Mars Crossing

1 Ares Vallis

It gave him a sense of déjà vu.

Ryan had been here before. When could he have been here? Never; it was impossible. But yet he felt that the territory was familiar.

They had crossed an area of low hills, and then for two days they had walked through a region of immense buttes, imposing flat-topped mesas that loomed hundreds of meters above them. Ryan felt the pressure of the landscape, felt that they were as small as ants moving across an inhumanly large landscape.

Now they had left the mesa territory behind. The land was furrowed. Low, rolling ridges ran parallel to their direction of travel, with half-buried boulders tumbled in clusters around. It was a flood plain, Ryan realized. An ancient deluge had carved these grooves and moved these boulders. In his memory this rang a distant bell, but he couldn’t quite bring it to mind.

A low, lone mountain—a volcano, perhaps—rose up out of the plain, and it too looked weirdly familiar. As they moved across the land, and moved into a new perspective, he saw that it was doubled, like the twin humps of a Bactrian camel, and that didn’t surprise him. Of course it was a double peak.

Because now he remembered where they were. He’d been here hundreds of times in virtual reality, learning about Mars geology. Suddenly it all came back to him in vivid detail: the Twin Peaks, the oddly named rocks: Yogi, Flat-top, Barnacle Bill, Moe. As a kid, he’d spent whole days downloading the pictures of this place from the Internet; it was when he’d first become interested in Mars. More than anything else, this place was the whole reason he was here. It was the landscape of his dreams.

It was the Pathfinder site.

They were crossing Ares Vallis. Yes, of course, to get from Coprates Chasma to Acidalia they had to cross Ares Vallis, they had no choice. But of all the spots to cross it, right here! “But this is history,” he whispered. “We’re walking on history.”

“Say again?” Tana’s voice said.

Instead of answering, Ryan started to walk faster. It had to be right here, just ahead of them. He started to jog, barely even noticing the boulders he had to detour around. Right, exactly here. They couldn’t be far away from the actual landing site; it couldn’t be more than a hundred meters.

Right here!

He stopped abruptly.

Where?

The ridged terrain spread out in all directions. He could tell from the perspective of the mountain that they had to be at the right place. All the rocks looked familiar, but every time he looked closer at any one of them, it turned to be not quite right. It couldn’t be far away, but where, exactly, was it?

“Ryan!” It was Tana, coming up behind him, panting. “Are you all right?”

His legs ached. They had been walking for days, and even the brief exertion of breaking into a jog made him suddenly aware of the ache in his muscles. “This is the Pathfinder site,” he gasped. “Look!”

Tana looked around. “Say, you could be right. It does kind of look like it, doesn’t it? Is that why you were running?”

“It is! Take a look!” He pointed. “There are the Twin Peaks.” He swung around. “That big one over there? That rock is named Couch. Or maybe that one.” He stopped, momentarily unsure. It was easy to get confused. Was either of them really the boulder named Couch? Or was it another one that looked similar?

Tana looked around. “Wow,” she said. “Pretty neat. So, where’s the Pathfinder itself? It wouldn’t have moved, would it? So it must be here.”

“Let’s find it!” Ryan said.

“Wait a second,” Tana said. “You said that we weren’t going to make any stops, we weren’t going to go exploring.”

“It won’t take long,” Ryan said. “We must be standing practically right on top of it. It’s gotta be right around here. It’s got to stick out like a sore thumb in this.”

But it didn’t. After an hour of searching, Ryan finally had to admit that the Pathfinder was invisible. Even the inertial navigation system he had scavenged from the dirt-rover was no help; it told them exactly where on the planet they were, but the navigation system of the ancient spacecraft had only given its position on the planet to within a few kilometers. But they should be able to see it. “We know it’s here,” Ryan said. “So why can’t we find it?”

“Dust,” Tana said. “Think about it. How long ago did that land? Thirty years ago? How many dust storms have there been since then?” She thought for a second. “It’ll be so covered with dust that it will blend right in. Just a funny, lumpy patch of the soil.”

“Dust,” Ryan said, dejected. “You’re right. I didn’t think of that. Shit. We probably walked right past it and couldn’t see it. What now?”

“Onward,” Tana said. She quoted his own words back to him. “No sidetracks, no exploration, no sight-seeing, just speed. Agamemnon, or bust.”

“Agamemnon or bust,” Ryan echoed. “Okay. Let’s get a move on!”

2 The Arrow

Ryan Martin could not even remember a time when he had not wanted to be an astronaut. He could remember being six, and riding on his father’s shoulders. The Canadian night had been cool and clear, and he had leaned back and just gazed at the stars blazing above him, tiny lighthouses on the road to infinity. He could imagine that he was falling upward, endlessly falling among the stars, and thought, there. I’m going out there. He had leaned back, farther and farther on his father’s shoulders, and then let go, to feel himself falling upward.

