Exile-and Glory

by Jerry Pournelle

  "If I'm careful about what I eat, three or four hundred hours," Jacob said. "Perhaps longer."

  "We've got to get out of here," Glenda said.

  "I agree, but I confess I don't know how," Norsedal said. "I was telling you what Stoire did. It was very clever, really. First he programmed the computer to report a much lower percentage of Arthurium in the ore. Understand, the computer knew better, and the refinery operated just the same as it always did, but the reported recovery was low. They told the computer to forget about one storage area, and routed ninety percent of the Arthurium there. Simple, clean, and really very pretty. And once Stoire erases the real log, there'll be no record of it at all."

  They had explored every tunnel in the prison a dozen times, but found nothing. A hundred hours passed.

  There was nothing they could do. No laser equipment to send signals with. No electronics. Nothing but some mining gear and the basic materials for staying alive. Even that took a lot of work. The algae in the tank farms had died, and their own power source was fuel cells. There were tanks of hydrogen and oxygen for those, but the carbon dioxide scrubbers needed constant recharging. They had less time than Kevin had thought.

  "I would say two people have a thousand hours more oxygen," Norsedal said. "I could—" He hesitated. "I can add a couple of hundred hours to that, and it won't really matter."

  "I'll be damned if you will," Kevin said. "Something will turn up."

  "I doubt it," Jacob said. "C-4 is scheduled to go in about nine hundred hours. Daedalus is putting in the final equipment right now."

  "And then Stoire and Donnelly are gone," Kevin said. "But how does he get away with it?"

  Jacob shrugged. "It would be no great trick to put the Arthurium aboard C-4. As gold, for example. The bombs go off, C-4 heads for Earth. Somewhere between here and there a ship—it wouldn't have to be a very large one—meets them and when C-4 arrives in Earth orbit, the Arthurium is gone, with nothing left aboard that's not supposed to be there."

  "And it was stupid to leave us alive," Kevin said. "Once he's ready to leave, he'll come back with Donnelly and finish us. No evidence, no embarrassing bodies—"

  "More likely he will take Glenda on C-4," Jacob said. "Donnelly is part of his crew."

  "I'm going to go have another look around," Kevin said. "There's got to be something we can do."

  "I hope you think of it," Glenda said. "I can't."

  "Alas, nor I," Jacob added.

  Kevin prowled through the corridors of their prison. There has to be some way, he told himself. Ceres mocked him from below, less than three hundred kilometers down. It hung huge in the night sky.

  Three hundred kilometers down, and we're moving about half a kilometer a second relative to Ceres, Kevin thought. That's not very much velocity. Under a thousand miles an hour. It doesn't take much energy to get to that speed. How much gasoline does it take to accelerate a car on Earth up to a hundred miles an hour—a gallon or so? We only need ten times that, not even that much.

  There's plenty of hydrogen and oxygen. Marvelous rocket fuels if we only had a rocket. More than enough to get us down, except that the temperature of hydrogen burning in oxygen is a lot hotter than anything we have to contain in it—

  No. That's not right. The fuel cells do it. But they do it by slowing down the reaction, and they can't be turned into rocket engines.

  He remembered the early German Rocket Society experiments described by Willy Ley. The Berliners had blown up more rockets than they flew, and they were only using gasoline, not hydrogen. Liquid-fuel rockets need big hairy pumps, and Kevin didn't have any pumps.

  What did he have? Fuel cells, plenty of them, and so what? An electric-powered rocket was theoretically possible, but Kevin didn't have the faintest idea of how to build one, even if there was enough equipment around to do it with. He wasn't sure anyone had ever built one—certainly he couldn't.

  Back to first principles, he thought. The only way to change velocity in space is with a rocket. What is a rocket? A machine for throwing mass overboard. The faster the mass thrown away goes in one direction, the faster the rocket will go in the other, and the less you have to throw. All rockets are no more than a means of spewing out mass in a narrow direction. A rocket could consist of a man sitting in a bucket and throwing rocks backward.

  That might get a few feet per second velocity change, but so what? There simply wasn't enough power in human muscles—even if he did have a lot of rocks. Was there any other way to throw them? Not fast; and unless the thrown-away mass had a high velocity, the rocket wouldn't be any use. He went on through the tunnels, looking at each piece of equipment he found, trying to think of how it might be used.

  You can throw anything overboard to make a rocket. Hydrogen, for example. That's all Wayfarer's engines did, heat up hydrogen and let it go out through the rocket nozzle. We have hydrogen under pressure—

  Not enough. Nowhere near enough hydrogen and nowhere near enough pressure, not to get velocity changes of hundreds of miles an hour. Ditto for oxygen. Gas under compression just can't furnish enough energy. What would? Chemical energy; burning hydrogen in oxygen would do it, but it gave off too much; there was nothing to contain that reaction except the fuel cells and they did it by slowing the reaction way down and—

  And I'm back where I started, Kevin thought. Plenty of energy in the fuel cells if I could find a way to use it. Could I heat a gas with electricity? Certainly, only how—

  His eye fell on the hot-water tank in the crew quarters. An electric hot-water tank. There was a pressure gauge: forty pounds per square inch. Forty p.s.i.—He looked at the tank as if seeing it for the first time, then went running back to the others.

