Seveneves

Two weeks ago she’d been yanked out of a Fulbright scholarship at the University of St. Andrews in Scotland, given some basic training in how to live in space, strapped into a rocket, and shot up here in a tourist capsule.

Dinah, along with everyone else, made the obvious assumption that Luisa’s job was to be the first shrink and social worker in space. Judging from some interactions that had been happening as crowding and stress had gotten more intense, she was going to have her work cut out for her. A bunch of desperate people crowded aboard a pitching and rudderless fishing boat was an uncomfortably close match for the situation up here.

Luisa had a relaxed self-confidence that made it easy for her to admit that she knew absolutely nothing about such topics as orbital mechanics. But it was more than just that; she knew how to use her own ignorance as an icebreaker in conversations. Izzy was full of people who were skewed toward the Asperger’s end of the social spectrum, and there was no better way to get them to start talking than to ask them a technical question.

But when everyone else was busy, Luisa was not above googling her question down to Earth and latching on to a YouTube video, as she was doing now.

Dinah, floating behind Luisa’s shoulder, watched as the animation was replaced by a live shot of Doc Dubois and a stocky, bald white man standing next to each other on the flat pan of gray-brown dirt that she now recognized as the Moses Lake spaceport. In deep background behind them was another rocket being stacked on the pad, one stage at a time, by a tangled-looking arrangement of cranes, gantries, and cables.

Dinah vaguely recognized the one who wasn’t Doc Dubois; he was a tech pundit who popped up frequently on television and YouTube. He turned toward the camera and spoke: “This is Tavistock Prowse, coming to you from the world’s newest spaceport here in Grant County, Washington. I’m here with a man who needs no introduction, Doc Dubois, to talk about some of the recent controversial events surrounding the Arjuna Expeditions launches, many of which are originating from the improvised launch complex that you can see directly behind us. Arjuna has prepared an animation that explains what they are all about. So pop some popcorn and pull up a chair.”

Their image was replaced by a view of Earth that zoomed back, tilted, and panned to show it in its orbit around the sun. This was helpfully traced out by a thin, curved red line. The animation panned back. The orbits of Venus, Mercury, then Mars and Jupiter came into view. “Traditionally,” Doc Dubois said, “when we talk about asteroids, we’re talking about the asteroid belt, which is out between Mars and Jupiter.”

A ring of dust, with a few larger clumps, was now spattered into the huge gap between those two planets’ orbits. “There’s a lot of material out there that Our Heritage might one day be able to exploit, but it’s too far away to be easily reached by any spacecraft we have now.”

So Doc Dubois, in keeping with his rep for staying in touch with the zeitgeist, had adopted the Our Heritage phrasing, a suddenly popular buzzword and hashtag meaning “whatever gets accomplished in the distant future by the descendants of the people who make it onto the Cloud Ark,” or, to put it bluntly, “the only reason to go on living for the next twenty-two months.”

The animation began zooming back in, to the point where it showed nothing beyond Earth’s orbit. “But astronomers have known for a long time that not all of the asteroids are out beyond Mars. There are much smaller—but still significant—populations of asteroids in heliocentric orbits not that different from Earth’s.”

A finer and sparser dust of particles was now drawn in, forming a sort of fuzzy halo around the red line that represented Earth’s orbit.

“And that’s where Amalthea came from, is that correct, Doc?”

“Yes, bringing a hunk of metal that big from all the way out between Mars and Jupiter would have taken forever. Because we found it in an Earth-like orbit, it was a little easier.”

“And what do you mean by an Earth-like orbit?”

“These rocks all revolve around the sun just like the Earth. Some are a little inside Earth’s orbit, some a little outside of it, some cross the Earth’s orbit twice every time they go around the sun. We used to worry about those.”

“Now, not so much,” Tav put in.

Doc paused, and apparently thought better of acknowledging the joke. “Because we were worried about them, we made an effort to find them and to know their exact trajectories—their orbital parameters.”

Back to Doc and Tav, now walking across the pounded earth of the spaceport with a big truck in the background emblazoned with the Arjuna Expeditions logo.

“In recent years, companies like Arjuna Expeditions have mapped a whole lot more of those asteroids in the hopes of mining them. What we’re seeing in the last few weeks is a concerted effort by Arjuna, and an alliance of other private space companies, to throw those efforts into high gear.”

