The Medusa Chronicles

by Stephen Baxter

  Springer said nothing, returning his gaze resolutely.

  “Or about the weapons emplacements you’re installing at the sub-­Jovian point on Ganymede?”

  “Are you making it a condition of working with us that I have to reveal classified information?”

  Falcon gave in. “What, and miss Falcon Junior’s journey to the heart of Jupiter? Hell, no. Okay, Colonel, I’ll do as you say. I’ll—observe.”

  “By the way, you’ll have my cousin Trayne for company.”

  That surprised him. “Trayne? He’s a bright kid but—”

  “We need to have a Martian attached to this jaunt. Just to show Port Lowell we’re not excluding the Martians from any of this.”

  Falcon smiled. “And who better to play that part than Trayne? He’s family for you, and he evidently knows absolutely nothing about the politics . . .”

  “I’m not quite as cynical as that. I happen to believe Trayne will be a good crewmate.”

  “I’m sure he will,” Falcon said dryly. “He’s a Springer after all.”

  A curt nod, and a smile back. “I’ll be monitoring you all the way down, of course. But report to me in person when you get back.” And Thera Springer, her job done here, Falcon safely recruited, was already glancing at a wrist minisec, her mind evidently on her next meeting.

  And Howard Falcon’s thoughts turned, once again, to Jupiter.

  23

  In the pale air, a thousand hot-air balloons hovered in formation.

  Falcon, once more at his control station in the Ra with Trayne at his side, was awed despite his own previous jaunts into Jupiter. Each of those tremendous envelopes, around two hundred metres in diameter, was emblazoned with the sigil of the World Government, an Earth cradled in human hands—a design, Falcon knew and few others probably remembered, based on the mission patch of the Apollo-Icarus 6 spacecraft—and boldly marked with an identification number. And beneath each golden balloon was a knot of equipment, a suspended factory that Falcon knew must be an atmospheric processing plant, with a dock for small, needle-shaped craft, evidently orbital shuttles, freighters. Even as Falcon watched, one craft sparked rocket fire and soared away from its balloon, out of the farm and up into the higher atmosphere, heading for orbit and a rendezvous with an interplanetary tanker, into which it would offload its precious cargo of fusion fuel for delivery to Earth and the colony worlds.

  But it was the precise formation of the balloons together that was so impressive: a neat array in the hydrogen-helium sky, maintained despite a battering from the turbulent Jovian winds. It was a fantastic sight—and yet Falcon was reminded of a place and time far from here, of images of a wartime London sheltering under a sky full of barrage balloons: images that had been only a century old when he was born.

  The World Government Space Development Secretariat had supplied Falcon with more information than he needed on this, its grandest project: its helium-3 extraction operation, dozens of plants like this established deep in the clouds of Jupiter. Now Trayne consulted a display, bending forward stiffly in his exposit. “So this is the North Temperate Band Atmospheric Processing Station Number Four—NTB-4. The station’s a long way from the lower-latitude zones where the native biota tends to congregate.”

  That positioning was an act of conservation, Falcon saw, but also of simple common sense. He imagined a creature like a manta being drawn into one of those great extractor fans, or a medusa, kilometres across, at play in that forest of balloons . . .

  “There are a thousand aerostat plants in this one station alone, with ninety-eight percent fully operational at present. It seems there are frequent breakdowns.”

  “Hence the need for a crewed presence,” Falcon muttered.

  Trayne said dryly, “If you count Machines as crew, yes. There are said to be ten Machines for each Martian working at this facility. Each plant processes three thousand cubic metres of Jovian atmosphere per second, in order to extract one gram of the isotope helium-3 . . .”

  It sounded so little, just the merest trace to be extracted from Jupiter’s enormous reservoir of air. But that trace was enough to sustain a mighty interplanetary civilisation. And, economically, it was an effective, indeed a highly profitable operation.

