How to Build a Bottle Rocket

Everything has to start somewhere. Would-be rocket scientists with their eyes set on building a shuttle to Mars might find that the realization of their dream is a ways off. But they can satisfy their desire to create something that flies through a fun and easy alternative enterprise: learning how to build a bottle rocket.

To begin how to build a bottle rocket, one would actually need two 2-liter plastic soda bottles. The top and bottom part of one of the bottles are to be cut off, leaving only the cylinder-shaped middle section of that bottle. The cylinder must then be duct taped to the bottom of the other whole soda bottle.

Aerodynamics is a significant factor in learning how to build a bottle rocket, so some care must be taken in designing the fins and the nose cone. The fins of the rocket will be cut out from a manila folder. There should be a total of three fins in all and they must be triangular in shape. They are to be attached to the rocket with the use of duct tape and each fin must be equally spaced apart from each other. The nose cone can be made from a small plastic athletic cone. The square-shaped bottom of the cone must be cut off. Putting a piece of clay the size of a golf ball inside the cone's tip will increase the cone's mass, thus giving it added inertia.

A piece of string with knots tied on both its ends for added friction is then to be attached to the bottle rocket, with one knotted end of the string to be taped inside the top of the rocket and the other knotted end inside the cone. The cone is then placed on the rocket, with the string inside it. To make sure that the cone comes off when the parachute is deployed, one may make a pedestal made up of three inverted fins (again made from manila folder) positioned right below where the cone shall rest.

The parachute is to be made from a large plastic trash bag. First, the closed end of the bag must be cut off, after which the bag is to be folded in half lengthwise. It is then folded in half a second time, and then folded into a triangular shape with the closed end of the preceding fold as its base, followed by a second triangular fold. The excess material hanging out the triangle's base must be cut off. Once unfolded, the result should be two big circle-shaped plastic canopies.

One of the plastic circles is then to be folded in half, then in fourths and eighths, and finally to its sixteenths. Afterwards it is unfolded, and a piece of masking tape is placed around each crease mark along the circle's edge. Holes are then punched through each masking tape piece. The circle is folded in half and string is tied through the holes that had been made. The ends of the parachute strings are taped to the interior of the bottle rocket. The whole chute is loaded inside the rocket, and the cone is placed back onto the top.

Once one has figured out how to build a bottle rocket, all that's left is to half-fill the rocket with water, set it up on the launch pad, pressurize it and finally fire it up (so to speak) for launch. Watching it blast off, it's amazing to think that that spiffy-looking missile shooting up into the sky was actually built using the simplest of materials.