Mars Crossing

by Geoffrey Landis

  In the seven months it took to fly to Mars, there was plenty of make-work, but little in the way of actual useful tasks to do. They had measured cosmic-ray exposure, made measurements of the solar wind, and used the long baseline of the Quijote from the Earth to make precise timing measurements of gamma-ray bursters. But these experiments could be done just as well from an unmanned probe; their main justification had been to give the crew something to do.

  By the time the Quijote had been in space for a month, the crew's unofficial motto had been, "Mommy! Are we there yet?"

  A month before the landing, when Mars was little more than a small yellow smudge on the velvet sky, Ryan Martin had complained, "I'm going out of my mind. I don't care what happens on Mars, just so long as it's not fucking boring."

  "And I don't care if I never see the inside of this damn cabin again," Trevor Whitman added.

  As circumstances would have it, they both had their wishes granted.

  11

  DULCINEA DOWN

  As the systems engineer, the task of checking out Dulcinea and certifying her ready for launch was Ryan Martin's responsibility. Chamlong Limpigomolchai, the Thai geologist, had cross-trained on the propellant manufacturing plant, and probably was more familiar with its workings than Ryan was. He was Ryan's assistant and backup on the EVA.

  EVA—what an awkward term. Extravehicular activity. They had agreed before the mission that they would root out and destroy all of the confusing acronyms that space missions were prone to use, but somehow the use of the term "EVA" for any venture through the airlock of the Quijote's cabin had slipped out of their net. They needed a new word. Marswalk, maybe.

  Okay. He walked over and touched Cham on the shoulder. "Ready for a Marswalk over to the Dulcinea?" he asked.

  "I'm go," Chamlong said.

  "Then let's suit up."

  Ryan's suit was a light blue and sported a Canadian maple leaf painted on the chest. Each suit was color coded, to avoid possible confusion as to which astronaut was out on the surface at any given time. Chamlong's was the one with yellow-and-black stripes, and had the icon of an elephant neatly painted on the front.

  The Martian EVA suits—Marswalking suits—were a marvel of engineering. They had a hard shell for the torso with armadillo joints at the abdomen, shoulders, and crotch. The chest carapace was made from a lightweight composite, coated on the outside with an inch of foam thermal insulation. The sleeves, gloves, and leggings were piezoelectric fabric, as light and flexible as ordinary cloth, but woven out of a fiber that contracted with an electrical signal to a perfectly contoured pressure fit around the limbs. It was a compromise design: The chest carapace allowed easy breathing, and the contractile fiber allowed free arm and leg motion. The only bad part was that you couldn't scratch your nose. It seemed to Ryan that his nose always started to itch just the instant he put the bubble helmet over his shoulders. He had discovered that if he twisted his head to the side and stretched his neck, he could rub his nose against the radio speaker mounted just above his shoulders.

  Each suit had a thermophotovoltaic isotope generator mounted in the middle of the back, which provided electrical power for the oxygen production machinery. Heat from the radioactive isotope's decay was pumped through capillary-sized tubes in an undergarment to keep the chest and abdomen warm; the arms and legs were electrically heated to keep the astronauts from frostbite in the subzero Mars temperatures.

  The tough silicon-carbide bubble helmets absorbed ultraviolet and had a visor like a baseball cap that could be turned to keep the sun-glare out of your eyes, as well as a second dark visor that could be pulled down like sunglasses.

  All in all, they were practical suits, providing a self-contained Earthlike environment for traveling on Mars. On longer Marswalks, like all space suits, the suits would collect feces and urine for recycling. Ryan had long ago learned that when an astronaut stops in the middle of a task with an abstracted look on his face, it is proper to look the other direction and not bother them for a moment.

  Once they had suited up, checked each other's suits, and descended to the surface, it was only a short trek over to the Dulcinea. The upper stage and the four huge booster tanks sat on the sand like a slightly battered beer can surrounded by ostrich eggs. The whole assembly rested on four mantis legs.

