Mining the Oort

  "Well, then. Come by when you get a chance. Not right away; better wait till the surprise flare drill is over, otherwise we'll just get interrupted. Red 2-11, do you know where that is?"

  "No, but I'll find it."

  Clyne laughed. "You're right about that. That's one of the many things you can't get on the station: lost."

  His picture disappeared as he disconnected, and the screen went to its "ready" menu. Dekker hung thoughtfully before it for a moment, thinking about what to do next. Was he hungry? Not really, he thought, but still he would be, sooner or later. So he selected "food services," and was just learning that the dining halls were open twenty-four hours a day and that there were three of them scattered around the station when he heard a familiar polite cough from behind him.

  It was Toro Tanabe, peering in the open door to Dekker's room. If he hadn't heard the cough, Dekker might not have recognized him at once, because he had never seen Tanabe's face at about a hundred-and-fifty-degree angle from his own vertical before. "Come in," Dekker said, waving Tanabe to a loop on the wall. "Well. How do you like Co-Mars Two so far?"

  Tanabe took the question seriously. "It is not so bad, I suppose, if one does not expect comfort. But I do not care for this business of narcotics. I do not have strong moral feelings about dope, DeWoe, but it is foolish to have it on a station, when you must know you will be caught."

  "Evidently somebody didn't think so. Do they know whose it was?"

  "Not as far as I know. McCune would say nothing, and neither would this Parker person. Do you know him, DeWoe? No, I suppose not—I suppose it is only Earth people who think all Martians must know each other, just as Americans think of Japanese. Anyway," he said, beginning to look more cheerful, "in some ways this place is quite civilized. Voice-mail to Earth is available; I have already called my broker to buy my lottery tickets for this week."

  "Good luck with them."

  "Yes, thank you." Tanabe cleared his throat. He seemed slightly embarrassed. "I am just down the hall from you, DeWoe. I—ah—I think I should apologize for not asking if you would like to share quarters with me here, as we did at the academy."

  "Oh, that's fine," Dekker said, having never for a moment considered that option. If he were going to share quarters with anyone, the roommate he would have wanted wouldn't have been Toro Tanabe. It would have been Rima Consalvo. Or Ven. Or even Annetta.

  Tanabe appeared to be thinking along the same lines. "It is just that, if I have any luck, I think I may follow the local custom of 'duty wives' here. It has much to recommend it, I think."

  Dekker tried not to grin. "Do you have anyone in particular in mind?"

  "Not yet, no. I would not be surprised if you did, though. Although I do not think the choices are as large as one might have hoped; there are more men than women on the station, and I am told that most of the women are already taken."

  Dekker digested that before asking, "Do you happen to know if any of our people have taken, ah, duty wives?" Or become duty wives, which was what he really wanted to know.

  "I don't think so. I don't think they've had time. Still, if you have any particular plans I think it would be a good idea to start making your—holy God!" he interrupted himself, startled, as a harsh hooting sound blared all over the station. "What the hell is that?"

  "I think," Dekker said, "that it's the solar flare alarm. I'm pretty sure it's only a test, Tanabe. But maybe it isn't, so I guess we'd better get on down to the flare shelter."

  Dekker wouldn't have had to know where Co-Mars Two's flare shelter was—all he and Tanabe had to do was to follow the casually moving traffic, all in the same direction—but of course he did know; all those hours studying the virtuals had taught him the layout of the station. The shelter was not in the center of the structure, as it was on spaceships and on the terminals of the Skyhooks; on those things the safest places were central, because they rotated from time to time. Co-Mars Two didn't. The center of the station was filled with the reserve water tanks and the heavy machinery that pumped water and air around the station. The shelter lay just past those solidly radiation-opaque masses, on the side away from the Sun, and when there was no flare or drill in progress it was used as the station's gym.

  For two people just up from the training school on Earth, the hard part wasn't finding it, it was getting there. Neither Dekker nor Tanabe had yet mastered the art of getting around in zero-g and so they floundered and bumped into each other and the walls of the passages. Tanabe panted, "Thank God this is only a drill. I would hate to have to do this in a real emergency!"

