Having kids craft their own rockets and launch them is not only an exciting and engaging activity, it's also educational. Kids will love the experience and science of making their own models and watching them jump into action. Always provide adult supervision, and these projects will be entertaining for the whole family.
To complete this simple air-powered rocket you'll need a balloon, a plastic drinking straw, tape, and a kite string at least 90 cm (3 feet) long. The long, oval-shaped balloons work best, but a typical round balloon works just fine. Tie one end of the kite string to a door handle, chair, or some other support. Put the other end of the string through the straw and tie it to another support so the string is stretched tight. Inflate the balloon, but do not tie it. Use tape to attach the inflated balloon to the straw and let your balloon rocket fly from one end to the other. The thrust from the air escaping the balloon is what propels it along the string.
Water rockets are safe for younger kids and relatively easy to make. You'll need a 45-cm (18-inch) long cardboard mailing tube that's a least 7.5 cm (3 inches) in diameter, an empty plastic 500 ml drink bottle, poster board and fun foam to make this rocket. Cut the cardboard tube into 30-cm (12-inch) and 15-cm (6-inch) lengths, cap one end of the 15-cm (6-inch) piece and tape the 30-cm (12-inch) piece to that capped end. Fit the bottle into the open 15-cm (6-inch) end, make a cone top out of poster board and use the fun foam to make fins. To launch a water rocket, make or purchase a special launch pad that forces air and water through pipes at high pressure. The water pressure gushing into the bottle from the launcher will shoot this rocket into the sky.
These rockets launch using the fizzy lifting power of effervescent tablets and water. You'll need an empty film canister, effervescent tablets, water, a cardboard toilet paper roll, construction paper, and tape. Cut straight up through the side of the toilet paper tube and tape it around the film canister, leaving 3 mm (1/8 inch) of the canister's lid side exposed. Make a nose cone for the opposite end of the tube from construction paper and attach it with tape. After the rocket is constructed and decorated, fill the canister 1/4 full with water, drop a tablet in, close the lid and place the rocket on the ground with the canister side down. Step back quickly and watch the rocket fly.
A cardboard rocket flyer requires only the force you exert to be propelled forward. You'll need a cardboard tube as long as your forearm and two more cardboard tubes that are half that length, along with modelling clay, masking tape, a straw, glue, and a long piece of string. Place a marble-sized piece of modelling clay in each of the two shorter tubes, close them shut with masking tape and glue these tubes together side by side. After the paint is dry, lay the tubes on a flat surface and glue the longer tube lengthwise on top, positioning the shorter pair close to one end of the long tube, so they look like a pair of engines. Glue a straw to the inside of the long tube and after the glue dries, thread a long string through the straw. Have two kids hold the string taut between them and push and pull the rocket from one end to the other. The weight from the modelling clay pushes the rocket forward and back depending on the slope of the string.