The Medusa Chronicles

by Stephen Baxter

  12

  So they gave Falcon a ship. Hope Dhoni helped him board.

  The ship was essentially a dumb-bell: cylindrical spine with fusion engines and landing gear at one end, a spherical crew capsule at the other. In fact, it was similar to the venerable Discovery class of interplanetary craft that had first taken Falcon to Jupiter more than three decades ago, though on a smaller scale. The basic engineering logic, that you needed to separate your fusion-powered, radiation-leaking engine module from your habitable compartments, had not changed.

  However, everything not absolutely essential for Falcon’s voyage had been stripped away, making the craft lean and fast. Once aboard, Falcon was tucked in tighter than a Mercury astronaut in his primitive capsule—and that was a reflection Geoff Webster would have liked. Falcon had no need of independent life-support systems, and he would spend most of the trip out to the Kuiper Belt in induced sleep, so he needed little room.

  They had given the craft no name, leaving that to Falcon. He searched his memory, thinking of Webster. What of that dreamy day when the two of them had gone ballooning across the northern plains of India? Falcon’s not-so-subtle objective had been to persuade Webster of the joys of lighter-­than-air flight, and so gain his support in Falcon’s schemes. Without that trip, there would have been no Queen Elizabeth, no Kon-Tiki, no encounter with the medusa . . . It was bittersweet, yes. But so much had flowed from that one trip.

  “Srinagar,” Falcon said.

  “I’m sorry?” Hope said. She was leaning over him, into the cabin, with a medical-diagnostics minisec in her hand. She was here to finalise his integration into the ship.

  “My call sign. Srinagar. Will you pass it on?”

  Hope said nothing, and continued to work. She seemed reluctant to leave. Indeed, he was fairly certain that Hope had been wishing for something to crop up, some justification for her blocking his involvement in the Kuiper Belt mission.

  “I’ll be all right, you know,” he said, when she finally backed out and the techs prepared to seal him away.

  Hope unplugged the last of her diagnostic feeds; it whipped back into the body of the minisec. “Well, I hope you look after yourself out there.”

  He studied her; she sounded as if she’d been rebuffed. “Hope—”

  “Yes?”

  He rested his artificial hand on hers. “I’ll be fine. I meant what I said in that meeting, you know. I don’t have too many friends. But the ones I have, I value.”

  * * * *

  He lifted from Makemake at one gee, exceeding escape velocity within a hundred seconds, with Trujillo’s little puddle of light and warmth soon falling behind. Within another minute or two, the curvature of Makemake had brought the lights of Brown Station into view. But soon the whole of the little world was in his field of view and already dropping back.

  In free space Falcon increased fusion power by one gee increments, keeping a careful eye on the instruments, until he was satisfied that Srinagar was handling smoothly. He would burn at ten gees for three hours, bringing his speed to a thousand kilometres per second. It sounded fast, and indeed it was: at such a speed, he could travel between the Earth and the Moon in a matter of minutes. But the scale of the outer solar system was much vaster than the mere baby step between the Earth and the Moon. Even at this speed the trip from Earth out to Makemake would take more than two months—as indeed it must have done for the World Government delegates. And although Makemake orbited within the Kuiper Belt, just as did the target iceteroid, the hop would take Falcon across a broad swathe of that huge, sprawling swarm of iceteroids. He would restart the fusor no earlier than twenty-five days from now, and for most of that time he would simply cruise, unpowered.

  And asleep.

  “Makemake, Srinagar. This is Falcon. I’m signing off—I expect to wake in about six hundred hours. Tell Doctor Dhoni her patient is taking excellent care of himself.”

  Falcon cast one final glance back at Makemake, backlit by the sun. It occurred to him that all the worlds on which people had ever walked now lay in his line of sight, snug in their warm and cosy orbits; for an instant he felt the ancient and familiar unease of travellers across the ages, as their courses took them into the unknown. But the moment passed, and Falcon readied himself for sleep. He dreamed briefly of ballooning over the sunlit Himalayas with Geoff Webster and Hope Dhoni—with an irritated simp in the rigging, threatening to sabotage the heater . . .

  And then there were no dreams at all.

  13

  Twenty-five days of oblivion followed. Then Srinagar’s automatic systems roused its pilot.

  Once he’d ensured he was fully functional himself, Falcon checked the status of Srinagar. The little craft had weathered its crossing well.

  Then he checked his position. Just as planned his destination lay only a few hours of flight ahead, allowing for a final deceleration phase. He flipped the ship around to point its tail at his target, activated the fusor and began to whittle down his speed further.

  Other than the confirmation provided by his own navigational systems, there was nothing to suggest that Falcon had now travelled far across the Kuiper Belt. Nothing obvious lay ahead of him, save for blackness and a scattering of stars. The same was true in all directions except when he looked back towards the sun, now even smaller than when he had viewed it from Makemake, its light twice as feeble again. Although the Kuiper Belt was a vast swarm of icy bodies, the distances between them was still immense enough that each seemed to float in perfect isolation.

