Water Powered Rockets

Here are some ideas for a couple of simple air and water powered rockets that we tested out here in the department. Both these simple designs can be easily made in the classroom.

 
 

Water powered film cannister

Here is a simple design, using a 35mm film canister as the 'rocket'. Make sure the rocket is used either outdoors or on a mat, since some mess is produced by the 'engine'!

1. Take a toilet tube and mark a spot 25mm from the end. Cut 5 slits up to that point and fold the slits out - these form the base of the rocket launcher. Take a paper or plastic plate and tape down the toilet tube with the legs bent out 'flat'. Decorate your rocket launcher as required.

2. Take your 35mm film canister - this will be the rocket. The clear ones work best, in which the lid press fits inside the canister.

3. Fill the canister about 1/3 full of water, then drop in about ¼ of an Alka-Seltzer (or equivalent) tablet. Put the lid on tightly and quickly place lid down inside the launcher tube - keeping your face away from the tube.

4. Depending on the temperature of your water the canister will launch quickly or slowly. Stand well back from launcher tube whilst waiting for the launch. Experiment with the amount of the various ingredients to achieve the best propulsion effect.

The Alka Seltzer water rocket
 

NB. You can also power this rocket with Vinegar and Baking Powder. But we have to admit that we were unable to make this one work as well as the Alka Seltzer. If you want to try it... Place a tea spoon of vinegar inside the canister. Twist some tissue around a small amount of baking powder, then fit the lid onto the canister such that the edge of the tissue is caught under the lid. This will prevent the tissue paper containing the baking powder from falling into the vinegar. When the lid is on, quickly drop the canister lid down into the launcher tube. The tissue paper slows down the production of gas by preventing the vinegar immediately reaching the baking powder, although the launch can be very fast so take care.

   
 

Classroom Straw Rockets

Very simple classroom 'mini rockets' can be made using paper or thin card, that are formed by wrapping the body of the rocket around a drinking straw. Fins can be added either a the front or back of the rocket, and their effect on the flight investigated. The rockets are launched by blowing through the straw - you might need to wrap a bit of sellotape around the straw a few cm back from the end so that the rear of the rocket makes a good seal.

A couple of our designs are shown here, weighted down slightly at the nose with some sellotape. Each rocket is only about 5cm long. Not very surprisingly, considering the relative positions of the fins, only one of the pair flew any distance!

simple rockets to 'fire' from a drinking straw
     
 

All our designs are Quality Tested!

Our thanks go to our laboratory rocket tester, Mike Alexandersen from Ash Manor School, who spent a week with us on work experience during April 2001. Mike's efforts enabled us to select a couple of designs that really work, and so we can say that these have been tested by a real school sudent!

Mike, our brave rocket tester