I repeated the process for the other tent. Everything went really easily.

Sigh… water.

In high school, I played a lot of Dungeons and Dragons. (You may not have guessed this botanist/mechanical engineer was a bit of a nerd in high school, but indeed I was.) In the game I played a cleric. One of the magic spells I could cast was “Create Water.” I always thought it was a really stupid spell, and I never used it. Boy, what I wouldn’t give to be able to do that in real life right now.

Anyway. That’s a problem for tomorrow.

For tonight, I have to get back to Three’s Company. I stopped last night in the middle of the episode where Mr. Roper saw something and took it out of context.

LOG ENTRY: SOL 30

I have an idiotically dangerous plan for getting the water I need. And boy, do I mean dangerous. But I don’t have much choice. I’m out of ideas and I’m due for another dirt-doubling in a few days. When I do the final doubling, I’ll be doubling on to all that new soil I’ve brought in. If I don’t wet it first, it’ll just die.

There isn’t a lot of water here on Mars. There’s ice at the poles, but they’re too far away. If I want water, I’ll have to make it from scratch. Fortunately, I know the recipe: Take hydrogen. Add oxygen. Burn.

Let’s take them one at a time. I’ll start with oxygen.

I have a fair bit of O₂ reserves, but not enough to make 250 liters of water. Two high-pressure tanks at one end of the Hab are my entire supply (plus the air in the Hab of course). They each contain 25 liters of liquid O₂. The Hab would use them only in an emergency; it has the oxygenator to balance the atmosphere. The reason the O₂ tanks are here is to feed the space suits and rovers.

Anyway, the reserve oxygen would only be enough to make 100 liters of water (50 liters of O₂ makes 100 liters of molecules that only have one O each). That would mean no EVAs for me, and no emergency reserves. And it would make less than half the water I need. Out of the question.

But oxygen’s easier to find on Mars than you might think. The atmosphere is 95 percent CO₂. And I happen to have a machine whose sole purpose is liberating oxygen from CO₂. Yay, oxygenator!

One problem: The atmosphere is very thin—less than 1 percent of the pressure on Earth. So it’s hard to collect. Getting air from outside to inside is nearly impossible. The whole purpose of the Hab is to keep that sort of thing from happening. The tiny amount of Martian atmosphere that enters when I use an airlock is laughable.

That’s where the MAV fuel plant comes in.

My crewmates took away the MAV weeks ago. But the bottom half of it stayed behind. NASA isn’t in the habit of putting unnecessary mass into orbit. The landing gear, ingress ramp, and fuel plant are still here. Remember how the MAV made its own fuel with help from the Martian atmosphere? Step one of that is to collect CO₂ and store it in a high-pressure vessel. Once I get the fuel plant hooked up to the Hab’s power, it’ll give me half a liter of liquid CO₂ per hour, indefinitely. After ten sols it’ll have made 125 liters of CO₂, which will make 125 liters of O₂ after I feed it through the oxygenator.