by Unknown
Spin, the pilot (Leroy to his mother, and to no one else), was deep in contemplation of the files in his checkpad. This was a good time to study them, no time more appropriate, but it was what he did with every spare moment anyway: he was refreshing his memory of the precise sequence and wording of the hundreds of steps involved in the launch, not because he was profoundly convinced he needed to memorize the stuff, but because he was afraid NASA would dock him for some nit-picking omission if he didn’t. Today’s ships mostly flew themselves, but there was always, always, that moment when something stalled, broke, got hung up, went haywire. It was at that moment that you had to do the right thing without stopping to think about it; no time then to consult a checkpad, and you couldn’t count on the robots. So Spin had already memorized the ship itself in a way that he could not have verbalized.
He was a pilot with a tendency and a preference for flying by the seat of his pants, the sort of thing that flight instructors (and submarine-driver instructors) try hard to train out of their students; the human proprioceptive system is fine-tuned for trees and savanna, not for air, sea, or space, and modern aircraft and undersea craft and spacecraft move too fast, in environments too strange, to function dependably as extensions of the body. But Spin’s was more than an intelligence of the muscles and nerves. When he sat in front of a board of screens and switches, took hold of a stick and set his feet on pedals, he and the machine became coextensive in a way that could be described only to those who had no need of the description; the uninitiated were likely to mutter about Zen and the art of spaceship piloting, or about Spin’s legendary native American shamanistic origins, or other such nonsense. It was not just the mass, the power, the flex, the speed—which he loved—but the logic, the irresistible Q.E.D. of movement through the space-time manifold. To perform a complex maneuver in three dimensions of space and one of time, to pull gees, to thread the eye of a probability needle, this was, for Spin, the triumphant demonstration of the concreteness and rightness of things, the essential reality of the real.
His commander watched Spin’s utter concentration on his checklists and momentarily wondered if his mind was really absorbing and filing those dry, abbreviated entries (“(178) BLR N2 SPLY ON, (179) BLR CNTRL PWR/HTR, POS A,” etc.) or whether he was daydreaming about something else—about professional advancement, about his intricate and apparently passionless love life, about the last time he had surfed the Banzai Pipeline. She decided it did not matter. When the ship moved, he would be there to fly it with her. Spin was a man whose existence seemed to reside in motion…
Beside the tiny screen with Spin’s face on it was the screen showing NAVCOM, the navigation and communication station, immediately below the flight deck. Frizzy-haired, freckled Melinda Wooster, even in repose and with plenty of work to do, managed to look actively bored.
It was not mere physical motion that she needed to excite her, but a challenge of any sort—if necessary, the merely physical would do. In moderate surf, for example, she could outsurf any man, including Spin; like him, she had a high regard for reality, although unlike him, she would not go near the water some days, would not pit her 158 centimeters and forty-four kilograms against storm surges many meters high and many tonnes in crushing power. For analogous reasons her love life was nowhere near as complicated as Spin’s. Her affairs tended to be brief contests; having won them, she found herself alone by choice.
With physical needs out of the way, what she liked best was chess, or go, or even Scrabble, despite the latter’s propensity to induce schizoid frustration whenever clever wordplay had to be foregone in favor of tactical board position. What Melinda liked best were games that allowed a display of sheer superiority, whether of vocabulary, skill, memory, calculating power, or strategy and tactics. She liked to get the answer before anyone else. She liked to win. Predictably, unless something went wrong on this short test flight, with its routine navigation and communications chores, there would be no new problems to solve, nothing to lick, and Melinda would be bored.
Her commander hoped she stayed bored.
From his mission specialist’s post deep in the ship Jimmy Giles looked up at the communications monitor and caught the commander looking back at him. He smiled and held her glance a moment before returning to his own checkpad. Jimmy was the most affable of the crew, but Braide knew very well it was a thin overlay on a seething soul, an attitude more hopeful than real. Jimmy was a man who needed a cause; it had to do with growing up Catholic, perhaps, with attending the Air Force Academy and becoming a career officer, with marrying young and siring a brood of girls, with long unquestioned striving after goals that other, more cynical men and women had erected for him.
