Mars Crossing

by Geoffrey Landis

  Their satellite flew as a secondary payload on a Delta rocket, hitchhiking its way into space with a free ride on the third stage of a rocket whose main mission was to put a communications satellite into geosynchronous orbit. The entire gang went to Florida for the launch, crammed into a battered Volvo station wagon. They stayed, eight of them in one room, at a cheap hotel on Cocoa Beach. It was the first time Ryan had ever been so far south.

  The launch was on a cold and cloudy day. The wind was so high that they had been certain that the launch would be canceled, but they went out to the public beach with their binoculars, their cameras, and a small battery-powdered radio. The tide line was covered with seaweed and the drying corpses of Portuguese men-of-war, improbably bright blue balloons slowly deflating in the air.

  The Delta had launched on the exact second the launch window opened. It climbed silently into the air, the light of the solid rocket boosters sparkling a trail across the choppy water, almost too bright to look directly at, and then vanished into the clouds. For a few seconds the cloud glowed with the light of the booster, and then it faded, and there was nothing left but the empty pad and the white smoke.

  Only then did the sound come rolling across the water, a roar so intense that you could feel it as well as hear it. And then that, too, faded into the distance, and there was only the surf and the seagulls.

  Not one of the Minions was old enough to drink, so when the announcement came that the launch had been a success, they celebrated by pouring grape juice over each other.

  The satellite—and more particularly Ryan's control systems—worked perfectly, taking photographs of the polar aurorae for over a year.

  Ryan spent that year going to classes when he had to, but never far enough away from the satellite control center that he could not be paged to return at an instant's notice.

  The control center consisted of a few computers and a fast Internet connection hooked up in a windowless room in the basement of the wind tunnel building. With the launch, the tight group of the Minions began to drift away to other projects and other concerns. Dave left for a year in Israel, Darlene got involved in a new project in the physics department, Anu quit to start up a software firm and become a millionaire, Steve got married and stopped coming around, and Ted simply declared that he needed to spend time on coursework, and wasn't about to let the satellite run his life.

  There were new undergraduates to help out, bright-eyed and eager, but of the original Minions, only Ryan stayed with the project to the end. Whenever anything went wrong, Ryan was there to debug the problem and design a work-around for it. They found that he had a talent for visualizing orbital mechanics, and an almost mystical understanding of the secret world of torque wheels and magnetic dampers and predictive control systems. He could figure out, from the slightest bump in a chart, which part was failing, how the underperformance was affecting the satellite, and what was needed to write a software patch to keep the satellite running.

  For Ryan, it was not just a student project. It was his life.

  5

  CALLING HOME

  It was a task that Ryan dreaded, but there was no help for it. Agamemnon expedition had left behind a complete set of high-bandwidth communications gear and a gimbaled high-gain antenna. He had to call Earth.

  After inflating the Agamemnon's main operations habitat, it took him an hour to get the communications gear powered up and to reset the computer to calculate the position of the Earth and adjust the antenna to track it. He almost hoped that the antenna would fail to lock on to the Earth; fixing that would give him another few hours to avoid making the connection. But no such luck.

  At least he didn't have to do it alone. He called in Estrela and Tana. "We're all in this together," he said. "Ready?"

  Estrela nodded, tossed her hair, and attempted a wan smile. Tana said, "Ready."

  He flicked on the camera and began transmitting.

  "Earth, Don Ouijote. This is Ryan Martin, Tanisha Jackson, and Estrela Conselheiro, calling in. We've reached the Agamemnon site at Acidalia Planitia." He paused. That was the easy part. "It is with great regret," he said, and then stopped. He didn't even know what to say. He looked over at Tana, but she shook her head infinitesimally and mouthed silently, "you." He turned back to the camera. "I regret to inform you that, uh, we've killed off—I mean, we've had some casualties here. Uh, that is, we. Shit. I hate doing this. Look, it's like this." He took a deep breath, and then said quickly, "We've had a bit of a hard time here, and Captain Radkowski and Bran— Trevor Whitman are dead. Got that?"

