| Now, launching a weather balloon sounds straight | | | | a large heavy steel tank and a 125 cubic ft helium |
| forward enough, blow up, attach payload, release! | | | | canister will stand about 6 ft tall and weigh a |
| But this isn't a party balloon we're talking about, | | | | hefty 100 pounds. So you'll need a car or jeep for |
| no, for a weather balloon, whether its a | | | | transportation, especially if you're going to track |
| meteorological balloon or camera balloon, there are | | | | your payload down when it lands. |
| a few things you'll need to consider when planning | | | | Batteries. |
| your launch: | | | | There's nothing more frustrating than loosing your |
| Size Does Matter | | | | payload, especially if you couldn't afford the |
| Don't be tempted to buy a smaller balloon and | | | | equipment to stream the images/data directly |
| just pump in more helium! Your balloon is going up | | | | back. If you're relying on GPS tracking to recover |
| up up, to around 90'000 feet off the ground. At | | | | your data manually you had better spare a |
| high altitude balloons expand due to the pressure | | | | thought for the poor electronics your hurling into |
| outside decreasing while the pressure inside | | | | the freezing environment of the upper |
| remains the same. As your balloon rises through | | | | stratosphere! At 90'000 ft up the temperature is |
| the atmosphere it will expand as the air thins. A | | | | about -50 degrees C and your average battery |
| weather balloon 5 ft wide at launch will reach a | | | | will cease to function. However you have a better |
| width of about 20 ft at peak altitude. It needs the | | | | chance of maintaining connection with your |
| extra inflation room for this. Your balloon will | | | | beloved balloon kits if you use lithium batteries |
| eventually pop, hopefully at its maximum altitude. | | | | NOT lithium ion batteries. No no, different kettle |
| Its not gonna reach this if you over fill it. So get | | | | of fish. You can buy energiser lithium batteries and |
| the right sized balloon to take the weight of your | | | | they last 8 times longer than standard ones but |
| radiosonde or weather balloon camera - of course | | | | more importantly they can withstand the cold |
| if your balloons maximum altitude is far above | | | | temperatures of the upper stratosphere! |
| what you need it for you have some wiggle | | | | The Actual Launch |
| room & can experiment with inflation, but at your | | | | Now, on the day you need to carefully consider |
| own risk! | | | | launch area, and weather conditions: Don't launch |
| Each cubic ft of helium will lift 28g of weight, | | | | near a military installation! They might think they're |
| however, the radiosonde needs to be lighter than | | | | under attack, and while the idea of men in |
| this for the weather balloon to rise. The balloon will | | | | camouflage running around on red alert may |
| rise faster the smaller the weight. The difference | | | | sound funny to you, I bet the idea of them |
| between the radiosonde weight and the liftable | | | | shooting down your weather balloon isn't! Don't |
| weight is called the 'free lift'. You can calculate the | | | | interfere with military air space and they won't |
| balloons accent rate easily as it works out at | | | | interfere with you. Next you need to make sure |
| 300ft per minute for every pound of 'free weight'. | | | | your launch area is away from obstructions such |
| The faster your balloon ascends the less chance | | | | as trees and telephone polls, preferably not in a |
| of something going wrong - a blow out, | | | | built up area for retrieval purposes. |
| equipment batteries failing, the payload landing | | | | For obvious reasons no wind is preferable, but |
| further down wind and being harder to recover. | | | | look up the wind direction before you launch so |
| Transportation. | | | | you know which direction it'll land in. If your |
| Now a weather balloon is not gonna weigh much | | | | launching a camera balloon you'll need a sunny day |
| right? Stick it in your pocket almost (if you have | | | | for decent exposure on your aerial photography. |
| really big pockets). But a helium canister does! It's | | | | |