Seveneves

by Neal Stephenson

  The task complete, he established a link between his tablet and the wireless network of this arklet and spent a few minutes moving video files around so that he could edit them later. Catching sight of himself in freeze-framed thumbnails, he was struck by the roundness of his face—a typical symptom of zero gee as the body retrained itself in how to distribute fluids through its tissues. Up here it was the mark of the newbie. Doob had been in space for six days; this was A+1.0, one year to the day since he had stood in the Athenaeum and watched the moon disintegrate.

  Arklet 2, now outmoded by newer models, was docked at the far end of a hamster tube on the port side of the big truss. Sooner or later it would probably be used for overflow storage or sleeping quarters. Doob passed through its docking port and began making his way down the hamster tube. As he’d learned on his way here, this was going to take a while; the tube was barely large enough to accommodate a svelte human in a polyester coverall. A large man in a pressure suit banged and scraped the whole way. And yet it was easier to do it with the suit on than to drag the empty suit behind you, or push it ahead of you, like a zero-gee murderer trying to dispose of a body.

  In a few minutes he was able to reach a node, right along Izzy’s central axis, where he had more space to move around, and there he began taking the suit off. This was not a full-fledged space suit, which, with its huge backpack life support system, would have been much too bulky for the hamster tube. It was just a helmeted coverall of the type worn by high-altitude pilots. It had a leak, and so was useful only as a costume. Escaping from it developed into a sort of wrestling match, with a lot of cursing and drifting around, banging into walls.

  At an opportune moment, he felt a sharp tug on the rear collar of the suit. This pulled it down to the point where he could shrug out of it and get his arms free. “Thanks,” he said, and then looked over his shoulder to see a familiar face gazing at him quizzically.

  “Aren’t you a little short for a storm trooper?”

  “Moira?!” Doob said. He grabbed a handle on the wall so that he could spin himself around and get a better look. His glasses had gone askew during the wrestling match, so he poked them back up on his nose. It was her all right, suffering from a clear case of moon face.

  He had last seen Dr. Moira Crewe at the Crater Lake announcement, where she had been assisting her mentor, Clarence Crouch, the Nobel Prize–winning geneticist—the poor sod who had been given the job of explaining the Casting of Lots to the world. Since then Clarence had died of cancer in his Cambridge house, surrounded by biological samples and scientific memorabilia that would not long survive the onset of the Hard Rain. No doubt it had been a blessing for him. Doob had lost track of Moira after that, but of all the people on Earth she was one of the most obvious candidates for inclusion on the Cloud Ark. She was of West Indian ancestry, wearing her hair in finger-length dreadlocks that had adapted pretty well to zero gravity—better than white-people hair, for sure. Moon face had added a few years to her apparent age, but Doob knew her to be in her late twenties. Raised in a dodgy part of London, she’d gone to a posh school on scholarship and went on to earn a biology degree at Oxford. She had gone to Harvard for her Ph.D., working with a project there on de-extinction. Her general charisma, and an accent that Americans found charming, had made her into the most well-known spokesperson for that project. She had done TED talks and other public appearances describing her lab’s efforts to bring the woolly mammoth back to life. After a brief sojourn in Siberia, working with a Russian oil billionaire who wanted to create a nature preserve stocked with formerly extinct megafauna, she had returned to the UK and begun postdoctoral work with Clarence.

  It was not the first time Doob had been pleasantly surprised to bump into a colleague who had, unbeknownst to him, been sent up to Izzy. It always raised an awkward point of etiquette. It was tempting to express delight and give the person a big hug, as you’d naturally do if you encountered them at a party in Cambridge or on the street in New York City. But none of them had come up here on a happy errand. And Moira anyway had a certain owlish way about her, a way of keeping her distance.

  And hugging people in zero gee was harder than it sounded. You had to get to them first.

  Doob held his arms out to his sides. “Hug,” he said.

  She did the same. “Is that what one does here?” she asked.

  “It is not unheard of. Moira, PCA, it is good to see you up here.”

