Titan n-2

by Stephen Baxter

  But it wasn’t true.

  It was an odd thing, a small detail, but to Rosenberg the lack of disturbance to the equipment piles emphasized their isolation on this lifeless moon more than any amount of theorizing.

  Benacerraf and Rosenberg, cleaned up, sat on the flight deck of Discovery — away from Bill Angel — and chewed the fat about equipment problems.

  What they were really doing, of course, was not talking about Bill.

  Rosenberg was suspicious of Angel, on some deep level. Bill seemed to have stabilized since the landing, as the NASA psychologists had suggested he would. But Rosenberg didn’t think the creature in the hab module was Bill Angel any more. The way he talked, the body language… He seemed to be coming in at an angle to the rest of the world. As if his head was stuck in some fourth dimension.

  Benacerraf shut Rosenberg up when he talked like this. How come scientists are so precise and picky about their specialisms, but always prepared to bullshit about stuff they know nothing about, like psychology? As far as she was concerned this situation wasn’t about trust; it was about management. Benacerraf approved of Rosenberg’s plans for their survival. But to achieve those plans they were going to need resources: time, muscle power, intellectual energy. She wasn’t convinced that the two of them, alone, were sufficient. She thought they needed Bill Angel to close the design. If they were going to survive here, they had to manage all their resources effectively. And that included Angel. She saw it as her job to manage Bill, the way they were going to have to manage other pieces of equipment, balky or otherwise.

  So now Rosenberg sat here and spoke, not about Bill, but about the Sabatier unit. The Sabatier was a simple piece of kit, basically a pipe surrounded by nichrome heaters. The Sabatier cracked carbon dioxide, collected from the life support system, by reacting it at high temperatures with hydrogen, in the presence of a ruthenium catalyst, to produce methane and water. The water was collected in a condenser coil, and the methane was vented to Titan’s air.

  “I think the catalyst is being poisoned by a build-up of amine vapors… The trouble must be further upstream, in the process, at the SAWD.” The solid amine water desorption unit removed carbon dioxide from the air by passing it over beads of resin inside steel canisters. Rosenberg started to list the steps he was taking to test this out. He said, “At least the systems are easier to work with, now we have a little more space to move around in. And every damn component doesn’t float off into the air every time you turn around…”

  And so on, a parade of detail.

  Benacerraf was chewing on a spindly carrot from the CELSS farm. “Rosenberg, how are we doing overall? What else do we need to do, that we’re not doing?”

  He clasped his hands behind his head, and rocked back in his seat. “Let’s go back to basics. During the cruise, where we had to rely on nothing but the resources we carried, we tried to close all the life support loops. We recycled all our waste, solid and liquid, and fed nutrients to the plants we grew, and cleaned the air… We did well; we survived six years in interplanetary space. But even so the closure was never perfect; we lost about five percent of most materials as they passed around the life support cycle, to leakage, unrecoverable waste, whatever.

  “Here on Titan, outside resources are available to us: water, in the form of bedrock ice, nitrogen and methane from the air, hydrocarbons — like the ethane and propane we can get from Clear Lake — and other compounds, like nitriles and ammonia. That means we can open up some of the loops.”

  Benacerraf said, “Water. We’re still recycling every drop we drink. I can taste the six-year-old piss in it, for God’s sake.”

  “If we could bring fresh water ice into the system we’d cut down the bulk we’re recycling by forty-five percent. And that would give us a system much better buffered against instabilities.”

  “We’re going to have to climb that damn mountain, aren’t we?”

  “It’s why we chose to land here, Paula.”

  She held her hands up. “I know. It’s just that mountaineering on Titan seems a much dumber idea down here than it did from orbit. What else? What about all those amino acids you say we need?”

  Rosenberg scratched his head. “Well, that’s the hole I can’t plug right now. We’ve taken a lot of samples from the air, the diolin slush. No aminos; all I’ve found is the prebiotic organic stuff I expected. If we’re not to be resupplied, there are some trace elements we need as well.”

