In comparing the effectiveness of various ways of imparting momentum to a projectile, physicists employ the concept of "impulse," which is given by the product of the force acting on the projectile and the time for which it acts. In the case of a spacecraft, a key indicator of performance is the impulse per unit vehicle mass, or "specific impulse," which is measured in units of time and usually expressed as seconds. High specific impulses arise from propulsion systems that generate high-velocity exhaust products. The exhaust molecules from a hydrogen-oxygen rocket are ejected with velocities of the order of three kilometers per second, corresponding to a specific impulse of 450 seconds at best, with the result that interplanetary travel based on chemical propulsion is reckoned in years. A fusion reaction, by contrast, ejects plasma products over three hundred times faster and makes attainable specific impulses as high as 100,000 seconds. That was why a fusion drive had been considered essential to maintaining a base on Mars, and why the Orion's projected flight-time was only fifty days.
The Orion was built in two major parts—a forward section and an aft section—connected by a quarter-mile-long structural boom. Its tail end was open to space, and consisted of a framework of girders, struts, and tiebars forming four unenclosed, cylindrical thrust-chambers strapped together in a cluster like a bundle of squirrel cages. Frozen pellets of a deuterium-tritium mix were fired into the chambers in pairs twice every second and imploded on the fly by focused beams of accelerated ions to produce a succession of fusion microexplosions—miniature H-bombs. The electrically charged, high-velocity particles released in the process generated forward thrust by reacting on a configuration of concave magnetic fields, while the uncharged neutrons and x-rays, to which the magnetic mirrors were transparent, could escape harmlessly into space. Magnetohydrodynamic windings at the stern converted part of the outgoing exhaust energy into electrical power for driving the ion accelerators and the superconducting field-generators. The remainder of the aft section, forward of the radiation shield screening the drive chambers, contained the rest of the propulsion system, berthing facilities for the Orion's complement of reconnaissance craft and surface landers, and storage compartments for ground vehicles, construction materials, and heavy equipment.
The forward end of the connecting boom terminated in a large, vaguely spherical housing, referred to in typically colorless NASO parlance as the Service Module, which contained the main air-generating plant and other systems essential to supporting life, plus an independent chemical motor and associated fuel tanks; in the event of an emergency the ship's entire tail could be ditched and the backup propulsion system used to get the mission home again.
Accommodation for the vessel's occupants was distributed among four smaller spheres—Globes I through IV—located ahead of the Service Module and offset symmetrically from the centerline to form a square lying in a plane perpendicular to the main axis. Rotation of the entire ship about this axis, coupled with an arrangement for pivoting the spheres, enabled centrifugal and linear components of force to be combined into a resultant simulation of unit gravity normal to the floors, irrespective of the ship's acceleration. A fifth sphere—the Command Globe, containing the control and communications center—formed the Orion's nose, and was interconnected with the others and with the main structure by a web of supporting booms and communications tubes.
"The god-awful ugliest thing I've ever seen in my life!" Clarissa Eidstadt said as the NASO European Division's shuttle closed in upon the Orion ten thousand miles above Earth. "What did they do—copy an eggbeater?" The team had been scheduled to shuttle up from El Paso, Texas, but was flown to Kourou, Guiana, at the last moment, because NASO officials had decided not to antagonize a protest rally that was besieging the El Paso facility. A chemical present in rocket exhaust had been found to cause cancer in mice when administered for six months in ten thousand times the concentration measured at the pad immediately after a launch.
"Oh, I'm not so sure, Clarissa," Thelma said, leaning back in her seat and tilting her head to one side as she contemplated the image being shown on the cabin view-screen. "In a way, I think it's quite beautiful."
"You do? Then I'll know never to buy you an eggbeater as a present. You might frame it and hang it on the wall."
"I'm not talking about how it looks," Thelma said. "I'm talking about what it represents. . . . One day people will probably go to the stars in something evolved from it."
"How wonderful." Clarissa stared fish-eyed again at the screen through her butterfly spectacles. "Say, know what—my kitchen will never look the same again now you've said that."
Osmond Periera, who was sitting a row ahead of them, turned his head. "I wonder if, when that happens, we'll have learned how to imitate the alien star travelers who visited Earth during the mid-Holocene period. It appears extremely likely that they navigated by means of reactive, psychosympathetic beacons tuned to their mental energy spectra. The geometric spacings of numerous ancient monoliths can be interpreted as yielding a mathematical series that reflects the corresponding psychic resonances."
"Now I can sleep," Clarissa murmured dryly in Thelma's ear. "I've always wondered about those geometric monolith spacings."
"That's really fascinating," Thelma said to Periera in a louder voice. "Is that why pyramids everywhere are the same shape?"