  Ryan circled her, doing an external inspection. Both of the oxygen tanks were venting a thin, wispy trail of white vapor. That was okay: it indicated that the tanks were full. The zinc white of the thermal paint on the booster tanks was shaded lightly pink at the bottom with dust; that was expected, though, and the thermal modeling allowed for it. Other than that, there was no external damage visible.

  "So far she looks okay," he said slowly. There still seemed something just a little bit odd about the condition of the ship, as if there was something he should have been seeing but wasn't, but he couldn't put a finger on what it might be. "Anything look out of place to you?"

  "Negative here," Cham replied.

  "Pretty good condition for an old lady who's been sitting out in the cold for six and a half years," he concluded. Maybe that was all it was; he had expected the ship to look more worn, dirty, and wind-battered from half a decade of exposure on the surface.

  Between the number two and number three booster tanks was an access ladder that led to a small circular hatch. He climbed up while Chamlong waited on the sand below. The hatch release rotated freely, and he unsealed the hatch and wriggled through the opening, which was just barely big enough to take a Mars suit. An awkward design, but for the return ship every kilogram counted, and there was no need for a hatch that would allow a more dignified entrance. Inside, he flipped the circuit breakers on, and lights illuminated the cabin.

  It was a near duplicate of the cabin on Quijote, except for the presence of an additional set of indicator panels for the chemical machinery that had manufactured the fuel. The computer system was already running. He powered up the CRT to read out the internal displays, and while it was coming to life, looked over the mechanical gauges.

  They had checked the fuel a hundred times by radio link, both before launch from Earth and during flight. But from the gauges inside the cabin, the indicators didn't make any sense. What they showed should have been impossible. The computer came up, and he turned his attention to it. It didn't make any sense, either.

  Chamlong poked through the hatch and took a look at him. "What is it?"

  "Wait one," he said. He sat down at the system engineer's station, staring at the readings but not really seeing them. What was different?

  Dulcinea had been designed to sit on Mars for two years, making propellant for the return mission. It had instead been sitting on Mars for nearly seven, waiting for her crew. But it still had propellant; the almost invisible plume of white vapor from the tanks proved that. So why were the sensors wrong? The mechanical gauges for the two oxygen tanks read zero; the two pressure gauges read screwy—one tank impossibly high, two other tanks way too low.

  Ice, he thought. Mars is cold and dry, and the Martian atmosphere contains very little water vapor. But over the course of seven years, the tiny hit of humidity the air did hold would condense onto the cryogenic lines and freeze. Some ice could be clogging the sensors. That shouldn't be a failure mode, but building up over seven years? He called up a schematic for the mechanical gauge and studied it.

  Maybe. He showed the drawing to Chamlong. "Right there," he said. "The heat exchanger pipe for the intake manifold. Suppose it built up a layer of ice?"

  "You think that could really happen?"

  Ryan shrugged. "Got any other ideas?"

  Chamlong looked at the drawing. His doctorate was in planetary science, but he also had a mechanical engineering degree and a good understanding of the mechanism. "If I were to go down and tap on the manifold, if there's ice on it, it might break it free."

  Ryan was dubious. "I suppose it's possible. Might adhere too tightly, though."

  "I'll try it." Chamlong stood
up. "If I knock some of the ice free, the reading will change, and at least then we'll know what the problem is. If not—well, if not, we'll have to think of something else."

  Ryan nodded. "Okay, sounds good. At least it's a plan, anyway."

  He would remember that phrase, later. "Sounds good."

  Ryan toggled over to an exterior camera—still working line, after sitting useless for almost seven years—and watched Chamlong bend over and select a rough volcanic stone about the size of a brick. He picked it up, walked to the first of the booster tanks, and then moved around behind the tank to where the heat exchanger was.

  "It's hard to get in close enough to see very much, but I think I see some ice," Cham's voice said over the radio link. "You ready in there?"

  "I've got my eye on the gauge."

  Steadying himself with one hand against the tank, Chamlong gave it a light tap with the rock.

  The gauge hadn't moved. "Nothing," he reported.

  "Okay. I'm going to try a little harder."

