Get ready for lift-off - The main ingredients of effervescent vitamin C tablets are citric acid, sodium bicarbonate and calcium carbonate. This provides an ideal “fuel source” for a FIZZ-POP rocket. If possible use a 35 mm film canister (Figure 13). Break a vitamin C tablet into quarters and blu-tac one quarter to the inside of the lid. Fill the film canister about one-third full of water. Attach the lid. 

Figure 13 - Film canister & fuel source

Invert the canister and place on a flat surface. The water will react with the tablet causing the release of carbon dioxide, the pressure of gas will build up and it will eventually blow the canister body away from the lid. Children can make and decorate paper rockets before attaching them to the film canister fuel cell. See the NASA website for ideas. You can investigate any change in performance of the rocket (time to lift off or height attained) using smaller or larger bits of vitamin C tablet or by varying the volume or temperature of the water.

Why not try videoing the launch process. See the section on using simple digital video cameras elsewhere in this issue.

Because of the popularity of digital cameras, it is becoming harder to acquire film canisters (ask in your local film developing shop). However, there are adequate substitutes. Vitamin C tablets often come in a tube with a close fitting lid, such as the one in Figure 14. This works very well as a rocket. We have also tried another plastic tablet container and this too was excellent - more patience required here because it took a much longer time to build up enough pressure inside the container to blast it away from the lid. With these two bigger containers we used a whole vitamin C tablet each time.

Figure 14 - Alternative rocket bodies

Blow up that sausage 2