How to Build a Bottle Rocket With a Parachute.

Have you ever wanted to be like a NASA scientist.  Well now you can with my easy steps on how to build your very own bottle rocket.  You will be able to understand the concepts of physics, while having FUN building a rocket.    

You will need the following:
one Cardboard box (You will need to cut out three wings.)
At least three empty soda bottles (2 litter size)
One role of plastic drop cloth. This can be found at any local hardware store.  I used 0.7 mil size (thickness).  I would not go much bigger.
One tennis ball 
One spool of nylon twine

Tools you will need:
one pair of good scissors 
One sharpie
one 12' inch ruler
One spool of duct tape
One hole puncher
you may also want a drill 

First you will want to drink any of the soda inside your soda bottles. Then you should cut the labels from the bottles. Repeat for all the bottles you have.

Pick the best bottle for the engine.  This means make sure there are no holes or cuts in the bottle.  You should never have to cut the engine bottle. 

It is now time to make the middle of the rocket.  Take one of the other soda bottles and cut the bottom and neck off of the bottle.  

Use the picture as a diagram.

Save the neck of the bottle you will need it for latter!

Cut a flat piece of cardboard from your box.  Now you should trace three triangles and cut them out.  

The hypotenuse side should be 6' inches, the adjacent side should be 5' inches, and the opposite side should be 3' inches.

These measurements are what I used, you could test other shapes and sizes to see what fits your rocket best.  

You should now take the middle section of the rocket and attach it to the engine using duct tape. The middle section should fit on to the bottom part of the engine.  Then tape around the edge to secure the two parts together. 

Now attach the wings by using duct tape.  You can evenly space the wings by finding the circumference of the bottle and dividing it into three parts.  You should attach the adjacent side to the bottle and the opposite side should be towards the bottom. 
to find circumference use this formula : 

You may also want to put the wings on a angle.  This will make your rocket spin when it is launched.  If it is spinning it means that the rocket is going straight up. 

After this step your rocket should look like the picture. 

The nose cone is the top of the rocket.  This piece will fall off the rest of the rocket when it is launched and will fall back to earth.  

My teacher helped the class with this part because it is dangerous.

He had to heat the bottom of the bottle so it would get a rounder shape.  After he was done heating the bottle, I was able to cut the neck of the bottle off.  

*Save the neck you will use it in the next step.*    

This part is what will hold the parachute until it deploys and will hold the nose cone on until it falls down to earth.

You should take the two neck pieces that you have saved and tape them together.  Put the bottle openings together and tape around them to secure them.  Look at the image to see what it looks like.   

Now take the deploying devise and slide it in to the first part of the rocket you made earlier. Then take the nose cone and slide it on top of the deploying devise.  It should fit perfictly but easy enough to come apart. 

You are almost  done!  All you need now is a good parachute. 

I used this website to make my parachute:
http://www.lnhs.org/hayhurst/rockets/

Only use the directions on how fold and cut the plastic.  Make sure you follow the directions, it is easy to make a mistake.

Now you will take your plastic canopy and punch holes in it so you can loop the shroud lines (nylon string) and make a good parachute. 

First you will pick twelve spots evenly around the canopy (make sure to mark the spots with the sharpie.).  You can do this by finding the circumference and dividing it by twelve.  Then put an inch of duct tape (front and back) on each spot.  This is where you will punch holes in the canopy with the hole puncher.  The duct tape will make the holes stronger.

Now cut the length of your nylon string.  These will make your shroud lines. Each string should be as long as the diameter of the canopy.  You can now tie the strings to the canopy.
  

Now drill the hole in the tennis ball using a drill.  The hole is where you will pass the shroud lines through and make a knot so they will not come out. 

Now you have a working rocket.  Go out now and launch your rockets. 
Always remember to be safe and have fun!

The physics behind the bottle rocket is Newtons 3rd Law that "For every action there is an equal reaction."  The water and air pressure cause the water to push out of the rockets engine and move upward. When the rocket is coming down, the parachute gets released from the rocket.