Aurora.

Kim Stanley Robinson.

1.

STARSHIP GIRL.

Freya and her father go sailing. Their new home is in an apartment building that overlooks a dock on the bay at the west end of Long Pond. The dock has a bunch of little sailboats people can take out, and an onshore wind blows hard almost every afternoon. "That must be why they call this town the Fetch," Badim says as they walk down to take out one of these boats. "We always catch the brunt of the afternoon wind over the lake."

So after they've checked out a boat, they have to push it straight off the side of the dock into the wind, Badim jumping in at the last minute, hauling the sail tight until the boat tilts, then aiming it toward the little corniche around the curve of the lakeshore. Freya holds the tiller most firmly, as instructed. The boat leans over and they go right at the tall lake wall until they almost hit it, then Badim exclaims, "Coming about," just as he said he would, and Freya swings the tiller hard and ducks to get under the boom as it swings over them, and then they're tacking in the other direction, in a reach across the end of the bay. The little sailboat can't point up into the wind very far, Badim says, and he calls it a tub, but affectionately. It's just big enough for the two of them, and has a single big sail, sleeved over a mast that to Freya looks taller than the boat is long.

It takes quite a few tacks to get out of the little bay and into the wider expanse of Long Pond. Out there, all of Nova Scotia is visible to them: forested hills around a lake. They can see all the way to the far end of Long Pond, where afternoon haze obscures the wall. The deciduous trees on the hills are wearing their autumn colors, yellow and orange and scarlet all mixed with the green of the conifers. The prettiest time of year, Badim says.

Their sail catches the bigger wind that rushes across the middle of the lake, which is silvery blue under the gusts. They shift to the windward side of the cockpit, lean out until they balance the boat against the wind. Badim knows how to sail. Quick shifts in the wind, to which they lean in or out; now they're dancing with the wind, as Badim puts it. "I'm very good ballast," he says, rocking the boat a little as he moves. "See, we don't want the mast straight up, but tilted downwind a bit. Same with the sail, not pulled as tight as you can, but off enough for the wind to curve across it the best. You can feel when it's right."

"Look at the water there, Badim. Is that a cat's paw?"

"Good eye, that is a cat's paw. Let's get ready for that, we're going to get wet!"

The surface of the lake winkles in a mirrorflake curl, approaching them fast, and when the gust causing the cat's paw hits them, the boat heels hard. They lean back into it and the boat gurgles forward, slaps into and across the oncoming waves, knocks up dashes of spray that blow back at them. Long Pond's water tastes like pasta, Badim says.

At the end of forty tacks (Badim claims to keep count but with a smile that says he doesn't), they're just a kilometer or so up Long Pond. It's time to turn and make the straight run downwind to their dock. They turn and suddenly it's as if there's hardly any wind: the boat goes quiet, the sail bellies out ahead and to the side as Badim lets out the sheet, the little tub rocks forward in jerks and seems to be going slower. They watch the backs of waves pass them. The water is bluer now, and they can see farther down into it; sometimes they catch glimpses of the lake's bottom. The water bubbles and gurgles, the boat rocks awkwardly, all in all it feels like they're laboring, yet in no time at all they're coming back into their bay, and it's obvious by the way they pass the other docks and the corniche that they're really bombing along. There's time to watch their own dock come at them, and now in the bay they can again feel the wind rushing past, and hear the waves passing the boat, falling over in little gurgling whitecaps.

"Uh-oh," Badim says as he leans out to see past their bellying sail. "I should have come at the dock with the sail on the other side! I wonder if I can swing back out and get on the other beam, and come back in right."

But the dock is almost on them. "Do we have time?" Freya asks.

"No! Okay hold on, take the tiller and hold it just like it is now. I'm going to go forward and jump off onto the dock and grab the boat before you go by me! Keep your head down, don't let the boom hit you!"

And then they're heading right at the corner of the dock. Freya ducks into the seat and holds the tiller hard, the bow of the boat crashes into the corner of the dock while Badim is in the middle of his leap, he sprawls far onto the dock, there is a loud cracking sound where boom meets mast, the boat cants and swings around the dock, sail flapping hard out in front of the mast, the boom loose and flopping out there too. Badim scrambles to his feet and from the dock's side leans out to grasp the boat's bow, just within his reach, and then he has to lie flat on the dock and hang on. The boat swings around on the wind and points up into it, the sail swings around wildly and Freya ducks to get under it, but with the boom disconnected from the mast she has to jump down into the cockpit to get below it.

