Notes:

1. Make the rupture disc out of aluminum foil. The disc diameter should be 25mm. Puncture the center of the disc with the inflation valve. Glue the inflation valve needle to the disc; this will keep the disc water tight.

2. Drill a 21mm (0.826 in.) hole through the center of the bottle cap top. The bottle cap is used to hold the rupture disc against the mouth of the bottle.

3. Attach an air pump to the inflation valve. Fasten the pump hose to the launch pad. Pump air into bottle until the rupture disc breaks open. Once the disc is ruptured, water will rapidily exit the bottle and propel the rocket.

Instructions provided by Sean Eagleton.