Stephen Baxter - Ark

They stood and waited. Zane sounded absent, as always. Maybe he was absorbed on some project of his own-the warp assembly was demanding enough. But it seemed to Holle that he increasingly disappeared into the dark places inside his own head. He would lie in his couch, or just float, hanging from some bracket like an empty suit. She’d tried to persuade Mike Wetherbee to take a look at him, but the doctor had protested he was no psychiatrist, and anyhow he was in a tremendous sulk about Miriam’s stranding and wouldn’t consider psychiatric cases. Holle, still smarting herself over her separation from Mel, could sympathize with that. Mike had tried to get Zane to talk to specialists on Earth by the downlink, but the time delay had destroyed any chance of empathy.

However, Zane was on the ball today, it seemed. After a couple of minutes an indicator over the airlock door flashed from red to green. Holle turned to Masayo. “You want to lead?”

“What, a jarhead like me? You go ahead.”

“This is your first EVA of any kind, right?”

“Thanks for reminding me.”

“Just don’t throw up inside that suit, there are only five that fit me and that’s one of them. Let’s go.”

She pulled down a handle and the door slid open, revealing the gleaming airlock chamber, and a small window showing the blackness of space beyond.

They emerged from the airlock into sharp, dim sunlight. Holle and Masayo, weightless, stood on the nose of Seba, an insulation-blanketed tower fifty meters high. The tether between the hulls was a triple steel cable that ran vertically up from the nose of the hull, gleaming in the flat sunlight. Holle showed Masayo how to fix the attachment at his waist to the tether cables. Leaning back she followed the tether’s line up through the incomplete circle of the warp generator, hanging directly above her head. Beyond that the second hull, Halivah, was suspended in the sky, nose down, two hundred meters away. It was an extraordinary metal sculpture, hanging in the pale light.

She looked at Masayo. He stood awkwardly in the stiff suit, his face hidden by a gold sun visor. She asked, “Ready?”

“Let’s get it over.”

Holle threw a switch. The suit winches cut in and they rose up, smooth and silent, their legs dangling, climbing the cables effortlessly, with Holle just ahead of Masayo. “The crossing will take a few minutes.”

“Kind of slow,” he muttered.

“Well, that’s for safety. You in a hurry? I could always override the regulator-”

“Hell, no.”

“Oh, come on, enjoy it. Look around. Get your bearings. There’s the sun, over there.” She pointed. The sun, five times more remote than from Earth, cast an oddly dim light and sharp, strange shadows. It was no longer bright enough to banish the stars that filled the sky all around them, more crowded than seen from any mountaintop on Earth. “Look, you can see the launch stage…”

The Orion launch frame drifted alongside the tethered hulls, its thermal-resistant pyramidal cap still in place, the pusher plate still gleaming. Without the bulk of the hulls the interior looked gutted, and that mighty thermonuclear engine was stilled for good. The hulk was now serving its final purpose as a construction platform as spacewalking astronauts, all of them Candidates trained for the job, put together the warp assembly at the hull tether midpoint. Aside from that Holle could see the freeflying platforms that supported Venus’s planet-hunting telescopes, both of them sailing far from the vibration and bright lights of the hulls. There was no point looking for the antimatter miner; that was fifteen million kilometers away, plying its hazardous trade between Io and Jupiter. All these components were scattered in the blackness, but they twinkled with lights, with humanness, like a little town in the orbit of Jupiter.

Masayo was looking around uneasily, his hands clamped to the restraint at his waist.

“And there,” she said, “is Jupiter.” She pointed the other way from the sun.

Jupiter was a disc, golden-brown, visibly flattened, the only object in the whole universe away from the Ark cluster itself large enough to show as anything other than a point.

“Kind of disappointing,” Masayo said.

It was a common reaction among the crew. “Oh, you think so?”

“It looks no larger than the moon, from Earth.” He held out a thumb, waggling it, occluding the planet from his sight. “King of the worlds! Somebody told me it masses as much as all the other planets combined. Is that right?”

“Yeah. More than three hundred Earths.”

“But it’s just a ball of gas. I can see those big cloud bands, but so what? Even the Great Red Spot is just kind of mud-colored.”

“You should talk to Joe Antionadi.”

Joe had specialized in climatology, among other disciplines, and he spent long hours in the cupola studying Jupiter, a super-laboratory of climate. The Great Red Spot was actually a permanent storm system, centuries old, that prowled endlessly around Jupiter’s cloud bands. There were disturbing parallels between it and some of the huge new hypercanes roaming Earth’s equator.

But they weren’t here for Jupiter itself, but for the products of its magnetosphere.

“You need perspective, Lieutenant. Why are we so far out? Why don’t we orbit close in, skimming a hundred kilometers over the clouds like they used to orbit Earth?”

“Radiation, right?”

“That’s it. Jupiter is a high-radiation environment. A human worker down there would pick up over three thousand rem a day-a lethal dose is around five hundred.” She leaned back, trusting the tether, and waved her suited arms. “And believe me, if you could see the planet’s magnetic field you wouldn’t think Jupiter is so small. It has ten times the strength of Earth’s, it stores twenty thousand times as much energy, and it stretches far out, even beyond our radius here, twice as far. And it traps charged particles from the sun.”

“That’s what makes the radiation environment so lethal.”

“Right. But it’s the interaction between Io and Jupiter’s magnetic field that’s important for us.” Through Venus’s telescopes Holle had seen the mighty aurorae that played over Jupiter’s nightside, and heard the crackle of radio waves emanating from the tortured gases. Io’s flux tube, a system of high-energy plasma, was a natural antimatter factory.

“Hell of a way to go about your business,” Masayo said.

They had reached the tether’s center point now, and Holle slowed them to a stop. Looking around from here she could see the great band of the warp generator, essentially a compact collider ring, wrapped around the tether. Spokes like a bicycle wheel’s attached the ring to a hub at the midpoint of the tether. On the ring she saw a welding spark, and two suited workers moved patiently around a freshly installed panel.

Masayo asked uneasily, “Is there some reason why we stopped?”

“Point to the sun. Just do it.”

“It’s over there.” He pointed again, his finger fat in the heavy glove. “Oh. No, it ain’t.” The sun had shifted visibly around their sky, as had Jupiter, the stars. “We’re turning. ” He grabbed onto the tether.

“Take it easy. That’s Seba down below, where we came from.” She pointed. “That way is down. The other way’s up. OK?”

He forced himself to relax, muttering. “Up, down, up, down.”

“Good. We’ll make an astronaut of you yet. It’s just a slow rotation for now. Takes an hour to complete. Not enough so you’d notice the centripetal force inside the hulls, but it’s enough to keep the tether under tension. Later we’ll spin up faster.”

When the warp assembly was completed vernier rockets would be used to spin the whole assembly, the twin hulls rotating around the tether midpoint like two handholding skaters whirling around on the ice. The rotation, completed once every thirty seconds, would induce an apparent gravity of about forty-four percent of a G in the nose airlocks-and because the centripetal forces increased the further you got from the center, the gravity would rise too, to around sixty-six percent of a G at the base of each hull.