  PCA was an abbreviation for “present circumstances aside” and had become a staple of Facebook, Twitter, and the like.

  “I had heard you’d come up,” Moira said, “but it didn’t quite register, as I’ve been awfully preoccupied.”

  “I can only imagine,” Doob said. “While I’ve been running around shilling for the Cloud Ark, you’ve probably been doing actual science, huh?”

  “Getting ready to do it might be more precise,” she said. Her big brown eyes, behind a geeky but stylish pair of glasses, strayed in a direction. “Is that what they call forward?” she asked.

  “Yes.”

  “Well, the place where I’m working is about as far forward as it’s possible to get, because they want my lab to be sheltered by the big rock.”

  “Amalthea.”

  “Yes. And if we go there, I can show you a bit of what I’ve been up to. I feel I should offer you tea as well, but I don’t know how to make it here.”

  Doob smiled at her way of talking. She had been a fiend for theater at Oxford, and might have become an actress. Intensely conscious of the difference between the way her people in London talked and the way people talked at her school and at Oxford, she’d become good at switching between those accents for effect. “I’d be happy to have a look,” he said. “I think I know the module you’re talking about—I saw it docking a few days ago, and was curious.”

  HE HOOKED THE UNOCCUPIED PRESSURE SUIT TO THE WALL OF MOIRA’S lab and it hung there, an inanimate observer, as Moira showed him around. Never one for the life sciences, Doob couldn’t understand everything she was saying to him, but he didn’t care. Being able to relax and let someone else explain science to him was a welcome turnabout.

  “Do you know about the black-footed ferret?” she asked.

  “No,” Doob said. “I think you can pretty much assume that my answer to all questions about biology and genetics is going to be in the negative.”

  “Ninety percent of their diet was prairie dogs. Farmers killed almost all of the prairie dogs and so the population of black-footed ferrets crashed to the point where only seven remained. From that breeding stock, it was necessary to bring them back.”

  “Wow, only seven . . . so inbreeding must have been an issue?”

  “We speak of heterozygosity,” she said, “which just means the amount of genetic diversity within a species. In general, it’s a good thing. If you have too little of it, then you start to see the sorts of problems that we associate with inbreeding.”

  “But if the breeding stock is reduced to only seven . . . then that’s all you have to work with, right?”

  “Not quite. Well, technically yes, I suppose. But by manipulating some of the genes, we can create heterozygosity artificially. As well as getting rid of some of the genetic defects that would otherwise propagate through the whole population.”

  “Anyway,” Doob said, “it’s obviously of interest to us now.”

  “If the Cloud Ark’s as populous as they claim it’s going to be, and if people come up with frozen sperm samples and ova and embryos and all of that, then the human population is probably all right. We’ll have enough heterozygosity to make a go of it. My work here is going to be more concerned with nonhuman populations.”

  “Meaning . . .”

  “Well, you’ve probably heard that we’ll be growing algae as a way to generate oxygen. Which is only the start of a simple ecosystem that will have to be developed and grown, and become much less simple, over the years to come. Many of the plants and microorganisms that will make up tha
t ecosystem will be cultivated from initially small breeding populations. We don’t want to have a repeat of the Irish potato famine, or something analogous, with the plants we rely on to make it possible to breathe.”

  “So your job will be to do with them what was done in the case of black-footed ferrets.”

  “Part of my job, yes.”

  “What’s the other part?”

  “Being a sort of Victorian museum curator. Did you ever visit Clarence’s home in Cambridge?”

  “No, I’m sorry to say. But I heard his collection was magnificent.”

