Can’t we send up a probe that will collect water samples and bring them back to earth?
I'd just as soon we park them in low-Earth orbit and work on there, if you don't mind.
As the illustration shows, this moon is larger than our own. With ice to land and take off from, it can’t be a remote or automatic rocket with our technology and a six year manned mission for that alone would be impractical.
Spectrometer reflections have shown it as water, so even if it has other chemicals in it they can be separated. With a number of moons out there having water, that supports work in the asteroid belt without the lift needed to bring water from earth.
The speed (fuel and power) needed in kilometers per second to leave earth is 11.2 kilometers per second. On Ganymede it is a fourth of that requiring 2.7 km/sec. Easier lift off to orbit and then travel with cargo of water where needed.
Additionally the energy needed to escape the gravity well of the sun to and from the asteroid belt to Jupiter is less than half as from earth to the asteroid belt.
Distance would be more a factor of time once escape or approach velocity is reached.
Our species could be gone tomorrow if we have no self sustaining outposts off planet. So it takes 500 years — let’s start next Monday.