  He turned off the camera, and slumped down. "Okay, it's done."

  "We're not done with the broadcast, are we?" Tana said. "We have to tell them more than that. And I thought we were going to ask for advice."

  Ryan shook his head. "No. I mean, yes, no we're not done."

  "Then—"

  "It will be half an hour before we get a reply from Earth," he said. "It'll probably be a while after that before we get anybody who can give us anything we need. Don't worry. We have time." He composed himself, turned the transmitter back on, and then gave them a brief synopsis of how Captain Radkowski and Trevor Whitman had died. He kept it strictly to the facts, with nothing about Trevor Whitman actually being Brandon Weber, nor about their conjecture that Radkowski had been murdered.

  The person who appeared on the monitor looked startled. He looked like he'd just woken up. "Uh, Don Quijote, Houston. We got you." Ryan didn't recognize him; he wasn't one of the regular communicators. "Uh, this is great. Wow, it's really great to hear from you. We were worried—" Just at the moment the news about Radkowski and Trevor must have arrived; the technician looked startled. "Wait one," he said.

  Ryan calculated the time on Earth. 05:45 Greenwich; that would make it 12:45 at night in Toronto, 11:45 at the space center in Houston. Late; they were transmitting to the second shift. No wonder they had to wait, probably had to go wake somebody up.

  It was a slow conversation. Ryan and Tana talked for a while, answering some of the questions from Earth and ignoring others. Then they would break and listen to the feed from Earth, replies to their queries of half an hour ago.

  First, they learned there was still no hope of a rescue mission. Ryan had never expected one; he'd asked just out of a perverse sense that he had to check the obvious. Second, they were told that the engineers on Earth had not come up with any unexpected new ideas, although not for lack of trying. Their only chance was still the Brazilian Jesus do Sul return rocket, at the pole. There were now hundreds of news reporters asking for interviews; Houston was holding them off, but did they want to talk to reporters? When their "no" answer came through, nobody seemed surprised.

  "Copy that," was the reply. "One more thing for you. Hold on a moment. I think you may want to hear this directly from our orbital mechanics guy."

  The orbital mechanics guy, as it turned out, was a middle-aged woman. Ryan recognized her; what was her name, Lorentz? She had a reputation for being both hard-working and smart. She spoke in a Texas accent, launching in without bothering to say hello first. "We tracked down the complete specs on that Brazilian rocket, checked it out against a matrix of trajectories available for your launch window. Here's the lowdown. Stripped to the bone, no rock samples, dump all the spare supplies, no margin for underperformance: You'll have fuel for one hundred and forty kilograms of human payload. That's top; you'd be wise to leave a little margin."

  "Copy," Ryan said. "What if we—" Then he stopped. If they what?

  What could they think of that the ground engineers hadn't already thought of? If she said one hundred and forty kilograms, that was the end of it.

  One hundred and forty kilograms.

  Now they knew.

  Only two of them were going back.

  6

  RYAN IN LOVE

  In his own little social world, Ryan was boisterous, talkative, and outgoing. Outside of the nearly vanished circle of the Minions, though, the guidance counselors la
beled him withdrawn and introverted. He hadn't paid any attention to the tall, talkative girl who chanced to sit near him in the cafeteria whenever he came down for a meal, not even when she began to talk to him, and slowly but patiently drew him out. It didn't occur to him that she might be interested in more than a lunchtime companionship until she invited him to her dorm room, closed the door, put a Nirvana CD to play on her stereo, and started to take off his clothes. "It was the only way I could get your attention," she told him.

  Kaitlyn was, he discovered, the smartest person he had ever met, and he was eternally baffled by what it was she saw in him. Sex, to her, was playful. They would take her Toyota Corolla on long weekends up to Maine, and they would take an old logging road far into the woods and camp, making love far into the night. "Let's try something new," was her catch-all phrase. Or they would tryst on one of the rooftops of the Institute, the altitude and the fear of somebody coming across them adding to the thrill of sex.

