The Final Frontier

by Neil Clarke

  In Q&A she knew DARPA was sold; they’d get their funding. Roger was right: everything was dual use.

  She’d been up for ten days. The cramped, dark space was wearing her down. Save them. They had to make it. She’d pulled a DNA sequencer and a gene printer from the storage bay. As she fed it E. coli and Mycoplasma mycoides stock, she reviewed what she’d come up with.

  She could mute the expression of the bat genes at this stage, probably without disrupting hibernation. They were the receptors for the triggers that started and stopped the process. But that could compromise rousing. So mute them temporarily—for how long?—hope to revive an immune response, temporarily damp down the antisenescents, add an antifungal. She’d have to automate everything in the mixture; the ship wouldn’t rouse her a second time to supervise.

  It was a long shot, but so was everything now.

  It was too hard for her. For anyone. She had the technology: a complete library of genetic sequences, a range of restriction enzymes, Sleeping Beauty transposase, et cetera. She’d be capable on the spot, for instance, of producing a pathogen that could selectively kill individuals with certain ethnic markers— that had been one project at the Lab, demurely called “preventive.” But she didn’t have the knowledge she needed for this. It had taken years of research experimentation, and collaboration, to come up with the original cocktail, and it would take years more to truly solve this. She had only a few days. Then the residue of the cocktail would be out of her system and she would lose the ability to rehibernate. So she had to go with what she had now. Test it on DNA from her own saliva.

  Not everyone stuck with Gypsy. One scientist at the Lab, Sidney Lefebvre, was wooed by Roger to sign up, and declined only after carefully studying their plans for a couple of weeks. It’s too hard, Roger. What you have here is impressive. But it’s only a start. There are too many intractable problems. Much more work needs to be done.

  That work won’t get done. Things are falling apart, not coming together. It’s now or never.

  Probably so. Regardless, the time for this is not now. This, too, will fall apart.

  She wrote the log for the next steward, who would almost surely have the duty of more corpses. Worse, as stewards died, maintenance would be deferred. Systems would die. She didn’t know how to address that. Maybe Lefebvre was right. But no: they had to make it. How could this be harder than getting from Guangzhou to Dublin to here?

  She prepared to go back under. Fasted the day. Enema, shower. Taps and stents and waldos and derms attached and the bodysuit sealed around her. She felt the cocktail run into her veins.

  The lights were off. The air was chill. In her last moment of clarity, she stared into blackness. Always she had run, away from distress, toward something new, to eradicate its pain and its hold. Not from fear. As a gesture of contempt, of power: done with you, never going back. But run to where? No world, no O, no gravity, no hold, nothing to cling to. This was the end of the line. There was nowhere but here. And, still impossibly far, another forty-four years, Alpha C. As impossibly far as Earth.

  3.

  Roger recruited his core group face to face. At conferences and symposia he sat for papers that had something to offer his project, and he made a judgment about the presenter. If favorable, it led to a conversation. Always outside, in the open. Fire roads in the Berkeley hills. A cemetery in Zurich. The shores of Lake Como. Fry was well known, traveled much. He wasn’t Einstein, he wasn’t Feynman, he wasn’t Hawking, but he had a certain presence.

  The conferences were Kabuki. Not a scientist in the world was unlinked to classified projects through government or corporate sponsors. Presentations were so oblique that expert interpretation was required to parse their real import.

  Roger parsed well. Within a year he had a few dozen trusted collaborators. They divided the mission into parts: target selection, engine and fuel, vessel, hibernation, navigation, obstacle avoidance, computers, deceleration, landfall, survival.

  The puzzle had too many pieces. Each piece was unthinkably complex. They needed much more help.

  They put up a site they called Gypsy. On the surface it was a gaming site, complex and thick with virtual worlds, sandboxes, self-evolving puzzles, and links. Buried in there was an interactive starship-design section, where ideas were solicited, models built, simulations run. Good nerdy crackpot fun.

