So were born the O’Neill Colonies, forged in the very same nuclear fires that would one day consume much of mankind.

A generation later—and more than five years after the May Day Horror of Fifty-Three—Lidia Song Wu clung to a glistening steel handhold built into the external surface of one of the very same rock-and-metal bodies that had once threatened humanity’s continued existence. Marking the time by the rhythmic hissing of her p-suit’s respirator, Wu crept slowly and cautiously along the long axis of the asteroid shell that housed the Vanguard colony.

In Wu’s eyes, the ironies of the world’s current circumstances were as profound as its tragedies. The people who lived and worked within Vanguard and a handful of other tamed, nuke-bored rocks might be the Earth’s only chance of emerging from the darkness that had shrouded it—both literally and figuratively—since the outbreak of the Third World War.

After the first nuclear bombs had exploded over London [70] and New York, Tel Aviv and Riyadh, Karachi and New Delhi, nearly half a billion people, had died. The postatomic horror that followed the blasts made the Bell Riots of 2024 look like a Boy Scout jamboree. Terrorists and rogue states exploded so-called suitcase-nukes and released toxins and biological warfare agents, everything from sarin to ebola. Legions of battle-suited, drug-addled soldiers had been sacrificed in scores of dubious “conventional” battles on the ground after the computers necessary to guide the bigger tactical nukes had failed. Millions more civilians, including those responsible for maintaining even the pretense of law and order, continued even now to be slaughtered by the thousands in various conflicts around the world, as the remnants of the world’s great powers and genocidal warlords like Colonel Green fought over the scraps.

Only up above it all, in the artificially created O’Neill habitats, did human civilization, technology, and culture stand an even chance of survival, the hostile environment of deep space notwithstanding. Only here, beyond the brown-and-orange haze of the still-fading remnants of the nuclear winter of Fifty-Three, could a traumatized humanity lift its eyes from the banal horrors of day-to-day survival.

Only here could a person find solace in the hope that better things lay ahead.

Even back in 2031—still referred to by most who had experienced it as the Year We Dodged the Bullet—the idea of constructing O’Neill-type space habitats was not a new one. Rafts of books had been written over the past century or so about the concept, its benefits, and its theoretical problems. In fact, it had been some of the works of the earliest space-age science writers—luminaries such as Asimov, Sagan, Ferris, and Zubrin—that had fired Wu’s young imagination, spurring her to flee Hong Kong’s inflexible social stratification to pursue an engineering degree at Cambridge. The twentieth-century scientific essayist Gerard K. O’Neill, [71] another of Wu’s favorites, had been among the first to champion the idea of constructing large-scale, permanent human habitats in space.

Now, clinging precariously to the hide of the Vanguard asteroid as she inched cautiously along its length, Wu understood viscerally that she and her colleagues were living out O’Neill’s wildest dreams.

Wu felt a sudden, violent tug on the toolkit she had strapped to her thigh. Instinctively, her gloved hand grabbed for the small box. It took a moment for her to realize that the kit itself was secure; she had merely forgotten to close the cloth flap that covered it, leaving it vulnerable to the outward centrifugal pull of the asteroid’s spin-generated artificial gravity.

Sloppy,she thought, chiding herself. Wu was all too aware that such accidents could easily get people killed. She quickly sealed the flap, pausing just long enough to recheck her suit for any other loose objects. Satisfied, she resumed her careful hand-over-hand motion toward photovoltaic array gamma-six.

Wu understood well that performing even basic maintenance work on the outer shell of a spinning O’Neill colony could be even more difficult and dangerous than the first spacewalks of the earliest Soviet cosmonauts and U.S. astronauts. True, her pressure suit was tremendously more advanced than the one that had kept Aleksei Leonov’s blood from boiling as he stepped into the airless void that lay beyond the skin of his Voskhodcapsule. Wu didn’t have to contend, as Leonov had, with a garment that grew so distended that it had to be almost completely depressurized before she could go back inside. Wu’s Kevlar-laced suit resisted the stiff-limbed “balloon” effect so prevalent during those ancient EVAs of nearly a century ago. It responded easily to the motions of her limbs, with joints assisted by small but powerful electrical servomotors. The internal fans and heat exchangers kept her helmet’s faceplate almost entirely fog-free, no matter how much she exerted herself. And the paper-thin [72] insulators of which her gauntlets were composed allowed her to work with the smallest of tools with almost a jeweler’s precision. Wu sometimes imagined that Buzz Aldrin, the U.S. Gemini program’s extravehicular-activity pioneer, would have been awed by the pressure suits that so many O’Neill-colony dwellers now took utterly for granted.

No, dealing with a p-suit wasn’t the most challenging aspect of her job. The real difficulties lay in staying connected to the surface of a hollow asteroid that spun rapidly enough to create a feeling of almost Earth-normal gravity in the habitat’s outermost levels. Because of this unending centrifugal motion, those inside the asteroid thought of its exterior layers, all the way around the roughly cylinder-shaped asteroid, as “down.” One became progressively heavier as one moved “down” toward the asteroid’s skin. At the moment, Wu was as far “down” as it was possible to be on Vanguard.

For Leonov and Aldrin, coming untethered from their respective spacecraft while in orbit had been a real worry. Had that happened to either man, the result would have been a slow drift away from the capsule. With nothing to push against, the lost person never could have been recovered.

Wu knew that if she were to come untethered from fast-twirling Vanguard, her own inertia would launch her, projectilelike, into space with better than a one-gee acceleration. Rescue might be possible before the suit’s resources exhausted themselves, but using a powered skiff to locate and match velocity with her would be no mean feat.

She therefore had to hang on for dear life as she worked, like a supine window washer working on a skyscraper that had been pitched onto its side. A multiply redundant safety net of diamond-composite tethers held her suit to the asteroid’s rough, metal-rich surface, which was still being pitted even now by exposure to the L-5 region’s high concentrations of dust particles.

Years ago, Wu had learned to avoid vertigo by ignoring [73] the noticeable movements of the Earth and the Moon, both of which steadily wheeled over and past the asteroid’s extremely short horizon, only to reappear less than a minute later from the opposite direction.

Wu finally came to a stop when she reached the edge of a football-field-sized cluster of space-black photovoltaic collectors, one of the habitat’s principal sources of electrical power. Using a key strapped to her leg, she opened a small junction box mounted beside the array. Replacing the burned-out relay took only a few moments. Once she had finished and run a quick diagnostic test on the relay’s keypad, she tapped a control near her suit’s neck ring, engaging the radio transmitter.

“Wu to al-Arif.”

“I read you, Liddie,”came Zafirah al-Arif’s smooth voice in response. There was very little static on the connection, probably because sunspot activity was currently in its low but slowly rising phase. Wu chose to regard this as a good omen.