Water pressure missile

The first launch https://youtu.be/k5DawNX3BPg

I saw this idea on the internet and decided to try it myself.

All it takes is:

Water pipe
Cork
Valve stem
A plastic bottle
Hot glue
Cardboard and 2 A4 pages
A way to stand the pipe vertically

I connected the pipe to our trampoline and wrapped duct tape on one end to thicken the pipe and hold the bottle tightly before launch.

I filed the cork and pushed it into the pipe. I drilled the cork and pushed into the hole a valve stem that I cut out of a bicycle tire. Then I sealed all points with instant glue.

The missile is launched by pouring a little water into the bottle, putting it upside down on the pipe and pushing down so that it locks on the duct tape. Then connecting a bicycle air pump to the valve and pumping air until it launches.

At first we launched regular plastic bottles but they flew awkwardly to a very limited height and air resistance turned them over. We realized that bottles have to look like missiles and have an aerodynamic form. So we cut small fins from cardboard and glued them to the base of the missile we also glued two A4 pages together and formed them into a cone for the the top of the missile.

The last stage was to build a portable launching pad that we can take with us to trips and impress the spectators.