I've just recovered a GoPro Hero 7 camera from a stratospheric balloon. It maxed out at around 25 km altitude, so I would really like to see the recordings. The camera was fully recharged and equipped with a 64 GB microSD card formatted with exFAT.

Recording was started, and the first file (GH010026.MP4) is a 4 GB, 17 min duration video of the balloon being filled with Helium.

Next file (GH020026.MP4) is a 4 GB, 18 min duration video of launch and the first ascent.

Next file (GH030026.MP4) is a 3 GB, 13 min duration video, a continuation of the previous video.

And – that's that.

Then there's a 7.9 MB file – a few seconds in duration – called GH010027.MP4 – apparently recorded after landing (my colleagues apparently turning the camera off). Funny thing about this file: In Linux terminal, it has today's date, but no time. In Nemo File Manager, it has a time of 18:34, which is about 20 minutes into the future!

Where's the rest of my 1½ hour long flight?

What are my chances of finding the missing footage? I haven't written anything to the card since.

Did my colleagues do anything wrong when they turned off the camera?

Does anyone know what is the logic behind the file naming on a GoPro?