Beaver Scouts : Programme Ideas

Seltzer Tablet Rocket

These plans are not to size. Photocopy and enlarge until measurements are correct. Check with ruler. Use coloured paper or colour in with paints or crayons. Correct length 105mm

5...4...3...2...1...liftoff! As the solid rocket boosters kick in, the Space Shuttle Atlantis slowly lifts it?s 2 million kilograms off the launch pad and another mission is underway. Today, rockets with enormous payloads are commonly launched, but less than 60 years ago, most people thought rockets even close to this size existed only in science fiction. Historians aren?t quite sure who invented the first rocket, but by the year 1250 AD, Chinese warriors were launching simple bombs using gunpowder for propulsion. For over 500 years, these simple rockets were used only for military purposes. They were crude, had no steering mechanism, and often blew up before they even got off the ground. Things started to improve in the early 1800?s, however, when William Congreve, an English scientist, added a simple guidance system to his gunpowder fired rockets. It wasn?t until the early 1900?s that the analytical science of rocketry really came into its own. American scientist Robert Goddard studied how much thrust could be obtained from a variety of different fuels. In 1926, he launched the first liquid-fueled rocket from his aunt?s farm in Massachusetts, and the space age began.

All rockets operate on the same basic principles of propulsion. In this activity, you will construct a rocket that is fueled by a seltzer tablet. The paper rocket in this activity is propelled according to the principle stated in Isaae Newton?s third law of motion: ?For every action there is an opposite and equal reaction.? Gas pressure builds inside the film canister due to the mixing of Alka Seltzer and water. This action continues until enough pressure builds to blow apart the canister from its lid. The reaction?s the launch of the rocket. The activity has educational value but it is also great fun. Ask your Beavers to bring a film canister down to the meeting from which they can make their rocket. The rockets can shot up to 5 metre into the air and in doing so it can be messy as fuel falls out of the canister so launch all rockets outside. Take off is a little unpredicable so have your Beavers stand back from launch pad.

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Seltzer Tablet Rocket

Materials
An empty film canister with lid that snaps inside – usually the clear plastic type; markers, crayons, or colored pencils, tape; glue; scissors; Alka Seltzer tablets; water; straw; (Optional launch pad: wood block, coat hanger or other stiff wire,) It is most important to use film canisters with lids that snap inside. Do not use lids that close around the outside of the canister.

Construction
1. Enlarge the pattern until sizes are correct onto coloured paper. Cut the fins out. Cut the nose cone and body out as one piece.
2. Tape the body onto the film canister, roll the paper around the side, and tape the end down. The lid end of the film canister goes down.
3.Roll the nose cone around in the shape of a cone and tape together. Straighten the nose cone point to the centre of the rocket and tape it to the sides.
4.Fold the fins so that the coloured side is out. Tape and glue the fin halves together to form a complete circle.
5. Slide the fins over the body and tape in place.
6. Cut a 30 mm piece of drinking straw and tape it to the side of the body to act as a guide at launching.

Launch Time
This is an outdoor activity. Place a 1/2 of an Alka seltzer tablet in the container and one teaspoon of water, snap on the lid quickly and place rocket on launch pad. Everyone should stand away from loaded rockets when they are on the launch pad. It may take 15 to 20 seconds to build up enough pressure to launch, so a loaded rocket should not be approached prematurely. These rockets can shoot 5 meters or more into the air. No sharp objects should be placed on top of the nose cone or elsewhere on the rocket.
Make a launch pad with a block of wood and a straight piece of wire. Drill a hole for the wire and insert the wire straight up to guide the rocket at lift off.

Wrap-up
One way to record the results of different ?fuel? mixtures is to make a simple graph of height vs. amount of water. Such a graph gives a clear, visual record of the observations and can be used as evidence to support interpretations. Design and launch other rockets powered by two, three or more film canisters. Design a two stage rocket.

Beaver Scouts : Programme Ideas

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Seltzer Tablet Rocket

Seltzer Tablet Rocket