"Are you okay?" Badim exclaims. Their faces are only a meter or two apart, and his look of dismay is enough to make her laugh.

"I'm okay," she assures him. "What should I do?"

"Come up into the bow and jump up onto the dock. I'll hold on."

Which he has to, because the boat is still trying to go downwind, but backward now, and into the shallows. People on the corniche are watching them.

She jumps up beside him. Her push almost drags him off the dock; his knee is braced against a cleat in a way that looks painful to Freya, and indeed his teeth are clenched. She reaches out to help him pull the boat closer and he says, "Don't catch your fingers between the boat and the dock!"

"I won't," she says.

"Can you reach down in there, and get the rope in the bow?"

"I think so."

He pulls hard, draws the boat in closer, she leans way out and snatches the rope where it goes through a metal ring in the very bow of the boat. She pulls the rope out of the boat and takes a turn around the cleat on the back corner of the dock, and Badim quickly snatches it and helps her take more turns.

They lie there on the dock, staring face-to-face, eyes round.

"We broke the boat!" Freya says.

"I know. You're okay?" he asks.

"Yes. What about you?"

"I'm fine. A bit embarrassed. And I'll have to help fix this boom. That's a very weak link though, I must say."

"Can we go sailing again?"

"Yes!" He gives her a hug and they laugh. "We'll do it better next time. The thing to do is to come in with the sail on the other side of the boat, so we can curve in toward the side of the dock, just ease across the wind and come in from the side, then turn up into the wind at the last second, and grab the side of the dock just as we're slowing down into the wind. Should have thought of that before."

"Will Devi be angry?"

"No. She'll be happy we're both safe. She'll laugh at me. And she'll know how to make that joint between the boom and mast stronger. Actually, I'd better look that thing up and find out what it's called. I'm pretty sure it has a name."

"Everything has a name!"

"Yes, I guess that's right."

"And since that thing is broken, I think she's going to be a little angry."

Badim says nothing to this.

The truth is, her mother is always angry. She hides it pretty well from most people, but Freya can always see it. It's there in the set of her mouth; also she often makes little impatient exclamations to herself, as if people can't hear her. "What?" she'll ask the floor, or a wall, and then go on as if she hasn't said anything. And she can get obviously mad really fast, like instantly. And the way she slumps in her chair in the evenings, staring grimly at the feed from Earth.

Why do you watch it? Freya asked her one night.

I don't know, her mother said. Someone has to.

Why?

The corners of her mother's mouth tightened, she put an arm around Freya's shoulders, heaved through her nose a big breath in, sigh out.

I don't know.

Then she trembled, and even started to cry, then stopped herself. Freya stared at the screen with its busy little figures, perplexed. Devi and Freya, staring at a screen showing life on Earth, from ten years before.

On this evening Freya and Badim come home and burst into their new apartment. "We crashed the boat! We broke the thing!"

"The gooseneck," Badim adds, with a quick smile at Freya. "It connects the boom to the mast, but it isn't very robust."

Devi listens distracted, shakes her head at their wild story. She's chewing her salad in front of the screen. When she is done eating, the muscles at the back of her jaw stay bunched. "I'm glad you're okay," she says. "I've got to go back to work. There's some kind of thing going on at the lab."

"I'm sure it has a name," Freya says primly.

Devi eyes her, unamused, and Freya quails. Then Devi is off, back to the lab, and Badim and Freya slap hands and rattle around the kitchen getting out cereal and milk.

"I shouldn't have said that about the name," Freya says.

"Your mom has been known to have some edges," her father says, with an expressive lift of the eyebrows.

He himself has no edges, as Freya knows very well. A short round balding man, with doggie eyes and a sweet low voice, mellow and interested. Badim is always there, always benign. One of the ship's best doctors. Freya loves her father, clings to him as to a rock in high seas. Clings to him now.

He tousles her wild hair, so like Devi's, and says to her, as he has before, "She has a lot of responsibilities, and it's hard for her to think about other things, to relax."

