Balloon Rocket Experiment

Years ago, my older son and I raced balloon rockets across our living room. This year, for summer science camp we took our balloon rocket making supplies over to a friend’s apartment to try outdoors with the kids. As you can imagine, a balloon rocket experiment was lots of fun for three very rowdy boys.

Balloon rocket race experiment for kids. Indoor or outdoor science activity!

While the kids played by themselves, the moms set up the course. If you have mostly older kids they can do this all by themselves. Our mix of kids were mostly younger. Plus, we wanted to chat!

What you need:

  • Balloons
  • String
  • Scissors
  • Straws
  • Tape
  • DIY science campers


Extend the length of string as far as you can, given the limitations of your space. Tie one end securely (we tied it on the fence). Thread one straw through each string and tie up the other end. Slide the straw all the way to one end of the string.

How to make a balloon rocket. Indoor or outdoor activity for kids.

Blow up a balloon. Without letting the air out, carefully tape the balloon to the straw. Clasping the neck of the balloon tightly, count to 3. Let go! Watch your balloon whizz down the course!!

Balloon rocket races. Kid activity.

As you can imagine, with two 5 year olds, a 9 year old and a 3 year old, it was difficult (actually impossible for us) to get all the balloons ready to go at the same time, so we didn’t have so much as a race as a free-for-all.

My 9 year old was the only one who could remotely focus on the science behind the balloon rocket experiment. I asked him why the rockets go so quickly and he correctly responded that the energy escaping air creates a forward moving force. He and I were also able to compare the speed of a small balloon with a large balloon.

Balloon rocket experiment for kids. Summer science fun.

(I know what you are thinking this balloon looks like.)

Older kid variations:

  • Compare the speed and distance of differently shaped balloons.
  • What happens if you use a shorter straw?
  • We used thin straws. What happens if you use a straw with a wider opening?
  • Compare different types of string. You could use twine, yarn, thread… etc.
  • Tie strings on an upward slope, a downward slope and flat. What’s the difference in speed?

After the boys lost interest in the the balloon rockets, the 3 year old was quite entertained when I simply blew up a balloon and let it go. No need for the straw and string for her!

This is a super easy science experiment with so much entertainment value. I highly recommend it. It’s also a great activity to do indoors on a rainy day.

Now head on over to Coffee Cups and Crayons to see how she and her kids made homemade silly putty! So cool.

More Summer Science Camp:

On this blog: Ice cube on a string, Solar oven, Homemade compass

At Coffee Cups and Crayons: Mentos geyser, Dancing raisins, Density layers

What summer science have you been doing with the kids?

Simple summer science projects for kids


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  1. says

    Oh, Erica, I LOVE this! I can imagine kids having a blast with this! In fact, a few years back I wrote a scene in a novel (which is now shelved forever–the novel, not the scene) that included something very similar, only with water :)

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