Coy's Water Rocket

Define the Problem

I have to design a bottle rocket with a 2 liter bottle and customize the bottle with fins and a cone. Our main objective is to get the bottle rocket to go up high and then deploy a parachute.


Research and Generating Ideas

Building the rocket light weight but heavy enough to not make the rocket from falling side ways

Have all wings and edges the same lengths and weight

Have a enough power to take off but I have distribution to keep the power steady throughout the launch

Lift - On a rocket, Lift is a side force used to stabilize and control the direction of flight.

Thrust - This is the force that produces lift-off

Drag - Drag is created by air resistance. Imagine running down a track with a small parachute attached to your back. You would notice that it is more difficult to run with the parachute pulling you back versus running with no parachute.

Drag means to not have any extra weight or baggage to hold you back such as a piece to short or to long

Thrust acts through the center of gravity

Weight acts through the center of gravity.

Drag acts through the center of pressure

Lift acts through the center of pressure.

Pitch refers to an up and down movement of the rocket's nose.

Yaw refers to the side to side movement of the rocket's nose.

All rockets will rotate about their center of gravity during flight.

Lift and drag makes up mechanical forces

Gravitational force is a field force

Weight= Mass x Gravity

Mass x velocity= momentum

Air density changes with altitude, so the value of this variable depends on the height at which you expect to fly

Drag increases with the square of velocity

The frontal area is the area of the geometry you would see if the rocket were coming right at you

The center of pressure is the point through which the drag force acts and any wind forces

standard (lawndart), tumble, and backslider recovery systems are considered passive designs

Active Recovery system

Newtons 3rd law of motion.” For every action, there is an equal and opposite reaction.”

A recovery system is part of the rocket that allows the rocket to safely return to earth after launch.

Stability keeps the rocket from going sideways or rotating wrong

Two points control stability Center of Gravity and Center of Pressure

These two points also control your static margin

Tube volume and Deploy volume work your recovery system

Identifying criteria and specifying constraints

Materials List

Pvc pipe


Foam board


2 liter bottle

Nose tip

Ping pong ball

Exploring possibilities

Make the static margin the highest you can but try not to affect the weight of the rocket. When you make the weight heavier you will have better propulsion but your rocket will go down quicker.

Selecting an Approach

Developing a Design Proposal

Making a model or prototype

Testing and Evaluating the Design, using specifications

I tested all of my rocket on whiteboxlearning and in person. I tested my fins, cone, static margin, and weight. My results were not as good as some, but I could make the parachute bigger to make it better. I could also make the fins sturdier.

Refining the Design

Based on my test, I need to change the parachute and make it bigger.  I would also have to make the parachute deploy later not right after take off. This refine will make the product I whole lot better. I would also have to make the fins stronger and make them stay on the bottle.

Creating or Making It

If I had the right material, time, money, and work force I would make the parachute deploy better and make the parachute bigger so it will make the bottle float down better and not hit the ground as hard. This would allow the buyer to have the best experience.

Communicating processes and results

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