Space is inhospitable for humans, but not so bad for tech. With no need for a cushy room-temperature, you mostly need to think about increased radiation and temperature swings.
I can't find details on NASA's designs, but I suspect you'd mostly need a new casing. Something radiation-tolerant (most plastic degrades quickly) and maybe radiation-shielding if it messes with the electronics too much. For temperature you could just run it through a few cycles on Earth and see what breaks. Probably nothing, given the GoPro's lack of moving parts and general ruggedness.
The rugged, icy, salt-water environments the GoPro is designed for are, in many ways, a lot more demanding than space.
To add to that - vacuum can also mess up sealed components that were manufactured at 1ATM. This is mostly a problem with electrolytic batteries and capacitors which puff up when the atmospheric pressure is removed. For batteries mitigations include manufacturing at low pressures or constraining the expansion mechanically.
Pretty sure a GoPro underwater housing would be perfectly capable of maintaining 1ATM in space. They are designed to handle many times that in external pressure.
My GoPro won't work if it's too cold (lithium battery).
They're using GoPro 4's, which is somewhat interesting, as the 11 just came out. So, old tech (8 years old or so) that's been heavily modified to work in space. I'm reminded some janky PowerPC powers the FORTRAN code that runs the Hubble.
It is romantic to think that the Earthrise photo was taken with a Hasselblad medium format camera.
It seems unlikely that the GoPros in question are rad-hard (there is no rad-hard GoPro that I'm aware of); it's more likely that they chose them for some other reason (perhaps some sort of validation or testing), or that these have fewer heat dissipation issues than the newer models. Heat dissipation is a frequent cause of issues for electronics in space.
They are old because the design was locked long before launch.
If they found new cameras with better heat dissipation, they would still go with old ones, otherwise they would have to recertify the new ones, which would take ages.
I can't find details on NASA's designs, but I suspect you'd mostly need a new casing. Something radiation-tolerant (most plastic degrades quickly) and maybe radiation-shielding if it messes with the electronics too much. For temperature you could just run it through a few cycles on Earth and see what breaks. Probably nothing, given the GoPro's lack of moving parts and general ruggedness.
The rugged, icy, salt-water environments the GoPro is designed for are, in many ways, a lot more demanding than space.