I'm pretty sure they are looking for water on other planets as opposed to purifying salt water because they don't want to fuck up earth's environment. They say we are going to overpopulate the planet soon-ish at this rate, so the moon and mars will probably be the best places to move to. Of course the new planets need their own water supply. This won't really be in most of our lifetime's but life on the moon should be possible quite soon. It's already possible for civillians to fly into space too, after paying millions of dollars and enduring months of astronaut training ofc.