“What exactly is Sean Probst thinking, Doc?” Tav asked.

“He’s not telling us. But the science of orbital mechanics doesn’t leave a whole lot to the imagination. In Part Two of this video, you can learn more about the dance of orbiting bodies in space, and the intricate choreography needed to make an asteroid show up in the right place at the right time.”

Luisa’s finger hovered over the link that would play the next video, but before tapping it, she turned around to look at Dinah. “Just trying to figure out what you do for a living,” she said, in an accent that came from everywhere, but mostly from New York. “You’re with Arjuna, right?”

“Shh!” Dinah warned her jokingly. “I’m still trying to stay friends with the Russians.”

“What’s that about?” Luisa asked.

She was referring to a recent series of testy meetings, and sometimes out-and-out confrontations, between the Russians—still thinking and acting as a bloc under the leadership of Fyodor Antonovich Panteleimon—and the Arjuna contingent, which actually prided itself on being “disruptive.” This was a commonplace bit of biz jargon. But try explaining to a grizzled cosmonaut why being disruptive was a good thing.

Dinah was inclined to say something like “It’s cultural,” but she felt a little intimidated about using that sort of cocktail-party banter around someone with Luisa’s credentials.

“Look, surprises in space are almost always bad,” Dinah said. “Traditionally, every mission is planned out to the nth degree, and there’s a contingency plan for everything. You don’t improvise. You can’t improvise, because there’s nothing to improvise with.”

“I’m just remembering the duct tape in Apollo 13.”

“Yeah, that was one of the rare exceptions,” Dinah said, “and people are still talking about it decades later. So, to the Russians, the idea that someone can just show up unannounced, and make a claim on our resources—”

“What resources?” Luisa asked.

“They’re breathing our air,” Dinah said. “Taking up space, using bandwidth, you name it. Larz hitched a ride up here on the assumption he’d stay on Izzy and work for us—instead he’s taking off with Sean. And they are taking almost all of my robots.”

“But they’re sending more, yes?”

“Absolutely. Look, all I’m saying is that it was a surprise. And the sooner Sean and Larz get out of here, and on their way, the less likely it is that Fyodor is going to strangle them with his bare hands.”

“On their way to where?” Luisa asked.

“A different orbit.”

“Heliocentric or geocentric?” Luisa asked, deadpan, then gave Dinah a wink.

“Geocentric first. Then heliocentric,” Dinah answered with a trace of a smile.

“But I thought we were already in a geocentric orbit.”

“The wrong one, as far as Sean is concerned. Izzy’s orbit is angled with respect to the equator. It has to be that way so Baikonur can launch to it—Baikonur is as far north as Seattle. But when you are doing interplanetary stuff, which is what Sean has in mind—basically, whenever you want to get out of low Earth orbit—you want to be in an orbit that’s closer to the equator. Because that’s pretty much where the rest of the solar system is—including the big chunk of ice that Sean wants to grab and bring back here.”

“Ymir,” Luisa said, pronouncing it as she’d heard Sean do: ee-meer. A word from Norse mythology referring to primordial ice giants. Sean’s code name for a particular hunk of ice that his project had identified, and that he meant to bring back.

“Yeah. Not an official name. Sean doesn’t divulge much.”

“And how do you get from one to the other?” Luisa asked. “From a geocentric orbit—that’s what we’re in now, right?”

“Yes.”

“To a heliocentric one?”

“Well, first he’s going to have to do a plane change—from the angled Izzy orbit we’re in now, to one closer to the equator. He’ll rendezvous with the rest of his gear.”

“Why didn’t they just send everything up here?”

“Plane-change maneuvers are expensive. It’s not too bad if the only thing plane-changing is Sean and Larz and a Drop Top, but it would be ridiculously wasteful to send the whole expedition package up here only to plane-change later.” Dinah didn’t mention the other reason, which was that the biggest part of Sean’s package was so screamingly radioactive that it couldn’t be allowed anywhere near Izzy.

“Okay. But we’re still talking geocentric, right?”

“Correct, we’re still just a few hundred miles high.”

“So, how do they get from the rendezvous point to a heliocentric situation?”

