Triumphant (Genesis Fleet, The)

by Jack Campbell

  “Yes, sir,” Cameron said. “But, as Ensign Reichert pointed out to me, that’s assuming the targeted ship doesn’t know in advance when that missile will be fired at it. If we do know that, and we initiate an evasive maneuver based on that rather than waiting to detect the launch of the missile before we try to dodge, that buys us at least a couple of seconds, and our chances of evading the missile will be very good.”

  “That’s the best news I’ve heard in a while,” Rob said. “Good work, you two. What does ‘very good’ mean in terms of us not getting hit by a missile?”

  “Pretty close to a hundred percent, sir,” Reichert said. “The probability of hit calculations assumes the targeted warship will continue its vector at least until missile launch is detected. At the velocities we’re traveling, even a tiny shift in vector a couple of seconds earlier than that will be more than a missile can compensate for.”

  “Let’s set it up,” Rob said. “We don’t have a lot of good options, but if this allows us a means to deplete his supply of missiles, it’ll help the odds we’re facing. We’ve got less than ten minutes left to intercept.”

  “The maneuver will be sometime in the last minute,” Lieutenant Cameron predicted confidently. “We’ll have it for you before then, sir.”

  Rob felt himself relaxing as he watched his display. Physics ruled in space. Go fast enough and relativity started to really mess with things, but Newton’s old rules governed most matters that humans had to deal with. Anything like this, the movements of ships in space, their curving tracks through the emptiness and their velocity and the time when they’d pass close enough to each other to exchange fire, could all be calculated precisely, down to the last decimal place. The math, as complicated as it could get, was easy and predictable.

  What wasn’t predictable were the actions of humans. Which was why Rob was in command of Saber instead of some artificial intelligence program. “There are two basic problems with AIs in command of weapons,” one of Rob’s instructors back at Alfar had told the class. “The first is that, from the point of view of the enemy, an AI is too predictable. It has to operate by the rules written into its code, even if that code is supposed to be mimicking human thought process. The second problem, though, is that from the point of view of our own side, an AI is unpredictable in all the worst ways. Think of every time your comparatively simple home computer systems have malfunctioned or glitched or done the wrong thing, even when no malware was involved, and imagine that in charge of weapons that can kill you. That’s why humans remain in the loop for critical systems. Each of you has to decide whether the AIs assisting your actions and decision making are giving you the best advice, or even good advice. Don’t default to letting them decide for you, or you won’t know how to decide for yourself when you need to.”

  That wasn’t how Earth Fleet had worked, though. They’d been wedded to checklists and procedures that made decisions for them. If Vicki Shen was right, the commander of the enemy force had no practice in making his own decisions because he always did what the book said. And Rob finally had a way to use that weakness.

  “He’ll launch at fifteen seconds before intercept,” Ensign Reichert reported. “If he follows the Earth Fleet combat rules programmed into his weapon controls.”

  “And if he has missiles,” Lieutenant Cameron added.

  “All right,” Rob said. “I want to set up a maneuver to evade the missile, and then . . . come back around for another intercept.” That return maneuver would require enough time for him to figure out what to do next.

  “Yes, sir.” Cameron’s hands flew across his display. “Sending to you, Captain.”

  Rob’s display lit up with the proposed maneuver, a wide swing up and around, making the most efficient use possible of Saber’s existing momentum. He checked the time left, seeing that it was just less than two minutes, then approved the maneuver. “I’m putting this one on automatic to make sure we shift vector at just the right moment,” he told Cameron.

  Touching the glowing control marked “confirm,” Rob let out a slow breath to calm his voice before activating Saber’s internal communications. “All hands,” he said. “This is the captain. We’re less than two minutes to intercept. We’re going to try to fool the enemy into expending some of his missiles on this run, so stand by for last-moment evasive maneuvers.”

  One minute left.

  A Leader Class light cruiser could carry only four missiles because of their size and mass. The missiles had to be big enough to carry enough thrust and fuel to engage a target, as well as the necessary sensors to track the target, and the warhead itself, which was big enough that a single missile hit would have a good chance of inflicting damage on a destroyer like Saber. Reduce how many missiles the enemy had, or confirm that the enemy hadn’t purchased missiles along with the cruiser, and the odds against Saber would go from impossible to only extremely bad.

  But if he was wrong, if Vicki Shen and he had misjudged the actions of the enemy commander, and that missile was fired a second earlier at, say, a fifty percent chance of a hit, then Saber might very soon be in serious danger. This wasn’t a sure thing. But it was the best he had.

  In the final seconds before the evasive maneuver, as Saber and the enemy warships rushed through the final thousands of kilometers that had separated them, Rob had a moment to wonder which Leader the light cruiser had originally been named for. Whoever it was, how would they feel if they could know that the ship once named in their honor was now being used by those intent on conquering nearby star systems? Or had the leader themselves once been a conqueror who was crowned by success into someone to be admired by people many generations removed from the carnage?

  The maneuvering warning alarm blared.

  Five seconds later, as the automated command activated, Saber’s thrusters kicked in hard, pitching the destroyer up onto a higher vector that would carry her past the three enemy ships at too great a distance for an engagement. Some of the force of the sudden change in her path leaked past the ship’s inertial dampers that kept the stress from tearing apart Saber and her crew. Rob heard Saber’s hull protest with a prolonged groan of metallic pain as he felt that force push him down into his seat.

