The Martian Read Online Free PDF Page A

know, other than that edge case, there’s no reason.
    So I finally decided I’d just take the hit. I’ll be losing some air every time I enter or exit a pop-tent. The good news is each pop-tent has an air feed valve on the outside. Remember, these are emergency shelters. The occupants might need air, and you can provide it from a rover by hooking up an air line. It’s nothing more than a tube that equalizes the rover’s air with the pop-tent’s.
    The Hab and the rovers use the same valve and tubing standards, so I was able to attach the pop-tents directly to the Hab. That’ll automatically replenish the air I lose with my entries and exits (what we NASA folk call ingress and egress).
    NASA was not screwing around with these emergency tents. The moment I pushed the panic button in the rover, there was an ear-popping whoosh as the pop-tent fired out, attached to the rover airlock. It took about two seconds.
    I closed the airlock from the rover side and ended up with a nice, isolated pop-tent. Setting up the equalizer hose was trivial (for once I’m using equipment the way it was designed to be used). Then, after a few trips through the airlock (with the air-loss automatically equalized by the Hab) I got the dirt in.
    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 O 2 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 O 2 . The Hab would use them only in an emergency; it has the oxygenator to balance the atmosphere. The reason the O 2 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 O 2 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 CO 2 . And I happen to have a machine whose sole purpose is liberating oxygen from CO 2 . 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