  “So what are the options?”

  “We go seek aminos on the surface. Some place we haven’t looked.”

  “Like where?”

  “The bottom of Clear Lake. Or carbonaceous chondrite craters,” he said.

  She turned, looking irritated. “I hate having to ask you to explain all the time, Rosenberg.”

  He shrugged. “Then read up. Carbonaceous chondrites are a kind of asteroid. Cratering bodies in this neck of the woods come in four main groups. There are a lot of icy bodies: loose stuff like comet heads, maybe disintegrated moons. Then the M-type asteroids are metallic, metal-rich and dense. The S-types are silicaceous. Rocky. And the C-types are the carbonaceous chondrites. Water, iron, stone and carbon. If we find a carbonaceous chondrite crater we might find kerogen.”

  “What’s that?”

  “A hydrocarbon. A tarry stuff you find in oil shales. It contains carbon, oxygen, hydrogen, sulphur, potassium, chlorine, other elements…” He smiled. “It’s the nearest thing to a nutritional broth we’re likely to find out here. Mom’s condensed primordial soup.

  You know, we can reach a lot of craters with the skimmer, when we set it up,”

  “All right. When we fix the skimmer, we’ll discuss it. What else?”

  What else, what else…

  As the session went on, Rosenberg started to feel hunted, as if everything was coming back to him. Questions, questions. What if he got an answer wrong? It is too much for one person, he thought, this responsibility for all our lives.

  But he did his best to answer Paula’s questions.

  When Paula had gone, he stayed in his seat and stared out into Titan’s twilit gloom.

  Benacerraf felt pressured as well, of course. Rosenberg just came up with options; Benacerraf had to make decisions about them.

  But all the time they were skirting around the biggest issues. There was the problem of Angel, for one thing. And the real limiting factor to their chances of survival, here on Titan: not water, not amino acids, but energy.

  The run-down of the Topaz suite was the final limiting factor, even if they could bridge all the other gaps in the loops. When the power faded below some critical threshold, the cold was going to get them at last.

  Rosenberg had no plans, no ideas, how to get over that.

  Rosenberg was the smartest person on the whole damn moon. If he couldn’t figure a way out of this, nobody was going to. And then he would die. And not at some remote, far-future date, but here, on this crappy moon, and soon. All of this — the orbiter, Apollo, their neat little gadgets and improvised tools — all of it would still be here, but his spark of consciousness, his unique self, would be gone. It would be like a shell, slowly decaying, presumably buried for good in the drifting slush in a couple of hundred years. Eventually, there would be no sign he’d even existed.

  That was unbearable to Rosenberg. He’d come here, in some vague way, to find the future, to find answers, to do science. To escape Earth. But now, this. There had to be a way out of this trap, the abandonment by NASA, the dwindling resources, the cold…

  Beyond the tholin-streaked windows of the flight deck, the gloomy slush-covered ground of Titan stretched off to an orange-stained, concealed horizon. In all the world that Rosenberg could see, under a brown-black lid of a cloudy sky, only a handful of human artifacts — the bundles of equipment under yellow parachute fabric, the stained white conical walls of Bifrost — showed any color other than the universal murky orange-brown.

  He closed his eyes, for a few seconds.

>   Then he got up, and went back to work.

  Later, Rosenberg went out again, to help Benacerraf in her efforts to deploy the skimmer.

  The skimmer — properly, the TGEV, the Titan Ground Effect Vehicle — was a fifty-million-dollar improvisation, put together by Boeing, at Seattle, in under eighteen months. Right now it was still folded up in its palette on the side of the orbiter like a construction toy. Benacerraf had it halfway out, like an aluminum dragonfly struggling to emerge from its chrysalis. Rosenberg helped her haul on the lanyards.

  Abruptly the main fuselage sections locked, and four legs popped out at the corners, telescopic tubes with wide orange footpads. With a couple more hauls, they had the skimmer unfolded, and set upright on the surface.

  Rosenberg — sweating inside his suit, pulled muscles aching — walked slowly around the craft.

