Date: Thu, 29 Jun 1995 11:42:58 -0800
From: Matt Gulick <mgulick@RADIUS.COM>
Subject: Re: Aquajets (rockets)
At 10:39 AM 6/29/95, Rod Keen wrote:
>G'day all
>last weekend on our channel 4 tv there was a program about rocket
>makers (not NASA ESA etc). Most were either solid or liquid burning
>fuel. One even had a motor that would power a Tomahawk cruise missle!
>Anyway one of the other types fired was what is called an _AQUAJET_
>basically its a plastic drink bottle (2 litre) with pressurised water
>as its propellant. What a brilliant idea for Cubs, and, if we tie
>someones foot to it maybe we can lose a cub or two (given the correct
>bribe) ONLY JOKING!
>Does anybody have construction info for this type of rocket? or know
>where i can ask?
It is really quite simple. You need a plastic bottle (1 and 2 litre both work great) a rubber cork that will fit snuggly in the bottle (The cork kind work but not as well), a bicycle pump and a pump needle (the kind used for basket balls).
Drill a small hole through the stopper so that the pump needle fits through very snuggly. Fill the bottle 1/3 with water. More watter will just weigh down the bottle as there will not be enough air pressure to expell it all. Insert the stopper and attach the bike pump. Start pumping and expect to get wet.
You can build some kind of stand for the bottle but I found that building fins for the bottle worked best. They functioned as legs for launch and then kept the bottle stable during flight. They can be made of cardboard but will "melt" after a few launches. I used plastic binder inserts (the ones used to seperate sections) with great success.
Matt Gulick
I used to be a Bear...
Date: Sat, 1 Jul 1995 06:56:38 -0400
From: Jeannie Dixon <DIXONJ@LINCC.CCLA.LIB.FL.US>
Subject: rockets
My Girl Scout troop hosted a Science event a few months back. One of the activities was building and launching rockets. Everyone really enjoyed this, and several of the leaders and moms present who were also Cub Scout leaders took the idea to their dens. They report that the boys loved it as well.
Take a toiler paper tube and mark a spot 1" from the end. Cut five slits up to that spot and fold the slits out (this forms the base of the rocket launcher). Take a paper plate (or a plastic plate) and tape down the toiler paper tube (with the "legs" out flat). Decorate with markers, stickers, etc. if desired.
Take this outside. Your 'rocket' is a 35mm film canister. The clear ones work best, but the black ones will do fine. The best ones are the ones with the cap that fits INSIDE the canister. (Hmmm, this is hard to describe without you seeing my hand motions!).
Fill the canister about 1/3 full of water (part of our activity was experimenting with how much water to use; started with half-full; then almost full; then about 1/3 full). Take 1/4 tablet of Alka-Seltzer (or equivalent store brand) and drop into canister. Put the lid on tightly and place LID DOWN into the toilet paper tube. Step back. It takes about 1 minute or so for the rocket to launch, but we achieved some pretty impressive heights!
Any place that does film processing will GLADLY give you as many film canisters as you are willing to cart off. K-Mart and Wal-Mart both were generous, but the best place was a local film developing store that had LOTS of the Fuji film canisters (these are the clear ones with the 'inside fitting' lid).
We got this idea from the January 1995 issue of _Family Fun_ magazine.
Jeannie Dixon
Girl Scout Troop 223 (now Cadettes!)
Tallahassee, FL
dixonj@lincc.ccla.lib.fl.us
Date: Fri, 30 Jun 1995 18:42:14 -0500
From: Gary Stedman <stedmang@CADVISION.COM>
Subject: Rockets....
I've never tried the water rockets that have been posted, but we'd had great success with YOP rockets. (YOP is a yogurt drink that comes in a small plastic bottles with tight fitting caps). We've had a lot of fun launching these rockets in our group. (Sorry Rod - these rockets aren't big enough to tie cubs to!!!!)
How to Build and Launch a Yop-Rocket
To Build a rocket
1) Get a YOP bottle from the nearest store. (YOP is a yogurt drink and it can be purchased almost everywhere you can buy yogurt)
2) Clean off all the labels and wash it out well
3) Decorate it anyway you want (put wings on it, colour the bottle, etc)
To Launch a rocket
NOTE: STAND BACK WHEN LAUNCHING THIS ROCKET - It goes up fast and strong
1) Put some vinegar into the bottle (About 1 1/2 to 2 inches is enough)
2) Wrap a tablespoon of baking soda inside a single sheet of toilet paper. The rocket works better if you only use a single layer of toilet paper (single ply)
3) Put the wrapped baking soda into the cap of the YOP bottle The wrapped baking soda should be big enough to just fit inside the depression in the lid.
***** Steps 4,5 and 6 have to be done quickly *****
4) Pop the cap back into the bottle The tighter the better. If the baking soda is the proper size, it won't fall into the vinegar when you put the cap down.
5) Put the bottle on the ground with the cap side down
6) STAND BACK!!!!!!!!!!!!!!!!!
7) Clean up the remains of the toilet paper
How does it work?
The baking soda and the vinegar combine to form carbon-dioxide gas. This gas builds pressure inside the YOP bottle until the seal on the cap can no longer hold. At that time the cap pops off and the escaping carbon-dioxide pushes the rocket up into the air.
Wrapping the baking soda in the toilet paper slows down the reaction because the vinegar has to soak through the paper to get to the baking soda. This gives you time to put the rocket down and stand back.
KAA (Gary Stedman), 75th Midnapore Scout Group, Calgary Alberta Canada
Last edited: February 22, 2004
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