers or paint would also be fun.
Once the rockets are decorated you’re ready to launch the rockets. This is best done outside since it is messy.
Launching Film Canister Rockets
Launching the rocket is simple you just need water, Alka-Seltzer and the film canister. The fun part is figuring out how much water and Alka-Seltzer will make your rocket go the highest.
Fill Rocket with Water
To start have the kids fill their canister with water. I had a container of water they could use to scoop water out of with their canister.
We found that it worked best when the water was between a quarter and half of the canister full. (this leaves some room for pressure to build). Have fun experimenting and seeing how much water works best for your rockets.
After filling the canister with water it’s time to add the Alka-Seltzer.
Prepare the Alka-Seltzer
Since we did this science experiment with a group before we started I broke the Alka-Seltzer tablets into quarters and had them in a bowl.
The kids could try using one or more pieces and see which sent their rocket up higher.
Ready to Launch!
When you’re ready to launch drop the Alka-Seltzer into the water in your rocket.
Quickly snap the lid on tightly and place the canister lid-side down on the ground.
Step back, count down and get ready for blast off!
Within seconds of putting the lid on, the lid will pop off, and the canister will launch into the air!
Safety: Before launching the rockets talk to your kids about safety. Never lean over the canister once the lid is on and always supervise children.
The Science Behind the Alka-Seltzer Rocket
This simple rocket is powered by a chemical reaction. When Alka-Seltzer mixes with water, it creates carbon dioxide gas (CO₂). As the gas builds up, pressure increases inside the closed canister.
Eventually, the pressure becomes too much for the lid to hold, and it pops off—launching the rocket into the air!
Scientific Concepts Kids Learn:
- Chemical reactions (acid + base = gas)
- Gas expansion and pressure
- Newton’s Third Law of Motion: For every action, there’s an equal and opposite reaction. The gas pushes down, the canister rockets up!
Want to take the experiment further and be more official? Try Change the amount of water or Alka-Seltzer and see how it affects height. Grab a notebook and write down your hypothesis, test results and conclusion.
Why Kids Love This STEM Experiment
- It’s quick, easy, and exciting
- It shows real cause-and-effect
- It sparks curiosity about chemistry and physics
- It makes learning feel like play!
Whether you’re doing a summer science camp, a homeschool unit on space, or just need an exciting afternoon activity, film canister rockets are a fantastic way to explore science with your kids.
Related Posts:
Ice Cream in a Bag (edible summer science)
Why is the Statue of Liberty Green? Science Experiment
Fizzing Colors (easy kitchen science)
Why Do Apples Turn Brown ? (Science Activity)
Have you tried this with your kids? Share your results or tag me on Instagram @thekeeledeal so I can see your rocket launches!
Pin This for Later!
Love hands-on science? Save this post and try it with your kids next time the weather’s nice!
