Raft xs-1

by Stephen Baxter

  “Vaguely…”

  “You see, if Rees’s gravitational slingshot idea is going to work we will have to drop the Raft onto a precise trajectory around the Core. The asymptotic direction is highly sensitive to the initial conditions—”

  She held up her hands. “You’d better stick to words of one syllable. Or less.”

  “I’m sorry. We’re going into a tight orbit, very close to the Core. The closer we pass, the more our path will be twisted around the Core. But the differences for a small deviation are dramatic. You have to imagine a pencil of neighboring trajectories approaching the Core. As they round the singularity they fan out, like unraveling fibers; and so a small error could give the Raft a final direction very different from the one we want.”

  “I understand… I think. But it doesn’t make much difference, surely? You’re aiming at a whole nebula, a target thousands of miles wide.”

  “Yes, but it’s a long way away. It’s quite a precise piece of marksmanship. And if we miss, by even a few miles, we could end up sailing into empty, airless space, on without end…”

  “So how is the Mole helping?”

  “What we need to do is work out all the trajectories in that pencil, so we can figure out how to approach the Core. It takes us hours to work the results by hand — work which, apparently, was performed by slavelike machines for the original Crew. It was Rees who had the idea of using the Mole brains.”

  Sheen pulled a face. “It would be.”

  “He argued that the Moles must once have been flying machines. And if you look closely you can see where the rockets, fins and so on must have fitted. So, argued Rees, the Moles must understand orbital dynamics, to some extent. We tried putting our problems to a Mole. It took hours of question-and-answer down there on the kernel surface… but at last we started getting usable results. Now the Mole provides concise answers, and we’re proceeding quickly.”

  She nodded, juggling her drink. “Impressive. And you’re sure of the quality of the results?”

  He seemed to bridle a little. “As sure as we can be. We’ve checked samples against hand calculations. But none of us are experts in this particular field.” His voice hardened again. “Our Chief Navigator was Cipse, you see.”

  She could think of no reply. She drained the last of her globe. “Well, look, Grye, I think it’s time I—”

  “Now, then, where can old Quid take a drink around here?”

  The voice was low and sly. She turned, startled, and found herself looking down at a wide, wrinkled face; a grin revealed rotten stumps of teeth, and black eyes traveled over her body. She couldn’t help but shrink away from the Boney. Vaguely she was aware of Grye quailing beside her. “What… do you want?”

  The Boney stroked a finely carved spear of bone. His eyes widened in mock surprise. “Why, darling, I’ve only just arrived, and what kind of welcome is that? Eh? Now that we’re all friends together…” He took a step closer. “You’ll like old Quid when you get to know him—”

  She stood her ground and let her disgust show in her face. “You come any nearer to me and I’ll break your bloody arm.”

  He laughed evenly. “I’d be interested to see you try, darling. Remember I grew to my fine stature in high-gee… not this baby-soft micro gravity you have here. You’re muscled very attractively; but I bet your bones are as brittle as dead leaves.” He looked at her acutely. “Surprised to find old Quid using phrases like ‘micro gravity,’ girl? I may be a Boney, but I’m not a monster; nor am I stupid.” He reached out and grabbed her forearm. His grip was like iron. “It’s a lesson you evidently need to learn—”

  She thrust at the wall of the Quartermaster’s with both legs and performed a fast back flip, shaking free his hand. When she landed she had a knife in her fist.

  He held up his hands with an admiring grin. “All right, all right…” Now Quid turned his gaze on Grye; the Scientist clutched his drink globe to his chest, trembling. “I heard what you were saying,” Quid said. “All that stuff about orbits and trajectories… But you won’t make it, you know.”

  Grye’s cheeks quivered and stretched, “What do you mean?”

  “What are you going to do when you’re riding your bit of iron, down there by the Core himself — and you find you’re on a path that isn’t in your tables of numbers? At the critical moment — at closest approach — you’ll have maybe minutes to react. What will you do? Turn back and draw some more curves on paper? Eh?”

  Sheen snorted. “You’re an expert, are you?”

  He smiled. “At last you’re recognizing my worth, darling.” He tapped his head. “Listen to me. There’s more on orbits locked in here than on all the bits of paper in the Nebula.”

