The plan had been that once Aurora 2 arrived the first crew would head back to Earth, leaving the bigger second team to expand on what they had already built—an embryonic settlement that marked, everybody had hoped, the start of the continuous human habitation of Mars. The tiny beachhead had already been christened, a bit grandiosely, Port Lowell.
Now that wasn’t going to happen. After two years the first crew remained stuck here—and the word was, because of the priority of the shield work, there wasn’t likely to be a retrieval mission until after sunstorm day itself, more than four years into the future.
The crew understood the need to stay, for they were all intensely aware of the threat posed by the sun. Despite its greater distance, the sun was actually a much more baleful presence here on Mars than on Earth. The home world’s thick atmosphere offered you the equivalent shielding of meters of aluminum; Mars’s thin air gave you only centimeters—no better than if you were riding a tin-can spacecraft in interplanetary space. The neighborhood magnetosphere was no use either. Mars was still and cold, frozen deep inside, and its magnetic field wasn’t a global, dynamic structure like Earth’s, but a relic of arcs and patches. On Mars, the solar climatologists liked to say, the sun engaged directly with the ground, and you had to hide from flares that wouldn’t even be noticed on Earth. So they understood, but that didn’t make the prospect any warmer.
The mood was hard to lift. They were tired, all the time: a sol, Mars’s day, was half an hour longer than Earth’s, just too long for the human circadian system to cope with. In all their simulations, nobody had anticipated that one of the most serious problems on Mars would turn out to be a kind of jet-lag. And now they were stranded. Thanks to Aurora Zero there was no fear of running out of resources. They could tough it out here; Mars would feed them. Still, most of the crew had been bereft at being cut off from their families and homes for so long.
But Helena, though horrified about the prospect of the sunstorm, and perturbed at the work they were going to have to do to ride it out themselves, was quietly pleased. She was growing to love this place, this strange little world where the sun raised a tide in the atmosphere. And Mars hadn’t even begun to give up its secrets to her yet. She wanted to travel to the poles, where every winter there were blizzards of carbon dioxide, or the deep basin of Hellas where, it was said, it got so warm and the air so thick you could pour out liquid water and it would stand, without freezing, on the ground.
And there were human secrets on Mars too.
British-born Helena still remembered her disappointment at the age of six after being woken in the small hours of Christmas Day, 2003, to listen for a signal from Mars that had never come. Now she had come all the way to Mars herself—and had seen with her own eyes the dust-strewn wreckage on Isidis Planitia, all that remained of the brave little craft that had come so far. This hadn’t meant much to the Americans on the crew, but Helena had been pleased when they had allowed her to christen this rover Beagle . . .
“Lowell, Beagle.” The voice of Bob Paxton, back at Lowell, spoke softly in her headset, cutting through the President’s words. “Almost time. Look up.”
“Beagle, Lowell. Thanks, Bob.” She tipped back her head to inspect the sky.
The spaceship from Earth came rising grandly out of the east, bright in the Martian morning. Helena waited by her rover until the glinting star that should have taken her home had started to dim in the dust at the horizon, its single pass over Mars complete.
Goodbye, Aurora 2, goodbye.
President Alvarez folded her hands and looked into the camera.
“The coming days will be difficult for all of us. I would not pretend otherwise.
“Our space agencies, including our own NASA and U.S. Astronautical Engineering Corps, will of course play a crucial role, and I have every confidence they will rise to this new challenge as they have in the past. The controller of the ill-fated Apollo 13 lunar mission once memorably said, “Failure is not an option.” Nor is it now.
“But the space engineers cannot win through alone. To achieve this we will all have a role to play, every one of us. My dreadful news may shock you now, but tomorrow another day will dawn. There will be newspapers and websites, e-mails to send and phone calls to make; the stores will open; the transport systems will run as they always do—and every workplace and school will, must, be open for business as usual.
“I urge you to go to work. I urge you to do the best job you can, every minute of every day. We are like a pyramid, a pyramid of work and economic contributions, a pyramid supporting at its peak the handful of heroes who are trying to save us all.
“We all lived through June 9, and we overcame the lesser problems posed on that difficult day. I know we can now rise to this new challenge, together.
“As long as humankind survives, our descendants will look back on these fleeting years. And they will envy us. For we were here, on this day, at this hour. And we achieved greatness.
“Good fortune to us all.”
You’re missing the point.
Bisesa wanted to scream at the softwall, to throw a cushion at the President. This shield is heroic. But you have to look beyond that. You have to recognize that all this has been engineered. You have to listen to me!
But for Myra’s sake, as she learned about the impending end of the world, she stayed outwardly calm.
The vagueness of the dates Alvarez quoted baffled her. Why be so elusive? The astrophysicists who had come up with this prediction seemed so precise about everything else that they would surely have narrowed it down to a day.
The date was surely selected by the Firstborn, of course, as was everything about this event. They would pick a day that mattered to them, somehow. But what could matter about a day in April 2042? Surely nothing in the human domain: the Firstborn were creatures of the stars . . . Something astronomical, then.
“Aristotle,” she said softly.
