An old colleague of mine suggested another possible reason that the 3G iPhone we put in our capsule may have failed during it’s descent. Apparently, if left out in the sun too long or otherwise overheated, iOS will shut down the device in order to prevent damage. Since Apple lists the 3G’s non-operating temperature as above 45C, I would imagine that this would happen around there.
We were so worried about the phone freezing in the almost vacuum of near-space that we were actually relying on the heat generated by the GPS, network transmissions, and battery charging to support the heat generated by the heated sock it was incased in. The data, however, suggests that the device didn’t lose enough heat to kill the external battery as it appeared to still be charging the phone on the way down!
Is it possible that we overheated the phone? I will have to test once we get another 3G to play with.