Water Bottle Rockets and Launcher

Making and Launching a Bottle Rocket

Tools and Materials

• Electric drill with 1/16-, 5/32-, and ¼-inch bits
• One No. 4 size rubber stopper (1 inch long, 1-inch diameter at the fat end)
• One 8-inch length of 3/16-inch (outside diameter) copper tubing
• Bicycle pump with inflation needle
• Heavy card stock
• One 2-liter plastic bottle
• Duct tape
• One drinking straw, minimum ¼-inch diameter
• Four 1-inch-square wood blocks
• One ½-inch plywood board, 12 to 16 inches square
• One ¼-inch threaded steel rod, 18 inches long
• Four ¼-inch nuts
• Two washers, ¼-inch hole, 1-inch diameter 

Make the Stopper Assembly

1. Drill a 1/16-inch hole through the middle of the stopper.

2. Widen the hole by drilling the 5/32-inch bit about ½ inch into the top (wider part) of the stopper.

3. Insert the copper tubing into the 5/32-inch hole.

4. Push the inflation needle into the hole in the bottom of the stopper so that it feeds into the copper tube.

Build the Rocket

5. Make fins from card stock; attach to the bottle with duct tape.

6. Tape the 8-inch drinking straw to the side of the bottle (oriented from top to bottom).

Build the Launchpad

7. Attach square blocks to the corners of the launch platform (plywood), using quick-setting glue or 1¼-inch wood screws.

8. Place the rocket in the center of the launch platform and mark the spot directly below the plastic straw.

9. Drill a ¼-inch hole through the mark; insert the steel rod into the hole, and fix in place with nuts and washers.

Prepare the Hydro-Pump Rocket for Launch

10. Attach the bicycle pump to the inflation needle.

11. Fill bottle one-third full with water, below top of copper tube.

12. Push the stopper assembly firmly into bottle's mouth.

13. Invert the rocket, and slide the soda straw onto the rod.

Launch the Rocket

14. Pump air into the rocket. The amount of pressure required to fire the rocket will vary, depending on how clean the seal between the rubber stopper and the rocket is and how firmly the stopper is placed.

15. After several pumps, the pressure inside the rocket will be great enough to overcome the friction holding the stopper in place. Now comes the cool part, as the stopper releases from the rocket, and the rocket launches high into the air, shooting a trail of water behind it. Zoom!