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    High Altitude Balloon Tutorial
    === Launch Day, in Pictures! ===

    The below images are an attempt to tell a story of what it's like during launch day. Images are from three different launches mixed together, so don't get confused at people wearing different clothes in different pictures haha. Here we go . . .

    After everyone meets up at the planned launch location, we all start taking out our 'stuff' and getting it all ready to go. Here you can see me and Nick trying to figure out if GPS is properly reporting the coordinates. A thumb pointing towards the mouth is a sign of genius [cough].

    When transporting the helium tanks in your vehicle, make sure to wrap them in a blanket and tie them down securely. Compressed gas can be dangerous. Use two people to lift them - don't roll them around on the ground. They weigh about 120 pounds each.

    A tarp is laid out to protect the balloon for the pointy stuff on the ground. The helium tanks and other equipment are placed strategically around it. We put on latex gloves to protect the balloon from the damaging oils on our hands. We also make sure we aren't wearing any clothing that could pop the balloon (such as belt buckles). And finally, we discuss the game plan so everyone is prepared and on the same page.

    A custom large nozzle made from PVC piping was attached to the hose and pressure valve for the helium tank.

    As the balloon gets inflated, a large bed sheet is placed over the balloon to prevent it from blowing in the wind. This method is easier than having people hold the balloon with their hands. A sheet larger than what is shown in the image would have been better.

    It's better that one person is dedicated to holding the balloon nozzle, and another for controlling the air from the tanks. But here is an image of just one person doing both.

    The balloon is tied off, and the sheet is removed. We use a spring scale to measure the exact lifting force for use with simulating the balloon trajectory. The package and parachute is then attached to the balloon. We perform one last systems check to make sure everything is working properly.

    The balloon is slowly and carefully released. A second person holds the package to make sure it lifts up properly and doesn't swing wildly.

    warning: If you release the balloon suddenly - before the string is tight - this will cause a shockwave that could damage the connections to the package.

    It goes up very fast. Glaring sunlight makes it difficult to photograph it . . .

    We pack up while running one last simulation of the balloon trajectory to predict the landing spot. We talk about where we are heading and go in one big convoy. There is no need to rush as you don't want to drive in the opposite direction that the balloon is heading.

    The results of the final simulation are calculated, and then the GPS coordinates are messaged to everyone using Twitter. Everyone plugs in the coordinates into their preferred mapping system, or at least follows the convoy. It has the feeling of a race to see who can find the balloon first.

    Some people have fancy APRS tracking devices in their cars that give the current balloon location.

    Others have it 'plugged' into computer software.

    The balloon expands and expands due to reduced air pressure, until it literally becomes the size of a small house. Finally a pop, and the package free-falls back to Earth - only to be saved by a parachute. It drifts some distance more while it's simultaneously being chased down by a caravan of cars.

    This is an image from the on-board camera. You see that vast expanse of mountainous wilderness with no roads in sight? Good thing the wind blew our package in the opposite direction! Otherwise, we'd have to plan for a lot of forest hiking. We've been incredibly lucky that almost every landing site we've had could be seen from inside a car on the road. And even once it literally landed on a road.

    Geez, there is this huge field of nothing-ness, yet why did it have to get hooked on the one and only power line?! The way to plan around this is to use a very long string between the parachute and the package. So if it gets caught in a tree or power line you can just cut the string to recover the package. Or maybe climb the tree and saw off a branch. We yanked a few times and the parachute then unhooked itself.

    Always wait for everyone to arrive at the landing site before recovering the capsule. This is not just so everyone can get a photograph, but also for the engineers who might need to do something with the capsule before everyone goes to lunch.

    Remember that you will be driving in obscure back roads with big drainage ditches. It took 800 lbs of engineers to sit on that hood to get the 4-wheel drive vehicle unstuck . . . (that's me sitting casually on the hood)

    And sometimes you'll have to trespass onto someone's land to recover the balloon. This farmer, confused at the dozen or so nerds wandering his field with laptops and cars with lots of mounted antennas parked nearby, drove up to ask "what are you doing on my land?" We told him "we dropped something."

    On our drive back, after an exhausting night of work and an early morning all-day launch, we get lunch at a restaurant to share stories, data, and memory cards from everyone's cameras. Conversation wise, it's nerd heaven =P

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