Industry
Water seen as biggest hurdle to Moon settlement; large lunar city unsustainable
A study says up to 1 billion tons of water may exist near the Moon’s poles, but that would be insufficient to sustain a large lunar city over the long term. Assuming 500 tons per person a year for living and farming, a city of 1 million people would run out of water in about two years without recycling. Even with a 98 percent recycling rate, water would be depleted in about 100 years.