Jimmy had nothing much to do on this particular flight except to test a range of secondary systems: cargo bay doors, teleoperators, instrument mounts, and the like. His real responsibilities would come later, when the full-sized descendants of this test ship began operational missions. His rating was mission specialist in satellite guidance and telemetry, but his real specialty was C3-I—command, control, communications, and intelligence. He hadn’t set out to do this; when he’d applied to the Air Force’s astronaut program, he’d been a fighter pilot who wanted to fly aerospace planes. The Air Force had needs beyond a few good pilots, however; the Russians were moving into interplanetary space at an alarming rate, had already established a long-term manned base on the moon, and were talking of doing the same on Mars. The Air Force had made Jimmy an astronaut, but not a pilot, for he’d unknowingly revealed an aptitude for dealing with robots and computers. So they made him an expert in electronic surveillance, cryptography, countermeasures, which increasingly meant, as it had ever since Turing conceived the general-purpose computer, the analysis of computer software.
He was disappointed at the assignment, but he believed in his country; he did his job as cheerfully as he could, and he proved somebody right by doing it exceedingly well. Like all men of faith, he had doubts, he had lapses, and he carried with him a mass of guilt. No one knew that better than his present commander.
On the little screen which peered into PROP, propulsion control, the workstation immediately opposite NAVCOM on the deck below, Commander Braide saw Linwood Deveraux tweaking the instruments on a console almost as complex as her own. If Braide was responsible for the ship’s brain, Spin its nerves, Melinda its eyes and mouth, and Jimmy its fingertips, Linwood was responsible for its guts.
She did not know what was going on in Linwood’s mind right now, but she would have laid even money that he was fussing over instrument readings that were less than optimal. Linwood seemed determined to take everything at face value, although he’d seen plenty of surprises in the course of his checkered career and produced more than a few surprises of his own. Linwood had been in the astronaut corps for almost twenty years now, had not gotten into space until he was forty; his longest tour was two months aboard Archimedes, although he had made several shorter excursions. As a member of a flight crew he was versatile and dependable, and as a scientist he had produced an impressive bibliography of papers on solar physics, but he was only one among some 200 astronauts, pilots, and assorted mission specialists, and he thought that to NASA he was nothing special; Linwood thought there were a dozen men and women who could have done his job as well as he. His commander thought differently.
She had heard the story, unacknowledged by the world at large but true, heard it from him and from half a dozen others who confirmed its key passages: Linwood, though he held no patents, had substantially created the engine that was about to take him and the rest of them for a wild ride…
The world doesn’t plunge into the future as fast as the shock merchants would have us believe, but within any couple of decades there are liable to arise one or two differences that really make a difference—steam engines, women’s suffrage, quantum theory, that sort of thing. In the first decade of the twenty-first century, engineers were consolidating a technology that physicists had been promising for
over half a century but had only recently delivered: controlled nuclear fusion. No individual, not even a single generation of researchers, stood out in the braided history of that struggle. Some years after the turn of the century a thirty-five-year-old nuclear physicist named Linwood Deveraux stumbled upon an amusing technical wrinkle in the design of fusion reactors one quiet evening in the den of his Livermore, California, home.
Since the 1960s one of the leading schemes for controlling fusion, known as inertial confinement, had involved the implosion of tiny spheres of frozen hydrogen, spheres so small that hundreds could fit on the head of a pin—and every sphere a miniature H-bomb. The nation’s weapons laboratories, Los Alamos in New Mexico, Livermore in California, Sandia in both states, had a monopoly on the classified knowledge essential to inertial confinement projects; who else regularly set off nuclear bombs and measured their behavior? Who else could generate mathematical models of nuclear explosions on the world’s fastest computers?