His father had caught him by the legs before he hit the ground—his father had always had incredible reflexes—and all that he had felt was disappointment.

In the Scouts, he had been on the archery range. He hadn’t cared much about target shooting, and unlike the other boys, he had no secret longing to hunt and kill. But the bow itself seemed to him a thing of perfect beauty, an object that could not have been more elegantly designed. He marveled over its clean and simple design. One day he took his bow, drew it back as far as he could, and aimed it directly upward into the sky.

The arrow flew up, straight and true, and vanished with a whisper into the aching blue above, and he stared after it, his bow arm still extended in the air, mesmerized by the beauty of the flight.

“Martin!” the scoutmaster shouted. “What the hell are you—”

The arrow came down, so fast it was only a streak, and with a soft whickersnack buried itself to the feathers in the Earth.

The scoutmaster turned pale, his eyes bulging, and then he exploded. “Martin! Get over here!” He grabbed him, his fingers digging painfully into his shoulder, and ripped the bow out of his hands.

Ryan had almost forgotten he still held it.

None of the other boys had been watching when Ryan had launched his arrow skyward, and they all turned to stare, battled at the sudden inexplicable fury of the scoutmaster.

“You—you—” The scoutmaster was completely incoherent, and slowly, almost as if from a dream, Ryan came to his senses and realized, yes, it might have killed someone. It might have killed him. It had been a dangerous thing to do.

But in his mind’s eye he could still see it, that one perfect moment when the arrow hangs in the air, quivering, straining, longing to go higher, and then falls, defeated.

And he realized, that is me, the arrow is me. That is where I want to go.

To go upward, forever upward, and to never come down.

3 Camp Agamemnon

They were tired, and then more than tired, a complete weariness that transcended all consciousness. The world compressed down to one step, then another, then another. The landscape had changed color, darkening from the light, almost orange color of their original landing site to a dark burned-brick color. They were walking on bare bedrock. But none of them looked at the landscape, none of them focused any farther ahead than the next step.

Ryan kept a readout of their position using the inertial navigation system from the dirt-rover. Occasionally he would read out their progress—“Three hundred kilometers to go”—until at last Tana told him to stop; it was too depressing. None of them dared to think of what would happen if the inertial navigation failed, if they were unable to find the Agamemnon site as they had been earlier unable to find the Pathfinder.

Two hundred kilometers to go.

One hundred kilometers.

When they came to the edges of the Agamemnon camp, it took them several minutes before they even recognized it. A discarded drilling-lubricant cylinder. Not far past that, a seismic recording station. They were beyond curiosity now, and the technological detritus went unremarked.

They crested a dune, and started down the far side, and none of them looked up until they almost stumbled over the camp.

Agamemnon lay before them.

“We’re here,” Tana said, almost in a whisper.

Ryan looked up. “We’re here. It’s here!”

Estrela, trailing behind, echoed in a whisper, “Here. Here!”

The Agamemnon camp was spread out. The Agamemnon lander itself sat a kilometer off to the east, a squashed hemispherical shell sitting on its heat shield and surrounded by the shreds of its airbag cushion like a half-melted mushroom. Spread all around were the remains of the encampment: the abandoned fuel-manufacturing plant and its electrical generator plant; two bubble habitats, long deflated; a toolshed; a domed greenhouse module; a half dozen scientific stations; communications antennae; a sheet metal quonset hut; piles of trash and discarded equipment; electrical and data cables spread spaghetti-style across the ground. No one from the doomed Agamemnon had bothered to be neat; they were too worried about survival.

Every horizontal surface was covered with a layer of dust.

There was no hope that Agamemnon’s electrical generating plant would still work, but the bubble habitats both seemed intact. Over the six years they had been on Mars the gas that had originally inflated them had slowly leaked away, but when Ryan checked, they were still intact.

Using the Agamemnon camp was a risk. If any of the original fungus had survived the six years on Mars and was still viable, and still virulent, they could face a repeat of the runaway infection that had ultimately led to the Agamemnon disaster. In theory it would not survive the six years without a host. In theory, even if it survived, it would not colonize healthy humans. In theory, even if it did, they had the pharmaceuticals to be prepared for it this time. In theory.

But they had little choice.

Ryan salvaged several solar array panels from the lander, and after cleaning away the dust layers, found them still functioning. It would be enough power to provide heat and light for the habitat.

And, if the transmitters still functioned, enough to communicate with Earth.

“We’ve got a new camp, crew,” Ryan announced. He should have felt triumph. Instead, all he felt was weary. “And it looks like everything still works.”

