The main part of your rocket is the body or PRESSURE CHAMBER. We will be using a 2 liter bottle for our project.

Nose cones and fins are not only for performance but add character and style to your rocket. Be sure to take some time thinking out the design of your rocket before committing to a plan of action.  The cone is made from poster board or bristol board. You can make the cone by simply cutting a large circle out of the poster board (about a 6 inch radius). Cut a line from the outer edge of the circle to the center on the radius. Overlap the cut edges and turn the circle while holding one edge stationary until you get the desired cone shape. Secure the cone with staples or tape. Attach to the bottle with tape or similar adhesive. Duct tape works well.

Fins are the guidance system for your rocket. Without them a rocket would tumble end over end. Fins can give your rocket life and beauty. Fins can portray aggressive power or aerodynamic grace. To ensure stability and safety, the minimum number of fins on a rocket is three (3).

Attach the fins to the lower half of your rocket. If you are using 4 fins they should be at 90-degree angles. 3 fins should be at 120-degree angles.

For more information check these sites:

http://www.ag.ohio-state.edu/~rockets/cgi-bin/design_zone.cgi

http://hometown.aol.com/hayhurst1/h2orocket.htm

http://www.geocities.com/rocketcorps