“There’s a bunch of different ways to do it,” Dinah said, “but if I know Sean he’ll go through the L1 gateway.”

“I have no idea what that is,” Luisa said, then finally lost a fight to suppress a giggle. “But once again I feel that I have been dumped into a sci-fi movie when I hear people around me talking like that.”

“Doc Dubois probably covers it in that video,” Dinah said, nodding at Luisa’s tablet, “but the gist of it is really straightforward.” Looking around, she spied a mesh bag stuffed with clothing. She pulled it out of its niche and let it drift in the center of the cabin. “The sun,” she said. Now patting herself down, she found in her pocket a small plastic bottle of pills—antinausea medication she had fetched for one of the new arrivals. She opened it up and pulled out the ball of cotton stuffed into its top, then let the cotton drift in the air a little closer to Luisa. “The Earth, in its heliocentric orbit.” The sick crew member would have to wait for a few minutes. Dinah carefully tapped a few pills free from the bottle’s open neck and let them float for a moment while she pocketed the bottle. Then she began to arrange the pills in the space already staked out by the “sun” and the “Earth.”

“Asteroids?” Luisa guessed.

“These are more like abstract mathematical points,” Dinah said. “They’re called the Lagrange points, or the libration points, and there’s five of them around every two-body system. Always in the same basic geometry. Two of them, L4 and L5, are way off to the sides. I’m not going to try to show you those because we don’t have room. But the other three are all along the line running between the sun and the Earth.” She pushed off and glided to the far side of the “sun” and stationed a pill there, exactly on the opposite side from where the “Earth” was. “This is L3, very far away, invisible to us because the sun’s always in the way, not that useful.”

Gliding back toward the hovering cotton ball, she stopped herself against a bulkhead and placed a second pill out beyond it. “This is L2, outside of Earth’s orbit.” Finally, she put a pill in between the “sun” and the “Earth” but much closer to the latter. “And this is—”

“L1, by process of elimination,” Luisa said drily, and laughed. “You space people love to count down, I know your ways.”

“It’s where the gravity of the sun and the Earth balance,” Dinah said, “and people sometimes call it a gateway because it’s an easy place to effect a switchover between a geocentric and a heliocentric orbit. This even happens naturally sometimes: an asteroid in a heliocentric orbit will wander close to L1 and get captured by the Earth. Or, going the other way, there’s a case where an Apollo upper stage orbiting around the Earth passed near L1 and got ejected into a heliocentric orbit for a number of years. Later it came back through the same gateway—only to get ejected again.”

Luisa nodded. “Like changing from the D to the A train at Columbus Circle, in New York terms.”

“A lot of people have used the analogy of a switching yard or a train station to describe it, yeah,” Dinah said.

“So you think Sean and his crew are headed that way.”

“Once they get all their—” Dinah paused.

“Their shit together?” Luisa suggested.

“Thank you, yes,” Dinah said with a smile. “They need to get to a higher orbit than we are in now if they are going to reach L1. That means burning their engines, expending a lot of fuel in just a few minutes, and then coasting for a few weeks. They’ll have to pass through the Van Allen belts and soak up a lot of radiation. No avoiding it, unfortunately. L1 is four times farther away than the moon.”

“Or what used to be the moon,” Luisa said under her breath.

“Yeah, which means that in a few days Sean and his crew are going to be farther away from Earth than any humans who have ever lived. When they get to L1—which will take five weeks—they’ll have to execute another burn that will switch them from the D to the A train—place them into a heliocentric orbit. And from there they can plot whatever course is going to get them to the comet.”

Luisa had gotten a bit sidetracked by the first part of what Dinah had said. “Farther away from Earth than anyone in history,” she repeated. “I wonder if there might be a certain feeling of jealousy at work in Fyodor’s reaction, knowing that after all the time he has spent in space—”

“Some rich whippersnapper is going to show up and make his accomplishments look minor,” Dinah said, nodding. “Could be. Fyodor’s got the Russian granite face, you can’t tell what’s going on inside.”

“Anyway,” Luisa said, “they go and fetch the big ball of ice and then reverse all of those steps to come back to what by that point will hopefully be the Cloud Ark.”

