Why not just go to the source of lunar ice.

I should point out that the reason Earth has so much water despite
being within Jupiter's orbit is due to our huge gravity. Asteroiods
have small gravity, and therefore the solar winds have been powerful
enough to blow their water away. Mars has more gravity than
asteroids, but still not enough to hold on to most of its water. Its
pretty obvious that most of Mar's northern hemisphere was once ocean,
but now its gone. most NEA's lost most of their water and ice about 4
billion years ago.