Titan (GAIA) Read Online Free Page A

It’s transparent or translucent. It lets most of the light go through to whatever’s underneath. Does that suggest anything to you?”
    Cirocco looked up from her careful examination.
    “What do you mean?”
    “Okay. We know the wheel is hollow. Maybe the spokes are, too. Anyway, picture the wheel. It’s like a car tire, big and fat and flat on the bottom to give more living space. Centrifugal force pushes you away from the hub.”
    “I’ve got all that,” Cirocco said, slightly amused. Gaby could be so intense when explaining something.
    “Right. So when you’re standing on the inside of the wheel, you’re either under a spoke, or under a reflector, right?”
    “Yeah? Oh, yeah. So—”
    “So it’s always either daytime or nighttime at any particular spot. The spokes are rigidly attached, the reflectors don’t move, and neither can the skylights. So it
has
to be that way. Permanent day or permanent night. Why do you think they’d build it that way?”
    “To answer that, we’d need to meet them. Their needs must be different from ours.” She looked back at the picture. She had to keep reminding herself of the size of the thing. Thirteen hundred meters in diameter, 4000 around the outer rim. The prospect of meeting the beings who built such a thing wasworrying her more each day.
    “All right. I can wait.” Gaby was not that interested in Themis as a spacecraft. To her it was a fascinating problem in observation.
    Cirocco again looked at the picture.
    “The hub,” she began, then bit her lip. That camera was still running, and she didn’t want to say anything too hastily.
    “What about it?”
    “Well, it’s the only place you could dock with the thing. The only part that’s motionless.”
    “Not the way it is now. That hole in the middle is pretty big. The first time you reach anything solid, it’s moving at a pretty good clip. I can calculate—”
    “Never mind. It’s not important right now. The point is, only at the very dead center of rotation could you dock with Themis without a great deal of trouble.
I
sure wouldn’t want to try it.”
    “So?”
    “So there must be a compelling reason why there’s no docking facilities visible there. Something important enough to sacrifice that location, some reason for leaving a big hole in the center.”
    “Engine,” Calvin said. Cirocco glanced at him, got a glimpse of his brown eyes before he turned back to his work.
    “That was my thought. A real big fusion ramscoop. The machinery is in the hub, electromagnetic field generators to funnel the interstellar hydrogen into the center, where it gets burned.”
    Gaby shrugged. “Makes sense. But what about docking?”
    “Well,
leaving
the thing would be easy enough. Just drop out a hole in the bottom and get escape velocity for free, plus some to fool around with. But there ought to be some sort of dingus that would telescope out to the center of rotation when the engine isn’t running, to pick up scout ships. The main engine
has
to be there. The only other way would be to space engines around the rim. I’d want three, at least. More would be better.”
    She turned to face the camera.
    “Send me what you can about hydrogen ramscoop engines,” she said. “See if you can give me some idea of what to look for if Themis has one.”
    “You’ll have to take your shirt off,” Calvin said.
    Cirocco reached up and switched off the camera, leaving the sound on. Calvin thumped her back and listened to the results while Cirocco and Gaby continued to study the picture of Themis. They came up with no new insights until Gaby brought up the matter of the cables.
    “As far as I can tell, they form a circle about midway between the hub and the rim. They support the top edges of the reflecting panels, sort of like the rigging on a sailing ship.”
    “What about these?” Cirocco asked, indicating the area between two of the spokes. “Any idea what they’re for?”
    “Nope. There’s six of them, and they