“Not exactly,” Dinah said. “And that’s where things get interesting.”

“Oh, I thought they were already pretty interesting!” Luisa said.

Dinah was limited, here, in what she was allowed to say. “Maneuvering a space vehicle—which is designed and engineered to be what it is—around the solar system is one thing. Moving a huge raggedy-ass ball of ice is another.”

“It’s going to take a long time,” Luisa said, nodding. “And it might not work.”

“Yeah. Look, I just make robots.”

“All of which will be making the trip?”

“Yes,” Dinah said. “They’ll be needed on the comet’s surface, for anchoring cables and netting. It’s a big chunk of ice. It’s brittle. We don’t want it to fall apart like a dry snowball when thrust is applied.”

“A dry snowball,” Luisa repeated. “Is that a thing, where you come from?”

“The Brooks Range? Yeah. Terrible place to make snowballs.”

“Unless you’re the kid sister,” Luisa said, “and everyone’s throwing them at you.”

“No comment on that.”

“In Central Park,” Luisa said, “the snowballs were wet and they were hard.”

DAY 90

When Ivy had opened the meeting on Day 37 with the words “five percent,” Dinah and most of the others on Izzy had looked around themselves and seen a lack of progress that had troubled them. Which, of course, had been Ivy’s point. On that day, twenty-six people had been in space, eight of whom were just barely surviving in temporary Luk shelters. The Banana had, with a bit of crowding, accommodated everyone.

On Day 73, when Ivy had opened another meeting in the Banana with the words “ten percent,” the situation had been transformed. There had been no question anymore of fitting Izzy’s whole population into the Banana; most of them had had to watch the meeting on video feeds. Thanks to Sean Probst and his Arjuna launches out of Moses Lake, no one quite knew what the total off-Earth population was anymore. Allegedly there was a Google Docs spreadsheet where it was being kept track of, but no one could agree on where it was. The population had certainly gone into the triple digits at least a week before.

In the first two weeks of its operation the new shake-and-bake spaceport at Moses Lake had launched three rockets. One had crashed into a high-end vineyard near Walla Walla, destroying several acres of grapes that would have made excellent wine, had there been enough time left on Earth’s clock to age it properly. The others had made it to Izzy.

Most of Arjuna’s big payloads, though, were being launched not from Moses Lake but from sites nearer the equator, whence they could get into orbits closer to the plane of the ecliptic. At least two heavy-lift rockets, one from Canaveral and one from Kourou, had effected a rendezvous and docking maneuver in a low orbit above Earth’s tropics. Others were said to be in the works. But little was known of this project. Communication wasn’t Sean Probst’s strong suit, and his career in private enterprise had instilled a habit of playing his cards close to his vest. In this he seemed to be of one mind with the small cohort of people aboard Izzy, like Spencer Grindstaff and Zeke Petersen, who had impressive security clearances. Dinah and Ivy, comparing notes and sharing fragments of circumstantial evidence, had assembled at least a vague theory of what was going on. Ostensibly, Sean Probst was a wild card. But Arjuna had been mailing Nats to Sparky for weeks, and Sparky had been giving them top priority on launches to Izzy. It seemed, therefore, that Dinah’s results—the feedback she was sending to Arjuna about which Nats worked in space and which didn’t—were of great interest to NASA. And it was significant that at least one of Sean’s payloads had been launched from Canaveral—which was, of course, NASA’s flagship launch facility. Even more so was a launch out of Vandenberg Air Force Base that added a small additional module to the growing Arjuna complex. They knew it was small because of the size of the rocket used, and they knew it was top secret spook stuff because of the precautions that had been taken on the ground—that much had been reported by ordinary citizens, who had been forced to the shoulder of Highway 101 by a long military convoy, and who had aimed long lenses at the launch pad only to find their view blocked by tarps and camo nets.

