“Red versus Blue crap?”

“Yes. And even though no one is sharing anything with me—yet—I like the feeling of that. People who claim they are motivated by the Purpose end up behaving differently—and generally better—than people who serve other masters.”

“So it is like believing in God.”

“Maybe yes. But without the theology, the scripture, the pigheaded certainty.”

Einstein and the Cyc nodded and looked thoughtful. But also, or so it seemed to Ty, a little let down.

“Sorry I didn’t have an answer to your question,” Ty said.

“What are you going to do next? Now that your Seven is disbanded?” asked Sonar.

“Go back to my bar.”

“On Cradle?”

“On Cradle. Once, an astonishing wonder of technological prowess. Now a quaint, outmoded precursor to the vastly superior Gnomon.”

“I’d like to see it,” Sonar said.

“We have rooms. Apartments where people can stay, around the courtyard in the back.”

“They must be expensive.”

“They are free,” Ty said.

“How do you get one of those free rooms?” Einstein asked.

“Beats me. The Owners hand them out to people who serve the Purpose.”

“Very important people, then.”

Ty shrugged. “They can’t kill you for asking. You’re right about the Seven. That’s gone. Our Ivyn died. You took his place.”

Einstein cackled nervously. “I’m no replacement for Doc!”

“You don’t have to replace him. Not in that sense. But look what you did. You made first contact with these guys.” He nodded at Deep. “And first contact of another kind with the Diggers.”

Both Einstein and Sonar Taxlaw blushed deeply.

“The Cyc came along and replaced Memmie. That’s not a traditional Seven. But if we can pry Beled and Kathree apart, and if we can round up a Julian and a Camite who don’t hate each other, we’ll have ourselves a Nine. The first Nine ever assembled.”

Ty was just running his mouth, letting the cider talk. Sonar, however, was taking it all seriously. “But only one of the Aïdan subraces will be represented,” she pointed out.

“Bard is plenty.”

“You should include the other four,” Einstein said.

“That makes thirteen. An unlucky number. And a bit of a crowd, frankly.” But the youngsters across the table from him were looking heartrendingly sincere. Ty broke eye contact. “I’ll bet I could talk the Owners out of a few free rooms, for such a momentous occasion.”

“Are you really going to ask them?!” Sonar exclaimed.

“Nah. As an ancient saying has it, it’s easier to ask forgiveness than permission. You are all welcome at the Crow’s Nest.” Ty looked over at Deep. “Just go easy on the cold baths, man. The plumbing in that place has seen better days, and I’m the only one who knows how to fix it.”

Acknowledgments

THE PREMISE OF THIS BOOK CAME TO ME CIRCA 2006, WHEN I WAS working part-time at Blue Origin and became interested in the problem of space debris in low Earth orbit. Researchers in that field had raised concerns over the possibility of a chain reaction smash-up that might create so many fragments of orbiting shrapnel as to render space flight practically impossible. My studies in that area turned out to be of little direct relevance to the company, but the novelist in me scented an idea for a book. During the same period I had also become aware of the immense amount of usable matter present in near-Earth asteroids. Thus by late 2006 I had come up with the basic premise of Seveneves. So the first acknowledgment goes to Blue Origin, which was founded circa 2000 by Jeff Bezos under the name Blue Operations LLC and where I had many interesting early conversations with him and other people involved with the company, including Jaime Taaffe, Maria Kaldis, Danny Hillis, George Dyson, and Keith Rosema. It was from Keith that I first heard the idea for the multilayered emergency shelter bubble that appears in this book under the name of Luk. Some of the Baikonur material is very freely adapted from the reminiscences and photographs of George Dyson, Esther Dyson, and Charles Simonyi.

Hugh and Heather Matheson provided background on mining—the industry, the culture, and the lifestyle—which helped me in creating Dinah. If I have stretched truths in my treatment of the MacQuaries’ mine in Alaska and their use of ham radio, it is my fault and not theirs. For the record, Hugh recommended that Rufus’s operation be situated in the Homestake Mine near Lead, South Dakota, or in the Coeur d’Alene Mining District, Idaho, but I put it in Alaska anyway, to get it farther from the equatorial zone.

Chris Lewicki and the staff of Planetary Resources supplied valuable suggestions during an informal visit that I made to their offices in November 2013. Numerous members of their engineering staff were more than generous with their time on that occasion. (Later Chris mentioned to me that he and other members of the company had been pleasantly surprised to learn that someone was producing science fiction in which the asteroid mining company was, for once, the good guys.)

Marco Kaltofen helped me flesh out the technical details of Ymir’s “steampunk” propulsion system and read over the relevant sections of the first draft with a careful eye. Seamus Blackley also supplied useful input during this phase. Having invoked those people’s good names, I’ll reiterate that if I’ve taken liberties—accidentally or on purpose—with scientific fact, it should be blamed on me and not on them.

Tola Marts and Tim Lloyd helped sketch out and visualize some of the details of the space hardware described in the book, a project that is still ongoing. Readers may be comforted to know that, thanks to Tola, various aspects of the Eye and the associated tether systems have been designed with appropriate engineering safety factors.

Kris Pister’s work on small swarming robots, which I have been following on and off for several years, was formative in the discussion of Nats.

Karen Laur and Aaron Leiby contributed time and effort to envisioning a game based on TerReForm, and though those efforts were stymied by the usual difficulties in obtaining capital, they did help sharpen my thinking about various aspects of the story. As part of a different prospective game project, Tim Miller of Blur Studio, with input from Jascha Little, Zoe Stephenson, Russel Howe, and Jo Balme, came up with ideas and concept art (produced by Chuck Wojtkiewicz, Sean McNally, Tom Zhao, and Joshua Shaw of Blur) for a number of different robots. Ed Allard devoted many hours of his time to prototyping the same game. Again, this work hasn’t led to an actual game yet, but it had the side effect of helping me put flesh on the bones of the story. Thanks also to James Gwertzman for introducing me to Ed and for his advice and feedback on this front.

Ben Hawker of Weta Workshop read the manuscript and pointed out that Cradle would be rusty, a detail that had somehow escaped me; hasty last-minute alterations ensued.

Stewart Brand and Ryan Phelan, by dint of their connection with the Long Now Foundation’s Revive and Restore Initiative, had much useful background to supply on the genetic challenges associated with reviving species from small breeding populations.

While the first two parts of the story are a tale of straight-up global disaster and hastily improvised technology, I always viewed the third part of it as an opportunity to showcase many of the more positive ideas that have emerged, over the last century, from the global community of people interested in space exploration. Many of the big hardware ideas in the latter part of the book have been kicking around in the literature for decades and will be recognized as old friends by longtime readers of hard science fiction.

Particular recognition and thanks are owed to Rob Hoyt of Tethers Unlimited. Following in the footsteps of the late Robert L. Forward, Rob has worked on a number of ideas in the realm of “big space machines.” One of these is the Hoytether, a hugely scaled-up version of which has found its way into this book as the basic design scheme of the tether connecting the Eye to Cradle. Another is the Remora Remover, which, in principle, is the same device as the Lamprey. Rob is also coauthor of a 2000 study on high-altitude rotating tethers, based on early work by Forward and others, that serves as the basis for the glider-to-orbit transfer described in the opening pages of the third part of this book. He deserves credit for all of those contributions as well as thanks for having given the manuscript a close read.