4 The Minions

Through grade school Ryan had built model rockets, taught himself calculus and aerodynamics, built his own telescope and a special tracking platform for it so he could watch the Russian space station Mir when it passed overhead and plan for the day when he, too, would be up there, looking down on Canada from above. In high school his science fair project, a gyroscopic stability system for a model rocket, had won a prize and a scholarship, enough that, along with earnings from an outside job programming computers to recognize speech, he could afford to go to MIT.

To Ryan, being an undergraduate at MIT had been like being at a banquet with each course more appetizing than the last. Finally he was stimulated to stretch his limits, and sometimes to exceed them.

At the end of his freshman year, Ryan got involved with a project to fly a student-designed satellite. He volunteered for the task of building the control system. It was a small but intensely dedicated team.

They had two unofficial mottoes. The first was, “It doesn’t have to be good—it does have to be done.” The second was, “We don’t need no stinkin’ sleep!” Everybody else called them the satellite gang, but to one another, they were the Minions of the Satellite God. They made a pact with each other: The satellite came first. Everything else—their sleep, their health, their grades, their lives—came second.

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 Quijote. 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 labeled 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.

But Ryan barely looked at her, although she tried in a dozen subtle ways to contrive to be there, nearly naked, when he was in the habitat, and he would hardly have been able to miss her. But he never made a move.

Ryan was good-looking. Oh, not as good as João—Santa Luzia, who could possibly be as gorgeous as her beautiful João had been?—but he was fine. But he seemed to pay no attention to her.

Two women, and only one would get to go with him back home. Well, the odds were much better than they had been. She knew men, and knew that if there had been two men, somehow the men would have contrived a way to show that it was logical for the two men to go home to Earth and the women stay behind to die. It was just the way of the world.

She wondered if Tana knew how much she hated her.

9 The Canadian Astronaut

At SPAR Aerospace, Ryan Martin worked on designing tether deployment systems for space; much later, his expertise on the use of tether systems played a major part in his role in the failed Mirusha rescue attempt. He spent a year in France, to earn a degree in space studies at the International Space University in Strasbourg, and the day he came back to Canada he put in his application to join the small Canadian astronaut corps.

His application went in just in time to apply to join the first Canadian cadre selected specifically for duty to the space station. His low amount of piloting time counted against him. He had taken flying lessons and spent as much time as he could afford practicing, but he certainly had far fewer hours in the air than the RCAF pilots that applied for the same few slots. But no one had a more thorough grasp of every aspect of astronautics and microgravity science than he, and in the end that counted more than his relative lack of flight hours. He wasn’t being trained to be a pilot anyway; the Americans would never select a Canadian to fly their shuttle. For the tasks Canada wanted astronauts for, they needed expertise in all areas, and no one scored higher than Ryan.

He graduated at the top of his astronaut training class.

His appointment to the astronaut corps elicited mixed feelings for him; during those years the fate of the space station was uncertain, and whether the space station had any role at all in the future exploration of space, or if instead it was an expensive orbiting dinosaur, was quite unclear. He wondered if the real future might instead lie in commercial space, where new, small launch vehicles were beginning to make enormous profits from launching tiny, cheap satellites.

But he wanted to do more than just send up other people’s satellites.

Ryan Martin wanted to go to Mars.

Mars was his obsession. He thought about Mars, made calculations, read every book, science or science fiction, that had ever been written about Mars, published papers suggesting possible solutions to the finicky engineering details of a Mars mission. After a while he started to be invited to give lectures about Mars missions, and he found that he was good at it. He would rent an airplane and fly to some distant city and talk. Schoolchildren, Masonic temples, library groups—he loved the moment when a group of strangers suddenly warmed up, and his contagious enthusiasm spread.

He didn’t chase women—to tell the truth, he had never learned how to approach a woman—it seemed to be an arcane trick that other men learned in some class he had failed to attend—and so he treated all the women he met exactly the same way he treated the men: as coworkers or as friends. But occasionally women would ask him out, and he wasn’t against going out to a restaurant, or to a concert, or for a walk on the beaches of Lake Ontario. And afterward, if sometimes a female friend asked him back to her apartment, or his, well, he had taken no vow of chastity.

He had only two rules to his relationships, rules that he never broke. Never promise anything.

And never fall in love.

10 Riding the Slingshot

Butterfly had been designed for short hops and aerial reconnaissance, not for a two-thousand-mile flight, and it had not been designed to carry three people. Over the months that they spent at Acidalia, Ryan ripped out every part that was not critical to flight: all the redundant control systems, the scientific instrumentation. He cut off the landing gear; when she landed, the Butterfly would land on snow. And she would never take off again.

They would have no margin, but at last he had an airplane that would make it to the pole.