"We're doing okay though, right, Badim? We're almost there."

"Yes, we're almost there."

"And we're doing okay."

"Yes, of course. We will make it."

"So why is Devi so worried?"

Badim looks her in the eye with a little smile. "Well," he says, "there are two parts to that, as I see it. First, there are things to worry about. And second, she is a worrier. It helps her to bring things up and talk through them, talk them out. She can't hold things inside very well."

Freya isn't so sure about this, because not many people seem to notice how mad Devi is. She's good at holding that inside, anyway.

Freya says as much, and Badim nods.

"Good, that's right. She is good at holding in things, or ignoring things, up to a certain point, and then she needs to let it out, one way or another. We're all like that. So, we're her family, she trusts us, she loves us, so she lets us see how she really feels. So, we just have to let her do that, talk things out, say what she really feels, be how she really is. Then she can go forward. Which is good, because we need her. Not just you and me, though of course we need her too. But everybody needs her."

"Everybody?"

"Yes. We need her because the ship needs her." He pauses, sighs. "That's why she's so mad."

Thursday, and so Freya goes into work with Devi rather than spending the day in the creche with the little kids. She helps Devi on Thursdays. Freya feeds the ducks and turns the compost, and replaces batteries and lightbulbs sometimes, if they're scheduled for replacement. Devi does all kinds of things, indeed Devi does everything. Often this means talking to people who work in the biomes or on the machines in the spine, then looking at screens with them, then talking some more. When she's done she grabs Freya by the hand and pulls her along to the next meeting.

"What's wrong, Devi?"

Big sigh. "I told you already. We started to slow down a few years ago, and it's changing things inside the ship. Our gravity comes from the ship rotating around the spine, and that creates a Coriolis effect, a little spiral push from the side. But now we're slowing down, and that's another force, about the same as the Coriolis effect in some ways, and cutting across it so it's reduced. You wouldn't think that would matter so much, but we're seeing aspects of it they didn't foresee. There was so much they didn't think about, that they left for us to find out."

"That's good, right?"

Short laugh. Devi always makes the same sounds: Freya can call them up if she wants to, sometimes. "Maybe so. It's good unless it's bad. We don't know how to do this part, we have to learn as we go. Maybe it's always that way. But we're in this ship and it's all we've got, so it has to work. But it's twelve magnitudes smaller than Earth, and that makes for some differences they never thought through. Tell me again about magnitudes?"

"Ten times bigger. Or smaller!" She remembers in time to keep Devi from saying it.

"That's right. So even one magnitude is a lot, right? And twelve, that's twelve zeros tacked on. A trillion. That's not a number we can imagine very well, it's too big. So, here we are in this thing."

"And it has to work."

"Yes. I'm sorry. I shouldn't burden you with this stuff. I don't want you to be scared."

"I'm not scared."

"Good. But you should be. So there's my problem."

"But tell me why."

"I don't want to."

"Just a little bit."

"Oh, I've told you before. It's always the same. Everything in here has to cycle in a balance. It's like the teeter-totters at the playground. There has to be an equilibrium in the back-and-forth between the plants and the carbon dioxide in the air. You don't have to keep it perfectly level, but when one side hits the ground you have to have some legs to push it back up again. And there are so many teeter-totters, all going at different speeds up and down. So you can't have any accidental moments when they all go down at once. So you have to look to see if that is about to start happening, and if so, you have to shift things around so that it doesn't. And our ability to figure out how to do that depends on our models, and really, it's too complex to model." This thought makes her grimace. "So we try to do everything by little bits and watch what happens. Because we don't really understand."

On this day it's the algae. They grow a lot of algae in big glass trays. Freya has looked at it through a microscope. Lots of little green blobs. Devi says some of it is mixed in with their food. They grow meat like the algae, in big flat tanks, and get almost as much of their food out of these tanks as they do out of the fields in the farming biomes. Which is lucky, because the fields can suffer animal disease, or crop failure. But the tanks can go wrong too. And they need their feedstocks to have something to turn into food. But the tanks are good. They have a lot of tanks going, in both rings, all kept isolated from the others. So they're all right.