  One summer they spent in urban spelunking. She showed up in his dorm room one day with two flashlights and a crowbar. The game was, find a manhole and see what was underneath it. Sometimes it was nothing. Sometimes it led to tunnels and pipes that seemed to go everywhere in Cambridge. "Hmm, guess you're not claustrophobic," Kaitlyn had said the first time he got stuck and had to wait in the dark while she went to fetch a block and tackle to pull him out. "You should be an astronaut."

  She was the first girl he ever fell in love with. A week after they both graduated—he in computer science, she in mathematics—Kaitlyn asked him to marry her. He hadn't even told his parents yet—he was going to spring it on them when he went back home for the American Thanksgiving holiday when a pickup truck sideswiped her going around a curve, and her Corolla fishtailed and hit a lamppost.

  It was hard for him to believe that she was really dead. For years afterward he would wake up with some thought in his head, and think, I'll have to remember that to tell Kaitlyn.

  It took him a long time to get over her. He moved back to Toronto and got a job working on software for an aerospace company. Eventually a quiet, patient girl named Sarah, who he kept running into at work, broke through his reserve and attracted his attention. She worked as a temp, adept at filling in at secretarial jobs when the company was shorthanded, but her real avocation was viola, which she played in a chamber orchestra in Toronto.

  He had never heard a chamber music concert, he finally had to admit to her. He wasn't really quite sure what kind of music it was. "Well, I guess I'll just have to show you," she told him.

  And from then, his weekends were filled with music. Sarah was both patient and had a sense of humor; her musical tastes ran from Beethoven to Weird Al, and she was fond of pointing out little things to him. "Listen there. That's a cowbell," she might say, or, "See what you think of this, it's written for glass harmonica. You play it by rubbing your finger on wine glasses."

  He got accustomed to her company, and when she went out of town for a performance, he missed her, and hung around his apartment, not knowing what to do with himself.

  They were tentatively beginning to talk about making a commitment for life. The only thing was that Sarah was always so tired. She barely had the energy to go to her concerts. She looked pale.

  She hadn't always been so tired. When she first started to chat to Ryan over lunchtime, over breaks at work, she had been full of energy. "She's a real 240-volt live wire," was how the other engineer in his office described her. Now she could barely make it from breakfast to lunch.

  Ryan took her to a doctor.

  The doctor ordered tests. When the tests came back, he wouldn't talk about them, but ordered more tests, and a CAT scan. When the new tests were completed, a new doctor came to talk about them, a specialist.

  It was cancer: in her liver and her pancreas, and beginning to spread. The cancer was aggressive and inoperable. The day before Easter, he brought a minister and a wedding license to the hospital, and they were married. Three days later she was dead.

  Twice was enough. He went back to school for three more degrees, one in astronautical engineering and two in computer science, and decided that from then on he would stick to his studies, and would never curse another woman by becoming too close to her.

  7

  BUTTERFLY

  Butterfly didn't look like anything, least of all like an airplane. It was a pile of thin, transparent foil.

  The Martian atmosphere is more than a hundred times thinner than the Earth's atmosphere. Even with the low gravity of Mars, flying in the thin air of Mars is a challenge. To fly, an airplane has to have forty times more wing area than an airplane on Earth, or else fly six times faster. Or else weigh forty times less.

  Butterfly did a little of each. Its wing area was absurdly high, by the standards of Earthly airplanes, and it flew at nearly sonic speed; yet despite its high speed and large wing area, it weighed almost nothing. It was constructed out of a monomolecular membrane, a tough plastic sheet so thin as to be almost invisible. The main spars of the wings were pressurized bags, balloon-stiffness providing the rigidity. The fuselage likewise was stiffened by inflation. Ultralight foam ribs formed the wings into a high-lift airfoil.

  "Do you know why they named it Butterfly?" Ryan asked.