  Sitting on its spidery legs the skimmer was a spindly, open-frame box built around a ducted fan, with a skirt of flexible metal mesh draped around its base. The fan’s housing curved upwards above the center of the craft, a shaped funnel. There were two metal-framed couches in front of the fan, each big enough to accommodate a suited crew member, and there was a simple control box with a joystick in front of the left-hand seat.

  Inside the fan housing there was a rotor blade, designed to push the thick Titan air down through the duct and into the skirt, so providing the hovercraft effect that would lift the skimmer off the ground. The fan was run off series-wound electric motors, powered by two big silver-zinc batteries that could be recharged from the Topaz.

  The frame was shaved-thin aluminum, to save weight. The skimmer carried its own navigation computer, communications system and cargo space for maps, samples, tool-racks, spare battery. There was even a fold-out tent, so that astronauts could spend a night away from Discovery on an extended EVA.

  It was a sophisticated piece of equipment. But the skimmer, with its umbrella antennae and fold-up seats, looked in the light of his helmet lamp as if it had come out of someone’s hobby shop. Like some backyard Victorian inventor’s dream of space travel.

  With her hand in Rosenberg’s, Benacerraf climbed up into the left hand seat. She was maybe four feet off the ground; the duct mouth flared above her like a huge crown. She dug a reference card out of a slip pocket, and began throwing switches.

  Suddenly bulbs sparkled over the framework, green and red and white, with big, down-pointing floods that splashed light over the gumbo.

  “Wow,” said Rosenberg. “It looks like a Christmas tree.”

  Benacerraf said, “I think—”

  There was a noise from the duct, a whump-whump that carried easily to Rosenberg through the thick air. Rapidly, the rotor increased its speed, and the noise smoothed out to a whir.

  From beneath the skirt, a thin sheet of gumbo blasted out across the ground in all directions. It was like a paint-sprayer; it took only seconds for Rosenberg’s legs, almost up to his waist, to be coated in crap.

  “How about that,” Benacerraf called.

  Rosenberg shouted, “If you’re going to lift that thing, Paula, strap in.”

  Benacerraf began fumbling at the restraints at her waist.

  The whir rose in pitch to a thin whine, and the skimmer shuddered. It lifted off the ground, the skirt billowing beneath it. Benacerraf whooped, and Rosenberg applauded.

  If it worked, the skimmer would extend their range of operations hugely. Any kind of surface car was going to be impractical, given the stiffness of the tholin slush. But the ground effect vehicle idea might have been made for Titan, with its low gravity, all this lovely thick air… The best way to get around in these conditions.

  Except for human-powered flight on Leonardo wings, of course. But that was a little beyond the imagination of NASA.

  The skimmer hung with its four footpads suspended about a yard off the ground. Rosenberg thought he could see the murky Titanian air being sucked into the mouth of the duct, particles of aerosol crud marking the airflow. The central duct jerked this way and that, blasting its jet of air for directional control. There wasn’t much sophistication in controlling the craft; you swivelled the ducted fan, taking care not to disrupt the air cushion that held the whole thing up, and went where the downward blast took you…

  But now the skimmer was wobbling from side to side, as if suspended from an invisible wire. Benacerraf was wrestling with the joystick. “It handles like shit,” she called. “It’s nothing like the training vehicle at Ellington. This is completely unstable. I can feel it. It feels as if it’s about to—”

  Abruptly the front of the skimmer tipped upwards, and the skirt lifted clear of the ground. A great gush of gumbo came fountaining out from beneath the skimmer, falling in slow, complex arcs back to the ground. With its cushion of air lost, the skimmer slipped backwards, its rear two legs slamming into the ground.

  Benacerraf worked to kill the fan, and the skimmer tipped forward, settling at last on all four legs.

  The skimmer looked like an ungainly meteorite, fallen to ground at the center of a great radial splash of churned-up gumbo.

  As the fan noise died, Rosenberg stepped forward. He checked Benacerraf was okay, and they started to talk about ways to gain control of the stability.

