First off, there is no water in space. There are theories of water in space, but NASA has never experienced even a drop of it. Understand, there is plenty of Hydrogen and Oxygen that can and does combine to form water and ice, but there is no appreciable water in space. There are no oceans, lakes, streams, rivers, swimming pools or even puddles. There is no place but Earth where a scientist can actually collect water. However, let’s play along with this silliness and imagine that there was water in space. Let’s even make it easy. Let’s pretend that there is water on the moon.
At slightly less than 8.5 pounds per gallon, water is too heavy to transport. The space shuttle weighs about 165,000 pounds. A million gallons of water would weigh about 8.5 million pounds. The Saturn V rocket alone weighed only 310,000 pounds. That translates to about 35,000 gallons of water. The point is, even if water did exist in space, which it doesn’t, it would be too heavy and too expensive to bring here.
We already have more water on Earth than we can ever use. We need to forget about outer space and get water here on Earth to people who really need it.