# How to Build a Bottle Rocket With a Parachute

by Contributor

A bottle rocket is a 2-liter bottle with compressed air and water released in an upward direction. It has everything to do with science because we can use this tool to learn many concepts about motion, forces, energy and flight as well as the scientific method. Using it with a parachute is another story. Here we'll show you how to do just that.

## Bottle Rocket Construction

Cut the top and the bottom off of one bottle, so that the center portion or a cylinder remains. Tape the cylinder to another bottle to create a fuselage (a place to store the parachute). Get the manila folder; fins will be made from it.

Cut three shapes out of the folded bottom in the shape that the diagram shows. Your fins will be triangularMark straight lines on the bottle by putting the bottle in the door Make three fins and tape them on the rocket. Be sure that the fins are spaced equally around the rocket body. This can be achieved by using a piece of string and wrapping it around the bottle and marking the string where it meets the end. Mark the string and lay it flat on a meter-stick or ruler. Find the circumference of the bottle by measuring the length of the string to the mark. Once you know the circumference, then you can divide it by three to find the distances the fins should be separated. or a right angle and trace a line on the bottle with a marker. Use these lines as guides to place the fins on the bottles.Use the athletic cone to make your nose cone. Use fairly rigid scissors and cut the bottom square off of the cone. Depending upon your project's mass limitations, place a golf ball sized piece of clay in the tip of the cone. This will add mass to the cone and give the rocket/cone more inertia. Then, using scissors, trim the cone to make it symmetrical. Tie a knot in the end of each piece of string to give it more friction and tape it using a piece of duct tape to the inside of the cone and to the inside of the rocket body.

Make a pedestal for the cone to sit on. It should be high enough up so that there is space between the cone and the top of the parachute compartment. You can make a pedestal out of the same material you will make the fins, the manila folder. Make three mini-fins, invert them and tape them on the rocket where the cone should sit.

Lay your garbage bag out flat. Cut off the closed end. It should look like a large rectangle and be open at both ends. Lay down the bag on a flat surface and smooth it out. The bag has a long side and a short side and is open at both ends. Fold it in two so that the short side is half as long as it was originally. Make sure the edges are perfectly lined up during each fold. Fold it in half along the long axis. Make a triangle with the base of the triangle being the closed end of the previous fold. Examine the base of the triangle and find the shortest length from the tip to the base. This is the limiting factor for chute size. The most pointed end will end up being the middle of the canopy. For an example; if you want the diameter of the chute to be 34 inches then measure 17 inches from the center of the canopy (the most pointed side of the parachute) along each side, mark it and then cut it. After cutting it, unfold it. If you have been successful there should be two canopies.

Keep experimenting. There are hundreds of ways to construct a bottle rocket. Creative design is really just a matter of thinking hard about what you can do with the materials you have,and the experimenting to see what works. Don't be afraid to try something else. Most likely the worse thing that can happen is your rocket does something very weird and everybody laughs. That's what make these things fun. If you go beyond what you read in this article,you will truly be a rocket engineer.

#### Items you will need

• 2 (2-Liter) Bottles
• 1 Small Plastic Cone
• Duct Tape
• Scissors
• String
• Manila Folder
• Large Plastic Trash Bag