The Balloon

If tires are the contact point between your car and the road, the balloon is your contact point between your balloon and the sky.  Just like you shouldn't cheap out on tires just to save a buck, likewise you shouldn't go find the cheapest balloon.  In my opinion there is only one place to buy them, Kaymont.  (http://kaymontballoons.com/).

Here is my logic.  There are a lot of balloons available for a little less on ebay, and you can even find surplus balloons on there too.  Other suppliers are out there such as ScientificSales (http://www.scientificsales.com), but no one runs through as many balloons as Kaymont.  No one.  They are the major supplier for most of the government agencies that are constantly sending out sounding balloons.  This means their inventory is constantly fresh and turning.

Why would that matter?  Two words:  Natural Latex.

The balloons we are working with are made of natural latex, and thus will age.  With age comes undesirable characteristics, most of which will limit the eventual height of your balloon's flight.  If you are trying to get as high as possible, getting a fresh balloon and storing it properly (cool, dark places) should be of high priority.  What fun is it to go to all the effort and have the balloon just blow out while you are inflating it?

I also bought two balloons so I had one as insurance.  Things happen, and with all the time and energy going into this project, I would feel like an idiot blowing out the balloon and not having a spare.

I would also note that I have seen on just about every reference site I have looked at that you need to wear gloves when handling the balloon.  For some reason your body oils are the devil on these balloons, and so you need to take efforts to keep your hands covered.  I would think nitrile gloves would be fine, there shouldn't be any reason you have to use latex gloves.  The real issue is getting your oils on the balloon (or so the story goes) so go with whatever is cheaper or more readily available.

Balloons are purchased by weight.  It appears that the defacto standard size for High Altitude Ballooning are 1200 gram balloons.  Expect to pay around $100 for these.  I was able to get a holiday special that brought both balloons to about $175.

I looked at going with a 1500gram balloon, but in discussing the use of hydrogen they were recommending I go with a smaller 1000gram balloon.  More for ground safety than anything.  In the end I compromised and went with the 1200 gram balloon.  This should take a 4-6lb package to 100-105,000ft.

When they come they look like a rectilinear lump of bread dough in a clear plastic bag about the size of a small lunch box.

We will see what happens.

Planning the Balloon

I have been going over this for months now, and researching, assembling and generally solving problems to the best of my ability.  There are a lot of pages out there that have documented how they have launched and some of the process, but I am finding that it is often the little things that can be problematic as I have been working on this.

Because of that experience, I am going to try and document the parts I used and why.  I will also try and document a few of the alternatives, and my reasoning for not using them where applicable.

I think the first thing that was a challenge was finding how different teams had done each of the separate elements of their balloons. For instance, how do you connect the parachute to a fragile foam structure?  Things like that you don't think of until you are well down the road.  Accordingly, I am going to try to break my posts up into pieces that focus on the individual elements and how we chose to solve the problems.

I will start at the top and work down thusly:

1. The balloon.  Selection, sourcing and size
2.  Hydrogen or Helium.  Considerations for both
3. Closing off the balloon and connecting to the rest of your rig.
4. The parachute
5. Attaching the parachute to the payload
6. The payload container
7. The payload - tracking
8. The payload - cameras
9. The payload - fun
10. Making and Attaching the radar reflector
11. Ground equipment
12. Procedures and equipment for filling the balloon
13. Procedures for activating and starting the payload equipment
14. Launching the balloon
15. Tracking from the ground
16. Recovery

It is a little bit ambitious, but I hope to use the above list to help me work through all the various bits and pieces of the project.  By documenting what we are doing, I hope I can spot any flaws and make changes before launch.

The Parachute

Honestly, this was one of the last things I purchased for this launch.  I just got it today though, and I have to give Top Flight Recovery a shout out.  Amazing!

Our choice was the Crossfire Parachute (scroll to the bottom of the page).  There are several reasons we went this direction:

1. Cost.  Their prices are some of the most reasonable I saw on the net for a similar setup.  At half the cost, it was well worth looking at.
2. Made to order.  You get the choice of two colors to make the chute.  We chose yellow and day-glow orange.
3. The Lines.  They use a Nylon flat braided line.  They also only have eight lines total (4 loops).  This was appealing in that it seems they would be far less likely to tangle.
4. Customization.  The fact they are made to order, I requested they put a loop on the top to attach the balloon.  When ordered I didn't know how this would go though, but I felt it was worth a try.

So, we ordered on Jan 8, 2013 at about 3pm Mountain.  Today is the 11th, and I have the chute in hand.  I was shocked!

 Note the custom loop... and how it is reinforced! 

The chute is beautifully made, and there is a hand written note on my ticket "Attach a loop at top!"  Using the same flat braided Nylon as the lines, they attached a nicely sized loop that will make attaching the balloon infinitely easier.  The seams are well reinforced, and the perimeter is backed with tape to give it extra strength.

In essence, I cannot say enough about the quality of the product, the ease of ordering, the time (or lack thereof ) to get it, and the customer service.

CF-36 CrossFire Chute - Cost: $34.95 + $7.00 Shipping.  $41.95 Total

Top Flight Recovery.  Check them out here:

http://topflightrecoveryllc.homestead.com/index.html