  The Martians were paid either in credit or in trade goods—oil or other complex organics—or sometimes in high-tech gear they could not yet manufacture themselves. It had always been that way, Falcon thought sourly. An empire bought bulk raw materials from its colonies in exchange for complex products from the centre, just as the Romans had traded with the provincial British, and the British in turn had traded with the colonial Americans. The Machines, meanwhile, had been rewarded with access to a few inner-system asteroids rich with the metals they craved.

  But, Falcon knew, a dependence on this collection strategy made Earth vulnerable too. Fallbacks were being explored, he had heard; since Geoff Webster’s day Falcon had maintained contacts in the World Council and other high echelons of the WG, so he knew that Space Development was already trying to establish similar atmospheric-mining operations in the clouds of Saturn.

  All that for the future. Right now it was time for Howard Falcon, agent of the government, to go to work.

  Viewscreens on Falcon’s console lit up with images of a human, evidently a Martian, a male aged perhaps forty, head cradled in a massive brace, and alongside him a Machine, its own “head” an ungainly cluster of sensor gear. Even after all these years, each time he encountered a Machine Falcon found himself looking into camera lenses in search of a soul.

  “Calling Ra,” said the human. “Welcome to Station NTB-4.”

  “Ra reporting in, NTB-4.”

  “I am Hans Young,” said the Martian. “Citizen Second Grade. I’m in charge of the human team attached to the Orpheus project. And before you ask—no, no relation.”

  Relation to whom? Oh, yes, John Young. Falcon ignored that bit of Martian bragging. “We’ve corresponded, Dr. Young. Good to see you.”

  Young waved. “And hi to you too, Trayne. How’s your mother?”

  “Good, thank you, Hans.” Trayne glanced at Falcon. “Mars is a small world.”

  “So I gather.”

  “And I,” intoned the Machine in a smooth synthetic voice, “will be known for the purposes of this expedition as Charon 1.”

  “Charon . . . More classical mythology. Orpheus’s guide across the Styx?”

  “Correct. I will guide the first stage of the descent. There will be further ‘Charons’ later. The mission must proceed in stages, adapting to the conditions we encounter as we travel deeper into Jupiter. It was thought appropriate to establish a series of base camps as we progressed. The logic is rather as when humans once challenged mountains such as Everest.”

  Falcon said dryly, “I can tell you that Earthlings still climb mountains.”

  “And so do Martians,” put in Trayne.

  “Let’s review the strategy,” Falcon said. “We won’t be able to track Orpheus even as deep as the thermalisation layer—we’ll manage only a few hundred kilometres, less than one percent of the journey he’s undertaking.”

  “Nevertheless your company will be welcome. And you will stay on station as one of a chain of relays.”

  “As agreed.” Falcon glanced at a clock. “I see Orpheus is prepared for launch. Is there any need for us to come aboard?”

  Young smiled. “Commander Falcon, one thing you learn when working with Machines: there’s no ritual, no routine. When they’re ready to go, they just go. Not so much as a countdown.”

  “I concur with that.”

  An image of a black cube appeared in the viewscreens.

  “It is I. Orpheus. Or, ‘Falcon Junior.’ Welcome to the project, Com­mander Falcon. Adam sends his personal regards.”

  “Thank you—”

  “Follow me if you dare.”

 
; The images relayed from NTB-4 shuddered, just a little.

  Hans Young glanced at an off-screen monitor. “He’s gone—he and the remaining Charons—bathyscaphe away!”

  “Just like that?”

  Young smiled. “Told you.”

  Trayne nudged Falcon and pointed through a window. “Look! There he goes!”

  A kind of ship had tumbled out of the base of one of the hovering balloons, a silvered sphere no more than a few metres across. As it fell through the air a canopy deployed and quickly inflated, slowing the drop to a steady sinking.

  Falcon tapped his controls and felt the Ra turn sluggishly in response. “There he goes indeed,” he muttered. “Come on, Trayne, we have an explorer to chase . . .”

  24

  Effortlessly at first, the Ra tracked the bathyscaphe as it descended into ever-thickening layers of Jovian air, followed by a swarm of camera drones. Bathyscaphe: that had been an archaic word even when Falcon was born, and yet it was apt, he thought, for what was this but a descent into a mighty ocean?