  “It was crammed with all of these stuffed birds and boxed beetles and mounted heads of beasts, gathered by Victorian gentleman-collector types in pith helmets, doing their bit for science on the fringes of the empire. Not scientists as we’d define them today but contributors to the scientific ideal. These things overflowed the museums and Clarence acquired them by the lorry-load, especially after Edwina died and couldn’t forbid it. Anyway, I’m that person now, except that the samples are all digital, and they are all on these things.” She tapped a thumb drive that was floating around her neck on a chain. “Or their rad-hard equivalents.” She pronounced the technical term with a dubious and ironic tone of voice, suggesting that she and the International Space Station would take a while getting used to each other. “You know the general story—I’ve heard you talking about it on YouTube.” She switched into a credible imitation of Doob’s flat midwestern vowels: “‘We can’t send blue whales and sequoias up on the Cloud Ark. And even if we could, we couldn’t keep them alive there. But we can send their DNA, encoded as strings of ones and zeroes.’”

  “You’re going to put me out of a job,” Doob said.

  “Good. Then I’ll put you to work here,” Moira said. “This is labor intensive as hell, and they’re not sending me enough help.”

  “I thought it was all automatic.”

  “If the Agent had given us another couple of decades to improve our gene synthesis technology, it might have become so,” Moira said. “As it is, we’ve been caught in a bit of a gawky adolescent phase. Yes, we can take one of these files”—she tapped the thumb drive around her neck—“and we can create a strand of DNA from it, beginning with a few simple precursor chemicals. But the amount of human intervention is still ridiculous.”

  “I’m guessing that is some pretty high-level human intervention too.”

  “My Jamaican grandfather worked in the engine room of a navy ship,” Moira said, “which is how our family ended up in England. When I was a little girl, he took me on a tour of one of those ships, and we went down into the engine room, and I saw it, the engine, with all of the bits exposed; the bloody thing was naked and men had to go crawling around on it with oil cans, lubricating the bearings by hand and so on. That’s a bit like where we are now with synthesizing whole genomes.”

  “But for now,” Doob said, “that’s far in the future, right?”

  “Yes, thank God.”

  “For now you’re going to be tinkering with intact organisms.”

  “Yes. Just so. Still quite difficult, but I think manageable.” She looked around. The module in which they floated looked nothing like a lab. Everything was sealed up in plastic or aluminum cases, taped shut and labeled with yellow sticky notes. “Sorry,” she said. “Underwhelming. Hardly worth the trip, is it?”

  “How can I help?”

  “Get me some fucking gravity,” Moira said. Then she laughed. “Can you imagine trying to do tricks with liquids in zero gee? Because that’s all a lab is.”

  “It must look frustrating to you now,” Doob said. “Everything in boxes, no gravity to make it all work.”

  “I know, I know,” she said. “I’m whingeing. They’ll put this thing on a bolo, won’t they?”

  “Maybe a third torus. Big enough to make something close to Earth-normal gravity. Lots of space to work in. A staff of eager Arkers.”

  “That’s your job now, isn’t it?” Moira said. “Cheerleader for the Ark.”

  “It was my ticket up here,” Doob said. He could feel a little warmth creeping into his face, and cautioned himself not to say anything he was going to regret. “We all needed that ticket. Now that we have paid the price of admission, we need to make it work.”

  Moira, perhaps sensing she’d gone a little too far, kept her silence and would not meet his gaze.

  “And as of today,” he said, “we have one year.”

  Part Two

  DAY 700

  ON DAY 700, ALSO KNOWN AS A+1.335 (ONE YEAR AND 335 DAYS SINCE the destruction of the moon), the Cloud Ark, as seen from the Earth, looked like a bright bead strung on a silver chain. For the reasons that Dr. Dubois Jerome Xavier Harris had tried to articulate during his soliloquy aboard Arklet 2, back on A+1.0, it was expensive, in terms of propellant, to maintain an actual cloud or swarm of arklets around Izzy. Much cheaper and more reliable was to have them precede or follow the space station along the same orbital path, like a queue of ducklings with Mom in the middle. Once an arklet had found its place in that train, changing its position was a maneuver whose complications were a perennial source of surprise and consternation to newly arrived members of the so-called General Population.