For the take-off, Ryan laid down two strands of the superfiber cable for three kilometers along the desert sand. At the far end he staked it down to bolts drilled into bedrock, and then went back and used the motorized winch to stretch it. The elastic energy that can be stored in superfiber is enormous: If it were to suddenly break, the release would snap the cable back at almost hypersonic velocity, setting free enough energy to vaporize much of the cable, as well as anybody who stood nearby.

Once he had it stretched, he held it stretched with a second anchor bolt. It formed a two-mile-long rubber band. Ryan would use the world’s largest slingshot to launch the airplane.

The airplane had only two seats, so Estrela and Tana both were crammed into the rear copilot’s seat of the airplane, Estrela perched on Tana’s lap. In their bulky Mars suits, they fit into the space with barely millimeters to spare.

Ryan closed and sealed the cockpit around them and took the pilot’s seat.

“Ready?” Ryan asked.

“As ready as we’re going to be,” Tana’s muffled voice said.

“Get on with it!” Estrela said.

“Armed,” Ryan said. He pulled out an arming switch on the remote control, and said, “Launch!”

The explosives fired in silence, but Ryan could see the flash behind him, severing the strap that held the stretched superfiber down. Instantly he was pressed back into his seat as the superfiber slingshot, attached to the airplane at the motor mount, grabbed the airplane and shot it forward. Behind him he heard Tana say “Yikes!” and Estrela let out a sudden grunt as the sudden weight pressed into her.

The ground rushed past them with terrifying speed. Ryan concentrated his attention on keeping the wings level; with even a slight brush of a wingtip against the sand the fragile airplane would disintegrate around them. He couldn’t spare any attention for the airspeed indicator, but he could feel the wings beginning to pull against the air. He held forward pressure on the stick to keep the nose down; they needed to reach flying airspeed as quickly as they could. He shot a glance down at the airspeed; not yet, not yet. Now.

He eased back on the stick—not too much, or the wings would be ripped off—and the ground dropped away under them. Now Butterfly was lofted like a kite being towed behind a running boy. The pressure from the slingshot eased off; they were running out of stretch. It had been only a few seconds. He concentrated on keeping his airspeed up while milking the last little bit of altitude out of the quickly relaxing slingshot.

The slingshot slackened and fell away. For a moment Butterfly was soaring. He commanded the valves on the liquid oxygen tanks open, armed the ignition switch, and watched for the green light. After a terrifying pause, it flickered on.

They were ready.

Ryan hit the ignition button, and with a shudder, the ram-rocket chuffed to life.

For the first time in weeks, Ryan felt a surge of hope. Maybe they would make it after all. They were flying. Flying!

11 Momentum Management

Other astronauts who flew up on the shuttle with him felt sick. Ryan felt exhilarated. Every part of it was exciting, the training, the launch, and now the free-fall. This was what he’d always wanted. He tried a slow flip, then a fast one. “This is great,” he said.

But he was here to work, not to play. He had the map of the space station memorized. The others went quickly to find the station physician, or at least to find vomit bags. “They’ll get over it in a day or so,” the station physician said. “How about you? You okay? Need a patch?”

“No. I’m fine.”

The doctor nodded. Ryan was fascinated to see how his body moved infinitesimally in the opposite direction as he did. “Some people aren’t affected. Guess you’re lucky.”

He went to work.

After a while, when he was alone in a module, one of the female astronauts floated over. She casually snagged a handrail next to him, and looked at him, floating upside down.

He looked up.

“Are you gay?” she said.

“Huh? No.” He tried to remember her name. He was supposed to know the names of all the people on the station, but he’d never been good with names. Britta, he recalled, Britta Silverthorne. That was it.

“Nothing wrong if you are,” she said.

“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.

In all directions, as far as it was possible to see, there was only ice. Estrela had to confront the secret that she had never shared with any of the crew: The immensity of Mars terrified her.

They moved in silence. Estrela felt as if she were alone on the face of an uncaring planet. She seemed to be walking in a narrow cavern, a knife-thin slot between the blue-white ice below and the dirty yellow sky above. She felt that she was small, an insignificant speck crawling across the wrinkled ice.

But, to her surprise, she realized on the second day that it no longer terrified her. The ice was just ice, the sky just sky. Neither ice nor sky cared who she was or what she had done. She didn’t have to explain herself to them, didn’t have to pretend to be anybody. She could forget the others, forget even João, in the presence of uncaring immensity. It was as if she weren’t even there at all.

Estrela walked as if hypnotized, half-numbed from cold, numbed from lack of sleep, ignoring the others, alone inside her suit.

Alone between the ice and the sky, Estrela Conselheiro felt free to be nobody at all.

16 The Buried Spaceship

It took them eight days to reach the pole.

