The Legacy of the Iron Dragon: An Alternate History Viking Epic

by Robert Kroese

  “This may be a stupid question,” Hiram Lee said, “but why do we need permission to bounce a signal off a giant dish? Can’t we just do it?”

  Dietrich Haas shook his head. “We’re way too high up. To concentrate the beam, the transmitter has to be at a height equal to half the radius of the dish. In the case of the DSA, that’s about a hundred meters.”

  “I can get you a hundred meters above the DSA,” said Aguilar, “but not for very long, and it’s going to be the last thing we do.”

  “We’d burn up in the atmosphere well before we get that low,” said Huiskamp.

  “I remember when they built the DSA,” said Lee. “Wasn’t there talk about using one of Geneva’s natural craters as a dish?”

  Haas nodded. “Geneva’s a young planet, geologically speaking, and it has very little liquid water. As a result, it’s got a lot of big exposed meteor craters on its surface. Some of them are more than two hundred kilometers in diameter.”

  “Why did they build a dish, then?”

  “Using an existing crater turned out to be impractical,” Haas said. “Most of the craters are fairly remote, and for optimal results, the entire surface would have to be lined with reflective material. A dish with a diameter of more than a few kilometers is overkill for a ground-based transmitter anyway.”

  “You said it would have to be lined ‘for optimal results,’” said Huiskamp. “What about suboptimal results?”

  Haas shrugged. “Most of the craters are relatively smooth and covered with snow and ice, which are reasonably good reflectors of high-frequency radio waves.”

  “So it might be possible to use one of the craters to concentrate our signal?”

  “In theory, sure. But we would have to be at precisely the right altitude and angle relative to the crater and Freedom. The odds of that happening….”

  “We do have some control over our orbit,” Aguilar said. “How many viable craters are there?”

  “That depends on how low we’re willing to go,” said Haas. “The lower we are, the smaller the crater can be.”

  “In about two weeks,” Huiskamp said, “we’re going to hit the planet. So the question isn’t how low can we get before we’re torn apart by the atmosphere.”

  “I wouldn’t count on transmitting at any lower than forty klicks,” Aguilar said. “At that point we’ll be well within the stratosphere, and this hunk of metal isn’t exactly aerodynamic. Drag will start slowing us down pretty fast, and then we’ll fall like a rock.”

  “Then we need a crater at least a hundred and sixty kilometers in diameter,” said Huiskamp. “How many craters of that size are there?”

  “With the appropriate surface composition?” Haas said. “Maybe five or six. I’d have to consult the planet’s topography data.”

  “Do it. And then work with Aguilar to develop a target trajectory that will put us at the right angle and altitude.”

  “With respect, sir,” Haas said, “you understand that this is like ice skating around a spinning basketball and trying to throw a marble so that it not only hits a precise spot on the basketball but then also bounces off to hit another marble a hundred meters away.”

  “Not exactly,” Aguilar said. “We’re not firing a single marble; we’re firing a constant stream of them. We can keep transmitting as long as we have power. So a better illustration would be trying to bounce a laser beam off a tiny mirror on the surface of the basketball. And it doesn’t matter if we miss 99.99 percent of the time. We only need to hit once.”

  “Also, we can eliminate some of the complexity by tweaking my orientation algorithm,” Lee said. “Right now the array is programmed to point at the center of Geneva, but there’s no reason it has to do that. We can orient it at any angle we want. We know Freedom is headed toward Chrylis, and it’s easy enough to calculate the angle of the DSA to Chrylis. All we have to do is match that angle with our array.”

  “Like banking a billiard ball,” said Aguilar.

  Haas snorted. “Except the person trying to make the shot can’t control where he’s shooting from.”

  “He doesn’t need to,” Lee said. “Most of the time the shot will be impossible, yes, but like Aguilar said, it doesn’t matter if we miss most of the time. The billiard player just has to keep his cue aimed as best he can and wait for the shot to line up. If his aim is good—and we know it is—he can’t miss.”