  Chamlong drew back the rock and gave the side of the aluminum manifold a solid thump. A snowstorm of white burst out of the interior, settled on the ground, and then quickly evaporated in the dry air.

  The gauge jumped, overshot, and settled down. 22.8 tons. Perfect!

  "You did it," Ryan said.

  "All right! Okay, let's try the other one." Chamlong went to the second tank.

  There was a thump, and ice broke free. The needle jumped and pinned itself against the high end of the gauge. A moment later there was a shuddering that he could feel from inside the spacecraft, and then Ryan heard Cham saying "Oh, shit!" over the radio. He looked at the view from the external camera but could see nothing—the entire outside view was blanked out in billowing white. Red warning lights started to come on in the cabin— overpressure, flow-rate monitor, temperature alert.

  "Shit!" he said. "Cham! Are you all right?" There was no answer. He jumped out of the chair and out the hatch. He ignored the ladder and jumped down into the sand, raising a plume of dust that momentarily obscured his vision. "Chamlong! Report!"

  Through the haze of cloud and dust, a torrent of liquid oxygen was jetting out of a broken pipe. It was insanely beautiful, a foaming fountain that glistened in the most delicate shade of pale blue. The pipe was waving back and forth, spraying the precious liquid over the spacecraft, and he could see the panels bowing as they encountered the sudden shock of liquid oxygen at a temperature of a hundred and eighty degrees below zero. He heard a bang—it must have been incredibly loud to be audible in the near vacuum of the Martian ambient—and on the other side of the ship, he could see that the second oxygen feed pipe had also burst. Both tanks were venting now, liquid oxygen foaming and bubbling like a torrent of blue champagne flowing across the sand, freezing and boiling at the same time.

  There had been ice in the valves, oh yes. But the ice had masked a worse problem.

  "Chamlong!" Ryan waded into the cloud of mist, and the faceplate of his helmet frosted over instantly. Blinded, he hit his emergency locator beacon and staggered back. "Chamlong, where are you!" He fumbled with his suit controls, overriding all of the thermal regulation to push the heat up to maximum, and then he waded back into the mist. Flakes of white, flush-frozen liquid oxygen, swirled around him, sparkling like fireflies in the sun. The yellow-and-black striped spacesuit had been deliberately designed to be easy to spot. It couldn't possibly be hard to find him.

  It was already far too late.

  12

  AFRICAN INTERLUDE

  John Radkowski's personal trainer, a woman named Alicia, loped beside him at an effortless jog as he sweated and clumped. She made it look so easy, but then, he figured that this was her job. "Concentrate on your breathing," she said. "Let your arms swing freely. Deep breaths. In, out. Loosen up. That's better."

  The dusty grass felt like rubber under his feet. It always did.

  Alicia never sweated, never even breathed hard. She was running backward in front of him now, doing stretching exercises with her arms as she ran, and having no difficulty keeping the pace. Her breasts bobbed tantalizingly, the two breasts out of phase, but he figured that keeping him excited was part of her job as well. It was probably why she was running backward like that in front of him. If he didn't like it, there were plenty of other trainers he could have chosen.

  "Looks like you're about warmed up," she said. "Ready to do some running?"

  "Ready," he said. Actually, he felt fat, clumsy, and out of breath, but there was little point in saying that.

  "Great. Here's the trail. See you after your run."

  "Sure thing, beautiful."

  Alicia curved around and headed back, and he went on into the savanna.

  It was low grass, yellow in the sunlight. In the distance a huge, solitary acacia tree stretched fractal fingers into the sky. He could see a series of gentle uphills terraced ahead of him. Not too bad. The African sun was bright but gave no warmth on his body, and the air was breezeless. He looked around and behind him.

  Emerging out of the forest from a break just a few feet away from the spot he had started from, the lioness stretched, yawned, and then stretched again. The yawn revealed enormous teeth. She roared, a deep rumbling cough that tingled deep in his belly. Then she looked up, eyeing him speculatively, and began to pad after him.