  "Glenda, Jacob, I've got it."

  Chapter Seventeen

  Jacob Norsedal bent over Kevin's pocket calculator. "I have worked it by three different methods and I get nearly the same answer each way," he said. "I believe it will work."

  "Sure it works." Kevin grinned. "Steam at forty p.s.i. will come out fast. About a kilometer a second."

  "I believe you," Glenda said. "But it sounds silly. Steam rockets?"

  Kevin shrugged. "It is silly. There are a lot more efficient systems. But this will work—"

  "In a low g field," Jacob said. "You will not have much thrust. Of course you won't need much."

  "I'm sure it works," Kevin said. "Now all we have to do is build it." He made himself sound confident; he knew how much room for error there was in his figures. "Look, it takes nine hundred and eighty calories to turn a gram of water into steam. We heat that steam up another thirty or forty degrees and let it out. The energy is moving molecules. We know the molecular weight of water, so we can figure the number of molecules in a gram and—"

  "I worked it too," Glenda reminded him. "And I get the same answer you do, but it doesn't mean I trust it."

  "What else can we do?" Kevin asked.

  "Nothing. You're right. Let's get to work."

  They disconnected the hot-water tank and drilled holes in it. Several turns of heating wire went through the holes, then they sealed them in epoxy. At one end of the tank they drilled a large hole and threaded a pipe into it, threaded a large valve onto the pipe, and welded a makeshift rocket nozzle beyond that.

  When it was done they tethered the tank and filled it with water, then connected a fuel cell to the heating leads. "Here goes," Kevin said. He threw the switch to start the heaters.

  Slowly the water inside heated, then began to boil. The pressure shown on the gauge began to rise. In half an hour they had forty-five pounds of pressure. "All right, let's try it," Kevin said.

  Glenda turned the valve to let out steam. A jet of steam and water shot out across the surface of the moonlet. Ice crystals formed in space and slowly settled to the rocket surface. The jet reached far away from them, well off the moonlet itself. The tank pulled against its tether lines, stretching the rope.

  "It works!" Kevin shouted. "Damn it, we're going to make it!" H
e shut off the electricity. "Let's get her finished."

  It didn't look like a spaceship. It didn't even resemble a scooter, crude as those were. It looked like a hot-water tank with fuel cells bolted onto it. For controls it had vanes set crosswise in the exhaust stream, spring-loaded to center, with two tillers, one for each vane; a valve to control steam flow; and switches to connect the fuel cells to the heaters. Nothing else.

  The tank itself was fuzzy: They'd sprayed it with Styrofoam, building it up in layers until they had nearly a foot of insulation. There were straps on opposite sides of the tank to hold two passengers on.

  The tank held nearly a hundred gallons of water. Kevin calculated that they had more than enough energy to boil it all in their two fuel cells, and they would only need sixty gallons to get to Ceres. The number was so small that he ran it four times, but it was correct.

  The strangest part was the stability system: a pair of wheels taken from a mining cart and set up in front of the water tank. Electric motors rotated the wheels in opposite directions.

  "Damndest gyros in the history of space research," Kevin said when they got the ship completed. "In fact, it's the damndest rocket ever."

  "It ought to have a name," Glenda said. "Something heroic, fitting a knight rescuing us from durance vile—"

  "How about Fudgesicle?" Kevin suggested.

  "You'll hurt its feelings," Glenda said.

  "The Gump?" Norsedal asked apologetically.

  "Stop that! Galahad. That will do nicely, I think."

  "You're crazy," Kevin said.

  Norsedal laughed. Glenda's own laugh was strained. "I'm about to get aboard that thing, and you say I'm crazy? And you built it? Kevin, are we ready?"

  "I guess so. I've been putting off the awful moment, but—"

  "Right. Come on, Jacob—"

  Norsedal sighed. "I have been over the calculations. That Gump cannot carry three people. You will be lucky to get down alive with two. Therefore I am not coming."

  "You have to!" Glenda insisted. "If you don't get down, it does us no good—"

  "Not true," Norsedal said. "I've given you the key words. And you do not know where you will land. Now it's true that I get around better in low gravity than I ever did on Earth, but it is also true that I am not athletic. I doubt that I can make my way over hundreds of kilometers of ravines—not in my present condition."

  "You're feeling the lack of insulin?" Kevin demanded.

  "Yes," Norsedal sighed.

  "One of us should stay with you—" Glenda said. She sounded doubtful.

  "Nonsense. You must go, because Kevin could do nothing alone once he gets there. Kevin should go because it is more likely I will be rescued if you two get down safely, and two are more likely to succeed than one. Now, are you ready?"

  "I guess so," Kevin said.

  "Then let's do it before we lose our nerve," Glenda said.

  "Right." The total mass of Galahad with full water tank was just under 550 kilograms. In C-2's tiny gravity it was no problem at all to carry it outside.