They came over the ice ridge, and Jesus do Sul was visible. Or the top half of the spacecraft was visible.

Jesus do Sul had sunk into the ice.

Estrela stopped abruptly, as if suddenly waking from a long trance. “Jesus do Sul,” she said softly, as if it were some puzzling words she were trying to understand, and then, more firmly, “Jesus do Sul.” Then suddenly she screamed and ran toward the ship. “João! João!”

Around the spacecraft, the snow was clean and undisturbed. Not even a ripple marked the locations where the two Brazilian explorers had fallen.

Ryan started to go to her, and Tana held him back. She switched over to the private channel. “Leave her be,” she said. “I think she needs to be alone for a while. Let’s go check out the spacecraft.”

They were desperately in need of the supplies. They had eaten the last of their ration bricks two days ago and were living on nothing but one liter of recycled water per day. It wasn’t enough, and they were all suffering from the effects of dehydration.

There was a habitat module at the base of the Jesus do Sul. Ryan knew where it had to be—he had watched the tapes of the Brazilian exploration hundreds of times and had memorized all the details of the base—but nothing was visible. It was buried beneath the snow.

Estrela was looking around frantically. “João!”

Tana ignored her own advice and went toward Estrela. “Estrela?” she said. “Are you all right?”

Ryan turned to the rocket. They had to get into the habitat, and they didn’t have any extra time.

The Brazilians had taken a much more streamlined approach to the design, and the part of the rocket that protruded from the snow looked like the spire of an onion-domed cathedral, with two smaller domes, the tops of the two first-stage boosters, to either side.

The dome at the top of the spire of Jesus do Sul contained the Earth Return Module, the uppermost stage of the Brazilian rocket. Ryan climbed the ladder to reach it. The hatch was over his head at an awkward angle. He pulled at the latch.

It didn’t move.

It’s locked, Ryan thought, and then immediately, no, that’s ridiculous. Nobody would put a lock on a spaceship hatch. It’s just stuck. He put his full strength against the latch and pulled. Nothing.

He paused to think. Cold. Cold, and dry, sitting in the cold and dry for eight years. The hatch had sealed solid against the rim. He went down the ladder back to the snow where he had left his skis, picked up one of the makeshift metal skis, and returned to the hatch. Using the end of the ski as a hammer, he methodically pounded, working around the edge of the sealed hatch. The metal of the ski twisted; he ignored it and kept working, moving clockwise around the seal once, twice.

He used the ski as a lever to pry against the hatch handle and tried it again. No success. He put both hands on the lever and pulled with his full strength against it, and felt something, a slight, almost infinitesimal give. He jerked it again, and then began to rhythmically pull with a succession of quick jerks. With an abrupt sucking, the bottom of the hatch pulled open, and then the top. He nearly fell backward as it opened.

The interior had two couches and a control panel. It was completely dark.

If even the emergency batteries were dead, they were in trouble. But no, when he switched over to emergency power, a feeble cockpit light came on, enough for him to see the controls.

Good enough. He looked around. The advice from the ground had mentioned that there was an EVA maneuvering gun, a small rocket engine mounted on a pistol-grip that could be used if ever there had been a reason to go outside the spacecraft. The ground crew had listed it as a possible item to discard to decrease the launch mass, but Ryan had a different use for it now.

Buried below the snow there was a habitat module, stocked with food and water and an electrical generator, all the necessities for the three hundred and fifty days the Brazilians had planned to stay on the surface.

Ryan intended to melt his way down to it.

17 At the Pole

He’s buried, Estrela,” Tana said. She tried to be as gentle as she could. “He’s at peace.”

Estrela’s only reply was an inarticulate moan. She had been on her knees on the ice, at the spot where João had lain, for an hour.

The ice was empty. Over the eight years since João had fallen, his body had slowly sunk into the ice, and new snow had fallen on top, until now only the barest shadow under the ice marked where he had died.

Estrela had been crying continuously. Tana had never before seen her cry; she’d always seen Estrela as being cold and unemotional, sensuous, yes, in her negligent way, but not affected by anything. Tana tried to remember what it felt like to love a man like that. Had she ever loved Derrick so much? She couldn’t remember.

Ryan had melted a tunnel down through the ice to the habitat. Or sublimed a tunnel, rather; at this pressure ice vaporized rather than melted. He was beginning to get the solar arrays cleared and the habitat systems powered up. Good old Ryan, she thought; if there’s any possible technical solution to a problem, Ryan will find it.

The heat of Estrela’s suit had vaporized down six inches of ice around her. The heaters on the suit were good, but at sixty degrees below zero, being pressed right against the snow was pushing them beyond their limits. Why, she must be freezing, Tana thought.

