The Moon Needs Water! (Part 1)
One of the things science fiction writers do is think. When we think about things like “what would the economics of interplanetary colonies look like,” we call that “world building.” At any rate, in my world building, I got to thinking about Lunar colonies. Or more specifically, the (lack of) water to support said colonies.
You may be saying, “But isn’t air more of a problem?” Well, yes, in that we stop living right quickly without air. But the moon has vast quantities of oxygen. It’s locked in the form of oxides in rocks, but it is there, and can be extracted with enough energy. What the moon lacks is water. Now, NASA has found “significant amounts” of water on the lunar south pole. Although when you drill down on that, you discover that the dirt in your average Earth desert has significantly more water than even a wet patch of the Moon. This is a problem.
See, back in my Navy days, I was told that humans need 30 gallons of water per person per day. (I’m old school, so this will be in English units. See here to convert to metric.) This is for bathing, laundry, cooking, drinking and the like. This does not include agriculture or industrial processes. It also doesn’t include flushing the toilets - ships use salt water for that. But lacking a better number, let’s stick with 30 gallons per person per day.
That means a village of 10,000 people needs 300,000 gallons a day. Obviously the village is going to recycle and reclaim as much as it can. Let’s assume a 99% efficient system. Pretty good, yes? That means we need to make up 3,000 gallons of water per day, or 25,050 pounds of water. That’s 401 cubic feet. One of the standard 40 foot shipping containers you see on the roads every day holds 2720 cubic feet, so our little town needs a container full of water every week.
But, you say, 99% efficient means 1% inefficient! Well, yes, but once you get to a village, with little kids and doggies and what not, as opposed to a monastic camp of highly-trained astronauts, waste will happen. But okay, we bump it up to 99.9% efficiency. We still need makeup water - 300 gallons (or a mere 4 ounces per person) per day. We’ll still need the container - just now once every nine weeks or so.
When you get to larger numbers of people, the volumes obviously go up. For a population of 100,000 at 99% efficiency, you need 1.5 containers per day! Tomorrow’s question is, “where’s the water coming from?”
You may be saying, “But isn’t air more of a problem?” Well, yes, in that we stop living right quickly without air. But the moon has vast quantities of oxygen. It’s locked in the form of oxides in rocks, but it is there, and can be extracted with enough energy. What the moon lacks is water. Now, NASA has found “significant amounts” of water on the lunar south pole. Although when you drill down on that, you discover that the dirt in your average Earth desert has significantly more water than even a wet patch of the Moon. This is a problem.
See, back in my Navy days, I was told that humans need 30 gallons of water per person per day. (I’m old school, so this will be in English units. See here to convert to metric.) This is for bathing, laundry, cooking, drinking and the like. This does not include agriculture or industrial processes. It also doesn’t include flushing the toilets - ships use salt water for that. But lacking a better number, let’s stick with 30 gallons per person per day.
That means a village of 10,000 people needs 300,000 gallons a day. Obviously the village is going to recycle and reclaim as much as it can. Let’s assume a 99% efficient system. Pretty good, yes? That means we need to make up 3,000 gallons of water per day, or 25,050 pounds of water. That’s 401 cubic feet. One of the standard 40 foot shipping containers you see on the roads every day holds 2720 cubic feet, so our little town needs a container full of water every week.
But, you say, 99% efficient means 1% inefficient! Well, yes, but once you get to a village, with little kids and doggies and what not, as opposed to a monastic camp of highly-trained astronauts, waste will happen. But okay, we bump it up to 99.9% efficiency. We still need makeup water - 300 gallons (or a mere 4 ounces per person) per day. We’ll still need the container - just now once every nine weeks or so.
When you get to larger numbers of people, the volumes obviously go up. For a population of 100,000 at 99% efficiency, you need 1.5 containers per day! Tomorrow’s question is, “where’s the water coming from?”