This is based on the Alka Seltzer pop-off. As an added extra we issued the group with paper, scissors, tape etc. and they had to build rocket bodies to go over the film canisters. They were given 15 minutes to design, decorate and fix the bodies. Points were awarded for sytle, aerodynamics and decoration as well as height gained.
We also used baking soda and vinegar as propellants. It gives a much better fizz, smells disgusting and stings like mad if you get it in your eyes or any cuts. Maybe alka seltzer is a better option 🙁