Seveneves - Страница 14

“Now, technically. .” she began.

“Technically, this is wrong,” he said. She admired the self-aware bluntness. “It is wrong because when you open the outer hatch and put that piece of ice out in space, where your robots can muck about on it, it is going to sublimate.”

Sublimation was essentially the same thing as evaporation, skipping the liquid phase; it just meant a process by which a solid, exposed to vacuum, gradually turned into vapor and disappeared. Ice tended to do this pretty quickly unless it was kept extremely cold.

“So Izzy is going to lose water,” Dinah said, “which is a scarce and valuable resource.”

“It’ll never be missed,” Rhys said blithely. “This isn’t the old days. Now that those people have made that announcement, rockets will be coming up here thick and fast.”

“Still, what Sean wants me to do is an Arjuna Expeditions project. A commercial thing. A private thing. And that water is a shared—”

“Dinah.”

“Yes?”

“Snap out of it, love.”

A long silence followed, concluded by a big sigh from Dinah. “Okay.” Rhys was right. Everything was different now.

“Now, what is it he wants, and how does ice enter into it?”

Her mild annoyance at his curiosity finally gave way. Maybe he could help. She turned her head toward the window and nodded at the familiar bulk of Amalthea, a few meters away. “That’s been my career, and my family’s career,” she said. “Working with minerals. Hard rock. Metallic ore. All of the robots are optimized for crawling around on a big piece of iron. They use magnets to stick to it. Their tools use plasma arcs or abrasive wheels to work it. Now, Sean’s basically telling me to shelve all of that. The future is ice, he says. That’s all he wants to hear about. All he wants me to work on.”

“There’s lots of it on Earth,” Rhys pointed out, “but you never think of it as a mineral.”

She nodded. “It’s an annoyance you have to clear out of the way.”

“Your colleagues down on the ground? Also working on ice?”

“Judging from email traffic, this is a company-wide directive,” she said. “They’re buying ice by the truckload, dropping it on the floor of the lab, refrigerating the building — fortunately it’s winter in Seattle; they only need to drop the temperature a few degrees. They’re all buying long underwear at REI so that they can work in a refrigerator.”

“What’s it like working for Mr. Freeze?”

“I was going to say the Penguin,” Dinah said, “but people in Seattle don’t carry umbrellas.”

“Nor do they wear top hats, in my experience. No, it’s definitely a Mr. Freeze scenario.”

“Anyway,” Dinah said, “yesterday’s shipment of vitamins contained a few of these.”

She opened a storage cubby next to her workstation and took out a bag made of the metallic gray plastic used to protect sensitive electronics from static electricity. Taped to it was a NASA business card.

“Nice to have friends in high places,” Rhys remarked. He had noticed the name on the card: Scott “Sparky” Spalding, the NASA administrator.

Dinah smiled. “Or low, as the case may be.”

It was a weak joke. Rhys didn’t respond. Dinah felt her face get a little warm. Not so much because of the failed attempt at humor as out of a kind of political defensiveness. “Scott told me a couple of weeks ago that he wouldn’t ditch me out. That he had my back.”

“What does that mean exactly?”

“That the robot work would keep going. That I would have a job. I didn’t believe him. But I guess he’s been talking to Sean Probst. Because Sean FedExed these to Sparky a couple of days ago, and now they’re here.”

She parted the bag’s ziplock closure, inserted her thumb and index finger, and pulled out a contraption about the size of a grain of rice. From a distance it looked like a photovoltaic cell, just a flake of silicon, but with a few tiny appendages.

“What are the dangly bits?” Rhys wanted to know.

“A locomotion system.”

“Legs?”

“This one happens to have legs. Others have things like little tank treads, or rolling cylinders, or slammers.”

“Slammers? Is that a technical term?”

“A mining thing. A way of moving heavy equipment around on the ground. I’ll show you later.”

“So,” Rhys said, “it would appear that the agenda is to evaluate a number of different ways that robots could crawl around on ice without drifting off and getting lost.”

“Yeah. Apparently all of these work, more or less, on the ground in Seattle. I’m supposed to evaluate their performance in space.”

