Free Artemis by Andy Weir Page B

sighed. “Dad. It’s just a friend who wants an air shelter in her bedroom. I’m barely charging her for it.” Residential air shelters were common, especially among recent immigrants. Newcomers tend to be paranoid about the whole “deadly vacuum outside” thing. It’s irrational—Artemis’s hull is extremely safe—but fear isn’t logical. In practice, personal air shelters quickly become closets.
    “What’s the illegal part?” he asked.
    I gave him a hurt look. “Why would you assume there’s—”
    “What’s the illegal part?” he repeated.
    “Her apartment’s in Armstrong up against the inner hull. I have to weld the shelter directly to it. The city requires all sorts of extra inspections if you weld to the inner hull and she can’t afford them.”
    “Hmf,” he said. “Pointless bureaucracy. Even the most rank amateur couldn’t damage a six-centimeter plate of aluminum.”
    “I know, right?!” I said.
    He folded his arms and frowned. “Darned city getting in the way of business…”
    “Preach.”
    “All right. Take what you want. But you have to reimburse me for the acetylene and neon.”
    “Right, of course,” I said.
    “You all right? You look kind of pale.”
    I was about ready to puke. Lying to Dad transported me back to my teen years. And let me tell you: there’s no one I hate more than teenage Jazz Bashara. That stupid bitch made every bad decision a stupid bitch could make. She’s responsible for where I am today.
    “I’m fine. Just a little tired.”

Dear Jazz,
    I got a big poster of the Roosa for my birthday. What a magnificent ship! It’s the largest spaceliner ever built! It can hold up to two hundred passengers! I’m learning all about it. I’m a little obsessed, but who cares? It’s fun.
    The ship is a marvel! It has full centripetal gravity, with a radius large enough that no one will get dizzy. It even helps people adjust to lunar gravity! They gradually slow the rotation over the seven-day trip to the moon. So when people first board, the passenger decks are at 1 g, and by the time they reach the moon, they’re at ⅙th g. They do the reverse on the way back to get folks accustomed to 1 g again. How cool is that?
    I still don’t understand the “Uphoff-Crouch Cycler Orbit,” though. I get that it’s a ballistic orbit that goes back and forth between the Earth and the moon, but it’s really weird. It’s like…start at Earth, then it’s at the moon seven days later, then it flings up way out of the Earth–moon plane and comes back to the moon fourteen days later…somewhere in there it just sits in an elliptical orbit around Earth for a couple of weeks…I don’t get it. And I won’t try. Point is, it’s an awesome ship.
    Someday, when I’m a rich rocket designer, I’m going to visit Artemis. We can have tea.
    Hey, when you and your dad moved to Artemis, did you go there on the Roosa ?
    Dear Kelvin,
    Nah, the Roosa hadn’t been built yet when we moved here. We came over on the Collins , the only spaceliner that existed at the time. It was ten years ago (I was only six), so I don’t remember all the details. But I remember we didn’t have artificial gravity. It was zero-G everywhere. I had a shitload of fun bouncing around!
    You got me curious about the orbit stuff, so I looked it up. It seems pretty straightforward. The ship goes through a cycle with each step taking seven days: Earth -> Moon -> (deep space out of Earth–moon plane) -> Moon -> Earth -> (deep space in the Earth–moon plane) -> Earth. And it repeats that over and over. If the moon stood still they could just go back and forth, but it’s moving around Earth once per month, which complicates the hell out of the cycler.
    I looked up the math behind how orbits work and then checked their numbers against those equations. It was pretty simple, you can do it in your head.
    Dear Jazz,
    Maybe you can do it in your head. I would give anything to be as smart as you. But I’m not. That’s