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Cool Water Rockets

Water Rocket Page
Newton's 3 Laws
Other Projects
Mission Log
An Introduction to Water Rocketry
Water Rocket Page
My First Rockets
Black Knight
FTC Rockets and T nozzle
Discussion Page
Therory Page
Red Hawk
Water Rockets and Beyond
x prize
About Me
Shoutouts to My Friends
Contact Me
Water Rocket Guestbook
Lawn Dart
Blow up on launch pad
Rocket at Apogee
Crushed Nose-Cone
Entertainment and News

Water Rocket Page

Since there are so many photos on this page I had to make them small. There for I have made more specific pages about the stages in my water rocket career. Click on the links below to check out each section. Note since there are not as many photos per section I was able to make the pictures bigger.

My Firtst Rockets

Black Knight

FTC Rockets and T-nozzle


In this section I will try to document all the rockets that I build. Since there are a lot of photos on this section of my web site, I decided to separate it into multiple pages. This will allow the pages to load faster.

Here is a picture of my first water rocket. It wasn't a great rocket but you have to start somewhere. As you can see in the picture the fins are made out of cardboard. We used duct tape to tape the fins to the rocket body. The rocket body is made from a 710ml soda bottle. The nose-cone is the top of another soda bottle. The first time we launched it, it went about 150 feet. Then I had the idea to add balast. So my friend Cameron and I found some rocks and put them inside the nose-cone. This made the rocket go higher.

My first water rocket

This is the same rocket as in the picture above except this rocket has smaller fins. Although the rocket had smaller fins the performance was about the same. Also the fins in this picture are made out of plastic, instead of cardboard. This was an improvement because the fins didn't get soaked.

My first water rocket with small fins

This is my first successful multi-bottle rocket. It is made out of two smart one water bottles. The first time we tried to do this we used duct tape to hold the bottles together. This didn't work to well and the bottles blow apart. The second time we used PL Premium (PL) for short. This time they held toghether perfectly. Adding an extra bottle really improved the height of the rocket. I think you can buy PL at any hardware store. (We bought ours at HomeDepot).

My first succesful multi bottle rocket

Here is a picture of my first backslider. It is made from four one liter smart one water bottles. We taped a crushable nose cone to the rocket, which was another smart one bottle. We added a crushable nose-cone so all our hard work wouldn't get destroyed.

My first bacskslider water rocket

Today we tested the rocket. The result the rocket came down sideways, instead of coming straight down. Rockets that do this are called backsliders. If you are wondering why this happens it is because the center of gravity is below the center of pressure. If this happens the rocket will back slide.

Black Knight


After several attempts at using a parachute and failing we decided that we needed a different kind of recovery system. So I went on the Internet and did some research. On Robert Youens water rocket page I discovered the Coney. The Coney uses a unique kind of recovery system. This rocket, instead of coming down straight, like you would expect, it comes down sideways. Why is this? This happens because the center of gravity is below the center of area. I thought that if I made a long skinny rocket this would move the center of gravity back behind the center of area because the fins are heavier than the rest of the rocket. This was a bad assumption, although it did work once, but I think that was luck. I found a more reliable way of moving the center of gravity back behind the center of area was to add weights to the fins in the form of quarters. The first time I tried this I added too many quarters (4) and the rocket was unstable. So I took off two of the quarters and it worked beautifully. My Dad also made a computer model to calculate the center of area. The math was a little bit beyond me so I can't explain exactly how it worked. We calculated the center of gravity by balancing the rocket horizontally on a knife blade. The center of gravity is the point at which the rocket balanced. If the center of gravity was behind the center of area we knew we had a backslider. Another way to calculate the center of area would be to make a cardboard cutout of the rocket and balance this on a ruler. The center of area would be the point at which the cardboard cutout balanced.

The below video is 3.36 MB.

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My Latest Backslide Water Rocket

The Coney

Rocket Stability A Detailed Analysis

Backslide Construction and Videos

In this picture you can see the rocket on its' decent. This rocket is my first backslider.