  Only one Kuiper Belt Object was of immediate concern to him, however, and with his cameras at maximum range, he could already pick out some details of it. The KBO was a misshapen lump of dirty ice, considerably smaller than Makemake but of fundamentally the same composition and origin. It was a comet—or rather, what would become a comet, if a gravitational encounter with another body ever sent it falling towards the sun. Chances were, however, that this particular lump would remain in the Kuiper Belt until the sun itself reached the end of its lifetime.

  But this KBO had been disturbed. Now, jutting out from the surface of the ice lump, and extending far into space, he saw a line as thin and straight as a laser beam.

  Falcon concentrated his sensors on this artificial structure, tracking along its length. One end of it was firmly anchored to the KBO. The other end—four thousand kilometres away—consisted of open latticework that flared out like the mouth of a trumpet. Along most of its length the structure was only fifty metres across, a latticework tube assembled from incredibly thin but rigid spars.

  The KBO was turning slowly in space, completing, he knew, one rotation every eight hours. The structure—which Falcon knew was called a “flinger”—swept around like the hand of a clock. Ordinarily, that eight-hour rotation would have been much too slow to be obvious to the eye, even with the benefit of Srinagar’s sensors. But at the extremity of the flinger, the motion was quite perceptible.

  The purpose of this device was to hurl comet ice into the inner solar system. Ice was water: the most precious commodity in the universe.

  Madri Kedar had been able to brief him about the accident that had seemed to trigger Adam’s silence, but only in general terms. What was known was that something had gone badly wrong with the flinger itself, as he could now see for himself. Although the basic shape of the trumpet was still intact, Falcon could see where the latticework had been buckled, ruptured. He kept having to remind himself of the scale of the details—those bent and severed spars were themselves kilometres long, hinting at the tremendous violence of the event. It looked repairable, though, given time and resources. Why had the Machines not set about the task as soon as the damage was quantified?

  Falcon opened the channel back to base.

  “Makemake, Srinagar here. All’s well with the ship. And downloading medical data; tell Doctor Dhoni I had sweet dreams. I’m on my final approach for
the KBO. I can see signs of the accident, but no obvious Machine activity. You should be picking up my image stream—I’ll keep sending all the way in. Enjoy the show.” Knowing that because of lightspeed delays there would be no possibility of a reply for some hours—given his history Falcon had something of a phobia about signal time delays, but in this situation he was rather glad to be isolated from Kedar and the rest—Falcon settled in for the deceleration phase.

  Meanwhile, however, he began transmitting recognition signals to the KBO ahead of his arrival, using common protocols. But there was no reply. Adam was down there somewhere, according to Kedar. All Machines ­emitted a continuous stream of housekeeping telemetry, and from the data the WG team had analysed on Makemake it was clear that Adam itself had suffered no obvious damage in the incident; his own individual telemetry feed continued to be received, showing no anomalies.

  Time to try the personal touch?

  “Adam, this is Howard Falcon. I’m on the approaching ship you must be seeing. I’m alone. If you can read this signal, send something back.”

  Still there was silence.

  By the time Falcon had completed the deceleration burn he was starting to pick up directly the telemetry feeds from many robots, each of them tagged with a unique serial number. Localising the signals was trickier, but they seemed to be clustered around the base of the flinger, either above or a short distance below ground.

  Adam’s signature was among that huddle.

  Falcon switched back to the Makemake channel to report. “Radio silence so far. But Adam’s definitely down there, and I’d give good odds it’s aware of my approach. I guess I’ve no choice but to attempt physical contact.” Falcon knew that his human stewards would have been much happier for him to wait for their assessment of the situation before taking any further action. He wasn’t the type to wait for permission.

  “I’m going in.”

  * * * *

  Slowly Srinagar approached the KBO.

  Despite its daunting size, the huge structure was in fact a very simple machine, essentially a massive slingshot exploiting the rotation of the KBO to hurl objects away into space. Slugs of refined, processed matter were loaded into open-topped buckets at the KBO’s surface. For the first hundred kilometres, they were hoisted up the length of the flinger by electric induction motors, until they passed through a point where gravi­tational and centripetal effects were exactly balanced. After that, the flinger’s own rotation did the rest of the work. Near the end of the flinger, magnetic brakes cut in sharply to arrest the bucket, harvesting some kinetic energy in the process while allowing the payload to shoot on its way through the widening maw.

  At that point the payload would be moving at quite a respectable clip: half a kilometre a second. Meanwhile, stationed around the throat of the trumpet, batteries of lasers, drawing on some of that harvested energy, directed their beams at the surface of the payload. The boiled-off volatile gases acted like steering rockets, accelerating the payload further and adjusting its angle of flight.

  This was only the first step in a great chain of commerce. Tugs would eventually grapple the free-flying payloads, gathering them into huge convoys bulk-graded by composition and size. Eventually these convoys would be sent on their way to the economies of the inner system, tagged with transponders and with their value, already ticking up and down in accordance with the vagaries of the frost market. All this volatile-ice represented essential supplies for the offworld settlements, water for the arid Moon, complex chemicals for a volatile-starved Mars. It seemed a paradox but it was far cheaper to import such materials all the way in from the outer system than to lift it from Earth’s deep gravity well, in addition to the environmental costs avoided.