  The appearance of the lioness sent a thrill of adrenaline through him that nearly erased his tiredness. There was, of course, nowhere to hide. The hills ahead of him looked impossibly far away. It would be an endurance contest. He wouldn't want to sprint too early. He kept up his pace, remembering to breath regularly. Uphill, slightly, but there was a level spot at the top of the rise.

  Behind him, the lioness started into an easy lope. Her eyes glowed yellow-gold with an interior light. She wasn't sweating, either.

  No point in looking behind him. He concentrated on his breathing, on his rhythm, on staying loose. He felt good.

  On the patch of level ground the lioness broke into a run, and he picked up his pace to keep her from gaining too much. He could hear her footsteps, hear her beginning to pant from exertion. This was what running was for, he thought. Man against beast, the original, pure competition. Uphill again, now, and the lioness behind him slowed to a walk. He couldn't maintain the pace, either, and slowed down as well. Then another stretch of level ground, and they both began to run.

  Then the lioness roared, and he knew that the final lap was on him. Sprint like nothing you've ever done, or you'll be caught. He pushed himself, trying for new records. A minute of this, two, and he thought he was going to burst. Surely he couldn't take any more. A hundred more feet. Fifty.

  A distant bell rang in his ears, and he slowed down to a stop. Behind him, the lioness slowed as well. When he looked back, Alicia had come up beside him.

  "Don't stop, you need a cool-down. Keep moving, keep moving."

  "Right."

  "That's better," she said. "Pretty good time. You sustained an average of 320 watts for almost ten minutes there. Watch your form on the sprints, you're going to turn an ankle if you're sloppy."

  "Got it," he said. "Turn an ankle. Bad."

  "Okay, then," she said. "Good workout. See you in two days?"

  He doubted he would see her in two days—now that they were on Mars, he would probably be too busy to keep up his exercise routine—but there was no point in saying that, either. "It's a date, beautiful."

  He raised his hands to his head. He couldn't see anything—it looked for all the world as though he was in Africa—but he could feel the helmet, and grabbed it and pulled it up. Africa shrank to two dimensions and pulled away.

  He put the virtual reality helmet back on its stand by the treadmill, grabbed for his water bottle and took a long pull, then pulled back the curtain on the exercise booth. The exorcise sessions were tiring, but he always felt refreshed and fully energized after. He wished that Don Quijote had a better exercise facility, one with a full sensory reality. In Hous
ton, he would have been able to smell the lion, would have felt a breeze, and the texture of the ground under his feet would have varied as the terrain changed. He would have been able to climb the rocks, swing from trees.

  More than that, though, he wished he could shower after exercising, but in the cramped cabin of Don Quijote that was clearly impossible, and, as always, a sponge bath was the best he could do.

  With Ryan and Chamlong out checking the Dulcinea, and Tana and Estrela out on EVA samples, the cabin seemed almost spacious. Trevor should have been monitoring the radio, but as Radkowski grabbed his sponge, he saw with some disgust that Trevor's eyes were masked and his attention distant, involved with some sort of simulation or video game. So nobody was paying attention to Ryan and Chamlong checking out the Dulcinea.

  Well, if there had been a problem, Ryan or Tana would have contacted him by an emergency page, which would get to him wherever he was. Still, it was a breach of discipline.

  While he started his sponge bath, he reached toward the radio to listen to what the rest of the crew was doing. And, as if in response—he hadn't even yet turned on the radio—the emergency page lit up. Somebody had hit the panic button.

  He hoped that it was nothing, but John Radkowski's instinct for trouble was already giving him warning signals. He had the sudden sinking feeling that they were in deep trouble.

  13

  CHAMLONG

  When Chamlong Limpigomolchai had been a small child, perhaps five or six, his parents took him to a temple. The golden Buddha had seemed uninteresting to him, but he vividly remembered the Nagas, the huge, brightly painted, seven-headed serpentine monsters who guarded the stairs. After the temple, his mother had taken him to have his fortune told. The fortune-telling woman had seemed more like a clerk than a wizard; she had taken his mother's money, barely glancing at the number written on the lucky stick he had shaken from the fortune tube, and pulled a sheet of tightly rolled paper out of a pigeonhole and handed it to her without a word of comment.