  “Ah, but he can,” Haas said, “and almost certainly will. Because we’re bouncing our ball off a basketball, not a billiard rail. A billiard table is two-dimensional, so a player moving around the table can rest assured that his shot will line up eventually. But a basketball is three-dimensional, meaning that if the player moves around the basketball on a single axis, the odds are overwhelming that the shot will never line up at all.”

  “He’s right,” said Lee. “To make this work, we have to pass directly over the crater.”

  “You mean directly between the crater and Freedom,” Aguilar said.

  “Right. By putting ourselves between the crater and Freedom, we remove one of the spatial coordinates as a variable. Then we only have two dimensions to work with instead of three.”

  “So we’re back to a billiard table, where the shot will line up eventually as long as we keep moving.”

  “But we also have to make sure we’re close enough to the table to make the shot,” Lee said.

  “Yes,” said Haas. “And if we get too close, we burn up.”

  Chapter Twenty-three

  Haas identified twelve craters that were large enough to act as parabolic antennae. Of these, five were too far from the equator for Arc-Zero to match the angle with Freedom. Of the remaining seven, four had been too badly misshapen by erosion or development to refract a signal predictably. Two of the remaining three were on the equator, where the temperature was high enough to allow occasional thaws, resulting in lakes forming at the bottom of the crater. Only one crater, about two hundred kilometers in diameter and coated with a permanent layer of ice, remained a suitable candidate. The crater was called Lucerne.

  The crew of Arc-Zero worked for three days on the math to calculate the thrust vectors that would be needed to put her on a path that would place her at the correct angle relative to Lucerne Crater while she was between forty-five and fifty-five kilometers of the surface. To get the angle right, they would have to time Arc Zero’s approach so that it passed just south of Lucerne Crater while the crater was pointing more-or-less directly at Freedom. Another complication was Arc Zero’s eccentric orbit: she was swinging around Geneva in an ellipse almost twice as long as it was wide, so her pass over Lucerne Crater had to be timed to coincide with the part of her orbit while she was closer to the planet. They referred to this confluence of factors—Arc Zero passing Lucerne Crater while she was between fifty and a hundred kilometers above the surface and Lucerne Crater pointed toward Freedom—as the “alignment window.” Haas’s illustration of bouncing a marble off a basketball while ice skating was beginning to seem overly optimistic.

  Calculating such a precise orbital trajectory was a balancing act, particularly when fuel was so limited. Ideally one would use small amounts of thrust early on to nudge Arc Zero into a trajectory that would eventually put it at exactly the right place at the right time, but there were so many variables that predicting where Arc Zero would be—relative to both Lucerne Crater and Freedom—several days in advance was nearly impossible. Fortunately, Geneva’s axial tilt was less than one degree (the planet’s eternal winters were legendary), and Lucerne Crater was located almost exactly on the equator, simplifying matters significantly. Aguilar executed several small burns to bring Arc Zero’s orbit more-or-less over Lucerne Crater, but timing the decay of her orbit with her proximity to Lucerne Crater and the orientation of Lucerne Crater toward Freedom was another matter. At last, in the interest of preserving fuel and their sanity, they had to put the calculations aside and wait.

  In another week, Arc Zero’s erratic orbit brought it into
the outer reaches of the stratosphere. After a few passes, the drag of the atmosphere, thin though it was at this altitude, was unmistakable: Arc Zero rumbled and shuddered, and after a half an hour, the temperature had increased by nearly ten degrees Celsius on the command deck. Cabins closer to the “front” of the station got so hot that they had to be sealed off. But then the rumbling subsided, and Arc Zero shot back out into space. In a little less than an hour, it would reach the vertex of the ellipse and arc back toward Geneva.

