Making (and using) an Overhead Water Rocket Launcher Introduction
Shortcut to the instructions, click here.

UPDATE: Here is an alternate, simpler water rocket launcher design that's easier to build and gives kids a tactile understanding of "pressure". The text explanation is here.

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Instructions page for the classic water rocket launcher
A simpler water rocket launcher design: instructions
For some variations of the water rocket design, click here
To learn how to hurl water balloons out of site with the water rocket, click here
To see the links to the best water rocket web sites I've found--including slow-motion launches, aerial photography and multi-stage rockets click here.
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If YouTube is blocked in your school, try this equivalent SchoolTube link Part 1

The PBS home improvement program Ask This Old House teamed up with to make an overhead water rocket on their annual kids program. If you want instructions for the overhead water rocket launcher in greater detail, you've come to the right place.

To go directly to the water rocket launcher how-to-build instructions click here

Photos by Heather Reeder at school

2-liter soda bottles turned water rockets are as shrieking good a time as a water park and a lot easier to build! They streak into the air faster than the eye can track while dousing everyone in the launch area with water. Occasionally, my middle school students host and teach classes of elementary school kids from across the street to make a take-home science project, and we always finish off with a couple of launches. Years later, when I teach those now-middle school kids, they never remember me, but invariably remember the water rockets!

I have been searching for the "perfect" water rocket for two decades. I finally have a design that I'm happy with: it's easy to make with locally available materials, dirt cheap, and it launches safely overhead. Of course, 2-liter bottles are free, and the launcher is virtually indestructible--no "O" rings or anything to wear out. A bicycle air pump provides the air pressure.

I am confident that a normally handy person can make this project in an hour or two. I have created step by step instructions for making a water rocket launcher. It's free--I do ask that you give me feedback about things like clarity of the directions and I ask that people outside North America inform me about the availability of the pipe sizes in their respective countries using metric measurement. It is a great joy when experimenters share design innovations and improvements that I can in turn share with everyone through this site. Feel free to link to or any page of it so others can access the material directly (there are many other science projects).


  A still from the Ask This Old House shoot.

WHAT A BIRTHDAY PARTY! Mike Werling's daughter asked for a science-themed 13th birthday party. These are party favors, Tracy Bahr's free standing variation.

They also used the overhead design to cool off. To see the other great science activities at the party check out Mike's cool blog,


These pictures were sent to me by Mr. Salvador Robert of Spain. He added the idea of a wider, more rigid pipe, except for the end. He also has a terrific website about bubbles (the link is the Google translated page).


To go to the instructions for making the water rocket launcher, click here

To learn how to hurl water balloons out of site, click here

To see the links to the best water rocket web sites I've found--including slow-motion launches, aerial photography and multi-stage rockets click here.

To read about the history of water rockets and how this design evolved, under construction

For a frank discussion of the safety issues involved with water rockets, click here

For some variations of my water rocket design, click here

To learn about Newton's laws of motion that make water rockets work and to calculate how high they go under construction

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Here are some pictures from Shannon--den leader of 3rd grade "Bear Scouts" from the southern state of Louisiana. The scouts, she wrote, "...built a luncher and designed their own rockets. We met to discuss the Scientific Method and compile our Purpose and Hypothesis. We built our rockets from re-cycled materials ONLY and then we launched after discussing the safety measures that you described on your website. We tracked weight of the rockets, amount of water annd air pressure for each boy and noted our observations. Then we calculated the distance using a program we found on the internet. The boys really had a blast."
"It was one of our favorite projects to date!"