  “Rubbish,” she spat.

  “Yes? Your little friend Rees doesn’t think so, does he?” He hefted his spear in his right hand; Sheen kept her eyes on the spear’s bone tip. “But then,” Quid went on, “Rees has seen what we can do with these things—”

  Abruptly he twisted so that he faced the star kernel; with surprising grace he hurled the spear. The weapon accelerated into the five-gee gravity well of the kernel. Moving so fast that it streaked in Sheen’s vision, it missed the iron horizon by mere yards and twisted behind the star—

  —and now it emerged from the other side of the kernel, exploding at her like a fist. She ducked, grabbing for Grye; but the spear passed a few yards above her head and sailed away into the air.

  Quid sighed. “Not quite true. Old Quid needs to get his eye in. Still—” He winked. “Not bad for a first try, eh?” He prodded Grye’s sagging paunch. “Now, that’s what I call orbital dynamics. And all in old Quid’s head. Astonishing, isn’t it? And that’s why you need the Boneys. Now then, Quid needs his drink. See you later, darling…”

  And he brushed past them and entered the Quartermaster’s.

  Gord shoved his thinning blond hair from his eyes and thumped the table. “It can’t be done. I know what I’m talking about, damn it.”

  Jaen towered over the little engineer. “And I’m telling you you’re wrong.”

  “Child, I’ve more experience than you will ever—”

  “Experience?” She laughed. “Your experience with the Boneys has softened your brains.”

  Now Gord stood. “Why, you—”

  “Stop, stop.” Tiredly Hollerbach placed his age-spotted hands on the table top.

  Jaen simmered. “But he won’t listen.”

  “Jaen. Shut up.”

  “But — ah, damn it.” She subsided.

  Hollerbach let his eyes roam around the cool, perfect lines of the Bridge’s Observation Room. The floor was covered with tables and spread-out diagrams: Scientists and others pored over sketches of orbital paths, models of grandiose protective shells to be built around the Raft, tables showing rates of food consumption and oxygen exhaustion under various regimes of rationing. The air was filled with feverish, urgent conversation. Wistfully Hollerbach recalled the studied calm of the place when he had first joined the great Class of Scientists; in those days there had still been some blue in the sky, and there had seemed all the time in the world for him to study…

  At least, he reflected, all this urgent effort was in the right direction, and seemed to be producing the results they needed to carry through this scheme. The tables and dry graphs told a slowly emerging tale of a modified Raft hurtling on a courageous trajectory around the Core; these sober Scientists and their assistants were together engaged on man’s most ambitious project since the building of the Raft itself.

  But now Gord had walked in with his scraps of paper and his pencil jottings… and his devastating news. Hollerbach forced his attention back to Gord and Jaen, who still confronted each other — and he found his eyes meeting Decker’s. The Raft’s leader stood impassively before the table, his scarred face clouded by a scowl of concentration.

  Hollerbach sighed inwardly. Trust Decker, with his instinct for the vital, to arrive at the point of crisis. “Let’s go throu
gh it again, please, engineer,” he said to Gord. “And this time, Jaen, try to be rational. Yes? Insults help nobody.”

  Jaen glowered, her broad face crimson.

  “Scientist, I am — was — the Belt’s chief engineer,” Gord began. “I know more than I care to remember about the behavior of metals under extreme conditions. I’ve seen it flow like plastic, turn brittle as old wood…”

  “No one is questioning your credentials, Gord,” Hollerbach said, unable to contain his irritation. “Get to the point.”

  Gord tapped his papers with his fingertips. “I’ve studied the tidal stresses the Raft will undergo at closest approach. And I’ve considered the speeds it must attain after the slingshot, if it’s to escape the Nebula. And I can tell you, Hollerbach, you haven’t a hope in hell. It’s all here; you can check it out—”

  Hollerbach waved his hand. “We will, we will. Just tell us.”

  “First of all, the tides. Scientist, the stresses will rip this Raft to pieces, long before you get to closest approach. And the fancy structures your bright kids are planning to erect over the deck will simply blow apart like a pile of twigs.”