  "Because it's so light and fragile," Tana said. "Like a butterfly."

  Ryan smiled. "Nope. Got named when the lead engineer took one look at it, shook his head, and said, 'Well, it butter fly.' "

  The only item of any real weight was the engine.

  A propeller was almost useless; the tenuous air of Mars is too thin to give a propeller much to grab. A jet engine is pointless; how can you burn carbon dioxide? Instead, Butterfly used a ram-augmented hybrid rocket engine. A feed stream of liquid oxygen was injected into a cylinder of dense rubber and ignited; the burning rubber forms a rocket engine. Rather than just shooting the exhaust product out through a conventional rocket nozzle, additional atmospheric carbon dioxide is collected—the ram part of "ram augmentation"—and mixed into the exhaust stream to augment the thrust.

  The result was a high-power engine that used the thin atmosphere of Mars to increase its thrust.

  This was the vehicle that Ryan Martin examined. His first task was to inflate its wing spars and fuselage with compressed gas; after that he had to fill the engine's tanks with liquid oxygen. This second task was a tricky problem. The Butterfly had been designed to use oxygen produced from the Mars atmosphere by the same chemical plant that manufactured rocket fuel for the return vehicle. But the fuel manufacturing plant for the Agamemnon expedition was identical to the one that had failed Dulcinea.

  But Butterfly was an airplane, not a rocket. It required less than a tenth of a percent as much liquid oxygen as was needed to launch the return rocket. Consultation with the experts on Earth concurred on the opinion that, for the tiny amount of liquid oxygen needed, Ryan could bypass the main atmosphere compression and Sabatier reactor and just use the electrolysis system and the Stirling liquefier. Taking precautions to avoid stressing the seals that has failed so catastrophically on Dulcinea, he should be able to fill the tanks in a few weeks of operation using only solar power. No more than a few months even under worst-case conditions.

  And so, drop by drop, Ryan fueled his airplane.

  8

  ON ANCIENT SHORES

  They were camped at the shore of what had, long ago, been an ocean. How many fossils were there in that ancient dry ocean bed, Estrela wondered? How far had life come? Had life on Mars emerged from its oceans, only to become extinct as the rivers dried and the planet froze? And what, exactly, had caused the oceans to evaporate and the atmosphere to leak away?

  Estrela was beginning, slowly, to come out of the deep depression that had enveloped her over the last weeks. Eight days at the Agamemnon campsite had revived her. For the first three days she had stayed inside the habitat dome, and then she took to leaving the habitat dome for just one hour each day.

  First she would
walk over to the greenhouse module. She was amazed that it had survived, untended, for years on the Martian surface, and even had plants inside, some sort of tough yucca and several evergreen shrubs. She rubbed her hand over them, feeling the prickly points. You are like me, she told them silently. We are survivors.

  Then she would go to walk along the deserted beach just before sunset.

  The water of the ancient ocean was long gone; the sands of the beach had long ago cemented into a rocklike caliche. She could read the ebb and flow of the waves in the ripples frozen into the sandstone. She would find a shallow basin and brush away the covering dust, and find below the white layer of evaporite, salt crystals.

  One time, walking a little inland, she found yet another fossil, embedded in the wall of a limestone cliff. It was exactly the same shape as the others, but this one was immense, as large as a whale, ten meters from end to end. Estrela wondered that these were the only type of fossils that they saw. Had there been only one form of life on Mars? Or perhaps only one type had fossilized.

  And the sun would set, and she would return into the habitat.

  Inside the dome was paradise, with plentiful liquids and warmth, with enough water to heat an entire liter of bathwater at once and let it dribble, sensuously, over her body. It felt like a decadent luxury.

  Her throat no longer hurt so much. She could even speak, in a voice louder than a whisper.

  She carefully plaited her now-blond hair, and barely wore clothing. Ryan was the one who would make the decision now, she knew. Two women, and he would be able to take only one home.