Stomp Rockets

These rockets use air pressure to launch your lightweight rocket skyward. Using simple materials, you'll be able to make your launcher in minutes and as many rockets as you want. The first time I flew these, they got stuck on the roof, so be prepared with a few extras just in case.

Materials

• 2L soda bottle
• 1/2" PVC pipe
• duct tape
• pen or pencil
• index cards
• sheets of paper
• bicycle inner tube

The higher pressure is generated inside the bottle when you stomp on it. Because air is a gas, it's also compressible, which means you can pack the same volume of air into a tighter space. When you decrease the volume, you increase the pressure. Since higher pressure always pushes, the rocket feels a push as soon as the bottle collapses down, which moves the rocket forward.