  “Gord, I don’t accept that,” Jaen burst out. “If we reconfigure the Raft, perhaps buttress some sections, make sure our attitude is correct at closest approach—”

  Gord returned her gaze and said nothing.

  “Check his figures later, Jaen,” Hollerbach said. “Go on, engineer.”

  “Also, what about air resistance? At the speeds required, down there in the thickest air of the whole Nebula, whatever shoal of fragments emerges from closest approach is simply going to burn up like so many meteors. You’ll achieve a spectacular fireworks display and little more. Look, I’m sorry this is so disappointing, but your scheme simply cannot work. The laws of physics are telling you that, not me…”

  Decker leaned forward. “Miner,” he said softly, “if what you say is true then we may after all be doomed to a slow death in this stinking place. Now, maybe I’m a poor judge of people, but you don’t seem too distressed by the prospect. Do you have an alternative suggestion?”

  A slow smile spread over Gord’s face. “Well, as it happens…”

  Hollerbach sat back, letting his jaw drop. “Why the hell didn’t you tell us in the first place?”

  Gord’s grin widened. “If you’d troubled to ask—”

  Decker laid a massive hand on the table. “No more word games,” he said quietly. “Miner, get on with it.”

  Gord’s grin evaporated; shadows of fear chased across his face, reminding Hollerbach uncomfortably of how much this blameless little man had endured. “Nobody’s threatening you,” he said. “Just show us.”

  Looking more comfortable, Gord stood and led them out of the Bridge. Soon the four of them — Gord, Hollerbach, Decker and Jaen — stood beside the dull glow of the Bridge’s hull; the starlight beat down, causing beads of perspiration to erupt over Hollerbach’s bald scalp. Gord stroked the hull with his palm. “When was the last time you touched this stuff? Perhaps you walk past it every day, taking it for granted; but when you come at it fresh, it’s quite a revelation.”

  Hollerbach pressed his hand to the silver surface, feeling his skin glide smoothly over it… “It’s frictionless. Yes. Of course.”

  “You tell me this was once a vessel in its own right, before it was incorporated into the deck of the Raft,” Gord went on. “I agree with you. And furthermore, I think this little ship was designed to travel through the air.”

  “Frictionless,” Hollerbach breathed again, still rubbing his palm over the strange metal. “Of course. How could we all have been so stupid? You see,” he told Decker, “this surface is so smooth the air will simply slide over it, no matter what speed it travels. And it won’t heat up as would ordinary metal…

  “And no doubt this structure would be strong enough to survive the tidal stresses close to the Core; far better, at least, than our ramshackle covered Raft. Decker, obviously we’ll have to go through Gord’s calculations, but I think well find he’s correct. Do you see what this means?” Something like wonder coursed through Hollerbach’s old brain. “We’ll have no need to build an iron bell to keep our air in place. We can simply close the Bridge port. We will ride a ship as our ancestors rode… Why, we can even use our instruments to study the Core as we pass. Decker, a door has closed; but another has opened. Do you understand?”

  Decker’s face was a dark mask. “Oh, I understand, Hollerbach. But there’s another point you might have missed.”

  “What?”

  “The Raft is half a mile wide. This Bridge is merely a hundred yards long.”

  Hollerbach frowned; then the implications began to hit him.

  “Find Rees,” Decker snapped. “I’ll meet you both in your office in a quarter of an hour.” With a curt nod, he turned and walked away.

  Rees found the atmosphere in Hollerbach’s office electric.

  “Close the door.” Decker growled.

  Rees sat before Hollerbach’s desk. Hollerbach sat opposite, long fingers pulling at the papery skin of his hands. Decker sucked breath through his wide nostrils; eyes downcast, he paced around the small office.

  Rees frowned. “Why the funereal atmosphere? What’s happened?”

  Hollerbach leaned forward. “We have a… complication.” He sketched out Gord’s reservations. “We have to check his figures, of course. But—”

  “But he’s right,” Rees said. “You know he is, don’t you?”

  Hollerbach sighed, the air scraping over his throat. “Of course he’s right. And if the rest of us hadn’t got carried away with glamorous speculations about gravitational slingshots and a mile-wide dome, we’d have asked the same questions. And come to the same conclusions.”

