Higher Education

by Charles Sheffield

  He could not avoid contact now. But at least the question of identity would be answered. Rick waited, and knew the exact moment when the other saw him. There was a reflexive jerk in the suit's arms and head, followed by a slight alteration of thrust vector.

  "You're pretty early," said a voice in Rick's headset.

  It was Jigger Tait, heading straight toward him.

  "Yeah. You too." Rick at once thought of Deedee's worried face. There was no reason at all why Jigger should not be out here—he was senior enough to go anywhere he pleased—but that did not explain why he would choose to be wandering around outside, alone.

  "You mean for heat-cleaning the smelter?" Jigger spoke casually, as though meeting Rick was the most natural thing possible. "Oh, I won't be staying for that. I've seen it before, with other apprentice groups, and anyway I have work that needs doing inside. I'll see you later."

  He jetted off and entered the open outer door of the airlock, leaving Rick perplexed. Jigger had offered not one word of explanation as to what he was doing. Rick could think of no reason why Jigger needed to be wandering around—prowling around, in Deedee's word—the smelting module. On the other hand, if Jigger wanted to prowl the interior unobserved, he would soon have the perfect opportunity with the apprentices all busy outside.

  Hopes for a quiet half-hour of serious thinking had faded at the first sight of that red spacesuit beacon. It faded farther when the airlock opened again and another suited figure emerged.

  Rick's initial thought—Jigger returning—vanished with one look at the newcomer. She was as slim as Jigger was muscular, and considerably shorter. He also knew exactly who it was. An apprentice's style in manipulating the motion controls of a spacesuit was as individual as a walk.

  "Hi, Alice." Rick moved toward her. "We're early."

  She must have expected to be alone, because he saw the instinctive jerk of surprise.

  "Rick? I didn't think there would be anybody else out here yet."

  "Me neither." He advanced until they were within a few feet of each other. "But you were exactly right. Initiative is the name of the game, and Polly sure grabbed it."

  "For today she did." Alice didn't sound upset, the way that Rick felt. "What was it you told me Vido Valdez said, when the two of you were always fighting? Are you still fighting, by the way?"

  "No. We get on just fine."

  "But you're not close?"

  "No, I wouldn't say we are." The conversation wasn't making a lot of sense to Rick. "What Vido said to me when?"

  "When Dr. Bretherton told the two of you to cool it, or get thrown out."

  "Oh, yeah. Vido told me, 'It ain't over 'til I say it's over.' "

  "That's what I meant. Well, I feel the same about Polly. She's riding high at the moment, but she hasn't won until we say she has. We just have to come up with better ideas."

  "Great." Rick knew his skepticism was showing through. "Got any?"

  "Not yet. That's why I'm here. But we will have. Come on."

  She led the way over to the smelter. It was open and airless and they wandered inside it together, examining the odd airlock, the places where suits could be stored, and the array of monitoring instruments on the lower flat end. They looked at the great inductive heating coils, which would soon raise the whole interior to a temperature of thousands of degrees. At the other end of the smelter Alice made another inspection of the control panel that allowed the segmented metal sectors to iris open or to close for an airtight seal. Finally they moved together along the curved outer surface of the cylinder, studying the little fusion drives that caused the cylinder to spin on its central axis or to slow to a halt.

  "Ideas?" Rick asked as they cycled back to their starting point at the base of the cylinder.

  "Some. I don't want to talk about them, though—they're still half-baked."

  Rick understood that completely. You might get what seemed like the world's greatest idea for the first half hour, and a day later you'd realize that it was a complete crock. In any case, this was no time for discussing secrets. The rest of the apprentices were beginning to appear from the lock, wandering in small groups over to the smelter. Because Rick and Alice were already there, it was natural for the others to treat them as a group center and gather around them.

  Polly arrived last, followed by Barney French. "I would like to describe the plan for today," she said in a wobbly voice, while she was still approaching the rest of the group.

  She was nervous, and no wonder. Everyone would have a role, but this was Polly's show. Barney wouldn't let her do anything that might destroy or damage the smelter, but it would be almost as bad to be given a public warning, or to have one of the other apprentices point out why what she was suggesting was crazy and dangerous.

  Polly moved to stand in front of the triple airlock. "The good news," she said, "is that we won't have to worry about rotating the smelter, because we don't have ore to melt and centrifuge. That means we don't need to inspect the fusion engines on the outside. The other good news is that we won't need to go to four thousand degrees, even though the structure can stand it. Twenty-eight hundred degrees will be enough to oxidize and vaporize all the residues that line the smelter.

  "Finally, we won't need anything like full atmospheric pressure for this to work. If we use pure oxygen at one thirtieth of a standard atmosphere, that will do nicely.

