Back in 2013, student Bryan Chan together with a couple of friends, strapped a GoPro camera and a SIM card to a weather baloon and sent it flying up into the stratosphere.
The general idea was to film the camera falling from such a high position and then, of course, publish the clip on YouTube.
However, thanks to lousy mobile coverage, after the camera fell to the ground, they couldn't pick up on the SIM signal and the GoPro was lost, for good.
So they thought.
Fast forward two years, a hiker finds the camera with all the amazing footage on it. The original owners were identified by the SIM card still attached to the balloon, thanks to the finder working at US telecom company AT&T.
According to its owners, the GoPro managed a maximum altitude of 98,664 feet (that's about 18 miles) and flew for a total of 98 minutes. The landing spot was around 50 miles away from the launch site.
"The problem was that the coverage map we were relying on (looking at you, AT&T) was not accurate, so the phone never got signal as it came back to Earth, and we never heard from it," explained one of the team on Reddit.
"We didn't know this was the problem at the time - we thought our trajectory model was far off and it landed in a signal dead zone."
Check out the video above to see the balloon's flight. It's worth every minute.