“Yes, Bisesa?”
“April 2042. Can you tell me what’s going on in the sky in that month?”
“You mean an ephemeris?”
“A what?”
“A table of astronomical data that predicts the daily position of the planets, stars, and—”
“Yes. That’s it.”
The President’s image shrank down to a corner of the wall. The rest of it filled up with columns of figures, like map coordinates. But even the columns’ titles meant little to Bisesa; evidently astronomers spoke a language of their own.
“I’m sorry,” Aristotle said. “I’m not sure of your level of expertise.”
“Assume nonexistent. Can you show me this graphically?”
“Of course.” The tables were replaced by an image of the night sky. “The view from London on April 1, 2042, midnight,” Aristotle said.
At the vision of the impossibly clear, starry sky, a sharp memory prodded at Bisesa’s mind. She remembered sitting with her phone, under the crystalline sky of another world, as the little gadget had labored to map the sky and work out the date . . . But she’d had to leave everything behind on Mir, even her phone.
Aristotle scrolled through display options, showing her stick-figure constellation diagrams, lines of celestial longitude and latitude.
She dumped all that. “Just show me the sun,” she said.
A yellow disk began to track, impossibly, against a black, star-filled sky, and a date and time box flickered in the corner. She ran through the month, April 2042, from end to end, and watched the sun ride across the sky, over and over.
And then she thought of what she had seen on her strange journey back from Mir with Josh. “Please show me the Moon.”
A gray disk with a sketchy man-in-the-Moon mottling appeared.
“Now start from April 1 and run forward again.”
The Moon made its stately way across the sky. Its phase welled until it became full, and then it began to shrink down, through half full, and to a crescent that enclosed a disk of darkness.
That
black disk tracked across the image of the sun.
“Stop.” The image froze. “I know when it’s going to happen,” she breathed.
“Bisesa?”
“The sunstorm . . . Aristotle. I know this is going to be hard for you to arrange. But I need to speak to the Astronomer Royal—the President mentioned her—Siobhan McGorran. It’s very, very important.”
She stared at sun and Moon, neatly overlapped on her softwall. The date of the simulated solar eclipse was April 20, 2042.
PART 3
THE SHIELD
19: Industry
Bud Tooke met Siobhan off the Komarov, just as before.
She had already told Bud she wanted to get straight to work, no matter the local time of day. He smiled as he rode with her to the main domes. “No sweat. We’re working a twenty-four-hour-a-day shift here anyhow—have been for six months, ever since the President’s directive came in.”
“It’s appreciated back home,” she said warmly.
“I know. But it’s not a problem. We’re all highly motivated up here.” He sniffed up a deep breath, expanding his chest. “A challenge is energizing. Good for you.”
Siobhan had felt on the edge of exhaustion for the last six months. She said dubiously, “I guess so.”
He eyed her, concern penetrating his military brusqueness. “So how was the trip?”
“Long. Thank God for Aristotle, and e-mail.”
This was Siobhan McGorran’s third trip to the Moon. Her first voyage had been wonderful, something she had dreamed of as a child. Even the second had been exciting. But the third was just a chore—and time consuming at that.
The trouble was, here they were, halfway through 2038, a whole year after June 9, already six months since Alvarez had made her epochal Christmas announcement—and now less than four years before sunstorm day. Siobhan knew intellectually, from her Gantt charts and dependency diagrams and critical paths, that the various subprojects of the mighty shield program were actually going quite well. But inside her head a calendar-clock ticked steadily down.
She tried to explain to Bud. “I’m a natural pessimist,” she said. “I expect things to go wrong, and am suspicious when they go well.” She forced a smile. “Some attitude for a leader.”
He angled his head so his frosting of crew-cut hair caught the corridor strip lights. “You’re doing fine. Anyhow, when it comes to motivation, leave that to me. I was once a pain-in-the-butt sergeant at training camps in the Midwest. I can get them down and dirty. Maybe between us we’ll turn out to be a good team.” And he put his arm around her shoulders and gave her a squeeze.
She could feel his strength, and detected a scent of aftershave. Bud did sometimes seem like a relic of the 1950s. But his indomitability, straightforwardness, and sheer good humor were very welcome. All of which was rationalizing, of course.
As he held her, she felt a deep and pleasant warmth spread out through her belly and rise to her face. She was sorry when the brief hug ended.
On her first visit, Artemis Dome had been a scene of lunar industrial experiments. Now, just a few months later, the scale of the operation had changed utterly. The dome had been sliced open and crude extensions built on it to provide a lot more acreage of processing facility, most of it in vacuum. It was an infernal scene, Siobhan thought, with grotesque spacesuited figures gliding through banks of pipes, ducts, and metallic vessels, and everything stained the ubiquitous charcoal gray of the Moon, like a caricature of the darkest days of England’s Industrial Revolution.
The product of this mighty effort was metal.
Aluminum was the main structural component of the mass driver launch system, while iron would be required for the electromagnetic systems that would be its working muscles. But the mass driver was going to be kilometers long. The lunar colonists were having to jump straight from a trialed process to industrial-scale production; the scale change was tremendous, the pressure immense.