  "The bad news is something that I didn't realize when I first thought of using heat to clean the inside of the smelter. When you melt a metallic asteroid by electric inductive heating, there is good conduction through all parts of it. In other words, heat travels easily to everything you want to melt. But we are dealing with just a thin layer of residue, too thin in places to conduct much of anything—heat or electricity. That means induction is inefficient, and so is conduction. Instead, we have to make the whole interior of the smelter into a radiating enclosure at a uniform temperature—a black body, that's called in physics. Unfortunately I don't know anything about black bodies—regardless of what some people around here might think."

  It produced a laugh, as Polly had intended. Rumors of her affair with Vido Valdez, darkest-skinned of all the apprentices, were widespread.

  "I still don't understand black body radiation," she went on. "Chick Teazle did all the work for me, and I want to give him credit."

  "Credit for me if it works," Chick said cheerfully. "But Polly's fault if it goes wrong."

  "It had better not go wrong." Now Polly was not joking. She had too much riding on this. "I've worked up the inspection schedule that has to be done before we begin, and the assignment for each of you will show on your suit's interior display. If anybody doesn't know what to do, or has trouble when they start doing it, come back to me. I'll be standing right here."

  Rick's assignment was straightforward: inspect the power supply for four of the inductive heating units on the periphery of the smelter. As he moved to do it, he realized that Polly had the worst job of all. She would just hover in space with no assignment, waiting and worrying until everyone else was finished.

  On the other hand, he wasn't going to skimp his own task for the sake of Polly's peace of mind. He checked the power supply, slowly and systematically, then the transformers, and finally the inductive coils themselves. Beside him, Gladys de Witt did the same thing for four other units. In the well-lit interior he could recognize her by the color coding bars on her suit.

  "Sure beats scraping," she said, as they finished the job and moved together back to the exterior of the smelter. "Wish I'd thought of it."

  Polly and Barney French were waiting for them with half a dozen of the apprentices. Others came drifting back, in ones and twos, while Polly kept an audible head count. Last of all were Vido Valdez and Alice Klein, appearing together around the outside of the smelter.

  "Right," Polly said. She sounded breathless, although she had not moved for the past half hour. "All in working order. Time to pressurize. I'll give the command, but you'll all be rec
eiving the same displays as I will."

  Status monitors flashed their reports onto Rick's suit display. There was nothing to see at the smelter itself, where both ends were now closed and airtight. The internal gas pressure crept slowly up to one thirtieth of an atmosphere.

  "Now we're going to begin heating," said Polly. "Before we start, we'll all get well out of the way."

  She led them away from the smelter and away from the main body of CM-26, to where the cluster of small co-orbiting asteroids waited.

  "I don't see how anything can go wrong," she said, "but just in case, we will use one of these as shielding masses. Get close to it, so you can see the SM but if you need to you can duck out of the way."

  As the apprentices moved into position, Rick noticed that Barney French was doing her own head count and assessment of position. She moved one person—Rick thought it was Lafe Eklund—back a little, so that he was better shielded by the asteroid's bulk. Finally she nodded to Polly.

  "Here goes." Polly's words sounded more like a prayer than a statement. Again there was nothing to see at the SM, but the suit displays showed a massive drain on the central power supply, and almost at once a rapid rise in ambient interior temperature.

  Five hundred degrees—eight hundred—eleven hundred.

  Rick, like everyone else, stared in fascination at the smelter. He realized that it was another of the million facts he did not know about this sort of mining. How high a temperature did a body have to reach before it turned red-hot? How high before it was orange or white-hot? Twelve hundred degrees, read the display. Shouldn't the heated SM be glowing now against its background of stars?

  "We don't like to waste power," Barney French said suddenly, as though she was reading Rick's mind, "so there is excellent thermal insulation between the SM's interior and exterior. You won't see a thing from here. But if you were inside—and managed to survive—you would find the walls starting to glow red at five hundred Celsius. If you were inside now, at twelve hundred degrees, they would be white-hot.

  "We still have a way to go. To give you an idea of what we're dealing with here, iron and nickel both melt at about fifteen hundred and boil at twenty-seven hundred in a standard atmosphere. Silicon boils at twenty-three fifty, silicon oxide at twenty-two hundred. We don't have any platinum or iridium in the dross, which is just as well, because platinum doesn't boil until thirty-eight hundred and iridium at over forty-one hundred. Mining can be warm work."

  The temperature had been climbing fast. It was up to eighteen hundred degrees. Rick tried to imagine the inferno inside the smelter. The oxygen would have gobbled up any pure metal into compounds, and the dross would be beginning to vaporize. The internal pressure had gone up, to more than a fifth of an atmosphere, and it was still rising.

  The inside pressure and temperature were now increasing in unison. There must be a simple explanation for that, if only he could think of it.

