Friday, August 16th: The Night Before the Launch.
This night consisted of fixing the
capsule and checking that the Arduino returned the right coordinates across the
walkie-talkie. Little known fact; we
designed and built the parachute mechanism that night, without any testing or
much planning. After several hours we
finished everything at 2:20 AM and went to bed
Saturday, August 17th: The Launch and Recovery
Waking up at 3:30 AM, I felt more
tired than before I went asleep. We
packed the truck and were leaving at 4:10 AM.
It was a much shorter trip than last launch, taking 90 minutes to drive
there. Arriving at Perrydale high school
in Perrydale Oregon, the launch site was better than could be expected. The only hazards were the track lighting
which surrounded the field. Given that
our nozzle lift was much higher than last time, these lights weren’t going to
be a problem. Since we arrived early in
the morning, the wind had not yet picked up.
The skies were clear, and it seemed like the launch would go well. Rolling out the tarp, Lee started on the
balloon while I organized the payload. For
what seemed like an eternity I stood around and watched Lee fill the balloon
because assembling wasn’t going to take a long time. I had gone through the motions of assembling
the capsule the night before, so I waited until 25 minutes before launch to
start assembling. The main reason we did
this was to give the GoPro as much in flight battery life as possible. On our previous launch the GoPro batteries
died before the balloon even popped. Furthermore,
we added a battery stick which connected to the GoPro’s mini USB in order to
prevent total power failure.
This is where the fun began. In reassembling the foam interior I ran
across some interference with the walkie talkie. Additionally, the Arduino was not sending
back the right coordinates. It took us
around 10 minutes to realize the batter powering the Arduino was creating an
electric field which messed up our transmission. Hacking away at the foam I oriented the battery
lines farther from the GPS. Once this
was finished, the transmissions which were irregularly spaced started to send
as coded. As a side note, we probably
should have done much more exhaustive testing and cleaned up the code for the
Arduino, but we didn’t. All seemed well
and we began taping the rest of the capsule.
Right before we started taping my phone in place the walkie talkie lost
power. They had been almost fully
charged the night before, so we were very confused as to why this
happened. Switching batteries between
the walkie talkies, we reassembled the capsule while charging the other
battery. At this point, Lee and I just
wanted to launch the balloon, problems and all.
Although this took place in less than half an hour, the stress from
problematic electronics and a diminishing launch window was immense. We eventually fixed everything and let it go.
It was a relief to let go of the balloon, considering that if everything but the GPS on my phone failed, we would still be fine. I then predicted that the walkie talkie would run out of power in 90 minutes. It lasted 20 minutes. You could say that the constant use of a walkie talkie on Hi-band consumes quite a bit of power. We probably should have done more math regarding its duty cycle. However, with the loss of our primary form of communication/location, my cell phone had not yet died. We actually managed to send back photos from my phone during the trip.
Despite the failure of the GPS recovery system, we consider the launch to be a great success, and we were able to capture some amazing footage. Our video can be seen at: https://www.youtube.com/watch?v=W-lo2QAYHZQ
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