For every action, there is an equal and opposite reaction. If you blow up a balloon and release it (without tying the end), the air in the balloon will go in one direction and the balloon itself will go in the opposite direction. Rockets use this same principle. The thrust coming out of the rear pushes the rocket forward.
The rockets we are about to build depend on generating enough pressure and releasing that pressure very quickly. It will build pressure by pumping air or through chemical reactions (which generate gaseous products).
Let us begin!
Seltzer Rockets: Place an Alka-Seltzer tablet in a white Fuji film container (Kodak black containers will not work) and fill one third full with water. Working fast, cover it up and invert it on the sidewalk. Back off … POP! You will see that there is an optimal water level for the maximum height. If you work fast, you can get roughly four pitches from a tablet. What happens if you try two tablets at the same time?
Paper Air Gun Rockets: Make a very long straw by taping two straws together. Roll an 8½ x 11 “sheet of paper into a long tube and tape it closed (younger children can wrap the paper around a peg to help). Cut the triangular flaps from the index cards and glue them together with hot glue at one end of the rocket. Cut a circle out of paper. You can trace the inside diameter of the roll of masking tape to get a good circle. To make a flat circle in a three-dimensional cone, start cutting the circle in half, but stop cut when it reaches the center. Slide one flap over the other to form a (nose) cone and tape it closed. Pile a lot of glue inside the cone and add the long straw and wait for it to dry. Slide the straw into the tube and seal the nose to the rocket body. When dry, blow into the straw to check for leaks. It should be impossible to blow. If you have a leak, go back and fix it now. Otherwise, slide over the metal tube and blow hard. Apply a nozzle from an air tank or compressor to blast these rockets hundreds of feet into the air! t body just below the nose cone and rebuild the straw cone assembly, holding it in place when ready.
Slingshot Rockets Punch a small hole in the bottom of a can of black Kodak film. String 5 rubber bands together and push one end of the rubber band chain through the hole from the outside, holding it with a paper clip on the inside so it doesn’t slide through the opening (like a pin). Hot glue the container to one end of a 6 “piece of ¾” foam pipe insulation and tape the circumference with a few turns of masking tape. The rubber bands should be hanging off the foam tube. Attach the triangle hot glue foam fins to the opposite end. To pitch, hook the rubber band over your thumb, pull back, and release.
Puff Rockets: Grab a clean, empty shampoo or lotion bottle. Make sure the bottle you choose gives you a good breath of air through the top cap when you tighten it. You will also need two straws, one slightly smaller than the other. And a small piece of foam. Insert the smaller straw into the hole in the lid. If you’re having trouble, either ream the hole or simply remove the cap and seal the connection with a piece of clay or lots of hot glue. Insert some foam into one end of the larger straw. Slide the larger straw (your rocket) over the smaller straw (your launcher). Squeeze the bottle hard! FAGOT! What bottles work best? Does the length of the straw matter? (We had a rocket that cleared 25 feet.)
Micro Paper Rockets – Spiral wrap a thin strip of paper around and along a wooden pencil and masking tape to secure (you can alternatively use a bare straw instead of making your own paper rocket body, but then you will need a tube slightly smaller launch pad.) Triangular hot glue fins made from a card at one end. Fold the opposite end twice and secure with a ribbon ring to make a nose. Insert the straw into the body of the rocket and blow hard!