Rocket backsliding

This is a picture of my dad and I standing next to our water rocket, with an Este's space shuttle sitting on the top of the rocket. The space shuttle caused the rocket to be unstable. As a result the rocket went about 50 feet, and then tumbled back to earth. Although it wasn't a complete success it still looked cool.

Backslider with Estes shuttle

In my right hand I have my newest water rocket (still under construction), in my left hand is the old water rocket.

Old backslider and (new backslider?)

This is what happens to a water rocket that does not backslide. As you can see in the photo below the nose pretty much got destroyed


This is a picture of me holding my Black Knight water rocket. Which is still waiting to be launched. Hopefully we will launch her today, and hopefully she will backslide.

Black Night

Last weekend we launch off our black knight water rocket. The first time we launched it it kind of backslid. When it hit the nose-cone was damage. We put the rocket on the launcher and popped the nose-cone out. When we launched the rocket again we added weight to the fins. This moved the center of gravity back below the cent of pressure. When we launched the rocket again it backslid.

Blow up on launch pad

Today we pressure tested our water rocket. We pumped it up to about 100 P.S.I. It held for about 20 seconds, and then the top half of the rocket flew off while the bottom half stayed on the launcher. The bottle between the part of the rocket that launched off and the part that stayed on the launch pad got torn apart. We are not sure why that particular bottle failed instead of another bottle, but we are going to need to build a new rocket. This time I think we will make it out of two sections of plastic mailing tube, and use the tops of a 1 liter 7-up bottle as the nozzle and nose-cone of the rocket.


Last weekend we launched our latest Black Night water rocket with a reduced nozzle. We experimented using less water and discovered that for bigger rockets with small nozzles using less water makes the rocket go higher. We used about 1 liter of water and got about 500 feet. Maybe higher! On our last launch our rocket went so high that we lost it on a house. The rocket was in the air for about 25 seconds. That's a long time, espcialy for a rocket using a backslider recovery system! We got some cool video of the launch, which I will get on my site as soon as possible.

Click below to play video. The video is 1.24 migabytes

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This weekend we launched off our first FTC rocket. It was an interesting day. The first two launches the rocket backslid. On the third launch we tried using about a cup of water. The rocket slot off the launch pad like a bullet being fired from a gun barrel. It was a beautiful flight. The rocket went straight up. It began to backslide and then it came down nose first and stuck into the ground like a spear. The nose-cone was twisted like a medal frame work after a hurricane. I think that the rocket came down nose first because the center of gravity moves forward as the rocket accelerates. So when we used less water the rocket accelerated faster, so the center of gravity moved foward of the center of pressure and as a result the rocket came down nose first. We will have pictures of the twisted nose-cone soon.

This is a picture of the nose-cone after the rocket came down nose first.


This is a close up of the nose-cone.


This weeken we launched off our second FTC water rocket. We nick named our rocket the Red Barron named after the famous Germen fighter pilot. The weekend before we had launched and our rocket had plumited nose-first. To mare sure that our rocket would backslide we used the spread sheet that my dad had made to calculate the center of gravity. The spread sheet takes into acount the fins and the nose-cone. We also wanted to test our new T-nozzle design. If you are not farmilar with T-nozzles it is basicaly a small nozzle that sits on the top of the launch tube. As the rocket lifts off the launch tube the flang on the T nozzle catches on the neck of the soda bottle. The advantage of using a T-nossle is you can take advantage of the innitial burst of the launcher, and can benift from a reduced nozzle. A reduced nozzle is an advantge because it alows for a long burn time and low drag. We were very happy with our results from our T-nozzle. Our next step will be to design a super-sonic T-nozzle. I will try to document our FTC rocket and T-nozzle design with a digital camera. So come back soon.

Below are some great links to other water rocket sites

Robert Youens Water Rocket Page

Water Rocket Garage

Bristols Water Rockets Index

Water Rocket Index

Clifford Health Water Rocket Page

Ulrich Hornstein Water Rocket Homepage An exelent site

NPL Water Rocket Challenge 2003

Experimental Water Rockets

Nick's Water Rocket Site Lots of info

I am not really into solid fuels rockets, but I thought that this was a cool site, so I added it to my links.

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