She reached out for Estrela’s arm and pulled her up. “Come on. Aren’t you cold? We have to get you inside.”

Estrela twisted her arm free and shoved Tana away. Wordlessly, she turned back to the little hollow she had melted into the ice and went back down to her knees.

Ryan came up. “I’ve got the habitat powered up.” He looked down at Estrela. “Has she been here this whole time? Is she okay?”

Tana shook her head. “I think she’s going hypothermic.”

Between the two of them, they managed to pull her to her feet. She struggled fiercely for a moment, and then allowed them to guide her without resisting.

After eight days sleeping inside the sausage, the tiny fiberglass habitat of Jesus do Sul seemed like a cathedral. Inside, Tana pulled Estrela out of her suit, and then released her own. “Yikes!” she said. “Sweet Christ, it’s cold in here.”

“Sorry,” Ryan said. “The power system is underperforming. It should warm up in a bit. Coveralls in the storage locker over here.”

Tana, starting to shiver, went to the locker. Ryan had already pulled on a coverall. The air in the little dome was frigid. Their breaths came out in white puffs, and the walls around them grew a coating of frost from the exhaled vapor in their breath.

Estrela, stripped down to only her suit lining, had not moved. She was completely still, not even shivering. The tears on her face had frozen into tiny glistening icicles down her cheeks and chin. Tana reached out and touched her on the side of the neck. Her skin was icy to the touch. Tana swore briefly under her breath.

“She’s hypothermic, all right,” she said. “She’s not shivering; that’s a bad sign. A real bad sign.”

She looked around. “We’ve got to warm her up. Can you heat up some water?”

“Water supply is still frozen.” Ryan shook his head. “It’ll be an hour before we get enough power to heat up anything.”

“That’s too long,” said Tana. “Wrapping her in a blanket won’t do, she’s so cold that there’s no heat to conserve. Her skin is too cold.”

Tana stripped Estrela down to bare skin. Estrela made no objection; she didn’t seem to even notice them. Then Tana peeled away her own clothes; first the coveralls and then her suit liner. The air of the habitat was frigid winter against her bare skin. She wrapped her arms around Estrela, hugging her as close to her as she could, trying to maximize skin contact. It was like hugging ice cubes.

“Can you find a blanket?” Tana asked.

Ryan went to their suits and detached the thermophotovoltaic isotope power supplies. He arranged these around Tana and Estrela. The waste heat from the radiators felt good. It helped. Not enough.

“You, too,” Tana said.

Ryan fetched a blanket, and then stripped. He hesitated for a moment at his underwear, and then turned his back and stripped them off. He quickly stepped behind Estrela and pulled her close, and then wrapped the blanket around the three of them.

But Tana had seen.

Christ almighty, how could he have a hard-on in a place like this? Tana thought. This is not an erotic situation. Just as quickly, she thought, I shouldn’t judge, it’s not as if he could help it. And at the same time, she thought, he got that from looking at Estrela, not me. I wish my body had an effect like that.

And then: It must be difficult for him, I guess.

“Come on, Estrela,” she said under her breath. “Warm up. Start to shiver. Come on, you idiot, you fool, you mad goose. Don’t die on us. Come on!”

She was still muttering it when she fell asleep.

18 Death at the Pole

After a full day powered up, the habitat was slightly warmer, but their breath still was visible in the air. Tana had spent the entire day inside, tending to Estrela. Ryan had spent it melting ice away from the rocket. Jesus do Sul now protruded vertically upward through the center of a deep shaft through the ice.

“I checked the rocket the best I can,” he said. “It’s in pretty remarkable shape for something that’s been sitting on the surface for so long. If there’s something wrong with it, it’s beyond my ability to diagnose.”

“Don’t tell me about the rocket,” Estrela said. She had mostly recovered from her episode of hypothermia, but she still looked pale. Spent. “I don’t care about the rocket. I want to know about João. What happened to João?”

Ryan shrugged. “Does it really matter?”

“It does matter!” she shouted. Her voice was hoarse, and it came out as a harsh whisper. “Tell me how João died!”

Ryan looked away. “They were poisoned.”

“What?” Estrela whispered hoarsely. “Tell me.”

Ryan sighed. “It was a simple mistake. Their fuel manufacturing plant made methane out of hydrogen, and it released carbon monoxide. No big deal; carbon monoxide is a natural component of the Martian atmosphere anyway. Do you remember that I had an episode of anoxia? The same thing happened to them. The sensors on their breathing electrolyzers were poisoned with sulfur contamination. But they were making fuel on the spot, so there was an excess of carbon monoxide. When their oxygen sensors failed, what got through was carbon monoxide. It poisoned them.”

“How do you know this?” Tana asked.

“Whose fault was it?” Estrela asked.