  The core group tested the site themselves for half a year before going live. Their own usage stats became the profile of the sort of visitors they sought: people like themselves: people with enough standing to have access to the high-speed classified web, with enough autonomy to waste professional time on a game site, and finally with enough curiosity and dissidence to pursue certain key links down a critical chain. They needed people far enough inside an institution to have access to resources, but not so far inside as to identify with its ideology. When a user appeared to fit that profile, a public key was issued. The key unlocked further levels and ultimately enabled secure email to an encrypted server.

  No one, not even Roger Fry, knew how big the conspiracy was. Ninety-nine percent of their traffic was noise—privileged kids, stoked hackers, drunken PhDs, curious spooks. Hundreds of keys were issued in the first year. Every key increased the risk. But without resources they were going nowhere.

  The authorities would vanish Roger Fry and everyone associated with him on the day they learned what he was planning. Not because of the what: a starship posed no threat. But because of the how and the why: only serious and capable dissidents could plan so immense a thing; the seriousness and the capability were the threat. And eventually they would be found, because every bit of the world’s digital traffic was swept up and stored and analyzed. There was a city under the Utah desert where these yottabytes of data were archived in server farms. But the sheer size of the archive outran its analysis and opened a time window in which they might act.

  Some ran propellant calculations. Some forwarded classified medical studies. Some were space workers with access to shuttles and tugs. Some passed on classified findings from telescopes seeking exoplanets.

  One was an operator of the particle beam at Shackleton Crater. The beam was used, among other purposes, to move the orbiting sleds containing the very bombs Roger had helped design.

  One worked at a seed archive in Norway. She piggybacked a capsule into Earth orbit containing seeds from fifty thousand unmodified plant species, including plants legally extinct. They needed those because every cultivated acre on Earth was now planted with engineered varieties that were sterile; terminator genes had been implanted to protect the agro firms’ profit streams; and these genes had jumped to wild varieties. There wasn’t a live food plant left anywhere on Earth that could propagate itself.

  They acquired frozen zygotes of some ten thousand animal species, from bacteria to primates. Hundreds of thousands more complete DNA sequences in a data library, and a genome printer. Nothing like the genetic diversity of Earth, even in its present state, but enough, perhaps, to reboot such diversity.

  At Roger’s lab, panels of hydrogenous carbon-composite, made to shield high-orbit craft from cosmic rays and to withstand temperatures of 2000° C, went missing. Quite a lot of silica aerogel as well.

  At a sister lab, a researcher put them in touch with a contractor from whom they purchased, quite aboveboard, seventy kilometers of lightweight, high-current-density superconducting cable.

  After a year, Roger decided that their web had grown too large to remain secure. He didn’t like the number of unused keys going out. He didn’t like the page patterns he was seeing. He didn’t consult with the others, he just shut it down.

  But they had their pieces.

  SERGEI (2118)

  Eat, drink, shit. That’s all he did for the first day or three. Water tasted funny. Seventy-seven years might have viled it, or his taste buds. Life went on, including the ending of it. Vital signs of half the crew were flat. He considered disposing of bodies, ejecting them, but number one, he couldn
’t be sure they were dead; number two, he couldn’t propel them hard enough to keep them from making orbit around the ship, which was funny but horrible; and finally, it would be unpleasant and very hard work that would tire him out. An old man—he surely felt old, and the calendar would back him up—needs to reserve his strength. So he let them lie on their slabs.

  The logs told a grim story. They were slow. To try to make up for lost time, Sophie had reprogrammed the magsail to deploy later and to run at higher current. Another steward had been wakened at the original deployment point, to confirm their speed and position, and to validate the decision to wait. Sergei didn’t agree with that, and he especially didn’t like the handwaving over when to ignite the nuclear rocket in-system, but it was done: they’d gone the extra years at speed and now they needed to start decelerating hard.

  CURRENT INJECTION FAILED. MAGSAIL NOT DEPLOYED.

  He tapped the screen to cycle through its languages. Stopped at the Cyrillic script, and tapped the speaker, just so he could hear spoken Russian.

  So he had to fix the magsail. Current had flowed on schedule from inside, but the sail wasn’t charging or deploying. According to telltales, the bay was open but the superconducting cable just sat there. That meant EVA. He didn’t like it, but there was no choice. It’s what he was here for. Once it was done he’d shower again under that pathetic lukewarm stream, purge his bowels, get back in the mylar suit, and go under for another, what, eight more years, a mere nothing, we’re almost there. Ghost Planet Hope.

