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 ...

Water gets pushed down, bottle flies up. Done? Oh no! The first step into more sophistication is the aerodynamics. But honestly, if you make something vaguely rocket-shaped with fins, it’ll ...

And most bottles aren't a great shape for smooth flight ... called 'reaction force' then pushes the body of the rocket forward. Here, water and air are shoved out the back. The water is heavier ...