I love the way that simple water is the thing we hope most to find on a remote planet. It's amazing how much of life is geared to that little simple molecule and how much use you can get out of it.
But I do wonder about the "we can get rocket fuel from water" line. Water is hydrogen and oxygen, yes, but you need to use energy to collect and filter the water in the first place, more energy to split it apart, compress the gas into storage (into liquids, no less), huge amounts of materials to store them safely, etc. And for "rocket fuel", you need an awful lot of it to get back to Earth. So the investment of energy required to make a single return trip is HUMONGOUS and may literally take years, lakes of water, fields of solar panels and heavy metal machines and containers to make it a reality.
And then you're left with the problem that H2O is 2 H's and only 1 O, which leaves you with a lot of highly-volatile chemicals just sitting around surplus right next to a huge source of oxygen (which can be more dangerous than an equivalent amount of petrol in the case of an accident). And we probably want a lot more oxygen than we do hydrogen, if we're going to be breathing it, and fuelling from it, and whatever else with it, so that means even more venting or storage of H that we've paid a lot to get and then won't be using (and to use, we need to use O with it in some form!). Sure, we can probably capture it and burn in the native atmosphere for heating, etc. somehow but that's even more expense to get it working and just as dangerous.
I'm not saying we can't use it, but it seems a bit of a pipe dream to suggest that we'll ever use it as a method of fuelling rockets - by the time you get all the equipment to use it there, and a sufficient source of energy up and running, and the plant operational and safe, then you've already used so much "other" technology to get to that point that it's probably a waste of time to be messing about with sticking a couple of electrodes into a puddle of water for the next hundred years to fuel a return journey.