  "It's never a real emergency," Dekker told him, with the wisdom of someone who had grown up on a planet where solar flares were sometimes a problem. He thought of explaining to Tanabe that the radiation from the Sun always came in two installments: first the visible-light sighting of the flare itself, then, hours later, the shower of particles. He would have done it, too, if he had been able to spare the breath. The two of them piled up at an intersection, and while they were collecting themselves to change direction from yellow to green Dekker caught sight of Annetta Bancroft and Dr. Rosa McCune, some way down the green corridor. They weren't moving toward the shelter. They were simply hanging there, and they were in the middle of an argument. It looked like a hot one, too; Dekker was astonished to see that Annetta was in furious tears, while the psychologist was stonily shaking her head.

  Tanabe was staring at them curiously, but Dekker tugged at his arm and the Japanese followed reluctantly. "What was that all about?" he panted.

  "Not our business, anyway," Dekker said, as a proper Martian. "They'll come along when they're ready. There's the shelter."

  It took a while to get into it, because there was a knot of people waiting at the heavy air-seal door, and a loud babble of talk from inside. When they had got through, Dekker looked around curiously. The room was bigger than he had expected, all six of its walls lined with the spring-loaded exercise machines everyone on the station had to use regularly to try to keep their bones hard and muscles from weakening. People hung about the room in clusters, at all angles.

  By the time Dekker had found something to anchor himself to he saw that Shiaopin Ye was swimming toward them. She was upside-down to Dekker, but he saw the expression of worry on her face. "What's the matter?" he asked.

  She shook her head, twisting around so that they were closer to a normal conversational position. "I don't know what kind of place we've come to, DeWoe. Were you there when they found narcotics in the cargo?"

  "Yes."

  "Did you know who it belonged to? It was in personal effects for the chief of station, Marine. And they woke him up and gave him a test, and he had drugs in his bloodstream. Rosa McCune is sending him down with the ship; now this man Parker is the chief."

  "Jesus," Tanabe said. "The chief? And he is being fired from his own station?"

  Dekker shook his head. "If he's doing drugs, he has to go. Of course. Especially the chief of station."

  "But if the chief of station is an addict," Ye persisted, "what does that say about Co-Mars Two?"

  Dekker had no answer for that. He squirmed around to look toward the doorway. The last few stragglers were coming in; he saw Annetta Bancroft hauling herself along the wall, no longer weeping but the expression on her face still furious. Close behind her were Rosa McCune and the deputy chief—no, now the chief. Parker gave an order, and the door closed, sealing them inside.

  He picked up a microphone. "Quiet down," he ordered. "I have an announcement. Narcotics have been found on the ship, and therefore Dr. McCune has ordered a blood test for all personnel. There is no actual flare. This is only a drill. But each of you will give a blood sample before you leave. The drill is over, but you can start lining up for your tests now." And added, as a late afterthought, "Please."

  Dekker realized very quickly that testing two hundred people was going to take time. That was an annoyance, but he became aware of a greater annoyance still. There was one simple biological t
ask he had neglected ever since getting on the ship. Before very long he would have to relieve his bladder.

  There had to be provisions for that in the flare shelter, he realized. There were; there were a dozen of them, along one stretch of wall.

  He was, however, now in zero gravity.

  He was grinning when he came out, proud of himself for having managed the unavoidably complicated machinery of a zero-g toilet, and he discovered his boss, Jared Clyne, hanging nearby. Clyne was grinning, too. "I saw you go in, so I thought I'd better stay around in case you needed help, your first time," he said. "How'd you do?"

  "I don't think I'll ever like it. But all right."