  "Twenty-two hundred," Polly said nervously, although every apprentice could see that on the suit display. "Three more minutes, and we'll hit twenty-seven. I'm going to cut power then and hold it for another two minutes, then give the command to open the big end as wide as it will go."

  "And what will happen then?" Barney asked the question in—for her—an oddly gentle voice.

  "The gas inside will blow out. The inside will be left clean."

  "True. But something else will happen that we have to worry about. I wanted you to have the first chance with this, Polly, but now I'm going to open it up. Anybody. What do we have to do when we let the gas inside blow into space?"

  There was a long silence. "Stay out of the way?" Chick Teazle said, in a let's-try-anything voice.

  "That, certainly. What else?"

  It was a real-time contest, the worst one yet. Rick struggled to visualize the operation. The gas inside was superheated, but there was no way it could damage anything when it came out through the opening aperture at the end of the smelter. It came out hard, because the inside pressure had increased to a third of an atmosphere. Jetted out.

  "Rocket!" he shouted, afraid that someone else would beat him to it.

  "Be more specific, Rick."

  "The gas that comes out will be in a jet, it will produce a rocket effect just like the drive on a ship. The smelter will be driven in the other direction."

  "So what do we need to do?"

  "Balance it." That came as a shriek from Polly, not Rick. "Use the little thrusters on the outside of the smelter to equal the push from the escaping gas. But I don't know how to work out the thrust!"

  "Nor does anyone else in the group," Barney said. "But I do! You're feeling crushed, Polly, but you shouldn't. This exercise makes two points. First, you all have a way to go before you look like mining engineers. Second—and more important—what you do when you work for Vanguard will almost never be a solo effort. You are part of a team, and no matter how much you want to succeed you should never forget that. Here's the information for the impulse correction."

  Thruster settings flashed onto the suit displays. Obviously, Barney had computed and stored them in advance. The necessary counter-thrust was small. Rick realized that nothing catastrophic would have happened, even if Polly had proceeded as she originally planned. The smelter would have moved away from CM-26 at a modest pace, and a ship would have been forced to go out and bring it back. Barney had interfered to make a point, not to prevent an accident.

  "Let's do it," said Barney. "Go ahead, Polly."

  At last, there was something to see. The end of the smelter began to open, and a cloud of incandescent gas spewed out into space. At the same moment half a dozen thrust units on the side of the SM flared briefly into action. To Rick's eyes, calibrating the position of the smelter against the starry background, nothing moved so much as a millimeter. From where he was hanging in space he could see into the open maw of the smelter. The inside shone a brilliant white, which as he watched faded to orange, to bright cherry-red, and at last to the dull glow of a dying ember.

  "Don't even think of it," Barney said. A few of the suited apprentices were already floating in the direction of the smelter. "You won't be able to go inside and see what it's like without frying for another couple of hours. Let's go and have a meal and come back later. You should be feeling good about things. I told you that the last group of apprentices finished the cleaning job in two days—but I didn't tell you that they needed until nearly midnight.

  "You beat them by"—she consulted her suit chronometer—"more than six hours. You've earned a reward. You can tell me later what it will be. Polly gets a veto vote, because you couldn't have done this without her brainwave."

  A reward. All through the meal the preferences had been kicked around. A party, a dance, a feast, a day without work assignments.

  The knock-'em-dead idea did not emerge until they were back in their suits, examining the results of the fiery purge of the SM.

  Those results were spectacular. The smelter wasn't just clean, it was immaculate. Not a trace of grime or metal residue or dust of any kind could be seen anywhere. The instruments and walls shone like new.

  "So what do you think?" Polly sounded diffident, but Rick could see her eyes, bright behind her visor.

  "Super-colossal-amazing." Deedee was standing next to her, and she reached down and ran her glove over one of the plane surfaces. It came away spotless. "Clean enough to eat off."

  She paused, and she and Polly stood staring at each other.

  "That's it!" Polly exclaimed.

  "If we're allowed to," said Deedee.

  "Allowed to what?" Obviously, Polly and Deedee had communicated an idea. Just as obviously, Rick had been present but somehow left out.

  "Party, of course," said Polly, in tones that suggested any fool would know.

  "In here," Deedee added. "We said it's clean enough to eat off the floor—so let's do it."

  "Eat, and dance, and riot."

  "If Barney will let us."

  "Why shouldn't she?
We'd have to fill it with air, of course, so we won't need suits."

  "And we'd have to bring food and drink over—no way we could prepare it here."

  "And a little cylinder rotation, to give enough gravity to dance."

  "And we'd want partitions, for privacy."

  "And couches in them, for you-know-what."

  They were off and running, while he was totally ignored. After another couple of exchanges he gave up and moved away. It was obvious that they didn't need him.