These diminutive superbombs were to be triggered by an array of powerful lasers or particle accelerators—ray guns, that is—arranged in a circle, pointing inward. Firing simultaneously, the beams would hit each frozen pellet as it fell into their midst. As the flash-heated surface expanded it would crush the sphere’s interior until the hydrogen nuclei were fused into new elemental combinations—ideally releasing some three orders of magnitude more energy than that used to trigger the blast. Provided that it did not instantly melt the machine or blow it to pieces, this thousandfold increase in energy could be used to produce electrical power. Or to do other things. Fusion research had long been entangled with the military’s yen for Buck Rogers-style death rays.
That was okay with Linwood Deveraux. As reticent and gentle and genuinely polite as his soft Louisiana accent and his long-nosed, sad face suggested he was, Linwood nevertheless loved things that went zap and boom.
His job, as one member of a brainy team at Livermore that called itself Q Branch, was to build an inertial confinement chamber that would convert thermonuclear explosions into directed beams of energy—ray guns thousands of times more powerful than those used as the spark plugs to ignite their hydrogen-pellet fuel.
In his basement den at home Linwood had a slim computerized drawing pad equipped with a nice fat CADD ROM chip, but he didn’t use it much. In Linwood’s opinion, computer-aided design and drafting systems, for all their power, were lumbering dinosaurs compared to a pencil and a scrap of paper during those critical stages of creation when ideas came quick and loose, when the less extraneous circuitry there was between brain, hand, and eye, the better.
Some of the things Linwood drew by hand on his table of varnished birch—its surface nebulous with rubbery Dandy Rub Cleaning Powder—he had no business drawing there. At the lab they used much bigger CADD machines, and it was bothersome to let light fall on the screens. At the lab the lighting was soft and indirect. At the lab the windows were covered with steel plates, and all transmitting and receiving devices were forbidden. At the lab the air was always filled with Muzak to discourage electronic eavesdroppers; the lab’s security consultants had correctly suggested that Muzak would drive spies crazy.
Linwood had his more useful ideas at home, in the morning shower, or after dinner sipping a glass of the local Wente Riesling, or lying in bed watching a favorite chip from his large collection of old Creature Features while his wife, Jeri, snored lightly beside him. Sometimes, after the movie had disintegrated into electronic snow, he’d get up and go downstairs to make sketches on his home drawing table. He’d smuggle them into work the next day, disguised as sandwich wrappings; there he could elaborate upon them even while listening to Muzak.
On this particular summer afternoon Linwood was sitting at his drawing table, his stiff eyebrows arched in quizzical alertness, his long, narrow beak quivering in anticipation of inspiration, while he savored unaccustomed quiet. Jeri and the girls had been gone for a week, driving east to a family reunion in Baton Rouge. He would join them by plane in a couple of days, assuming he survived that long on his bachelor’s diet of Coke, canned chili, and Fritos.
Bars of orange light penetrated the converted half basement. On the sill of the room’s only window, light collected under the chines of a small blue pot in which two lithops burrowed. Linwood put water in the pot perhaps once a month, and then only a spoonful. “Stone plants,” desert plants from southern Africa, the lithops thrived on deprivation. Their visible parts were their mottled tops, each about as big around as a marble, deeply creased in the center, as smooth and bisymmetric as a baby’s bum. Fleshy windows conducted sunlight down cellular light pipes to the plant’s photosynthesizing organs, sheltered an inch beneath the insulating soil. A lithops was Linwood’s kind of plant, efficient, private, and deep, content to live its life half under the ground.
At the precise hour when the late afternoon photons came screaming through the westward window, bouncing off the neighbor’s asparagus fern in a blaze of light, tickling the shy lithops, punching him in the eye, Linwood got his modest idea.
Several tricks were needed to design any fusion reactor, but they all required an intimate knowledge of the behavior of atoms and subatomic particles in the presence of strong electric and magnetic fields. That sort of knowledge, in turn, rested partly on a powerful intuition of geometry, and there is no useful theorem in geometry that cannot be at least qualitatively suggested with a paper and pencil. He sketched the lab’s current test machine, with its ring of lasers firing inward toward the tiny hydrogen pellet target, and the strong magnetic “nozzle” that contained and directed the resulting explosion.
