Seveneves - Страница 66

She had already accomplished much during Ivy’s soliloquy. The task at hand was to somehow attach the Lamprey to the X-37. The connection didn’t have to look good but it did have to be solid. Back in the days when every maneuver had been planned years in advance by NASA, this would have been a several-hours-long operation making use of custom-designed hardware. But lately the people of the Cloud Ark had been obliged to get good at lassoing random pieces of floating space junk, and so she ended up using a more highly evolved version of the trick that Rhys had come up with for reining in Tekla’s Luk. On that occasion, Dinah had fashioned a whip by chaining Siwis together. It had worked, but it was much heavier and more complicated than it needed to be. After the completion of T3 had left Rhys with some free time on his hands, he had begun tinkering with surplus Nats. Being old and obsolete, these were big, clunky, slow, and stupid compared to the new models — which was fine for Rhys’s purposes. He had turned them into a new kind of robot that he dubbed the Flynk, for flying link, and taught them to be really good at forming themselves up into chains and then doing the sorts of maneuvers in space that his great-great-great-great-uncle John, and Herr Professor Kucharski of Berlin, could only have dreamed about. There was much room for creativity here, but he had focused most of his efforts on problems that needed to be solved all the time.

Such as precisely the one Dinah needed to solve right now. The robot arm of the X-37 was sticking awkwardly out into space, an obvious target for grappling. A chain with a free end would whip around it easily, just as Rhys had once ensnared Dinah’s index finger with his necklace. All Dinah needed was a suitable chain. She happened to have one: a necklace of third-generation Flynks spiraled around the Flivver’s hull, ready for use. One end of it was already connected to the Lamprey. By invoking some computer code she was able to set the rest of it into motion, unwinding itself from around the Flivver and snaking out into free space, forming a U-shaped bend, or Knickstelle, that was aimed at the X-37’s robot arm.

“Ready to undock now,” she said.

Ivy had moved back to the port through which their guest had entered. “Undocking,” she said, and began running through the checklist that undocked the Flivver from the X-37.

Dinah meanwhile moved up to the pilot’s console and punched in a programmed series of thruster burns. As soon as Ivy confirmed separation, Dinah executed the program, effecting a small delta vee that made them back away from the X-37. The Knickstelle went into motion, as if the chain were passing around an invisible pulley, and began to propagate away from the Flivver and toward the X-37. Presently the chain’s end whipped around the robot arm and spiraled about it several times before grapplers on the Flynks found each other and engaged, lashing the chain into place for good.

Dinah released the Lamprey from the grip of the Flivver’s robot arm. The Flynk chain, still following a canned program, pulled the Lamprey in and made it fast to the X-37. The Flynk chain, the X-37, and the Lamprey were now a single object, and would remain thus until they were destroyed.

Dinah brought up the interface that controlled the Lamprey. This was a fire-and-forget device, but someone did have to fire it. She spun a control wheel that adjusted the box’s attitude, aiming its business end in a safe direction.

Getting things out of orbit was almost as complicated as launching them. Once a thing was in a legitimate, stable orbit, you couldn’t just drop it toward the Earth. It would stay in orbit indefinitely unless you slowed it down. Slowing it down generally meant using thrusters, which meant spending fuel. The Lamprey was a simple alternative.

“We’re undocked,” Ivy announced, moving back forward to the pilot’s chair. “Gonna nudge us free.”

A couple of pops from the thrusters signaled that they were gaining some distance from the X-37. Ivy spun the Flivver around so that they could see the X-37 perhaps a hundred meters away, floating upside down above the burning Earth, the elbow of its arm projecting toward the nadir, the Lamprey strapped to it and blinking.

“Okay, the Lamprey is giving me all green thingies. I see no red thingies. So I am activating it in three. . two. . one. . now.” Dinah tapped the Deorbit button.

Most of the Lamprey — the entire box — jumped away, headed toward Earth, propelled by white plumes of solid rocket exhaust. After a couple of seconds the motors burned themselves out and the box continued to coast away, unreeling a wire behind it. This came to a stop a minute later, dangling half a kilometer below the X-37, and pulled taut by tidal force.

