How to Make a Customizable Weather Balloon

In this instructable, you will learn how to make a weather balloon payload capable of carrying instrumentation and cameras to the edge of space. Using the  weather balloon, you can  collect data about the local environment, and utilize that data to encourage more responsible environmental habits.

This payload is supposed to be fully customizable, meaning you can swap components out for cheaper or more quality items. For example, if you are pursuing this project just for fun, you can opt out to not use an Arduino to data log  and just attach a couple of different cameras instead.

•Arduino
•Buzzer
•Double-sided tape
•Enclosure (Styrofoam cooler) 
•Exacto knife
•Go pro camera and case
•Gyroscope 
•Nuts (4)
•Parachute
•Pieces of rope (2)
•Prototype Shield
•Retainer mounts (2)
•Screws (4)
•SD  card Shield
•Strip of Velcro 

The first step is to find a suitable housing for your payload. In this tutorial, we'll be using a Styrofoam cooler. Its low weight, good insulation, and shock-absorbing properties make Styrofoam ideal.

Next, we need to decide where we'll place our electronics in the payload. In our case, we're using an arduino stack, go pro, buzzer, and battery pack, though there is plenty of room for additional hardware and sensors.

Mounting the camera is fairly simple. We start be firmly pressing down the Go Pro's casing, leaving an impression in the soft styrofoam. From here, we use our boxcutter to cut around the impression, leaving holes for the lens and the power button. Then, use double-sided tape to fasten the camera holder to the styrofoam.

Attach the SD card shield to the Arduino, and a prototype board on top of that. The prototype board isn't essential, but it's helpful for driving custom sensors and circuitry such as the buzzer in our project.

Place the Arduino stack in its planned position and mark it on the Styrofoam. Now, place a strip of Velcro on to the bottom of the arduino and adhere the stack to the payload base.

Connect any other harware to the arduino and adhere it either with velcro or double-sided tape. In this tutorial, we will be also attaching a buzzer to the prototype shield.

Now we'll focus on the other half of the enclosure. Start by finding the midpoint of each side and marking it. These will eventually be holes for the cord attaching the payload to the balloon and parachute, so be sure they're low enough to clear the base of the cooler. Once you're sure they're in the proper positions, make holes with a drill bit or box cutter big enough to let the rope through.

Mark the center of the bottom of the cooler to mark the proper place for the retaining plates. While not absolutley necessarry, these will make sure that even if the knots give way, the cords will not be able to slide out of the payload, keeping it from falling back to earth. After finding the proper placement, mark the locations of the mount holes and either drill them through with a drill bit, or simply push the screws through the soft styrofoam. Make sure the screws used are long enough to go through the enclosure and the second retaining plate. On the other side, line up the other retainer and thread nuts onto them, but do not tighten them all the way yet.

Pass the mounting cords through the holes on opposite sides of the cooler and then up throught the hole in the bottom retaining plate. Now, carefully hang the payload by its strings to make sure it's level, then tie the cords so that the knot is knot is within the hole in the bottom retaining plate. Make sure this is done well with multiple, secure knots. If these fail, there's a chance your payload will be hurtling toward the earth. Once the knots are ties, tighten down the nuts on the retaining plates to clamp on to the cords between them.

Attach the drag parachute to the strings on top of the payload. Again, make sure this knot is secure, for the same reason as before.

Before attempting to fill the balloon, ensure all components are secured well using tape or fasteners of your choice. 

Attaching and filling the ballon is one of the more challenging portions of the process. First off, bare hands or skin should never touch the balloon as this could compromise the latex. Latex or nitrile gloves are a must, as even fabric ones can hurt the delicate membrane. The amount of helium to use depends on the particular balloon and the desired burst altitude. This can be calculated from online tables and applications. As for it's attachment, this should also be performed with the utmost care. The tie around the neck of the balloon needs to be tight in order to keep helium from escaping or worse, your balloon from escaping. Multiple knots are a good idea. However, over tightening can damage the balloon and should be avoided. The cord coming off of the balloon should be attached to the fabric loop on the upper side of the parachute. This will keep the parachute completely condensed on the ascent, but allow it to open as soon at the balloon bursts.