Before Periera could answer, Joe Fellburg sat forward in the row behind, where he was sitting with Zambendorf and Otto Abaquaan, and frowned at the view of the Orion as it continued to enlarge on the screen. "What is it, Joe?" Drew West asked from his seat next to Thelma.
Fellburg stared for a few seconds longer at the huge ship, surrounded by shuttles, service craft, and supply ships, and the loose cloud of containers, pipes, tubes, tanks, and assorted engineering that would gradually be absorbed inside during the remaining three days before liftout from Earth orbit. "See those three shuttles docked at the stern cargo section . . . and the other one standing off, waiting to move in?" he said at last.
"What about them?" Thelma asked.
"Those aren't standard NASO models. Two of them are military transports out of Vandenberg or Travis, and one of the others looks like a British air force troop carrier. What the hell are they doing here?"
In the seat beside him, Zambendorf turned his head and gave Abaquaan an inquiring look. Abaquaan raised his eyebrows ominously. The anomaly of Ramelson and his colleagues' getting more involved in the mission than seemed reasonable had been followed by that of the training course at the NASO center at Charlotte, North Carolina, intended to provide the basic skills and knowledge needed by anyone flying with a space mission—how to put on and operate a spacesuit, the safety regulations enforced aboard spacecraft and in extraterrestrial habitats, emergency procedures, and so on. But the mission personnel whom they had met there had been of relatively junior status, such as engineers, scientists, maintenance technicians, medics, and administrators. The mission's senior management, officer corps, or whoever would constitute the upper levels of the organizational tree, had been conspicuous not only by their absence but by their not even having been mentioned. And as Drew West had observed, the mix of people encountered at the course and reflected in the personnel lists had seemed unrepresentative of the populations envisaged for space colonies. There were too many scientists and academic specialists: bacteriologists, virologists, biologists, physicists, chemists, sociologists, and psychologists . . . even some linguists and a criminologist. Obviously the mission offered many opportunities for diverse studies that the academic community couldn't be expected to miss—buses didn't leave for Mars every day of the week—but so many? And where were the agricultural technicians, the industrial workers, the clerks, and the service people who would be expected to make up a large percentage of any projected colony? Hardly any had been met. That seemed strange too.
And now, apparently, a previously unannounced, and by all the signs not insignificant, military force would be coming too. It was in keeping with everything else he had been able to ascertain, Zambendorf reflected as he sat gazing at the screen. Although he was still not in a position to fit the pieces into a coherent pattern, there hadn't really been any doubt in his mind for a long time now: Something very unusual indeed was behind it all.
As the last in a series of prototypes, the Orion was intended primarily to prove the feasibility of its scaled-up fusion drive and to test various engineering concepts relating to long-range, large-capacity space missions; like the experimental Victorian steamships that had preceded the gracious ocean liners of later years, its design took little account of luxuries or spaciousness of accommodation for its occupants. Its warren of cabins, cramped day rooms, machinery compartments, stairwells, and labyrinthine passageways reminded him more of a submarine than anything else, Massey thought as he lounged on his bunk and contemplated the view of Earth's disk being presented on the screen built into the cabin's end bulkhead. He and Vernon would share the cabin with two others, both of whom they knew from the training course: Graham Spearman, an evolutionary biologist from the University of California at Los Angeles, and Malcom Wade, a Canadian psychologist. Spearman and Vernon had left to explore the ship and Wade hadn't arrived yet; Massey, therefore, was making the most of the opportunity to relax for a few minutes after arriving on board, checking in, and unpacking his gear.
From his perspective in Globe II, the entire planetary surface of Earth—continents, oceans, and atmosphere—revealed itself as a single, self-sustaining biological organism in which the arbitrary boundaries and differences of shading that divided the maps of men were no more meaningful than they were visible. It was a truth that astronauts and other venturers into space had affirmed repeatedly for over half a century, but it had to be experienced to be understood, Massey realized. Only two days earlier he had paid a final visit to Walter Conlon in Washington, where on every side the world of human affairs scurried and bustled about its urgent business and consumed the output from thousands of lives. But already the whole of it had shrunk to a speck of no particular significance, barely discernible against the background that had remained essentially unchanged since before Washington had existed, and which might persist for long after Washington was forgotten.
The sound of the door being opened interrupted Massey's thoughts, and a moment later Malcom Wade pushed his way in, holding two bags and a briefcase in his hands and using a foot to shove a suitcase along on the floor. "Well, I guess I must have found the right place," he said as he closed the door with his back. "Hi, Gerry. I gather the other two are already here."
"Hello, Malcom. Yes—they've gone exploring. That top bunk's yours. How was the flight?"