Bud sketched some of the difficulties. “These are tried-and-tested processes on Earth,” he said. “But up here nothing behaves the same, not a heap of ball bearings or oil flowing in a pipe . . .”
“But you’re getting there.”
“Oh, yes.”
Meanwhile Selene Dome, once the Moon’s first farm, had been turned into a glass factory. It was simple: you pushed lunar regolith in one end, applied focused solar heat, and drew glass out the other end, shimmering hot, to be molded into prefabricated sections.
Bud said, “Every time a journalist gets through to me, I’m asked the same damn question: why are we making the infrastructure of the shield from lunar glass? And every time I have to give the same answer: because this is the Moon. And wonderful though it is, the Moon doesn’t give you a lot of choice.”
The Moon’s peculiar composition was dictated by its formation. The NASA geologists who had studied the first samples returned by the Apollo astronauts had been puzzled: this iron-deficient, volatile-free stuff seemed quite unlike the rocks of Earth’s crust. It was more like the material of Earth’s mantle, the thick layer between crust and core. It turned out that this was because the Moon was made of Earth’s mantle—or rather, of the great gout of it that had been splashed away by that primordial, Moon-making impact.
“And so that’s what we’re left with,” Bud said. “Igneous rocks make up ninety percent of the crust here. It’s as if we were learning to live on the slopes of Vesuvius. And there’s virtually no water, remember. Without water you can’t make concrete, for instance.”
“Hence glass.”
“Hence glass. Siobhan, glass grows naturally on the Moon. Wherever a meteor falls, the regolith fuses, and glass is splashed everywhere. So that’s what we use.
“And here’s the finished product.” With a showman’s flourish he pointed to glass components, some of them many times a person’s height, stacking up in a rudimentary store out in the vacuum. “There are no prototypes here, no test articles. Everything we make is intended to be launched; everything we build will wind up on the shield—everything you see here will fly. The designs they feed us from Earth keep changing, and we’re trying to optimize our manufacturing too, aiming for the minimum weight to provide a given structural strength. So the final shield will be a funny sort of hybrid, with the last components, five years younger, looking quite different from the first. But we’ll just have to cope with that.”
Siobhan gazed at the glass sections with genuine awe. They looked like nothing much, like buttresses for a fairground ride or a fancy trade-show exhibit. But these odd-looking struts of glass, and tens of thousands of others just like them, were to be shot into space, where they would be assembled to form the scaffolding of a mirror wider than the planet. Her wild back-of-the-envelope concept was already coming into physical actuality. She felt thrilled.
Bud was watching the workers beyond the window. “You know,” he said, “I think this could be the making of this crew. Before June 9 we were kind of playing up here, playing at being lunar colonists. Now we’ve got a sense of urgency, a specific goal, a schedule to fulfill. I believe this event will push forward the program of the colonization and exploitation of the Moon by decades, or more.”
That meant little to her, but she saw how important it was to Bud. “That’s wonderful.”
“Yes. But,” he added heavily, “sometimes I walk on eggshells.”
“Why?”
“Because this isn’t what these guys came here for. They’re mostly scientists, remember. Suddenly they’ve been drafted to work on an assembly line. Yes, there’s dynamism and adrenaline. But sometimes they remember their old lives, and they feel—”
“Resentful?”
“Well, I can take that. The worst thing is, they get bored. The disadvantage of overeducation. As long as I can keep them distracted we get along fine.” He peered out, the laugh lines around his eyes catching the light, and she thought he seemed very fond of his temperamental workers.
“Come on,” she said. “You haven
’t shown me Hecate yet.”
As they walked on, she slipped her hand into his.
Later he took her out of Clavius Base to see David’s Sling.
As they approached the site of the Sling, Siobhan stood up in the surface tractor’s bubble-dome pressure compartment to see better. Only three kilometers of the launcher had been completed, of a projected thirty. Even so, it was an astonishing sight: in the low sunlight, under a pitch-black sky and against a gray-brown backdrop of Moon dust, the launcher shone like a sword.
The engineers called it a mass driver, or an electromagnetic launcher—or, more simply, a space gun. The heart of it was an aluminum track standing on trestle legs, thin and light like all lunar constructions. Wrapped around the track was a coil of iron, a vast spiral that Bud called the solenoid. At the loading end spacesuited figures moved cautiously around a crane, which was hoisting a glistening pellet up onto the track. The track stretched away across the level floor of Clavius, soon passing out of sight beyond the Moon’s close horizon.
“The principle is simple,” Bud said. “It’s a cannon driven by electromagnetism. You wrap your cargo in a blanket of iron—which we can reuse, by the way. You put your cargo pellet on the rail. The magnetic field, generated from that blockhouse over there”—he pointed at a nondescript dome—“then pulses through the solenoid, and your pellet is pushed along the track.” The changing magnetic field induced electric currents in the iron blanket, and the currents then pushed against the magnetism: “It’s just the principle of the electric motor,” Bud said.
As he spoke he pressed his hand against the small of her back with a pleasing familiarity.