How to Make a Bottle Rocket

• 1). Fold your sheet of construction paper into a cone shape. Place it on top of the 2 liter bottle on the end without the cap. Adjust it so that it is a snug fit and tape it so that it holds its shape. Tape it to the top of the bottle and trim the excess construction paper from around the edges using the scissors. You now have a nose cone for your bottle rocket. This will help to stabilize it while it is in flight.
  
  
• 2). Cut your cardboard into 4 equal pieces. Cut it in half once lengthwise and once widthwise. You can design the fins however you want. The simplest design is to cut them in half across the diagonal to create 4 triangular fins. You can get creative with the fins as long as you make sure they are all the same size and shape and don't trim away more than half of the material. Start the base of the fin wide and taper it down to a point. The rest is up to you.
  
  
• 3). Attach the basketball pump adapter to your bicycle pump. Push it all the way through the cork so that it is firmly in place. This is how you will pressurize your rocket before launch.
  
  
• 4). Remove the cap from the 2-liter bottle and recycle it. Push the cork firmly into the bottle. The harder you push it in, the higher your rocket will fly.
  
  
• 5). To launch your rocket, balance it on its fins so that it points straight up. Pump the bicycle pump to pressurize the bottle. When the pressure is high enough, the cork will come out and the pressure will all be released at once. This will launch your bottle rocket.