Water Bottle Rocket Instructions

Rockets provide the means to carry large items into space.

Rockets are devices designed to fly driven by a one-time use propellant. Early rockets were developed around 300 B.C. using steam as their propellant. The Chinese experimented with gunpowder-based rockets beginning around 100 A.D. with attempts to create staged rockets beginning in the 16th century. Modern rockets are chemical driven. Liquid-based propellants allow massive rockets to carry heavy payloads into Earth's orbit and beyond. Water bottle rockets provide a low-cost means for science teachers to instruct students on the basics of rocket propulsion.

Things You'll Need

• Two bottles, 2 liters
• Duct tape
• Scissors
• Manila folder
• Marker
• Small plastic cone
• Clay
• String
• Large garbage bag
• Masking tape
• Hole puncher
• Cork that fits tightly mouth of bottle
• Hot glue gun
• Tire valve stem
• Drill
• Tire pump

Instructions

1. Prepare the payload section by cutting the top and bottom off of one of the 2-liter bottles. Use the duct tape to attach the resulting cylinder to the second bottle. Position the second bottle halfway in the cylinder.

2. Create the fins by cutting rectangles out of the manila folder and folding them into triangles. Use the marker to draw three vertical lines, evenly spaced around the bottle below the tape attaching the payload section. Use a room corner or door frame to ensure the lines are perfectly vertical or the rocket will tumble. Use the duct tape to attach the fins to the bottle. Optionally, a hot glue gun can be used.

3. Place a golf ball-sized piece of clay inside the plastic cone and duct tape a 10-inch piece of string to the inside of the cone and to the rocket body inside of the payload section. Cut three small triangles out of the manila folder and duct tape them to the top of the payload section. These triangles support the nose cone and ensures it comes off at the top of the rocket's flight.

4. Make a parachute out of the large garbage bag. Cut the closed end off the bag using the scissors. Fold the bag in half so the open ends meet each other. Fold it in half again, this time along the long axis. Fold a triangle. The closed end is the base with several inches remaining below the edge. Fold the triangle again and cut evenly across the bottom approximately 17 inches from the tip of the triangle. The result is two canopies. Fold each of the canopies in half, then again into quarters, and into eights and finally into 16ths. When unfolded, each crease marks the location of a parachute string. Cut and place a 1-inch piece of masking tape at the edge of the canopy at the crease marks. Use the hole puncher to punch a hole in each piece of tape. Attach a 34 inch piece of string to each tab and tie them together at the bottom. Attach the string bundle to the top of the second bottle inside the payload section.

5. Prepare the cork by drilling a hole the size of the tire valve stem. Insert the tire valve stem from the wide part of the cork. Use the hot glue gun to seal the stem in the cork. Fill the rocket halfway with water and tightly fit the cork assembly in the mouth of the bottle. Use the tire pump to pressurize the rocket. When the pressure exceeds the cork's fit in the mouth of the bottle, the rocket launches. At the top of the flight, the cone falls off the rocket, allowing the parachute to deploy.

References

• NASA: Timeline - A Brief History of Rocketry
• NASA: All About Water Rockets
• Lancaster High School: Mr. Hayhurst's Quick and Easy Bottle Rocket
• The Water Rocket Explorer: Workshop