Assemble the model rocket motor according to the manufacturer's directions. Most model rocket motors require tying a shock cord to the motor, then putting the motor into the appropriate tube.
Install the engine mount in the body of the rocket. The engine mount is a hook or tube that fits inside the rocket and keeps the engine in place. Glue the engine mount inside the body of the rocket according to the instructions provided by the manufacturer. Once the glue has dried, put the engine into the engine mount.
Prepare the fins of the rocket by sanding their edges and faces so that they are smooth and fit easily into the model rocket slots. Glue the fins to the body and allow the glue to dry. For a science project, try launching the same model rocket with fins of different shapes to see which shape makes the rocket fly best.
Glue the launch lug to the body of the rocket. The launch lug is a small, strawlike piece that supports the rocket on the launch pad.
Assemble the nose cone and parachute. Generally, a rubber band is attached to a hook in the body of the rocket and then attached to the nose cone and parachute. After the rocket is launched, the nose cone comes off and the parachute opens, allowing the rocket to land safely.
Paint the rocket and place any enclosed decals on it. The rocket is now ready to launch.
Photograph or videotape the launch and write a report about the aerodynamics of the launch, the effect of wind on the rocket, how model rockets are similar to real rockets or the effects of different fins on the flight. These topics can be presented for a model rocket science project.