They had moved out well past the Moon, heading away from the Sun. Atlantis was somewhere ahead of them, just off the plane of the ecliptic.
“We’ll soon be near enough for visible contact,” she went on. “We ought to get a lot of back-scattered light from this angle, so it will be easy to see.”
Rob was sitting by the forward screen, the electronic magnification turned up to the maximum. Nothing showed there but liberal quantities of random noise, producing a snow-storm effect on the display. “We’re less than twenty thousand kilometers out, according to the radar data,” he complained. “If that figure of a two-kilometer diameter is accurate, it should be showing better than twenty seconds of arc. We ought to be seeing it easily with this magnification — so where is it?”
Corrie frowned at the blank display screen. “We can pick up anything down to a second of arc with that set of cameras. And I just checked the pointing, it’s straight at Atlantis. I’ll bet that Regulo and Morel are playing games with the albedo again. There’s a variable reflectance material on the outside of Atlantis, so they can absorb solar radiation selectively, with just the ranges of wavelengths that are best for the interior. You might try taking a look in the thermal infra-red.”
Rob raised his eyebrows. “I’ll try. But I thought those variable albedo materials were still text-book. It’s a fancy technology. Let me see what we get with the ten to fourteen micrometer scanner. The resolution won’t be as good, but maybe we’ll pick up some sort of blob.”
He switched the channel selector, while Corrie leaned over his shoulder. “Regulo doesn’t let things stay in the text-books,” she said. “If there’s any way it can be transformed into a piece of hardware, he’ll do it. He was asking me the other day if you could make the Spider extrude materials at high temperature. I don’t know what he was after, but I suspect that you’ll find out when we get to Atlantis.”
“He asked me that, too.” Rob was tinkering with the fine tuning of the screen display. “It’s just a question of using the right materials for the extrusion nozzles — easy enough. Ah, there we are.” They stared at the screen, where a small, fuzzy ellipse had appeared.
“That can’t be it,” objected Corrie. “The picture we get ought to show a sphere.”
“It would, in the visible part of the spectrum. We’re looking at it in the thermal infra-red, remember, so we’re seeing differential heat emission from different sides. Atlantis must be rotating, with the side facing away from the Sun always a bit cooler. That’s why it looks lop-sided.” Rob was peering with interest at the display of the asteroid. “Two kilometers across, eh? What do you think Regulo would charge to make one like that for somebody else?”
“Price isn’t the issue. He couldn’t do it.” Corrie saw his skeptical look. “Honestly. It’s not that he wants the only one — though I suspect that he does. This one was a fluke. There will never be another like it.”
“Never is a long time. Why do you think it’s one of a kind?”
“Judge for yourself when we get there. Regulo found this about thirty-five years ago, when they were doing his first complete survey of the Belt. Nobody else realized the significance of the find, so he got the rights to it for almost nothing. Most people thought it was useless — who could use something with that composition? All the outside was water ice, more than you’d ever need for the volatiles of an orbit adjustment. There was a lump of metallic ores — very pure — sitting right in the middle, but it would be difficult to reach.”
“You mean it wouldn’t pay to tunnel in and mine it? I suppose not. There are plenty of other candidates around, with more ore and less water.”
“That’s what the other miners decided. But after he bought long-term rights, Regulo coated the outside with a black hi-temp plastic, started it rotating, and dropped it into a tight hyperbolic. Then he picked it up on the other side, once it was well clear of the Sun.”
Rob was busy at the calculator interface. After a few seconds he looked up and shook his head. “It wouldn’t work, according to me. You’d never melt it with a single fly-by.”
“Did I say that? He had his team pick it up near Mercury and put it into a Trojan orbit with the planet. He wouldn’t go near it himself, of course, not that close to the Sun. While the meltdown was going on he had a mining group confirm the first assay of the ores and do the core analysis in more detail. That became a lot easier after partial melt. It took five years to complete the change from ice to water, then they used some water in the drives to take it further out. Regulo met them near Earth and started the installation of the hydroponics systems. By that time, some of the others had begun to get an idea what he was doing.”
“And now he has it self-supporting?”
“Completely. Regulo says that with a few months’ warning Atlantis could survive if Sol went nova. He’d simply move the whole thing out to a safe range from the Sun.”
“But he’s exaggerating.”
“Of course he is.” Corrie laughed, throwing her head back. As she did so. Rob was distracted by her sudden resemblance to Senta Plessey. Would he be able to help Howard Anson with Senta, after this trip to Atlantis?
“But he’s entitled to exaggerate a bit,” Corrie went on, and Rob pulled his attention back to her. “He’s rather proud of that job,” she said. “He claims that he’s the only person in the whole System who would have thought of it.”
She looked at Rob, head cocked to one side. “You know, you two are alike in another way. Each of you is convinced that he’s the only smart person in the System.”
“Universe. Whereas?”
“Whereas Caliban is a lot smarter than both of you put together.” Corrie was laughing. “Smarter than Joseph Morel, too.”
“Caliban? Who the devil is Caliban?”
“You mean Regulo hasn’t told you? Then you have another treat coming. Just wait and see.”
She was in an unusually cheerful and fickle mood. That was all the response that Rob could get. She replied to all his questions with cryptic, evasive answers, while the cruiser bore them steadily closer to Atlantis.
Rob remained peering into the scope, seeking more details of the mystery asteroid ahead. Following Regulo’s work, it had become a sphere of water rather less than two kilometers across. It was surrounded by a restraining membrane of tough flexible plastic, a trapping surface for solar heat. The aquasphere was pierced by twenty metal-lined shafts that served as structural braces and also provided access from the exterior of the asteroid to the central metal sphere where living quarters and laboratories were located. Other entry to the two-hundred-meter central biosphere came from the ports that connected the living quarters to the aquasphere. As they drew closer, Rob could see the silver gleam of heavy drive equipment positioned near the outer edge of each entry shaft. The whole ponderous assembly was rotating slowly about its center of mass. Small attitude jets positioned at a number of points on the surface showed how the rotation rate was controlled.
“I thought you were just joking about getting away from a nova,” said Rob. “Now, I’m not so sure. There are drives all over that thing and they look like big ones. Do you know what sort of acceleration he can get on it?”
Corrie was busy at the communicator, tuning in for their final arrival. “Not much at all,” she said. “There’s plenty of power, but the limiting factor is the strength of the support shafts and the surface membrane around the aquasphere. They take the main stresses when Atlantis is accelerated. The interior is nearly all liquid water, even allowing for the support shafts and interior structures. You need monster drives for any acceleration worth speaking of, because Atlantis masses about four billion tons. That takes some shifting. Regulo usually doesn’t try for more than a hundredth of a gee. He gets around, but it takes a while.”