Ryan shrugged. “Once I knew what to look for, it wasn’t hard to see the evidence.”

“But whose fault was it?” Estrela insisted.

Ryan shrugged. “Nobody’s fault, really. It was an oversight.”

“An accident? It was just an accident?” She sat clown and looked away. “That’s all?”

“It was an accident. The same thing almost happened to us.” He looked up at her and saw that she was crying. “I’m sorry.”

Tana patted her on the back and echoed what Ryan said. “I’m sorry.”

19 The Final Choice

It’s time,” Ryan said. “We have to choose.”

Everyone was silent.

Ryan held out his fist. The ends of three strips of paper protruded. “Pick a strip. One of the strips is shorter than the rest. The two long ones go home.”

Estrela shook her head. “It doesn’t matter,” she said. “I’ve made my decision already. It doesn’t matter who draws which slip of paper. I’m staying.”

“What?” Ryan and Tana said, at almost exactly the same time.

Estrela smiled, a wan smile. “I surprised you, didn’t I?”

Ryan was gripped by a contradiction of emotions. His heart was telling him, let her stay here, let her stay, I’m going home. But his conscience told him that they couldn’t let her kill herself, not after all this; they were in here together. He said cautiously, “It’s a surprise, yes.” Then added, “But it wouldn’t be fair to have you make the sacrifice. We’ll all take the same chance.”

Estrela shook her head. “It doesn’t matter whether you go back or not. I’m staying here.”

“How would you survive?” Tana said.

Estrela tossed her hair, and for a moment a spark of her stubborn vitality showed through. “I can survive. I’ll go back to the American base; plenty of food and water there, plenty of supplies for the expedition that did not stay. Even a greenhouse.”

Ryan was startled. Yes, he thought, it might be possible. Maybe. “You can’t count on a rescue,” he said.

“In two more years they will send a ship,” she said. “Or maybe four. They will send the fourth expedition, and it will rescue me.”

She sounded so perfectly confident that for a moment Ryan believed it. Of course they would rescue her. Why had he ever thought they wouldn’t? And then common sense took over. “You can’t count on that,” he repeated.

Estrela shrugged. “Or six years. Or, maybe I won’t even wait for a ship. I’ll live here.”

“But, why?”

“I like it here,” Estrela said. “I’ve decided to stay.” She looked at them, looked at their surprised expressions, and laughed. “I know. You thought that I was a survivor, that I would do anything to get on the return trip. I thought that too. That’s why I killed Trevor, to take his spot.”

Tana looked up in surprise. “You—”

Estrela had a distant smile. She nodded. “Yes. That’s right. I killed him.”

Ah, Ryan thought. That should have been obvious. His death was too convenient. “Why?” he asked.

“Why do you think?” she snapped back. “Because only two of us could return. Because he was one more person who might make it back in what should have been my place. And because he was a liability to the expedition. That’s why.”

“What did you do?” Ryan asked.

Estrela looked him right in the eyes. “I stole the battery out of his emergency beacon,” she said, “and then I made sure his gyro compass was miscalibrated. And a couple of other little things like that. I wanted to make sure that if he got lost, he would stay lost. He was always sloppy in checking his equipment; I figured it would only be a matter of time before he got lost.”

“But why?” Tana said. “Are you sorry?”

“I told you. Somebody had to die. I decided it would be him.”

“I thought it was an accident,” Ryan said.

“Call it an accident, then,” she said. She shrugged. “I didn’t force him to wander around and get lost, I guess. You can call it an accident, if it makes you feel better.”

“And Commander Radkowski, too,” Ryan said, suddenly realizing. “You thought he wouldn’t pick you. So you killed him. It wasn’t Brandon at all; it was you!”

Estrela shook her head. “That was an accident. Sure, of course I wanted to kill Radkowski, didn’t you? But I’m not stupid. I was frantic when he died; I didn’t think we could make the pole without a leader.”

“An accident,” Ryan said slowly.

Estrela nodded. “He switched ropes at the last moment. He took the rope Trevor was supposed to use, and rappelled off the cliff before I could think of an excuse to stop him.”

“Shit,” Ryan said. “So what the hell are we supposed to do now?” He paused for a moment, and then asked, “and why are you telling us this? You were home free now. Why didn’t you just kill one of us? We never would have known.”

Estrela smiled. “I changed my mind.”

20 The Last Chance

Tana used the day to continue her inventory of the supplies left at the Brazilian base, and Ryan checked out the snow rovers left behind by the Brazilian expedition. Regardless of what had happened on the long road since they had left Felis Dorsa, or who would stay behind on Mars, Estrela’s idea to return to the American base at Agamemnon was clearly a sound plan. And the one who stayed behind, whoever it would be, would need supplies and a working snow rover.