  "Good," Clyne said. "Listen, we're going to be here for a while yet, so we can talk now instead of your coming to the office. You've trained on the emergency systems? Then I won't have to teach you anything. All you need, probably, is to walk around the station with me or one of the others in the section, so you can get the feel of the place. The virtuals are good, but, I don't know about you, personally I don't feel as if I know a thing until I get my hands on it. Wang's on shift now. He'll be off in about an hour; if you're up to it, why don't the three of us get something to eat and you can meet him?"

  "I'm up to it," Dekker said. "After that, maybe I should get some sleep."

  "No problem." Clyne turned himself around to look toward the exit. Half the crew were still clustered around there, waiting their turns to give blood samples.

  "Clyne?" Dekker ventured, puzzling over something. "Did you say this other person was on shift? You mean working as a controller?"

  "Right. Part-time. Everybody on the station gets a shot once a month or so."

  "Yes, but what if this had been a real flare? Don't the controllers have to take shelter, too?"

  "Ah, no, DeWoe. All the boards are in the flare shadow—they're put there on purpose, because the shelter here is between them and the Sun. They're pretty safe there. In a bad flare the controllers might take a little secondary radiation—you know, reemitted from the structure of the station itself. But the doses should be light. Of course, you have to keep track of light doses, too, because you have to watch your total lifetime exposure, so next time there was a flare a different team of operators would be manning the boards."

  He cast another look at the door, and shrugged ruefully. "We'll be a while yet. Where are you from, DeWoe?"

  "Sagdayev. It's a little deme on Mount—"

  "Oh, hell, DeWoe, I know where Sagdayev is. I'm from Kennedy—you know, on Elysium? But it's been a long time since I saw it." He looked at Dekker thoughtfully. "If you're from Sagdayev, you're probably related to Gerti DeWoe?"

  "My mother," Dekker said, waiting for the complaint about her he had learned to expect.

  He didn't get it. "She's a great woman, DeWoe," Clyne said sincerely. "My uncle served with her in the Commons. I'm glad to have you here."

  "Well, thanks," Dekker said, warming to the man. Anybody who admired Gerti DeWoe was automatically a friend of her son's; and, actually, the more he learned about Jared Clyne, as they talked, the better he liked the man. Clyne, he discovered, had been upped to full-time controller after Rosa McCune's purge of the "unstable," but he was pulling double duty as head of the damage-control unit—"It's not that I don't trust the other guys, DeWoe; it's just that I wanted to hang on until the station got back to strength."

  "Is it now?"

  "Well—not really. But closer, at least." He hesitated, then said, "Anyway, I don't have as much interest in time off as I used to. My wife was one of the ones who got sent down."

  "Oh, hell. Too bad."

  Clyne nodded. "I thought so—still, she was acting sort of jumpy, the last couple of weeks. What I'm hoping is that whatever it was that bothered her they'll fix in the clinics, and then she'll be back here—well, if I'm lucky, anyway." He cleared his throat and turned away, gazing at the diminishing crowd at the door. "Maybe we should start lining up," he offered.

  "All right." Dekker watched carefully as Clyne gracefully pushed himself from one wall to the other, neatly missing collision with any of the other people still in the shelter. He tried to copy him. He very nearly succeeded; with only one small bump he brought up just behind his boss, and looked around.

  There were only about thirty people left in the gym. Three people were taking the blood samples, Rosa McCune and, Clyne informed him, the station's two medical doctors. It wasn't a complicated procedure; a jab, a pause, a name scribbled on the little ampul of blood, a Band-Aid on the arm, and the subject was allowed to exit.

  Annetta Bancroft was just going through. When Jared Clyne saw Dekker was looking at her, he said, "Tough break for her."

  "Annetta? Why? I mean, she was obviously upset about something, because I saw her arguing with McCune just before they came in here. But I don't know what it was about."

  "I think I do," Clyne said. "I'd give big odds it was about Pelly Marine. McCune sent him down, you know? Found narcotics in his shipment from Earth?"

  "I heard."

  "Well, naturally Annetta was upset. She used to be his duty wife.

  38

  If you wanted to give Mars an atmosphere as dense as Earth's, you would have to find a lot of gas somewhere. How much is "a lot"? Call it about 4,000,000,000,000,000—that's four quadrillion—-tons of gas.

