It's great for backpacking as it weighs much less and takes up less space in your pack. All you have to do is add water, shake it up, and your drink is ready in less than 15 seconds. Maybe the astronauts can take advantage too.
You realize this whole thread started with the concept of dehydrated water, right?
So in principle you could carry a bottle of methane and burn that to get water. ;-)
You "just" have to capture and cool it down.
I mean, it's completely outside of viability, but it's not breaking ground science. You could do it perfectly well in a lab (if you had any reason to).
You can turn methane into water in theory. And you can technically do it in a lab (even though the easiest way by far to do it uses a lot of water). You can't do it on your backpack.
Not like I know how this stuff works. Someone says methane turns into water when burned, I imagine based on farts that it floats like in a nice balloon or Hindenburg, I figure this do be how this was intended ¯\_(:))_/¯
Then if you add some condensing coils and a transparent roof, you could also just leave the backpacking food in there and it'll slowly get moist and solar cook. After a twelve hour hike you'd get lukewarm edible mud, mmm.
Explosions are a minor risk, but if you can make water out of the hydrogen anyway, surely you can put out any resultant wildfires.
Cyberpunk Smokey would be proud.
Seriously though, I've often wondered if a weather balloon style lifter tethered to a backpack could help it be lighter. Probably with a less flammable gas, and only in sparsely forested areas.
as far as helium balloon, it would have to be a balloon of such enormous size to be of any benefit. To launch a couple pounds of payload to 90k feet required a balloon 8' in diameter on the ground.