  Soon Ra plunged through cloud level D, and into a gathering darkness. As the descent continued, the pressure and temperature steadily increased, and Falcon had Trayne call out regular readings. The Ra, of course, hanging under its envelope of heated hydrogen, was itself dependent on a balance of air temperature and pressure to stay aloft. The Ra was more advanced than the old Kon-Tiki and, thanks to technologies piloted in the oceanic air of Venus, could reach greater depths without risk of being crushed. Nevertheless, they had gone little more than two hundred kilometres—Orpheus’s descent had barely begun—when Falcon, reluctantly, called a halt.

  “We’re safe to hover at this level,” he reported up to NTB-4, and through them up to Mission Control on Amalthea. “Regret I can’t follow you any further, Orpheus. All your systems look nominal, as far as I can tell.”

  “Your company has been appreciated, Commander Falcon.”

  In the monitor, Hans Young smiled. “Like all the best Machines, he’s programmed to be polite. Prepare to hold your station, Ra, and to deploy transmission relay gear.”

  “Copy.”

  Falcon and Trayne got to work transforming the Ra into a stationary radio relay post. Antennas unfurled around the envelope, including the long, trailing receptors that Falcon, on other days, used to communicate with his friends the medusae. But both of them kept an eye on the images, in visual light, radar and even sonar, of Orpheus’s descent into a thickening murk. Most of the camera drones still followed, but one or two, it seemed, were already failing as the conditions grew tougher, the images they returned fritzing to empty blue.

  A key milestone came when Orpheus’s balloon envelope was cut away and allowed to drift off.

  “Too deep for hot-air ballooning now,” Falcon muttered. “But look at the rate of descent. It’s hardly increased, even without the envelope. Air resistance, and the bathysphere’s own buoyancy, is enough to slow it now.”

  “I don’t understand,” Trayne said, frowning. “I knew I shouldn’t have skipped those briefings at Anubis . . . Without the balloon, how will they bring Orpheus home?”

  Falcon studied him. “I guess you haven’t been around Machines much. Trayne, he won’t be coming home—nor will the Charons who are guiding him. Any more than Mariner 4 ever came back from its flyby of Mars.”

  “What?”

  “Never mind.”

  “That isn’t quite true, Commander,” said Charon 1. “Before his craft is finally destroyed—or rather before he is destroyed, there being no distinction between craft and passenger—Orpheus’s identity complex will be uploaded through the relay stations we will establish, including your own, and copies will be captured here at NTB-4 and at Amalthea. I understand that this kind of replication of minds gives humans no comfort, but it suffices for us if the copy is indistinguishable from the original. So you see, Dr. Trayne Springer, in a sense he will come home—”

  A flare of light showed up in several of the monitor screens.

  Trayne was startled. “What was that? Is there something wrong?”

  Falcon shook his head. “He already reached the thermalisation layer. Where it’s so hot that anything that can be heat-destroyed, will be. Certainly anything organic. That is the ultimate limit for Jovian life.”

  Hans Young said cautiously, “Well, the limit for the life forms we know of, Commander. That’s one objective of the descent. To see what’s down there . . .”

  To challenge the planet’s greatest depths had been one of Howard Falcon’s dreams since the Kon-Tiki. He longed to follow Orpheus. He could only wait here and watch.

  * * * *

  The fall continued relentlessly. The pressure and temperatures recorded by the probe continued to mount, leaving one comparison after another in their wake: a higher pressure than the surface of Venus, higher than Earth’s deepest ocean trench.

  And as the pressure gauge crept up towards two thousand atmospheres, the probe revealed another of its secrets. Its hull abruptly collapsed, and this time it was Falcon who thought some catastrophic failure had befallen it. But the handful of remaining cameras, specialised for depth, showed that while the spherical hull had imploded, a kind of open framework survived, a space-filling, regular arrangement of bars and nodes.

  “You see the design philosophy,” Hans Young said. “We do not fight the pressure, we yield to it. Though the Jovian air has flooded what was the interior, the craft still has some buoyancy, with small, very robust ballast tanks embedded deep in the surviving structure.”