  After three of these passes, they had a much better idea of the effects of atmospheric drag on the station. With each pass through the stratosphere, Arc Zero slowed a little, causing her orbit to decay a little faster. This was a self-reinforcing cycle: the more her orbit decayed, the faster its rate of decay. Aguilar could slow this rate, but only by spending more fuel than they could afford to lose. They were burning plenty of fuel as it was: because of Arc Zero’s awkward shape, it tended to pitch and roll unexpectedly. Aguilar had programmed the stabilizing thrusters to compensate for this to keep her from spinning uncontrollably, but this meant they were burning fuel almost constantly. All they could do was try to keep her together while she fell. Haas estimated that they had about ten to fifteen more passes before the accumulated heat caused by gas particles slamming against the leading edge of Arc Zero would melt the antenna array. A few passes after that, Arc Zero herself would break up. If any of the crew were still alive at that point, they’d quickly die from some combination of heat, rapid loss of pressure and asphyxiation.

  Aguilar and Haas huddled together, doing their best to incorporate his estimates of atmospheric drag into her calculations of orbital trajectory. Huiskamp sat patiently behind them, awaiting their verdict.

  “I think I can do it,” said Aguilar at last. “At this rate, in four more passes we’ll be below a hundred klicks. Three passes after that, we’ll be between Geneva and Freedom while Lucerne Crater is pointed more or less in that direction.”

  “More or less?” asked Huiskamp.

  “Best I can do, Admiral. We’re in a positive feedback loop. Minor variations can have big effects. For all I know, we could break apart before we ever get into position.”

  Two passes later, though, it was clear that Arc Zero’s orbit was decaying too fast. By the time Lucerne Crater was facing Freedom, the antenna would be fried, and the atmospheric drag would put her some three hundred kilometers behind the maximum angle of refraction.

  “Can we do another burn?” Huiskamp asked.

  “I don’t think it will be enough,” Aguilar said. “Propellant tanks are at ten percent, and we’ll need half of that just to remain stable.”

  “What if we lose some mass?” Lee asked.

  “It will have to be a lot. At least ten thousand kilograms.”

  “We’ve already tossed everything that isn’t bolted down,” Haas said. This was close to the literal truth: realizing that the more mass Arc Zero had, the more fuel it would take to adjust her orbit, they had dumped nearly all their supplies: most of their food, medicine, clothing, and equipment. They hadn’t expected to live for more than a few more days anyway, so it was unlikely they would need it.

  “What about water?” Lee asked.

  Haas shook his head. “Even if we could find a way to vent the tanks to space, the water would freeze on its way out, clogging the lines.”

  “Not if we vent it while we’re in the atmosphere,” Aguilar said. “The hull gets hot enough that it should prevent the water from freezing.”

  “True,” said Haas. “Instead, it will boil violently, probably sending us into a spin. If we don’t break apart, we’ll burn all our fuel trying to stabilize.”

  “Venting a little steam won’t destabilize us that much.”

  “You’re just guessing,” Haas snapped irritably. “You have no idea.”

  “Of course I’m guessing, Haas,” Aguilar retorted. “As are you, unless you’ve charted out the thrust potential of violently boiling water from a chunk of a space station hurtling through the stratosphere.”

  “All right, people, that’s enough,” said Huiskamp. “Sounds like it’s worth a try. Get ready to vent the water tanks on the next pass. Aguilar, do whatever you need to do to make sure we have enough fuel to get into position to transmit.”

  “Yes, sir.”

  “In any case, it won’t be enough,” said Haas.

  “He’s right about that,” said Aguilar. “We’ve only got five thousand liters of water on board. That’s five thousand kilograms.”

  “All we’ve got left is people,” said Lee.

  “Four people,” Haas said. “Average mass of seventy kilograms. That’s three hundred fifty kilograms.”

  “Not enough,” said Lee. “Also, you’re nuts, Haas.”

  Haas shrugged. “We’re all going to die anyway.”

  “What about air?” asked Huiskamp.

  No one spoke for a moment. Haas’s brow furrowed. “Actually,” he said, “we have about eight thousand cubic meters of air on board, not counting what’s in the tanks. At one point two five kilograms per cubic meter, that’s ten thousand kilograms.”

