What I learned about bottle rockets is the smaller the bottles, the higher the rocket goes. The rocket has to have water on the bottom for it to fly. What I did for my rocket is I got two 2 liter bottles. I cut part of the bottom off one of the bottles and taped them together. But, you have to make sure it’s not sideways. If the bottles are taped on sideways if won’t fly straight. Then, I cut out four fins and glued them on the bottom of the rocket. With the fins there is a better chance it with fly higher. Next, I cut out five strings for the parachute. We put a parachute on it so that when it comes down the parachute will slow it down for it not to hit the ground hard. For the parachute I got a plastic bag and taped the strings to it