  “And I too survive,” reported Orpheus. “Along with the Charons, downloaded onto chips of diamond. We are comfortable.”

  “Show-off,” Falcon muttered.

  The probe plummeted through one cloud layer after another, as exotic species of molecules congealed out of the thickening air. But the light faded quickly, and soon the last and sturdiest of the camera drones fell away, and no more visible-light images were returned.

  At about five hundred kilometres deep, the level once believed to have corresponded to Jupiter’s “surface,” Orpheus’s probing with radar, sonar and other sensors revealed the presence of masses of some kind drifting in the air, lumpy, granular. Quasi-solid “clouds” in an air of impossible density, Falcon speculated, which had perhaps fooled earlier observers into thinking this was a solid crust.

  But Orpheus soon passed through this intriguing layer and fell deeper yet. The dense hydrogen air through which he fell now seemed featureless—­and lifeless, lacking the sunlit glamour of the high clouds of the medusae. Time passed. Falcon was sure that reports on this stunt were being transmitted across the solar system, but he wondered how many viewers in their domes on Triton, or in the gardens of Earth, would be tuning out when the reports of this dull phase of the mission were sent to them at lightspeed’s crawl.

  The next milestone came at one thousand kilometres deep.

  “Pressure of eighty thousand atmospheres,” Orpheus reported. “Temperature eight hundred Kelvin. Pressure and temperature profiles have largely matched theoretical models so far. However the hydrogen-­helium slush outside the hull is now more usefully described as a liquid rather than a gas . . .

  “This is Orpheus. We are through the transition zone, and have reached Jupiter’s ocean of molecular hydrogen. The first sapients ever to do so.”

  Falcon glanced at Trayne. “I’m sure I can hear a trace of pride in that voice.”

  Trayne shrugged. “Why not?”

  “Phase one is complete. A further layer of hull will be discarded; my descent will continue, while Charon 2 remains at this waystation.”

  “I can confirm that,” called a new Machine voice: Charon 2. “I am ready to take up my station-keeping duties here.”

  And Falcon was astonished by what Charon 2 said next:

  “Godspeed, Orpheus.”

  The de
scent continued.

  25

  “My name is Orpheus. This telemetry is being transmitted via radio signals received by Charon 2 at the hydrogen gas-liquid interface, relayed via the Ra at the thermalisation layer to Charon 1 at Station NTB-4, and then to Mission Control on Amalthea. I am in an excellent state of health and all subsystems are operating normally. I remain fully cognisant of and fully committed to the objectives of the mission.

  “I am currently descending through an ocean of molecular hydrogen-­helium. I am quite safe. For this first descent I have been emplaced far from any of the great volcanic-like features we call Sources. Their investigation is for the future.

  “The pressure and temperatures I am experiencing are rising steadily. My configuration continues to adjust as designed. In the greatest depths my consciousness will be contained in little more than a swarm of slivers of enhanced crystalline carbon—an advanced form of diamond—kept solid at such extreme temperatures by the very pressures I will endure. In this way I will leverage the physical conditions to maintain my structure, as opposed to fighting them.

  “There is no visible light. I fall through darkness. But the hydrogen ocean is electrically neutral, and long-wavelength radio waves can penetrate the gloom.

  “Nevertheless—

  “Nevertheless I am aware of forms, structures, moving through the dark around me. Immense, shapeless masses.

  “These may be inanimate blocks of some more exotic high-pressure form of hydrogen. Drifting icebergs. Or perhaps they are animate, a form of life, living off the thin drizzle of complex compounds from the atmosphere above, or even feeding off this ocean’s gradual temperature differences, or the saturated electromagnetic radiation. Humans and Machines have found life wherever they have travelled; life forms here would not be a surprise. Their movement shows no pattern, however, no intent. Even if there is life, this featureless ocean may be too impoverished to support mind. An encounter with these deep Jovians, if that is what they are, must wait for more advanced missions than mine.