The algae tanks are green or brown or some mix of the two. The colors of things depend on which biome you're in, because the lights from the sunlines are different in different biomes. Freya likes to see the colors shift as they move from biome to biome, greenhouse to greenhouse, lab to lab. Wheat is blond in the Steppe, yellow in the Prairie. Algae in the labs is many different brownish greens.

It's warm in the algae labs and smells like bread. Five steps to make bread. Someone says they're eating more these days, but growing less. This means an hour at least to talk it over, and Freya sits down to paint with the paints in the corner of the lab, left there for her and any other kids who might visit.

Then off again. "Where to now?"

"Off to the salt mines," Devi declares, knowing Freya will be pleased; they'll stop at the dairy near the waste treatment plant, get ice cream.

"What is it this time?" Freya said. "More salt in the salty caramel?"

"Yes, more salt in the salty caramel."

This is a stop where Devi can get visibly irate. The salt sump, the poison factory, the appendix, the toilet, the dead end, the graveyard, the black pit. Devi has worse names for it she says under her breath, thinking again that no one can hear her. Even the fucking shithole!

The people there don't like her either. There is too much salt in the ship. Nothing wants salt except people, and people want more than they should have, but they're the only ones who can take it without getting sick. So they all have to eat as much salt as they can without overdoing it, but that doesn't really help, because it's a really short loop and they excrete it back into the larger system. Devi always wants long loops. Everything needs to loop in long loops, and never stop looping. Never pile up along the way in an appendix, in a poisonous sick disgusting stupid cesspool, in a slough of despond, in a fucking shithole. Devi sometimes fears she herself will sink into a slough of despond. Freya promises to pull her out if she does.

So they don't like chlorine, or creatinine, or hippuric acid. The bugs can eat some of these things and turn them into something else. But the bugs are dying now, and no one knows why. And Devi thinks the ship is short on bromine, which she can't understand.

And they can't fix nitrogen. Why does nitrogen break so often? Because it's hard to fix! Ha-ha. Phosphorus and sulfur are just as bad. They really need their bugs for these. So the bugs have to stay healthy too. Even though they're not enough. For anyone to be healthy, everyone has to be healthy. Even bugs. No one is happy unless everyone is safe. But nothing is safe. This strikes Freya as a problem. Anabaena variabilis is our friend!

You need machines and you need bugs. Burn things to ash and feed the ash to the bugs. They're too small to see until there are zillions of them together. Then they look like mold on bread. Which makes sense because mold is one kind of bug. Not one of the good ones; well, bad but good. Bad to eat anyway. Devi doesn't want her eating moldy bread, yuck! Who would do that?

You can get two hundred liters of oxygen a week from one liter of suspended algae, if it is lit properly. Just two liters of algae will make enough oxygen for a person. But they have 2,122 people on board. So they have other ways to make oxygen too. There's even some of it stored in tanks in the walls of the ship. It's freezing cold but stays as liquid as water.

The algae bottles are shaped like their biomes. So they're like algae in a bottle! This makes Devi laugh her short laugh. All they need is a better recyclostat. The algae always have bugs living with them, eating them as they grow. With people it's the same, but different. Growing just a gram of Chlorella takes in a liter of carbon dioxide and gives out 1.2 liters of oxygen. Good for the Chlorella, but the photosynthesis of algae and the respiration of humans are not in balance. They have to feed the algae just right to get it between eight and ten, where people are. Back and forth the gases go, into people, out of people, into plants, out of plants. Eat the plants, poop the plants, fertilize the soil, grow the plants, eat the plants. All of them breathing back and forth into each other's mouths. Loops looping. Teeter-totters teetering and tottering all in a big row, but they can't all bottom out on the same side at the same time. Even though they're invisible!

The cows in the dairy are the size of dogs, which Devi says is not the way it used to be. They're engineered cows. They give as much milk as big cows, which were as big as caribou back on Earth. Devi is an engineer, but she never engineered a cow. She engineers the ship more than any animals in the ship.

They grow cabbages and lettuce and beets, yuck! And carrots and potatoes and sweet potatoes, and beans that are so good at fixing nitrogen, and wheat and rice and onions and yams and taro and cassava and peanuts and Jerusalem artichokes, which are neither artichokes nor from Jerusalem. Because names are just silly. You can call anything anything, but that doesn't make it so.