  They stood on the rocky surface of the moonlet to let their eyes adjust to starlight. Ceres filled a full sixty degrees below them, a third of space, so close they could not even see all of it. It loomed huge and darkly forbidding, its surface lit by sunlight to a brightness much less than Earth's moon, but it was enormously larger than any full moon.

  "We won't have any trouble finding it," Kevin said.

  "No," Norsedal said. "But finding it is not your main problem."

  "Don't I know it."

  Glenda said nothing. All three of them had tried to work the problem of a landing orbit, and they couldn't do it with a pocket calculator. The equations for low-thrust trajectories were too complex, and they had too little data about Galahad's probable performance. They would simply have to navigate by eye and hope to cancel out all their velocities.

  They carried the hot-water tank to a low peak on the moonlet and pointed it so that the rocket nozzle was aimed as close to the direction they moved across Ceres's face as they could manage.

  "Time," Kevin said.

  "I'm scared—"

  "I'm terrified," Kevin said. "But what choices have we? You know damned well Stoire and Donnelly will be back—"

  "Yes. Let's do it."

  It took only a gentle effort to push the steam rocket away from the moonlet, but the cartwheel-gyros resisted any effort to turn it. Finally they got it oriented properly in space. Then they climbed aboard.

  "Full head of steam," Kevin said. "Almost fifty pounds. Ready?"

  "Ready—"

  He twisted the steam valve. At first both steam and water were expelled from the tank, but as they began to accelerate, the water settled and the exhaust valve let out only steam. C-2 dropped away. They missed it. It was a prison, but a safe one; now they had only their makeshift steam rocket.

  Galahad showed a tendency to tumble, but with the gyros resisting, they were able to control it with the steering vanes. A plume of steam shot from the tank, rapidly crystallizing into ice fog that engulfed them.

  "Damn. That's going to make it hard to see," Kevin said. "Nothing we can do about it." He peered down toward Ceres. It didn't seem any closer. Jacob's farewell faded in their headsets.

  Norsedal's calculations had shown that twenty minutes' thrust should be enough to cancel all their orbital velocity. It would use up just about half their fuel. Once Galahad was stopped dead in orbit above Ceres, they would fall toward the asteroid, and they would have half their steam left to counteract that.

  The trouble was that Jacob couldn't calculate how high above Ceres they would be when the twenty minutes were finished. As they lost velocity, they would lose altitude, and their orbit would no longer be a smooth circle, but an ellipse intersecting Ceres—somewhere. At the end of twenty minutes Kevin cut the power off. He was pleased that they still had thirty pounds of steam pressure.

  He waited for a half hour that seemed to take forever. They watched as Ceres grew larger. "Closer. But we're still a long way off. I think we should wait—"

  "Time sure goes by fast when you're having fun," Glenda said.

  Kevin grinned. "Yeah. OK, I can't stand it. Let's start up the steam again. There. Now we come right a bit—"

  "Too far!"

  He adjusted the vanes and overshot in the other direction.

  "We don't have any steam to waste—"

  "I knew that."

  "A little more—Kevin, I think you've got it! We don't seem to be moving so fast—"

  They were falling now, with much less horizontal motion. "Time to wait some more."

  As they came closer, they could see details on the craggy surface below. Rugged canyons, high peaks, deep valleys, and rocks everywhere. Kevin had a protractor which he used to measure the angle Ceres filled in the space below them. Then he used that to calculate their altitude. It was crude and certainly not accurate to better than ten percent, but it was all they had.

  "I read a hundred degrees," Kevin said. "That puts us just about a hundred kilometers above Ceres. If I've figured everything right, and if I'm reading the angles right—"

  "You have to be right, don't you?" Glenda said. "There's nothing else we can do."

  She was right. They couldn't get back to C-2 now, and they wouldn't be able to find the tiny moonlet even if they had the reaction mass.

  "Time for another turn," Kevin said. "I think."

  "We're still moving—"

  "Yes, but that's what the numbers say."

  "All right."

  And a year ago I was working equations in school, Kevin thought. Numbers to crunch and write down for examinations. Now they're something to stake your life on. He twisted the tiller slightly. The tank rotated, and he pointed the tiller the other way to stop it. It took several more adjustments before he thought he had it right. Now the steam jet pointed almost directly toward Ceres, counteracting the asteroid's pull.

  He was tempted to change the steam flow, but he did
n't dare. That was the part he couldn't calculate at all. The mass of their tank changed constantly as steam spewed out, and as the mass fell, the thrust increased. If they turned the steam valve up too high, it would more than counteract Ceres's gravity, and they would move away from it; and when they ran out of steam, they would fall again, this time with no stopping, impacting at seven or eight hundred miles an hour.

  "I feel like singing," Kevin shouted. "I am I, Don Quixote, the Lord of La Mancha, my destiny calls and I go—"

  "Which makes me Dulcinea, the scullery maid?" Glenda demanded.

  "You would rather be Sancho Panza?—No, that's Jacob. And Galahad is our charger. Now I need a broken lance and a bent sword—"