The next rocket out of Moses Lake had made an uneventful journey to Izzy. Its upper stage, lacking a place to dock, flew in formation with the space station about a kilometer “aft.” Fyodor stared at it balefully out the window and made repeated suggestions that its stores should be confiscated. Its cargo manifest was unusual:

 Spare propellant, and other consumables, that would enable Sean’s Drop Top to execute a plane-change maneuver and rendezvous with Ymir in equatorial orbit (for the word “Ymir” was now being used to denote both the spaceship that Sean was assembling and its faraway destination)

 Ice

 Fiber for combining with ice to make a stronger material called pykrete

 Several thousand Icenats: tiny robots optimized for crawling around on ice

Fyodor, and perhaps others as well, coveted the ice and the propellant. Pete Starling had begun rattling legal sabers down on the ground, threatening to seize the Moses Lake spaceport—a scheme that vanished overnight after Sean began to rattle sabers of his own, threatening to make a YouTube video exposing the Cloud Ark scheme as a poorly conceived panacea at best. It was strange, to say the least, that such open conflict could exist between the government’s left and right hands, but the world had become a strange place. Talking of it over meals or during after-work drinking sessions, Dinah and Ivy and Luisa could only speculate at the shouting matches that must be happening down on the ground between the Oval Office, the military, Arjuna Expeditions, and the Arkitects.

Dinah mostly just kept her head down and worked, programming the robots that Sean was going to take with him on his expedition. A comet core was not a solid piece of ice so much as an aggregation of shards, loosely held together by its own self-gravity—which was extremely weak. Merely touching it could cause big pieces to separate. Arjuna Expeditions had known this for many years and had put millions of dollars into inventing technology for capturing such difficult objects. Though “technology” might be too fancy a word for techniques that would have been recognizable to Stone Age hunter-gatherers: surround it with a net, draw the net closed with a loop of string.

Actually performing that feat in space was what Sean described as “an asymmetrical problem,” programmer-speak meaning that there were a lot of contingencies and detail work, so it wasn’t amenable to One Big Solution. Robots would probably end up swarming all over the surface of Comet Grigg-Skjellerup, cinching the net down and reinforcing weak spots by melting the ice, mixing the water with fiber, and letting it refreeze into pykrete. Dinah had offered to help out with that, and had been excited by the thought until Sean had brought her down to earth by pointing out some awkward realities. Communication between Izzy and Ymir was going to be limited by their one radio. They wouldn’t be able to send video. And latency was going to be significant: for a large part of the journey there would be a delay of several minutes as the signals traversed a distance comparable to that between the Earth and the sun. So programming robots on the surface of the comet would be nothing like looking out her window at the ones on Amalthea. Anything Dinah had to contribute, she had to contribute now.

In any case, Izzy’s population had dropped by two, and the level of tension and drama had fallen precipitously, when Sean and Larz had departed in the Drop Top on A+0.82. The plane-change maneuver took them to a rendezvous above the equator with Ymir. After more rendezvous operations extending over a week, and incorporating yet more payloads launched from Cape Canaveral as well as from private spaceports in New Mexico and West Texas, Ymir made a long burn of her main engine that placed her into a transfer orbit bound for L1. A few days after that, she beat the Apollo record for distance traveled from Earth.

Konrad Barth came to Dinah’s shop and knocked politely, for she happened to have her curtain drawn, and everyone knew that she and Rhys sometimes had sex on the other side of it. He entered, looked about nervously, and asked her if she knew anything about what Ymir was going to do. Before she could answer, he shook her off, took out his tablet, and tapped in his password. Then he spun it around to show her a photograph.

It took her a while to understand what she was seeing. Clearly, it was a picture of a man-made object in space. And it was a good picture, but surrounded by a glamor of pixels that spoke of considerable enhancement. Konrad had taken the picture using one of Izzy’s optical telescopes. He had turned it away from its usual objective, which was the system of fragments churning around the former center of the moon, and aimed it at this man-made object. The object was big and complicated, at a guess the largest thing humans had ever assembled in space with the exception of Izzy herself. The picture had been taken from a great distance while both Izzy and the object were moving with respect to each other, and he’d toiled with image processing software to reduce the blur. She could see clearly enough that, like Izzy, it consisted of a stack of modules that had been sent up atop different rockets and plugged together. The one on its tail sported a large nozzle bell, and was obviously its main propulsion unit. Some of the modules just looked like propellant tanks. Others looked like habitations. But far and away the most prominent, and the weirdest, part of this thing was a long spike or probe that extended from its forward end, making it ten times as long as it would have been otherwise. It was a truss, recognizably made in the same way as the new trusses on Izzy.