  Rees nodded. “But if we use the Bridge we’re facing problems we didn’t anticipate. We thought we could save everybody.” His eyes flicked to Decker. “Now we have to choose.”

  Decker’s face was dark with anger. “And so you turn to me.”

  Rees rubbed the space between his eyes. “Decker, provided we manage the departure cleanly those left behind will survive for hundreds, thousands of shifts—”

  “I hope those abandoned by your shining ship will take it so philosophically.” Decker spat. “Scientists. Answer me this. Will this adventure work? Could the passengers of the Bridge actually survive a passage around the Core, and then through space to the new nebula? We’re looking at a very different set-up from Rees’s original idea.”

  Rees nodded slowly. “We’ll need supply machines, whatever compressed air we can carry in the confines of the Bridge, perhaps plants to convert stale air to—”

  “Spare me the trivia,” Decker snapped. “This absurd project will entail backbreaking labor, injury, death. And no doubt the departing Bridge will siphon off many of mankind’s best brains, worsening the lot of those left behind still further.

  “If this mission does not have a reasonable chance of success then I won’t back it. It’s as simple as that. I won’t shorten the lives of the bulk of those I’m responsible for, solely to give a few heroes a pleasure ride.”

  “You know,” Hollerbach said thoughtfully, “I doubt that when you — ah, acquired — power on this Raft you imagined having to face decisions like this.”

  Decker scowled. “Are you mocking me, Scientist?”

  Hollerbach closed his eyes. “No.”

  “Let’s think it through,” Rees said. “Hollerbach, we need to transport a genetic pool large enough to sustain the race. How many people?”

  Hollerbach shrugged. “Four or five hundred?”

  “Can we accommodate so many?”

  Hollerbach paused before answering. “Yes,” he said slowly. “But it will take careful management. Strict planning, rationing… It will be no pleasure ride.”

  Decker growled, “Genetic pool? Your five hundred will arrive like babies in the new world, without resources. Before they breed they will have to find a way of n
ot falling into the Core of the new nebula.”

  Rees nodded. “Yes. But so did the Crew of the original Ship. Our migrants will be worse off materially… but at least they will know what to expect.”

  Decker drove his fist into his thigh. “So you’re telling me that the mission can succeed, that a new colony could survive? Hollerbach, you agree?”

  “Yes,” Hollerbach said quietly. “We have to work out the details. But — yes. You have my assurance.”

  Decker closed his eyes and his great shoulders slumped. “All right. We must continue with your scheme. And this time, try to foresee the problems.”

  Rees felt a vast relief. If Decker had decided otherwise — if the great goal had been taken away — how would he, Rees, have whiled away the rest of his life?

  He shuddered. It was unimaginable.

  “Now we face further actions,” Hollerbach said. He held up his skeletal hand and counted points on his fingers. “Obviously we must continue our studies on the mission itself — the equipage, separation, guidance of the Bridge. For those left behind, we have to think about moving the Raft.”

  Decker looked surprised.

  “Decker, that star up there isn’t going to go away. We’d have shifted out from under it long ago, in normal times. Now that the Raft is fated to stay in this Nebula, we must move it. And finally…” Hollerbach’s voice tailed away.

  “And finally,” Decker said bitterly, “we have to think about how to select those who travel on the Bridge. And those who stay behind.”

  Rees said, “Perhaps some kind of ballot would be fair…”

  Decker shook his head. “No. This jaunt will only succeed if you have the right people.”

  Hollerbach nodded. “You’re right, of course,”

  Rees frowned. “…I guess so. But — who selects the ‘right’ crew?”

  Decker glared at him, the scars on his face deepening into a mask of pain. “Who do you think?”

  Rees cradled his drink globe. “So that’s it,” he told Pallis. “Now Decker faces the decision of his life.” Pallis stood before his cage of young trees, poked at the wooden bars. Some of the trees were almost old enough to release, he reflected absently. “Power brings responsibility, it seems. I’m not certain Decker understood that when he emerged on top from that joke Committee. But he sure understands it now… Decker will make the right decision; let’s hope the rest of us do the same.”