  It would take years for any given packet of volatiles to arrive—but what mattered was not the speed of the flow, but rather its dependability. And that was precisely where the present problem lay. This KBO had not been generating its quota of volatiles, not for the best part of a year.

  Now Falcon was closing in. Cautiously he lowered Srinagar, descending parallel to the thin tower of the flinger. As far as he could tell, the damage was all up at the trumpet end, far off into space. Kedar had been able to give him few technical details of the accident, other than to say that it was something to do with a guidance and control fault of the bucket. Guidance and control, Falcon thought ruefully. The guidance and control of a camera platform had cost him dearly once, but there had been a human in the loop on that day in Arizona. There were only Machines here. He wondered how a system as reliable and indeed as simple as the flinger could have malfunctioned so badly, when fallible human reflexes had no part to play.

  Proximity alarms sounded. The surface rose to meet him, dusty, pocked with craters. Falcon deployed the undercarriage, gave the fusor one last pulse to knock his approach speed down to a safe descent rate of five metres a second—and then he was down. Srinagar fired ground-­penetrating anchors the moment it touched ice, the undercarriage compressing and rocking until stability had been achieved.

  Falcon had come down about fifty metres from the base structure of the flinger. It rose in the distance, a tapering cylinder, a vaulting demonstration of the laws of perspective. From Srinagar’s cabin Falcon watched the base for signs of activity, but there was no movement around any of the service entrances, and there was still no radio contact.

  Nothing for it, then, but to go in himself.

  * * * *

  Falcon readied himself for vacuum—it would be cold and airless out there, but no worse than the surface of Makemake. There were no paths here, though, because there were no people who needed them. He decided not to chance his wheeled undercarriage, preferring to plug into one of his other new ambulatory modules. The six-legged all-terrain chassis would no doubt unnerve “normal” people—it made him spiderlike, he guessed, and therefore tripped all sorts of buried fear responses in the human brain—but he could not help that. And besides he need not be concerned about human reactions here.

  He made a preliminary report before leaving the ship. “Makemake, Falcon again. I’m down on the KBO. Still no welcoming party. I’m going outside.”

  Then he lowered Srinagar’s ramp, opened the lock and picked his way out onto the ice.

  The legs were articulated in such a way as to keep his centre of gravity as low as possible, with the inverted V-shapes of the knee joints almost at his head-height. It had taken months to learn independent control of all six limbs. Now he felt he could climb any slope, stretch across any ­obstacle—could even leap hundreds of metres, if it came to that, in low gravity. Yes, on some level he probably did look monstrous—but out here in the outer solar system it was the human form that was badly adapted to the environment, not his own.

  He approached the flinger’s base structure, a blocky bunker. In this low-gravity environment it defied intuition, looking too fragile an anchor for such an immense engine. Rectangular service ducts were spaced around the base of the structure. No door or airlock protected the interior, for the Machines were as comfortable in vacuum as Falcon himself—more so. Falcon picked the nearest duct and approached at a cautious, unthreatening speed, resisting the urge to quicken his pace.

  All the while, Srinagar was continuing to attempt to make radio contact with the Machines. But they had not responded and, according to the telemetry he checked regularly, there had been no significant change in their positions.

  He paused at the base’s threshold where the ice gave way to the hardened surface of a shallow ramp that descended to lower levels. It was pitilessly dark down there. Falcon turned his eyes up to maximum sensitivity, making the best use of the few stray photons available to him, and details prickled in a grey-green overlay.

  He began to make his way down the ramp, one silent footfall after the next.

  Until this moment it hadn’t occurred to him to fear the Machines, but he could no longer ignore a grow
ing feeling of apprehension. It was almost like a metabolic imbalance in his life-support system, flooding his brain with the wrong chemicals. Fear was useful, though—fear was a friend. He had long believed that when human emotions finally slipped from his grasp, fear would be the last.

  The ramp levelled out. Now he was in the central space of the structure, which was a complicated factory floor where, when the flinger was operational, each payload bucket could be loaded with processed volatiles and sent on its way up the tower. All around him loomed powerful machinery, as well as the huge, root-like foundation struts of the tower itself, which must have extended down into the ice, many kilometres below his feet. There were grabs, scoops, belts, drills, cranes, generators, processors, huge snaking pipes and power lines—all of it registering in dim grey-greens, and all of it cold. Falcon was used to surroundings that made him feel small. That was the natural condition of a space explorer—and Falcon, after all, had explored Jupiter. But it had been a long time since he felt so vulnerable. Any one of these titanic machines could squash him like a midge.

  “Hello?” he called, using the Machines’ radio channel. “Anyone home?” No reply.

  He moved slowly along the service walkways that snaked around and under the huge machines. The equipment was dormant, but he saw no sign of damage. With the tools here, and the stocks of raw metal provided for the purposes of repair, there was no good reason for the flinger not to have been restored to full operation by now . . .

  Something made a sound.

  It did not carry through the air, for there was no air, but a sharp and powerful impact communicated itself through the metal fabric of the factory floor, through his chassis, into his body.