Mars Crossing

by Geoffrey A. Landis

  “Nope, nothing wrong if I were,” he agreed. “Happens I’m not.”

  “Oh. That’s okay; I just wanted to know.”

  He waited, saying nothing.

  She rotated herself over until she reoriented so that her head pointed the same way he did. “That’s better. Now I can look at you,” she said. “Say, you’re better in microgravity than any other newbie I’ve seen. You must have been upside before?”

  “Nope,” he said, “first time.” And then, “I think I like it.”

  “I’m impressed. You’re a natural.”

  There was a pause.

  “You did get the orientation, didn’t you?” Britta asked. “You know about our first-night custom here? The welcome-aboard ritual?”

  Ryan considered her. She was cute, in her way. She had a round face, with short dark hair and deep brown eyes; her rather baggy coveralls failed to conceal a body that was compact and fit. He knew about the space station’s rite of jus primae noctis, of course; there was no way to avoid it. The other astronauts—the male ones, anyway—had made sure about that, with a lot of ribald comments and pointed innuendo. But it was not his way of dealing with the people. “Sure.”

  She paused, licked her lips nervously, and looked at him sidelong. She was blushing. “You want to?”

  He looked at her calmly. “Are you asking?”

  She looked away. “I’m not supposed to ask.”

  “Are you?”

  “Well, damn it, yes. Yes.”

  “Well, then,” he said, “sure.”

  It was sweet and complicated, almost like an exercise in momentum management. And it was slow, so slow. Whenever he tried to be hasty, he pushed her away from him, and she would say, “Slow, keep it slow and easy.” Afterward, she clung to him, and in a few moments he realized, somewhat to his amazement, that he wanted to do it again.

  And sometime after that, she kissed him on the nose. As she drew her coveralls back on, she said, “I’m pleased to be able to say that you are now a member of the microgravity society.” Then she smiled, and said, “Very definitely pleased.”

  For the first few weeks Ryan was assigned to momentum management. This meant two things: garbage dump detail, and processing wastewater into fuel for the resistojet thrusters. He used the garbage dump as a chance to experiment with the tether, trying swinging deploys, crack-the-whip deploys, getting a feel for the tether system.

  “You actually like garbage detail, don’t you?” one of the astronauts said, incredulous. “You spend more time working on the garbage drop calculations—everybody else just reads out the computer and plops the answer into the drop parameters.”

  “One day we’re going to use a tether on the way to Mars,” Ryan said. “I’m getting ready.”

  The other astronaut shook his head. “You sure are,” he said. “You sure are.”

  12

  BUTTERFLY IN A HURRICANE

  Mars looked different from above.

  Ryan flew fast and low. He had to stay low, with the Butterfly so overloaded, he had to stay in the densest part of the tenuous atmosphere to fly at all. Still, the view was remarkable. From above, it was clear that they were following the coastline of an ancient sea. To the east, a jumble of mountains and chaos interrupted by ancient riverbeds flowing down to a beach. To the west, a flat and smooth basin, broken by craters.

  Tana pressed against the cockpit window, enrapt. She turned forward to point out something to Estrela, to ask about a massif that loomed on the horizon, and with astonishment saw that Estrela had her eyes closed. She was asleep.

  Asleep, through this greatest airplane trip ever taken!

  As the liquid oxygen burned off, the airplane gradually lightened, and Ryan slowly gained attitude. “No such thing as an airplane that flies itself,” Ryan’s flight instructor had told him, long ago, and on another planet. “You have to be alert every second. The moment you think that the computer is going to do the flying, the moment you think you can relax and stop paying attention, that’s when you’re going to screw up. That’s when pilots die.”

  Butterfly came as close to flying itself as any airplane ever did. Once the take-off had been completed, Ryan could have taken his hands off the controls and let the autopilot take over. They were heading due north.

  The land below had been shaped and reshaped by enormous impact craters and by vast lava flows. As they continued northward, Ryan noticed odd craters with a peculiar, melted look, as if the impacting meteoroid had splashed into thick ice cream.