  That's a lot in human terms, all right, but rather little in the larger numbers used by astronomers. Fortunately it doesn't all have to come from the Oort. There's a fairish supply on Mars itself.

  The principal things you need to make a planet capable of sustaining life are what scientists call "volatiles," principally water and air.

  If you look at the composition of the planets of the solar system, you can see that these volatiles are distributed in a fairly orderly way. Mercury, the planet nearest the Sun, has practically none; whatever it may originally have had of them has long since been volatilized by the Sun's heat and—because the hotter volatiles get the more rapidly their molecules move, thus attaining enough speed to overcome the pull of the planet—they have been lost into space.

  Venus and Earth, being farther from the Sun and also a lot bigger than Mercury, are luckier; they have retained much of their volatiles. Then, when you get farther out, past the asteroid belt, you find that practically all of the volatiles have been retained; in fact, the gas-giant planets, from Jupiter through Neptune, are essentially nothing but volatiles . . . but, partly because they are so large and their gravitational grip is therefore so firm, and also because these planets are so far from the Sun, and therefore so cold, the volatiles haven't been able to escape.

  All of that is quite orderly and sensible, and fits the pattern of how the solar system was supposed to develop—with one exception.

  There's the unusual case of the planet Mars.

  Mars seems to have been shortchanged on volatiles. It ought to have more than it does. It did have, once. There are clear indications of river valleys on Mars, which means that there must have been liquid water at some time. Indeed some of these features, like the Valles Marineris, are huger than anything on Earth. They look like a magnified Grand Canyon, and if, like the Grand Canyon, they were carved out by the erosion of liquid water flowing, that amount of water must have been very great. In fact it must have been enough, once, to have given Mars great oceans. How great? Enough, if the water involved had been spread evenly over the surface, to cover the planet half a kilometer deep. It wouldn't have been spread evenly, of course; it would have collected, like Earth's oceans, at low points. But it would have been a lot.

  So where did those volatiles go?

  Most of them must have been lost to space, simply because Mars's weak gravity could not hold them forever. They weren't all lost, though. Visibly, there is still enough of them left to make the Martian polar ice caps. Invisibly, bound into the minerals of the Martian surface, there is a great deal more.

  That's where the Oort program gets its biggest bonus. Once enough comets are
dumped on the surface to raise the surface pressure and the surface temperature a little, all those locked and frozen invisible volatiles can begin to become visible again.

  39

  On Co-Mars Two an exercise session was mandatory, every day, for everybody. It was also hard work. Worse than that, Dekker believed it was, for a Martian who never intended to go back to Earth if he could help it, largely unnecessary work: he didn't need the polysteroided muscles that had kept him alive through the training school, and if a little calcium migrated out of his bones, so what? "For your heart, then," Jared Clyne advised, "As one Martian to another, that's what I tell myself. It doesn't matter why you do it, anyway. The best reason for doing it is that you don't have a choice, because if you skip more than two or three days a month Rosie McCune will have you out of here on the next ship."

  So Dekker spent his hour a day in the gym, like everyone else, working his arms and legs against the springs that provided the only real resistance his muscles would ever get to fight against on the station. The machine he hated most was the one they called "the rack." You buckled your feet onto one set of springs and stretched up as far as you could to grip the handles of another set, and then you did your best to pull your left leg up and your right arm down, and then the other way around, for a prescribed minimum of ten nasty minutes.

  When he finished with the rack he was always aching. As he unstrapped himself he saw that the person who had begun working out next to him was Annetta Bancroft.

  She gave him a cheerful, but noncommittal, nod. "Hi," she said. "How are you getting along?"

  "Outside of aches and pains, you mean?" he asked, rubbing his thighs. "Just fine. And you?"

  She said she was doing just fine, too. The conversation might have stopped there if Dekker hadn't added, "I'm sorry about what happened. With Pelly Marine, I mean."