“Well!” Rhys said. “How fortunate for you, then, that—”

“That I have my very own chunk of ice. Yeah. Thanks for that.”

“All the sweeter for being contraband?” he asked, raising his eyebrows.

The double meaning was clear enough. “Not as romantic as a dozen roses,” she countered.

“Still,” he said, “what is it that a man is trying to say with a dozen roses? Simply that he is thinking of you.”

Shortly after she’d arrived on Izzy she had rigged up a curtain that she could draw across the opening of her shop’s hatch. It wasn’t much — just a blanket — but it shielded her visually when she wanted to take a nap in her shop, and it sent the message that she was not to be disturbed, at least without knocking first. She reached up now and drew the curtain across the hatchway. Then she turned back toward Rhys, who looked very keen, and very ready.

“How’s your space sickness?” she asked. “You seem a little more, uh, sprightly.”

“Never better. All bodily fluids fully under control.”

“I’ll be the judge of that.”

THE RUSSIAN INVASION BEGAN A WEEK LATER, WITH A SPATE OF flights producing what NASA described as “mixed results” and Roskosmos termed “an acceptable fatality rate.”

Seen from a distance, Izzy consisted almost entirely of solar panels. Structurally, these were to the space station as the wings of a bird were to its body, in the sense that their purpose was to have as much surface area as possible with minimal weight.

Most of the mass, strength, and brains were in the “body”—a stack of can-shaped modules running up the middle between the “wings”—which was tiny by comparison. From many angles you couldn’t even see it. The only parts of the stack big enough to be noticed from a distance were the add-ons from recent years: Amalthea at one end and the torus at the other.

The solar panels — as well as some other, vaguely similar-looking structures whose function was to radiate waste heat into space — were held in place by the Integrated Truss Assembly. The word “truss,” when used by structural engineers, just meant something that looked like a radio tower or a steel bridge: a network of struts joined into a lattice, giving maximum stiffness with minimum weight. In some parts of Izzy, those struts were visible, but more commonly they were covered up by panels that made them look more solid than they were. Behind those panels resided unfathomably complex wiring, plumbing, batteries, sensors, and mechanisms for deploying and rotating solar panels. With a few minor exceptions, none of the Integrated Truss Assembly was pressurized — none of it was meant to hold air or accommodate human beings. It was like the mechanical works on the roof of a skyscraper, exposed to the elements and rarely visited by humans. Astronauts went there on space walks to mess with the wiring or fix things that weren’t working, but most of Izzy’s crew spent their whole missions inside the much smaller stack of cans that made up the station’s “body.”

That was going to have to change.

Izzy herself could only expand so much. This was not a question of stacking on more cans, or adding additional tori. Beyond a certain point you simply couldn’t jam more complexity into such a focused volume. Electrical power was needed to run just about everything. Whenever it was used, waste heat was generated. The heat would build up in the space station and cook the occupants unless it was collected by a refrigeration system and piped out to radiators that would “shine” the heat, in the form of infrared light, into space. Jamming more people and systems into the central body of the space station would just require more solar panels, more batteries, more radiators, and more plumbing and wiring to connect them all. And this didn’t even address the human factors: how to supply people with food, water, and clean breathable air, and how to recycle carbon dioxide and sewage.

Knowing this, the brain trust behind the Cloud Ark — an ad hoc working group of governmental space agency veterans and commercial space entrepreneurs — had opted for the only strategy that could possibly work, which was decentralized and distributed. Each arklet, as the component ships were being called, would be small enough that it could be heaved into orbit on the top of a single heavy-lift rocket. It would draw power from a small, simple nuclear reactor fueled by isotopes so radioactive that they would throw off heat, and thereby generate electricity, for a few decades. The Soviet Union had used such devices to power isolated lighthouses, and they had been employed in space probes for decades.

Each arklet would accommodate a small number of people. The number kept changing as different designs were drawn up, but it meandered between about five and a dozen. Much depended on how rapidly it would prove feasible to mass-produce inflatable structures; these made it possible to create much more spacious volumes by housing people in what amounted to thick-skinned balloons. But making balloons that could withstand atmospheric pressure indefinitely while also standing up to solar radiation, thermal swings, and micrometeoroids was no small project.