Remarkable footage of the Grand Canyon from the edge of space has emerged, two years after the video was thought to have disappeared forever.
In June 2013, five students attached a GoPro camera to a helium weather balloon and sent it 30,000 metres into sky.
Launching it around 30km west of the Grand Canyon in Arizona, the students attached a cellphone with GPS to monitor the balloon's position, but when the phone when out of signal range the students were unable to retrieve the footage when it fell back down to Earth.
"We used GPS on a smartphone to continuously log the phone's location on its memory card," student Bryan Chan wrote on Reddit.
"The standard GPS receiver these days can track your phone well above 100,000ft. The phone was projected to land in an area with cell coverage. 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."
Although AT&T may have failed the boys with its network coverage, in a "twist of ironic state" a hiker – who happened to work for the telecommunications company – stumbled across the damaged phone years later.
She then took the phone to an AT&T shop and tracked down the owners of the phone using their SIM card.
In the final part of its journey, the video found its way back to the students and on to YouTube, where it has been viewed by more than 1.5 million people in less than a week.