  He was the only one onboard who’d been a career astronaut. Roger had conveyed a faint class disapproval about that, but needed the expertise. Sergei had been one of the gene-slushed orbital jockeys who pushed bomb sleds around. He knew the feel of zero g, of sunlight on one side of you and absolute cold on the other. He knew how it felt when the particle beam from Shackleton swept over you to push you and the sleds into a new orbit. And you saluted and cut the herds, and kept whatever more you might know to yourself.

  Which in Sergei’s case was quite a bit. Sergei knew orbital codes and protocols far beyond his pay grade; he could basically move anything in orbit to or from anywhere. But only Sergei, so Sergei thought, knew that. How Roger learned it remained a mystery.

  To his great surprise, Sergei learned that even he hadn’t known the full extent of his skills. How easy it had been to steal half a million bombs. True, the eternal war economy was so corrupt that materiel was supposed to disappear; something was wrong if it didn’t. Still, he would never have dared anything so outrageous on his own. Despite Roger’s planning, he was sweating the day he moved the first sled into an unauthorized orbit. But days passed, then weeks and months, as sled followed sled into new holding orbits. In eighteen months they had all their fuel. No traps had sprung, no alarms tripped. Sophie managed to make the manifests look okay. And he wondered again at what the world had become. And what he was in it.

  This spacesuit was light, thin, too comfortable. Like a toddler’s fleece play-suit with slippers and gloves. Even the helmet was soft. He was more used to heavy Russian engineering, but whatever. They’d argued over whether to include a suit at all. He’d argued against. EVA had looked unlikely, an unlucky possibility. So he was happy now to have anything.

  The soles and palms were sticky, a clever off-the-shelf idea inspired by lizards. Billions of carbon nanotubes lined them. The Van der Waals molecular force made them stick to any surface. He tested it by walking on the interior walls. Hands or feet held you fast, with or against the ship’s rotational gravity. You had to kind of toe-and-heel to walk, but it was easy enough.

  Let’s go. He climbed into the hatch and cycled it. As the pressure dropped, the suit expanded and felt more substantial. He tested the grip of his palms on the hull before rising fully out of the hatch. Then his feet came up and gripped, and he stood.

  In darkness and immensity stiller than he could comprehend. Interstellar space. The frozen splendor of the galactic core overhead. Nothing appeared to move.

  He remembered a still evening on a lake, sitting with a friend on a dock, legs over the edge. They talked as the sky darkened, looking up as the stars came out. Only when it was fully dark did he happen to look down. The water was so still, stars were reflected under his feet. He almost lurched over the edge of the dock in surprise.

  The memory tensed his legs, and he realized the galactic core was moving slowly around the ship. Here on the outside of the ship its spin-induced gravity was reversed. He stood upright but felt pulled toward the stars.

  He faced forward. Tenth of a light-year from Alpha, its two stars still appeared as one. They were brighter than Venus in the Earth’s sky. They cast his faint but distinct shadow on the hull.

  They were here. They had come this far. On this tiny splinter of human will forging through vast, uncaring space. It was remarkable.

  A line of light to his left flashed. Some microscopic particle ionized by the ship’s magnetic shield. He tensed again at this evidence of their movement and turned slowly, directing his beam over the hull. Its light caught a huge gash through one of the hydrogen tanks. Edges of the gash had failed to be covered by a dozen geckos, frozen in place by hydrogen ice. That was bad. Worse, it hadn’t been in the log. Maybe it was from the impact Sophie had referred to. He would have to see how bad it was after freeing the magsail.

  He turned, and toed and heeled his way carefully aft. Now ahead of him was our Sun, still one of the brightest stars, the heavens turning slowly around it. He approached the circular bay that held the magsail. His light showed six large spools of cable, each a meter and a half across and a meter thick. About five metric tons in all, seventy kilometers of thin superconductor wire. Current injection should have caused the spools to unreel under the force of the electric field. But it wasn’t getting current, or it was somehow stuck. He was going to have to . . . well, he wasn’t sure.