Linwood Sketch 1
What is the heart of a thermonuclear explosion? Provided it starts and ends clean—uncontaminated by heavy elements like plutonium or uranium, which are intrinsic to the brute force of real H-bombs—a thermonuclear explosion is a clear hot soup, a plasma of protons, electrons, ionized helium, free neutrons, un-ionized hydrogen atoms and leftover neutrinos and such. All the electrically charged particles will stay in the soup, if it is confined and shaped by electric and magnetic fields.
Most of the energy of the explosion, more than three quarters, is in the form of speeding neutrons. Neutrons aren’t significantly affected by electric or magnetic fields, but they can be slowed in a materially dense “blanket”—liquid lithium or some such substance—their energy thus converted to heat.
What happens to the heat depends on what the reactor is designed to do. A power reactor uses it to make steam, and eventually electricity, but in ray guns most of the heat is a waste and a nuisance. Over the decades ray gun designers had played with various ways of using the energy of a thermonuclear explosion, for example, by letting it squeeze magnetic fields to produce huge electrostatic charges, or by opening one end of the magnetic bottle to let the products spew out, or by focusing some of the energy into x-ray beams, and so on—but no matter what the scheme, most of the thermonuclear reactor’s energy was wasted as heat.
On his sketch pad, Linwood roughed in the liquid blanket and the circulating coolant systems required to dispose of the waste heat. There he paused.
To Linwood, with his passion for efficiency, wasting so much heat had always seemed criminal. Surely something clever could be done with those copious neutrons!
Linwood Sketch 2
In power reactors, neutrons were intrinsic to the fusion fuel cycle; they were captured to breed radioactive tritium, the rarer (because of its short half-life) of the two isotopes of hydrogen that composed the fusion fuel, the other being the more common deuterium. Tritium breeding was a secondary process, however, a civilian process. A ray gun orbiting in space would be supplied with all the tritium it was ever likely to need.
Linwood wondered about other neutron-capture scenarios. In the heart of the sun, neutron capture contributed to the formation of heavier elements…but to take advantage of stellar fusion processes was a dream of the far future, awaiting the day when truly monstrous magnetic fields
could be generated, capable of rivaling gravity at the heart of a star.
Linwood thought about all this a long time and drew nothing. Applying the old creative principle that when the going gets tough the smart go somewhere else, he balled up his rough sketch and threw it away.
He stared morosely at the lithops, now faintly glowing in the setting sun’s last light.
At the lab his discarded sketch would have been sucked into a high-temperature furnace and instantly reduced to fine ash, but at home Linwood had an open wastebasket beside his table, the contents of which he conscientiously burned…whenever he remembered to. The security disadvantages of this practice were offset by certain practicalities, one of which Linwood now demonstrated to himself—
—by changing his mind. He fished the crumpled wad of paper out of the basket and flattened it on his table. Now what if, instead…
The lithium-neutron reaction that yields tritium is quite efficient: a neutron entering a blanket of liquid lithium travels ten or twenty centimeters and scatters from a few lithium atoms, heating up the neighborhood before strongly interacting with one of them to create a helium nucleus and a tritium nucleus. A typical power reactor circulates the liquid metal lithium through heat exchangers, meanwhile tapping a small side flow from which the tritium is chemically extracted.
Instead of thinking of the lithium blanket as a coolant, optional for his purposes, Linwood tried thinking of it as an extra fuel tank. He imagined introducing lithium into an annular ring around the reaction chamber at a steady rate, letting it circulate long enough to be bombarded by sufficient neutrons to produce a good proportion of tritium. He imagined mixing this tritium-enriched fluid with a separate supply of deuterium. He imagined injecting the lithium-tritium-deuterium mix into a magnetically confined and compressed outflow of hot plasma from the primary reactor—in such a manner that it burst into a secondary fusion reaction, additionally heating an outgoing beam.