  The first of the three liquid oxygen tanks was sputtering, nearly empty. Ryan opened the valve to start feeding from the second tank, and felt the engine surge with the increased fuel flow. He diverted boil-off gas through the first tank to blow the last of the oxygen out, and then, satisfied that it was completely dry, jettisoned it. Freed of the weight and drag of the extra tank, Butterfly jumped upward.

  Two tanks left.

  Farther north he started to see white, at first just a narrow rim of shiny frost on the north-facing side of the crater rings, and then more and more frost, patterns of white in spiderweb traceries across the hills, limning the slightest changes in topography.

  He was approaching the polar circle.

  Ryan looked up. Ahead of him, the sky had lost its pale ochre color. It was an ominous deep brick red, with knots and swirls of darker color. He cursed under his breath and checked the altimeter. Eleven hundred meters above ground level. He pulled back slightly, trading speed for rate of climb, but it looked like there was no way he could gain enough altitude to climb over the storm.

  He could see something moving below. Snakes.

  He looked again. Under him, ribbons of white slithered snakelike across the landscape. It was rivers of blowing snow, he realized, following the sinuous path of least resistance across the lowest passes between the hills. The wind velocity at the surface must be horrendous, he thought; it would take fifty meters per second, or even more, for air as thin as the Martian atmosphere to pick up and carry snow.

  Spring was coming to the Martian pole. The winter snows, a mixture of carbon dioxide and water ice, were evaporating away with the return of the sun. The sheer mass of vaporizing atmosphere was blasting off the part of the snow that was made from water ice and blowing it south, creating little storms at the edge of the polar cap.

  He wouldn’t be able to fight those storms, not directly, but they would be local, not global. He banked to the west, turning parallel to the looming banks of cloud, hoping to circle the storm, looking for a gap between the storm cells.

  The land below was tundra now. He was at the arctic circle, and below the fluid rivers of airborne snow, the ground was patchy with ice. The ground was ridged in a network of enormous hexagons and triangles and squares all jumbled and fit together like a crazy jigsaw puzzle, the lunatic work of some mad geometer.

  He checked the level of liquid oxygen in the fuel tanks. The second tank was almost dry. There was no reserve set aside for detours; if he didn’t head back north quickly, they would not have enough range to make the pole.

  He switched the fuel feed to the third and final tank, purged out the last little bit of fluid from the second tank, and jettisoned it. At least the Butterfly would be more responsive.

  There. A pale color of sky, a wide canyon of clear air between the polar storms.

  “Hold on,” he said. “The ride is going to get humpy.” He banked to the right, following the edge of the storm north.

  The polar cap revealed itself as a series of ice cliffs, each one rising above the last, the ice glistening blue. Fast the ice cliffs, the polar cap itself was smoking, the ice boiling away in the summer sun.

  And then, suddenly, the ice below him dropped away. He was above an immense ice canyon. A hurricane wind drove down the canyon, a torrent of wind sweeping the airplane helplessly to the west. The wind from the entire evaporating polar cap was funneled into this channel, etching away the ice.

  This was the immense Chasma
Borealis. Over the eons, the swirling wind had carved away a kilometer’s thickness of ice, making a channel for the outflow of the evaporating atmosphere. The bottom of the chasm below him was jumble of dark rock, glacial moraine. He crabbed crosswind across the canyon, onward. To the left, an immense wall of blue ice rose a kilometer up from the jumbled rock of the base to the top.

  He barely cleared the top, and abruptly it was calm.

  At the top of the cliff was a rippled plain of snow-covered ice, stretching to the horizon. The pole, according to the inertial navigation system, was three hundred kilometers away.

  It might have been a thousand.

  Butterfly was out of fuel.