Since that night they had not talked about Estrela’s confession. Ryan was working alone in the tiny hangar that held the snow rovers when Tana came to him. She stood there, silent, watching him work. At last she called his name, and he looked up.

“Do you believe her?” Tana said. “I need to know.” She bit her lower lip. “Do you think she really did—?”

Ryan had the fuel cell of a snow rover taken apart. He was carefully checking the seals, making sure that the sulfur poisoning had not penetrated and embrittled the power system. It was his way of avoiding thinking about it. He put the fuel cell down and looked at Tana, thinking. “Yes,” he said.

“But are you sure, really sure?” Tana asked, and when Ryan nodded, she said, “So what should we do?”

Ryan considered for a moment. “What do you suggest? The death penalty?”

“No, no,” Tana said. “But we could—” she stopped. “I don’t know.”

“What more do you want from her? We can’t take her home and put her on trial. And even if we could, we don’t have any actual evidence of a crime, do we?”

“But, we have to tell somebody.”

Ryan shook his head. “Who would we tell? What would we say?” He waved his hand to indicate the planet around them. “She says she’s going to stay behind on Mars. Think of it this way. Mars is a prison more secure than Alcatraz could ever be, a prison with walls that cannot be climbed. Are you really worried that this isn’t penance enough?”

“But what do we do!? How can we just leave her here?”

“Ah.” Ryan sighed. Yes, that was it. Despite what Estrela had told them, leaving her behind still seemed a betrayal. After all the distance they had traveled together, how could they just leave her behind? But was there an alternative? “I don’t know,” he said. “I don’t know.”

He bent back to his inspection. After a while Tana was gone.

At last the night came, and the three of them ate in silence. After eating, they gathered in the pressurized module. The habitat was still cold, but not as cold as it had been. Ryan sat down and looked at Estrela with a long, steady gaze.

She looked back. “Well?” she said.

“No more holding back,” Ryan said. “I need to know. Tell me, why do you want to stay behind?”

“Do you really care?” she said. “I’m telling you that you get to go home. Take it, it’s your life, and I’m giving it to you free. Do you care why?”

“Ah, but I do care,” Ryan said. “We have been together too long for me to just leave you behind without ever knowing why. It’s too late for deception now. Tell me.”

“I did tell you. I changed my mind.”

Ryan shook his head. “That’s not enough. You said that you killed two people to get back home…and now that you’re here, you decided you don’t want to go. I’m not going to judge you, but I need to understand. Why?”

Estrela leaned back and closed her eyes. “All my life,” she said, “all my life I’ve been surrounded by people. In the city where I grew up. In the school. When they sent me north. Always, people all around me. Boys wanting to be with me to pull down my pants, reporters interviewing, even João, wanting to sit with me and drink coffee and talk, and talk.

“Even on Mars, we were never alone—here on Mars, we were more crowded than anywhere. Crowded in the habitats, crowded in the rovers. Always together. Even when I thought I was going off by myself, there were the voices in my earphones, telling me that I would never be alone.

“Did you know that this place terrified me at first? These huge, empty distances. But then, when we kept on walking, when the airplane crashed and you told us that we had to keep on walking, something changed. In that long walk, we were each of us alone, truly alone, and I found, yes, I can be alone. I can be just me. The snow doesn’t care who I am. The rocks don’t care who I am. The sky doesn’t care who I am.

“I tell you this. Always, all my life, I have been pretending to be somebody I’m not. For so long that I don’t think I even know who I really am.

“I’m done with that.

“I decided, I don’t care if I go back. I don’t need it. There’s nothing for me back there. I changed my mind. I like it here.

“I want to be alone.”

21 Leaving Mars

The sun on the horizon was almost blue, surrounded by a luminous golden orb of light and a double halo. The day was still; the snow reflected only the pale yellow sky.

And then the snow began to glow.

The snow erupted, cascading outward in a tidal wave of sudden incandescence, raising a billowing cloud that was lit brilliant red by a light from inside. The glow, a flame almost too bright to look at, rose slowly and silently, shrouded in the roiling cloud.

Jesus do Sul broke out of the cloud, and the light of its exhaust, a second and brighter dawn, set the icescape aglow. Gathering speed, it headed skyward. It was almost out of sight when the booster stage fell away. The Earth-return stage, only a tiny pinprick of light, sped off, like a fallen star rising again to return to its home, into space.

Below, an insignificant figure sat on a small ridge of ice. She continued to stare into the sky for long after the tiny speck of light had vanished.

And then she turned back to return to the habitat. There was no use continuing to watch; it would be nine months before their journey would finish. There was a lot for her to do before then.

Estrela Carolina Conselheiro was, at last, home.