  Then he saw it. Almost laughed at the simplicity and familiarity of it. Something like a circuit breaker, red and green buttons, the red one lit. He squatted at the edge of the bay and found he could reach the thing. He felt cold penetrate his suit. He really ought to go back inside and spend a few hours troubleshooting, read the fucking manual, but the cold and the flimsy spacesuit and the immensity convinced him otherwise. He slapped the green button.

  It lit. The cable accepted current. He saw it lurch. As he smiled and stood, the current surging in the coils sent its field through the soles of his spacesuit, disrupting for a moment the molecular force holding them to the hull. In that moment, the angular velocity of the rotating ship was transmitted to his body and he detached, moving away from the ship at a stately three meters per second. Beyond his flailing feet, the cables of the magsail began leisurely to unfurl.

  As he tumbled the stars rolled past. He’d seen Orion behind the ship in the moment he detached, and as he tumbled he looked for it, for something to grab on to, but he never saw it or the ship again. So he didn’t see the huge coil of wire reach its full extension, nor the glow of ionization around the twenty-kilometer circle when it began to drag against the interstellar medium, nor how the ship itself started to lag against the background stars. The ionization set up a howl across the radio spectrum, but his radio was off, so he didn’t hear that. He tumbled in silence in the bowl of the heavens at his fixed velocity, which was now slightly greater than the ship’s. Every so often the brightness of Alpha crossed his view. He was going to get there first.

  4.

  Their biggest single problem was fuel. To cross that enormous distance in less than a human lifetime, even in this stripped-down vessel, required an inconceivable amount of energy. Ten to the twenty-first joules. 250 trillion kilowatt-hours. Twenty years’ worth of all Earth’s greedy energy consumption. The mass of the fuel, efficient though it was, would be several times the mass of the ship. And to reach cruising speed was only half of it; they had to decelerate when they reached Alpha C, doubling the fuel. It was undoable.

  Until someo
ne found an old paper on magnetic sails. A superconducting loop of wire many kilometers across, well charged, could act as a drag brake against the interstellar medium. That would cut the fuel requirement almost in half. Done that way, it was just possible, though out on the ragged edge of what was survivable. This deceleration would take ten years.

  For their primary fuel, Roger pointed to the hundreds of thousands of bombs in orbit. His bombs. His intellectual property. Toss them out the back and ignite them. A Blumlein pulse-forming line—they called it the “bloom line”—a self-generated magnetic vise, something like a Z-pinch—would direct nearly all the blast to exhaust velocity. The vise, called into being for the nanoseconds of ignition, funneled all that force straight back. Repeat every minute. Push the compression ratio up, you won’t get many neutrons.

  In the end they had two main engines: first, the antiproton-fusion monster to get them up to speed. It could only be used for the first year; any longer and the antiprotons would decay. Then the magsail would slow them most of the way, until they entered the system.

  For the last leg, a gas-core nuclear rocket to decelerate in the system, which required carrying a large amount of hydrogen. They discussed scooping hydrogen from the interstellar medium as they traveled, but Roger vetoed it: not off the shelf. They didn’t have the time or means to devise a new technology. Anyway, the hydrogen would make, in combination with their EM shield, an effective barrier to cosmic rays. Dual use.

  And even so, everything had to be stretched to the limit: the mass of the ship minimized, the human lifetime lengthened, the fuel leveraged every way possible.

  The first spacecraft ever to leave the solar system, Pioneer 10, had used Jupiter’s gravity to boost its velocity. As it flew by, it stole kinetic energy from the planet; its small mass sped up a lot; Jupiter’s stupendous mass slowed unnoticeably.

  They would do the same thing to lose speed. They had the combined mass of two stars orbiting each other, equal to two thousand Jupiters. When Gypsy was to arrive in 2113, the stars in their mutual orbit would be as close together as they ever got: 11 astronomical units. Gypsy would fly by the B star and pull one last trick: retrofire the nuclear rocket deep in its gravity well; that would multiply the kinetic effect of the propellant severalfold. And then they’d repeat that maneuever around A. The relative closeness of 11 AU was still as far as Earth to Saturn, so even after arrival, even at their still-great speed, the dual braking maneuver would take over a year.