  Ryan made another fifty kilometers before the rocket died completely. Engine out, in the thin atmosphere Butterfly could glide about as well as a brick. He stretched the glide as far as he could, eking out a few precious kilometers, and then flared it in to the lightest touchdown he could. It skidded across the snow like a sled, and Ryan struggled to hold the wings level as it fishtailed down the snow. It sledded, bumping against the irregular ice, and sledded—Ryan was beginning to wonder if it was ever going to stop. Until suddenly there was a boulder in the middle of the ice field.

  There was no way to steer the aircraft. Ryan pulled back hard, but the airspeed was too low to hop the boulder. The rock ripped across the bottom of the fuselage. He did his best to keep the wings level, but the airplane slewed around and the right wing scraped on the ground. With a spray of snow, the wing buckled, and the ripped wing spar suddenly lost pressure. The wing bent back and tore off. The airplane rolled up, cartwheeled, and came apart.

  13

  NORTH

  Tana’s seat had come to rest upside down, completely detached from the fuselage, but remarkably intact otherwise. She unbuckled her harness and pushed the seat away. Debris from the airplane was scattered for a hundred meters down the ice. Estrela had been thrown clear and landed spreadeagled in a drift of snow a few feet away. Ryan, and the front half of the fuselage, protruded from a snowbank.

  She could see Estrela moving, and then standing up. Her body was smoking. She brushed the smoke away, and with relief, Tana realized that it was just dry ice vaporizing away from the heat of her body.

  In another moment, Ryan unfastened his harness and took a few steps onto the ice.

  They were alive.

  Ryan looked across at her. He seemed unhurt. The snow had apparently cushioned the landing.

  She toggled her radio on to the common band. “Ryan, Estrela, are you okay? Any injuries to report?”

  “Think I’m okay,” Ryan said. “Nothing broken, anyway.”

  “Foda-se!” Estrela said. “Yes, I’m okay. I think.”

  Tana wasn’t sure what she could have done if they had reported injuries anyway. The nearest emergency room was over a hundred million miles away. She looked across the ice. Liquid oxygen tanks, supplies, shards of aluminum-lithium alloy, the burned-out rocket engine, shreds of wing fabric; pieces of the Butterfly were spread on both sides of the skid mark the plane had made sliding along the snow. There was no way it was ever going to fly again. Jesus, that had been the most frightening moment of her life. She was amazed that Ryan had managed to hold it together for so long. “And what now?” she asked.

  The question hung in the air for a moment, and then Ryan answered. “What choices do we have?”

  A tremor shook the ice, and a moment later a sharp report. “What in the world—”

  Tana pointed wordlessly.

  A few hundred meters to the east, a geyser had sprung up from the snow, a brilliant white plume shooting a hundred meters into the air. Fragments of ice pattered down on the snow all around them. The ground below the geyser split open, and the glittering plume spread out, at first slowly, and then with increasing speed along the crack in both directions until it was a wall of glistening spray that raced toward the horizon in both directions.

  Ryan reached down and touched the ground tentatively. The polar cap surface was dust mixed with ice, a rough, crusty surface. He tapped it gingerly. It seemed solid. “Ice,” he said. He rapped on it solidly and looked up at them. “The crust is ordinary water ice. But below the crust, it must be carbon dioxide—dry ice. It’s slowly sublimating away in the heat. When it gets trapped—wham. It all blows out at once.”

  Already the sudden geyser was beginning to die away. In a few minutes, all that was left of it was a patch of broken snow.

  “For certain we can’t stay here,” Ryan said. “We head north.”

  “On foot?” Tana asked. Nobody said anything; the answer was obvious. “How far?”

  “About two hundred and fifty kilometers,” Ryan said.

  “You’ve got to be kidding.”

  It took Tana ten minutes of searching to find the inertial navigation system. The laser gyros had no moving parts; it was a design that had been built to locate airplane crash sites on Earth. She checked it. “Still working. We ought to write the manufacturer.” It had been designed to be tough.

  Ryan was ripping parts of skin off the Butterfly and examining their flexibility, but they didn’t seem to meet his needs. He moved over to salvage struts out of the wreckage of the seats, apparently a bit more to his liking. He looked up. “Do you know how to ski?”