Wade took off his topcoat and hung it in the closet space by the door. "Oh, fine—apart from taking half a day longer than it was supposed to. We had to divert to the European base in Guiana." He sank down with a grateful sigh on the bunk opposite Massey. He was a tall, thin-bodied man, with lank hair and pale eyes that always seemed to be glinting with some inner fervor.
"I heard about it," Massey said. "Hey, I think Graham's got a bottle of something stowed away over there. Could you use a drink while you're getting your breath back?"
"Mmm . . . later maybe, thanks all the same."
"Okay. So who else was on the shuttle?"
"Let me see . . . Susan Coulter, the geologist, and that electronics guy from Denver that we had breakfast with one morning at Charlotte . . . Dave Crookes."
"Uh-huh."
"Karl Zambendorf and his people were on it too." Wade cocked an eyebrow at Massey in a way that was partly expectant, partly curious.
"Oh." Massey did his best to keep his voice neutral. He didn't want to get into a long debate just then. Although he hadn't advertised his prime interest in the mission, the question of Zambendorf's being included had been a regular conversation topic at the training center, and Massey had found himself obliged on occasion to express his opinions. Wade described himself as a scientist and was apparently an advisor of some kind to a number of government committees, but he took Zambendorf quite seriously. Massey wondered exactly what he advised the government on.
"I think I know why he's here," Wade said after a short silence. He paused to wait for Massey to ask him why Zambendorf was there. Massey didn't. Wade went on anyway, "It's well known that the Soviets have been conducting extensive research into paranormal phenomena for years—and getting successful results too." Massey swallowed hard but said nothing. There were always anecdotes of anecdotes about things that people were supposed to have done, but never anything verifiable. Wade took a pipe from his jacket pocket and gestured with the stem. "It's been suspected for a while now that they've achieved some kind of significant breakthrough, and a lot of experts have been saying that the main Soviet center for that kind of work is their Mars Base at Solis Lacus—well away from terrestrial interference, you see." Wade paused and began packing tobacco into his pipe from a pouch.
"Well, I guess you know how I feel about all that," Massey said vaguely, while wondering uncomfortably to himself if the conversation was an indication of what to expect for the next fifty days.
"But it all fits," Wade said. "I know you're a bit of a skeptic and so on, Massey, but I believe in being scientific about things, which means being open-minded—in other words, willing to accept that there are things we can't explain. Whether we can explain it or not, we have to accept that Zambendorf is gifted with some abnormal abilities." He eyed Massey for a moment as if the rest should have been too obvious to require spelling out. "Well, I think Zambendorf is part of a classified Western research program to match the Soviets in harnessing paranormal phenomena . . . or maybe even to counter the Soviets. That could be why they're sending Zambendorf to Mars." Massey stared at him glassy-eyed, but before he could say anything, Wade added triumphantly, "And that would explain why the military is here—to secure the project from possible interference from the Soviets at Soils Lacus. Have you heard about that yet?"
Massey nodded. "We were told they're coming with us to do some training under extraterrestrial conditions . . . that the Pentagon bought some places on the ship at the last moment or something."
Wade shook his head. "Cover story. Do you know how many there are of them? There were three shuttle-loads disembarking when I came aboard—U.S. Special Forces, a British commando unit, French paratroopers. That's not a few seats bought at the last minute. That was scheduled a long time ago . . . And they're docked at the stern, which means they're unloading heavy equipment." He produced a lighter and watched Massey over his pipe while he puffed it into life. "In fact it wouldn't surprise me if the idea was to provoke a confrontation with the Soviets at Lacus in order to take their base out. Maybe our people are onto things that you and I haven't even dreamed about."
Massey slumped back and looked away numbly. Surely nobody at the Pentagon or wherever was taking the nonsense about the Soviets that seriously . . . But then again, large sectors of the government and private bureaucracies were dominated by political and economic ideologists incapable of distinguishing sound scientific reasoning from pseudoscientific twaddle, yet commanding authority out of all proportion to their competence. If they listened to kooks like Wade, they could end up believing anything. Surely the insane rivalry that had paralyzed meaningful progress over much of Earth for generations wasn't about to be exported to another world over something as ridiculous as the "paranormal."
Massey stared again at the blue-green image of Earth with its stirred curdling of clouds. Somehow the human race had to get it into its collective head that it couldn't rely on magical forces or omnipotent guardians to protect it from its own stupidity. Man would have to trust in his own intelligence, reason, and ability to look after himself. The decision was in his own hands. If he chose to eradicate himself, the rest of Earth's biosphere—far more resilient than popular mythology acknowledged—would hardly notice the difference, and then not for very long. And as for the rest of the cosmos, stretching away for billions of light-years behind Earth's rim, the event of man's extinction would be no more newsworthy than the demise of a community of microbes caused by the drying up of a puddle somewhere in Outer Mongolia.