  Arkies as such—people who had been selected in the Casting of Lots, who had spent up to two years in training for this mission, and who had been sent up here specifically to manage, and live in, arklets—understood it implicitly. As of Day 700, there were 1,276 of those, with about two dozen more coming up each day during the final surge of launches. New arrivals were assigned to empty arklets that awaited them at the head or the tail of the queue. These were launched on separate heavy-lift rockets about four times a day. Since an arklet consisted mostly of empty space, it weighed almost nothing compared to the lift capacity of a big rocket, and so they were always crammed from boiler room to front door with vitamins. These had to be extracted and stowed before the arklet could be occupied. Each arklet had its own unique manifest of stuff. Some of them were just full of compressed gas, such as nitrogen, which would later be used to fertilize crops. Others might be packed with enough diverse and seemingly random goods to open a space bazaar: medicines, cultural artifacts, micronutrients, tools, integrated circuits, spare parts for Stirling engines, Arkies’ personal effects, and, in one notable case, a stowaway who was found dead on arrival. With the exception of the stowaway—who was stashed in the morgue with the rest of the deceased—all of these items had to be extracted, cataloged, and stowed appropriately. Each arklet had some onboard storage space, so to some extent the storage was distributed—that being a fundamental tenet of the whole swarm-based Arkitecture. Bulk materials like gases could be pumped into external tanks or bladders: little ones dangling from arklets, big ones distributed around Izzy’s periphery where they could serve as extra shielding against radiation and micrometeoroids. So-called dry goods were likewise stashed in mesh bags that lived “outside” until such time as they were needed. Scarce and crowded “inside” space was reserved for organisms and goods that actually needed air and warmth. So, compared to the way it had looked a year ago, Izzy was spare and clean on the inside.

  Anyone who had not been chosen in the Casting of Lots and trained as an Arkie was categorized as General Population. There were 172 of those. The number grew only slowly, since most of the people who were qualified, and who were needed, ought to have been sent up a long time ago. Adding new members was attended by much political controversy down on the Earth. The Crater Lake Accord had ratified the general scheme of a Cloud Ark populated by those chosen in the Casting of Lots. It had been obvious, and uncontroversial, that experienced specialists were also needed, and so no one had quibbled over sending up the Scouts and the Pioneers. The concept of the General Population had been written into the Crater Lake Accord precisely to allow for that. People like Rhys Aitken, Luisa Soter, Dubois Harris, Moira Crewe, and Markus Leuker had been sent up under the “GPop clause” because they knew how to do things. For e
very one of them who got sent up, however, a hundred with similar qualifications were stranded on the ground, where some of them called their congressmen, chancellors, presidents, or dictators. The politics had become so involved as to throttle the incoming flow to a trickle. The remaining available GPop slots were being hoarded by national governments. They were being filled grudgingly and with byzantine premeditation.

  For Arkies and members of the GPop alike, it was easy to underestimate the “distance” separating Izzy from an arklet that was only a few kilometers ahead of or behind it in orbit.

  The difficulties entailed in moving from one arklet to another could be mitigated by physically docking arklets to a common structure, forcing them to fly in a rigid formation. Or so it might seem to people who had not been steeped in the laws of orbital mechanics. But the fact was that an arklet docked to the end of a truss far off to the port or the starboard wing of Izzy was not in a proper orbit at all. Left to its own devices—free, that is, of the constraints imposed, and the forces exerted, by the truss—it would converge on Izzy, cross through Izzy’s orbit, diverge from it, turn around, and converge again, on the same ninety-three-minute cycle that clocked Izzy’s orbits around the Earth. An arklet mounted “above” Izzy on the zenith would want to go “slower” and lag behind; one mounted “below” on the nadir would want to race ahead. To the extent that the truss structure prevented those things from happening—to the extent, in other words, that it succeeded in its basic function of holding all the modules and arklets in a fixed configuration—it was undergoing stress, exerting forces on those arklets to prevent them from doing what they wanted to do. Humans in those arklets would notice themselves drifting and bumping into the walls as their natural trajectories, as ordained by Sir Isaac Newton, were perturbed by the structure of Izzy. The larger Izzy grew, and the more arklets and modules were connected to her, the greater those forces became, and the closer she came to breaking.