  “Now you really have to be kidding,” Tana said.

  He held up one of the struts. It was a piece of aluminum-lithium alloy, strong and light. He had been able to flatten it down, and bent a crude curve at one end. He examined it critically, and then started to work on another. “Do you have another idea?”

  Tana shook her head.

  “North,” Ryan said.

  14

  TO THE FARTHEST NORTH

  The sun was circled by a luminous double halo, with mock suns on either side. It never set, but only circled constantly around them, dipping down almost to the horizon in front of them and then rising up at their backs.

  The ground was a jumbled chaos of pressure ridges and fragmented ice-blocks half buried in snow. In regions the ground was solid ice, crisscrossed with cracks that hissed out jets of snow-laden vapor, and in other regions gleaming new snow lay flat and smooth and inviting. Ryan cheerfully steered into the middle of one of these, and as his makeshift skis touched the snow, it hissed and foamed around him. All friction vanished, and he skidded helplessly away on a cushion of foaming carbon dioxide vapor.

  It took him an hour to painstakingly make his way out of the trap, warming each step down until he reached solid footing. After that, they learned to avoid the areas of new snow.

  After six hours of skiing, Ryan called for a halt. They pulled off their skis and inflated the emergency habitat.

  The emergency habitat was a cylinder, two meters long and a meter and a half in diameter, with translucent walls made of polyimide impregnated with netting of ripstop superfiber. An even, pinkish-orange light filtered through the habitat walls, making the inside look like the interior of a furnace. But the inside was cold. The only heat came from the radiators of the isotope power units on the Mars suits. It was so tightly crowded inside that it was hard for them to take their suits off; it had been designed to keep one person alive while waiting for rescue. But nobody was coming to rescue them. They silently stripped down to just the suit liners and piled together in the middle for warmth.

  It was nearly impossible to sleep, and they huddled together, too tired to move, too tired to complain. With the continuous sunlight, there was no sense of time. After six hours, without any discussion, they put their suits on.

  When they got outside, they saw that the waste heat from the sausage habitat had sublimed the ice away from under it, and the sausage had settled into a hollow half a meter deep.

  They continued north.

  For the first three days, snow geysers burst forth unexpectedly all around them, and they constantly worried that at any moment one might open beneath them. As they worked farther north, the snow geysers got smaller and less frequent
, until they stopped being a threat.

  In some places, the ice was just a thin crust suspended above a layer of gas below. The first footstep to touch it would trigger a collapse, and with a rattling crunch, an area as large as a soccer field would suddenly fragment and fall a distance of two or three centimeters.

  They would walk on the rough ice, and ski across the snow, until Ryan called a break. He inflated the sausage, and they crawled into the cold, stinking interior. It was a relief to take the suits off, even briefly. After a month of nearly continuous wear, every wrinkle and irregularity of the suits was rubbing their skin raw.

  But in the constant light, none of them could really sleep. They took to resting only for three-hour naps, huddling in a semiconscious stupor that was neither sleep nor wakefulness, until Ryan told them it was time for them to put on their suits and push onward.

  They came to cliffs of ice and laboriously hacked steps into the ice to climb. The route was upward, ever upward. Twice they came to immense crevasses, hundreds of meters wide, crossing their path. The depths were misty with a white fog, fading into darkness as far down as they could look. It was impossible to cross them, and so they detoured around, cursing at the delay.

  They continued north.

  15

  ACROSS THE ICE

  Estrela Conselheiro had experienced snow, but never so much of it. In the years she had lived in Cleveland, the winters had been mild, and snow was a rare thing, something that came once or twice a winter, melting in a day or so. Some of the older people in the city told stories of how in the last century it had been different, how the winters had been cold, and snow a meter deep, but no one really remembered.

  Now she was surrounded by it.

  In places the wind had sculpted the snow up in ridges like frozen waves. Other places the ice was swept clear of snow and glowed almost blue in the pale sunlight.