  “We’re carrying five times the weight of our water supply in air?” Aguilar asked dubiously.

  “Feel free to check my math,” Haas said indifferently.

  “This is nuts,” Aguilar said. “We have a single space suit. What are you going to do, vent the cabin and let the three people not wearing a suit asphyxiate?”

  “Of course not,” said Haas. “The sensible thing to do is to move the three people not wearing space suits to the hatch and let them get sucked into the vacuum when we open it.”

  “Jesus Christ,” said Aguilar. “You’re serious.”

  “Absolutely I’m serious. What does it matter, Aguilar? We’re all going to be dead in a few hours. We might as well make it count for something.”

  “He’s got a point,” said Lee. “We’re all just dead weight at this point.”

  “Nobody is dead weight,” Huiskamp snapped. “We’re human beings, God damn it. We may find ourselves making some tough decisions, but we’re going to make those decisions as human beings. Not animals. Not machines. Not Cho-ta’an. Human. Remember that.”

  “Yes, sir,” Lee said. “You’re right, sir. I’m sorry.”

  “What’s done is done, Lee. No need to be sorry. Let’s get to work on dumping that water. Aguilar and Haas, put your heads together and try to find a way to make this work—without spacing anybody. We’re a crew. We stay together to the end.”

  “Yes, sir.”

  *****

  Venting the water went more smoothly than anyone expected. After shuddering and groaning for another forty minutes, Arc Zero headed back out into space. By the time she reached the vertex of her orbit, Aguilar and Haas had run the numbers to the best of their ability. The news was not good. There was no way they could reach the alignment window without dumping a lot more mass. Unfortunately, the bulk of the mass was in Arc Zero’s structural members and hull, and if they detached the antenna array from the hull, they’d have no way to change its orbit or orient it.

  “Can we cut away part of the hull?” Lee asked. “The section antispinward past the last thruster is just dead weight.”

  “With what?” Haas asked. “We have no torch. There was a high-powered laser in one of the holds, but we lost it when GODCOM broke apart.”

  “We couldn’t have powered it anyway,” said Aguilar.

  “True,” Haas said. “And cutting through the hull would take days. We need to stop wasting time on fantasies and ask ourselves just how badly we want to send this message.”

  Aguilar grinned. “I got the impression you thought this entire project was a fantasy, Haas.”

  “No,” Haas replied. “It’s a reasonable use of our resources, given the situation. The odds of success are low, but it’s the best chance we have to ensure the survival of humanity.”

  “Then you think time travel really is possible?” asked Lee.<
br />
  “I don’t know that it’s impossible. What I do know is impossible is cutting through a space station without any tools. I suggest we spend our time on things we have not yet determined to be impossible.”

  “What do you two think?” Huiskamp asked, looking to Lee and Aguilar.

  “Does it matter, sir?” Aguilar asked. “We have a mission.”

  “This goes above and beyond anything that can reasonably be asked of an IDL officer,” Huiskamp said. “I can’t—I won’t—ask you to do this.”

  “Even if it means the extinction of humanity, sir?” Lee asked.

  “I can’t think in those terms,” Huiskamp said. “If I start thinking of myself as the savior of humanity, I’ll go crazy. I may be crazy already, for all I know. You three have kept me sane for the past eighteen months, and I’m counting on you to keep doing it for the next few hours. I don’t know if time travel is possible. I don’t even know if getting a message to Jason is possible. What I know is that I—we’re here for a reason. If I lose my faith in you three, then I’ve lost sight of what that reason is.”

  “Well I’m in,” Haas said. “Whatever it takes.”

  “What, specifically, are we talking about?” asked Lee.

  “Death by asphyxiation, or possibly decompression,” Haas said. “If you’re holding your breath, your lungs will explode and you’ll die rather quickly. If you don’t, you’ll lose consciousness after about fifteen seconds as the oxygen leaves your blood. Either way, you’ll be dead in less than two minutes.”