“We have positive current flow in the tether,” Dinah reported. “So it’s working.” The wire, sweeping through Earth’s magnetic field on its orbit, was picking up a weak electrical current, creating a force that would slow the X-37 down. The effect was slight, but within a few hours the X-37’s orbit would decay to the point where it no longer posed a danger to the Cloud Ark, and in days or weeks it would descend into the atmosphere and be annihilated.

Twenty minutes remained before the Flivver’s orbit would next cross Izzy’s. But the physical separation was only a few tens of kilometers and they were still “on swarm,” meaning that the Flivver’s computer was talking to the Cloud Ark network and searching parameter space for the safest and most efficient way to reintegrate with it and to dock. That, plus the Lamprey’s success in moving the X-37 out of the way, ought to have cleared up most of the red that had been maculating Parambulator displays at the time of their departure. But when Dinah and Ivy turned their attention back to those screens, they looked worse than before. It was not immediately clear why. Parambulator was a beautiful thing from the standpoint of mathematics and data visualization, but there were times when you just wanted to know what the hell was happening. You wanted a narrative.

A text came through on Ivy’s phone. It was from Markus. She read it out loud. “Approach using visual observation and manual control,” it said. “Warning: collision debris.”

“Already?!” Dinah exclaimed. It wasn’t a good start if they’d already suffered a bolide strike a couple of hours into the Hard Rain.

“It was fratricide,” Ivy said, still reading. “Looks like an arklet got cornered.”

Getting cornered was a problem that had arisen in simulations. The swarm as a whole would look for solutions that would prevent arklets from banging into each other with minimum expenditure of propellant. In a pinch, of course, it was okay to burn a lot of propellant to avoid a collision. But there were situations where a collision was going to happen no matter what, and there was nothing to do for it but choose the least damaging outcome. Getting cornered wasn’t supposed to happen; everything about Parambulator was supposed to prevent it. But the number of possible scenarios was infinite and nothing was ever certain.

“A controlled collision,” Ivy said, “no fatalities. But then some follow-on. Still being evaluated. There might be loose debris drifting around. That’s why he wants me to fly it in manually.”

“What kind of debris?” Dinah asked. “Hard stuff or—”

“Thermal protection, looks like,” Ivy said. “So that’s good.”

Apparently one of the modules, or an arklet, had lost some of the layers of reflective foil and insulation that were used to shield it from the heat of the sun. The stuff was feather light and so probably didn’t pose much of a threat to the Flivver. But it would look huge on radar and make Parambulator go crazy.

Ivy, in the pilot’s chair, was monopolizing the only window. Dinah didn’t like flying blind, so she pulled up the interface for the Flivver’s eyeball camera.

Julia began to make a weird repetitive noise, a sort of wet, gurgling drone.

She was snoring.

“Long day for her, I guess,” Ivy remarked.

“Yeah.” Dinah had no precedents to tell her how she should feel toward the ex-president at a time like this. On the one hand, her behavior had been reprehensible. On the other, she had, within the last few hours, lost her husband, her daughter, her country, and her job.

With a few moments’ panning around, Dinah was able to center Izzy in the camera’s frame, then zoom in. Izzy was on the night side of the Earth just now. In normal times — or what used to be normal — it would have been dark, but now she was lit up from below by the red glow of the atmosphere, punctuated from time to time by bluish flashes, like lightning strikes, as large bolides plowed into the air three hundred kilometers below. Of course, Dinah had never seen Izzy so illuminated, and it took a bit of getting used to.

From a distance Izzy looked fine, but at higher magnification Dinah began to see visual noise that gradually resolved into drifting bits of debris — the shredded thermal protection that Ivy had mentioned.

Izzy had become unfathomably complicated in the last two years. Dinah rarely saw it from a distance, so she didn’t have a strong sense of what was normal. But the more she zoomed in, the more certain she became that something weird had happened on the nadir side, near the junction of Zvezda and Zarya.

Complicated though she might be, Izzy was complicated in a way that was orderly, stiff, and stable. The one exception to that rule was Amalthea, but even that had become more regular as the Mining Colony’s robots had reshaped it. What Dinah was zooming in on now was messy, and it was unstable: big expanses of thermal shielding material that had been torn loose and were now stirring randomly in the nearly imperceptible wind. At a glance, it did not look like a serious matter. “Serious” would have meant a hull breach, air erupting from a hole, perhaps dragging debris, or even human bodies, along with it.