High-altitude ballooning. Russian Edition. Part 1.

Hi,

I've decided to try high-altitude ballooning. The maximum goal is to do a ballon which can be launched to the stratosphere, do some stuff (not only passively hang in there making pictures) and safely descent to the target location(this should be the hardest thing to acheive).

Typically this hobby is quite simple - you purchase a balloon, take helium tank, fill the balloon with attached payload and launch. But in Russia, there are several difficulties.

• It's hard to purchase proper HA balloon without spending all of your money
• It's hard to get necessary volumes of Helium. I don't understand why major exporter of natural gas on the planet has difficulties with helium on the internal market - but that's a fact. It costs a fortune here.

I wanted to do everything really cheap, so that my example could become an inspiration for someone else.

I seperated the project into several Phases.

• Phase 1 - cheap balloon filling and cheap balloon.
• Phase 2 - cheap payload
• Phase 3 - cheap control system

I already have some thoughts about all three of them and even working prototypes, but right now I'm focusing on Phase 1.

Cheap balloon is a quiestion for now - I can pucrhase 45'' baloon quite cheaply http://zatey.ru/production/prod/detail.php?ID=70273 ~ 2$, but 8' will cost a fortune - almost 70$.

According to this famous table http://www.chem.hawaii.edu/uham/lift.html, 45'' baloon should give me 500gr lift wich is enough for the start and I think I can use two of those balloons to increase the payload weight.

Cheap filling is the main task for me right now. I'm thinking about Hydrogen, coz Helium is an inert gas and you cannot get it from chemical reaction. Yes hydrogen is explosive, but I think with right safety measures it shouldn't be a problem even in case of explosion. So, I can get Hydrogen using electrolysis and from pure chemical reaction.

Electrolysis - Pros: requires only water as a chemical resource. Cons: requires electrical energy, generates oxygen on the other wire(which is not only bad that you have to separate two gases, but if mixed they could easily blow-up because electricity is very close).

Chemical reaction - Pros: easy to do, only chemicals are necessary and in relatively small amounts. Cons: exothermal reaction(some parts of generator could be melted), hazard chemicals.

I decided to go with chemical, aluminum and sodium hydroxide reaction.

Safety Note: Always use glasses and gloves, be very accurate with the reaction, sodium hydroxide is extremely dangerous thing! And hydrogen can explode. DO NOT EVEN TRY TO DO THIS AT HOME!

I did a lot of tests and found that standard liquid drain cleaner contains enough sodium hydroxide for the reaction. As a source of aluminum I tried different things, started with soda cans, but they have a protective layer which slows down the reaction. Then I tried aluminum foil and plates made of aluminum, results were great, but the reaction goes too quickly and dissolves too much heat. Then accidentally I tried duraluminum tube and the result was awesome - reaction went smoothly and not so quickly, but the volume of hydrogen was enough to fill the 91cm balloon.

This is the look of the last successfull setup (I had a bubbler, but it developed a leak, so I had to attach balloon directly to the reaction chamber, luckily duraluminum tube dissolves way less heat and reaction is going not very fast, so there almost no toxic foam, with foil it was bubbling out of every hole)

This one below is a picture of the reaction chamber. I found that this kind of plastic bottle from ice tea is the best, because I have loads of them, I can through used one away and I don't have to clean the bottle for every new reaction, actually the product of the reaction is very messy and it's very  hard to properly dispose it separately from the bottle, I'm not even talking about toxic lye which is still there.

you can see that the bottom part melted a little bit.

And this one below is a picture of the balloon lifting quite heavy rope attached to it. With this balloon lift was not great because balloon itself was damaged(lye and other products of the reaction from previous tests) and had a lot of water on it (it was raining that day)

So, now I have all the confirmations and I was able to find good source of sodium hydroxide and recently I found good source of aluminum. This is a duraluminum tube which I purchased in a store and it's very inexpensive (~2$), I think this volume is enough to fill a very big high-altitude balloon.

I still needed a bubbler, because the chemical reaction produce a fog which can go into the balloon and damage it or condensate on the walls of the balloon and reduce a lift. Also I was a little bit worried about the speed of the reaction and I think I need an option to attach two reaction chambers to the bubbler.

So, here it is - a new bubbler with ability to easily attach or detach a couple of reaction chambers even during the process. I've made it using a can, a garden irrigation fittings and a plastic valve for the hydrogen output.

Sorry for bad photo quality, I'll do better pictures later. On the left one you can see that the valve is opened for the attached chamber, left valve is closed because there is no chamber attached to it.

So, stay tuned, I'll update you with the test results.