Make a launchpad that holds the bottle with the neck downwards, lets you attach the pump and stand behind the bottle. One good method is to plant a spade or garden fork in the ground at a low angle ...

The problem with a lot of these water bottle rocket projects is that they leak where the bottle meets the launcher. In most cases this is a good thing as it’s almost impossible to build up ...

To construct their rockets, students used materials such as cardboard, plastic cones, and hot glue. Water served as the propellant, while an air pump pressurized the bottles before launch.

The bottle must be made entirely of plastic ... If no, make sure the valve can open to let air through from the pump. It may be damaged or screwed shut. If the rocket does fly but not very ...