Nov 21 2011

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Pre-launch preparations

On Friday the 18th we met to work on the project. Saturday night we continued our preparations, working late into the night and early into the morning on the design, the software, and the logistics.

Unfortunately, the foam we had originally ordered never showed up. To compound matters, the backup foam we ordered didn’t arrive in time, either. Thanks to Micah, who toured a nearby foam distributor in exchange for a small piece of similar foam, we had a backup piece of foam, but we had to scramble to learn how to use it and get it to adhere. It’s considerably different from the material we used for the cold test, so there’s some concern about its insulating abilities.

After discovering that copious amounts of hot glue in addition to two bolts and sewing would be able to keep the pieces of foam together, we tested the foam’s impact absorption capabilities. We had a hard time with calculations. Our resources and calculations were telling us we needed 2 meters of foam to protect the phone, but logic was telling us that was impossible. Finally we broke down and just started trying it out, first by dropping the thing with the phone inside, then by throwing it, and finally by beating it against the concrete. In all cases the phone performed like a champ, so we were reasonably certain that falling from altitude would not harm the phone.

We spent a significant amount of time on logistics as well. The timing of the competition was less than ideal; with winter fast approaching, the number of acceptable launch days was low, and conditions were not good even on those days. When we decided to launch on Sunday, it was because it was only forecast to be mostly cloudy instead of precipitating. Using the calculator available from habhub, and the ATT coverage tool, we discovered that we would have to travel West to make sure the phone wouldn’t land in the lake, but too far West and we would be completely out of cell range. We settled on a town called Ridgeway, which was just off a highway, not near an airport, at the edge of reception, and had a perfect launch location that was easy to get to, on top of a hill, and had no dangerous tall objects nearby. As for launch time, we wanted to do it early in the morning so that we would have more time to search, and late enough so that we would have enough light for photos.

Design of the app went well, too. Despite a near catastrophic moment that involved the difference between meters and feet, the app came together at the last minute, and even reported data back to a web service on this site while it had signal. In testing it ran for a few hours without issue and successfully made it through the transitions between stages of flight. Just in case it didn’t work, though, we also installed instamapper and wheresmydroid; two applications that could be used to help us get the phone back.

We got a few hours of sleep, then got started on launch day.

Permanent link to this article: https://www.apollo67.com/2011/11/21/pre-launch-preparations/