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.
Devi is called away from one of her regular meetings to deal with an emergency again, and as it’s one of Freya’s days with her, she brings Freya along.
First they go to her office and look at screens. What kind of emergency is that? But then Devi snaps her fingers and types like crazy and then points at one screen, and they hurry around to one of the passageways between biomes, the one between the Steppes and Mongolia that is called Russian Roulette, and is painted blue and red and yellow. The next one along is called the Great Gate of Kiev. The tall, short tunnel between the doors to the lock is crowded this morning with people, and a number of ladders and scaffolding towers and cherry-pickers.
Devi joins the crowd under the scaffolding, and Badim shows up a bit later to keep Freya company. They watch as a group of people ascend one of the scaffold ladders, following Devi up to the ceiling of the tunnel, right next to the lock-door frame. There several panels have been pulled aside, and now Devi climbs up into the hole where the panels have been moved, disappearing from sight. Four people follow her into the hole. Freya had no idea that the ceiling did not represent the outer skin of the lock, and stares curiously. “What are they doing?”
Badim says, “Now that we’re decelerating, that new little push is counteracting the Coriolis force that our spin creates, and that’s a new kind of pressure, or release from pressure. It’s made some kind of impediment in the lock door here, and Devi thinks they may have found what it is. So now they’re up there seeing if she’s right.”
“Will Devi fix the ship?”
“Well, actually I think the whole engineering team will be involved, if the problem turns out to be up there. But Devi’s the one who spotted this possibility.”
“So she fixes things by thinking about them!”
This was one of their family’s favorite lines, a quote from some scientist’s admiring older relatives, when he was a boy repairing radios.
“Yes, that’s right!” Badim says, smiling.
Six hours later, after Badim and Freya have gone into the Balkans for a lunch at its east end dining hall, the repair crew comes down out of the hole in the lock ceiling, handing down some equipment, then putting a few small mobile robots into baskets to be lowered by the scaffold. Devi comes down the ladder last and shakes hands all around. The problem has been located, and fixed with torches, saws, and welders. The long years of Coriolis push shifted something slightly out of position, and recently the counterforce of deceleration shifted it back, but meanwhile the rest of the door had gotten used to the shift. It all made sense, although it didn’t speak volumes about the quality of construction and assembly of the ship. They were going to check all the other slides like the broken one, to make sure the lock doors of Ring B weren’t impeded in other places. Then they won’t stress motors trying to close doors against resistance.