  They kept trying. Benacerraf kept taking the skimmer up, until the batteries started to flatten. They didn’t manage to get the skimmer to fly more than five yards before, every time, it veered off course and dug itself into the gumbo like a badly thrown frisbee.

  Rosenberg had a deep, pessimistic sense they were wasting their time. The design of the craft looked all wrong to him: its center of gravity much too high, the air cushion the wrong shape. With a ground-effect vehicle stability depended on the design of the air cushion, aerodynamic guidance. The Boeing people had done their best, but they just hadn’t had the time or facilities to test out their models of how the thing was going to behave in Titan conditions: the air density, the temperature structure, the gravity.

  The skimmer was a wipe-out. And that meant that wherever they went, they were going to have to foot-slog it. They’d travelled a billion miles, and now they were here they could go no further than they could walk.

  Their options had suddenly closed in even further.

  He’d been out a long time; he was tired. He went to the airlock.

  Once inside and de-suited he started to clean off the gumbo still sticking to his EMU.

  Fifty million bucks, he thought.

  * * *

  On the day of the funeral of Chen Tong, Jiang Ling arrived early at Tiananmen Square.

  She stepped out of her hotel onto the Avenue of Eternal Peace. She walked west under the canopy of sycamore trees, just budding, that fringed the bright red wall of the Forbidden City. The sky was suffused with a pearl grey.

  She reached the end of the sidewalk, and stepped forward onto a checkerboard of cement paving stones. The place was all but deserted. She walked to the center, her footsteps clicking loudly.

  The vastness of the Square swept away around her, like a frozen sea of stone.

  She turned, and looked around the frieze of monumental architecture that lined the hundred acres of the Square: the museums to the east, the Great Hall of the People to the west, Mao’s mausoleum to the south. And at the very center of the Square there was the Monument to the Martyrs of the People, a granite obelisk inscribed in Mao’s own hand with the epigram Eternal Glory to the People’s Heroes.

  And to the north there was Tiananmen itself: the Gate of Heavenly Peace, leading into the ancient Forbidden City. The Gate was a ten-storey rampart set in the massive walls of the Forbidden City; it was painted imperial maroon, capped by two tiers of sloping yellow-tiled roofs, the colors still washed out by the dawn grey. Five portals ran through the base of the Gate, and just above — flanked by inscriptions saying Long Live the Unity of the Peoples of the World and Long Live the People’s Republic of China — sat the massive, familiar portrait of Mao Zedong. The gigantic softscreen image, re
sponding to her presence, appeared to look down on her and smile in welcome. Something inside her melted. On the screen, a blue sky, fluffy with clouds, blossomed into view behind Mao’s corpulent face.

  Her memories never did justice to this place, she thought. Photographs had a way of making the Square seem as flat and uninspiring as the endless shopping malls and parking lots she had seen in America. But this was the Square: the largest public quadrangle in the world, the center of the country’s center — the north star, as Confucius would have said, to which all other stars are attracted. Standing here she was overwhelmed by the physical size of her nation, the history embedded in the ground on which she walked. And she was touched by her own significance, as the first astronaut, her role in the millennial extension of tianming, the Mandate of Heaven.

  This was, she believed, a sense of oneness which no Westerner could understand: certainly not the Americans, with their endlessly recycled images of the Tiananmen students of 1989, those unfortunate, misguided wretches with their Western clothes and English-language banners.

  This was China, after all: for all its faults and problems, founded on a billion souls, five millennia of history; this could never be America.

  And today, it was promised, she would meet the Great Helmsman himself. Her heart thumped as it had not when, during her endless tours, she had shaken the hands of presidents and kings. Perhaps, today, she would at last be released from the burden of her ceremonial duties, and permitted to return to what she loved: to fly, to sample again the light-filled glories of spaceflight.

  With hope and expectation, she walked forward towards the Great Hall of the People. The early morning cold dug through the layers of her light Mao suit, but soon the sun would rise, and pour orange light and warmth into the remote corners of the Square.