  The thrusters had just begun firing when another alarm sounded, high-pitched and urgent. “Missile launch detected from the light cruiser!” Ensign Reichert called out, her own voice strained by the effort of dealing with the stress of the vector change. “The launch was exactly when predicted.”

  Rob kept his gaze on his display as the symbol representing the missile fired from the light cruiser leapt out and raced toward an intercept with Saber. The ships were moving so fast that the destroyer was past the enemy in an instant, the enemy warships just out of range of Saber’s weapons. Rob’s display showed him what had happened in those moments of time during which human reflexes were too slow to cope, the missile’s path jerking as it tried to compensate for Saber’s course change, the violent stress of the necessary maneuver shattering the missile into a shower of fragments that raced off into space.

  He let out a breath he hadn’t realized he was holding. Saber was still coming up and around, her course bending in an immense curve that would steady out on a vector to once again intercept the enemy, though this time the destroyer would be approaching from above and to the right of the invaders. The stress of the maneuver had lessened, though, as the ship bent on a more leisurely change of its course. “Okay,” he said, trying to sound confident rather than shaken. “That worked.”

  “Captain?” Vicki Shen said, calling once more from engineering. “Do it again.”

  “What?” Rob glanced from the display to the image of his executive officer. “That’d be a waste of fuel, wouldn’t it? He saw what we did. He has to assume we’ll do the same thing on the next approach.”

  “It doesn’t matter,” Shen said. “I went through I don’t know how many evaluation drills in Earth
Fleet that all came down to whether or not you did what the checklists and the procedures said. It didn’t matter whether or not it worked. What mattered was that you followed the procedures. That guy we’re fighting is a successful product of that system. He got his rank by doing exactly what the procedures told him to do. I think if we make another run at him, he’ll do exactly what procedures say, and fire another missile when the hit probability reaches the right number.”

  “Even though he knows we’ll dodge it?”

  “Even though. I worked for guys like him, sir. He knows what the book says to do, and that’s what he’ll keep doing.”

  Rob rubbed his face with both hands, trying to decide whether or not to risk it.

  Would the enemy expect him to do the same thing? That’d be a stupid thing for Rob to do. But . . . the enemy commander didn’t know the dodge had been deliberate. He might convince himself it had been a lucky coincidence.

  “All right,” Rob said. “It’s worth the risk if we can get rid of another one of his missiles. Lieutenant Cameron, Ensign Reichert, I want the same thing worked up. Figure out exactly when he’ll fire a missile at us and how we need to evade it.”

  The two officers bent to their tasks while Saber continued around through space. Despite her velocity, immense by the standards of any world, to the humans inside her she seemed to be motionless. Even the nearest references, the three enemy ships, were so far distant at this point in the turn that they were mere specks of light against the star-spangled darkness.

  With Saber approaching this time from behind and above the enemy, and the relative speed at which the destroyer closed on the enemy slower than when all the ships were heading toward each other, the point at which the light cruiser would hopefully fire another missile was at a different place along the intercept curve. Still, it was just math.

  “Got it, Captain,” Ensign Reichert said. “He’ll fire when we reach this point, which will be at this time.”

  On Rob’s display, a point along the projected intercept route glowed, showing him the place and time Reichert had worked out. “Excellent. Lieutenant Cameron, can we manage a good evasion from there?”

  “Yes, sir,” Cameron said. “If we break upward again at the moment he fires, we should have a one hundred percent chance of getting clear.”

  “We broke upward last time,” Rob said. Repeating the same tactic twice in a row was worrisome enough, but doing it in exactly the same way? “And that’ll require a more intense maneuver than steepening our turn and diving faster, won’t it? More stress on the ship and the crew.”

  “Yes, sir. Captain, you said to do the same thing, so . . .”

  “So you laid out the same thing.” Rob waved an apologetic hand. “Sorry. You did what I said. Can we evade the missile by diving instead of bending our course up?”

  “I need to run that, sir.”

  “But we can evade by turning upward if we need to.”

  “Yes, sir. But, as you said, it’s a more intense maneuver. More stress on the ship and crew. We’d be at least in the yellow stress zone, and might shade into the red.” He paused as one of his hands danced over his display. “Yes, sir, we can ensure successful evasion of the missile by diving.”

  “All right. We’ll dive. Give me the maneuver.”

  “Yes, sir.” Lieutenant Cameron worked quickly, reminding Rob that while Earth Fleet hadn’t valued imagination or initiative it had trained its people extremely well in carrying out tasks. “Then . . . twenty-two minutes until we evade.”

  “Enter the maneuver into the system and I’ll set it to take place automatically again,” Rob said.

  “Yes, sir.”

  The maneuver command popped up on Rob’s display. He authorized it, then once again had nothing to do but wait.

  Once more, time counted down at what seemed a very slow pace.

  As the moment of the maneuver approached, Rob felt himself tensing. If the enemy commander ordered a missile launch earlier than the book dictated, it might put Saber at risk of being hit.

  He silently counted off the last seconds before the maneuvering alarm sounded, followed by Saber’s thrusters firing, and once again a report from Ensign Reichert.

  “Missile launch detected, exactly when predicted.”

  Saber tore past the enemy once more, this time diving under the three warships. Rob watched the missile race above Saber, too far off to engage the destroyer, and continue on into empty space. “When will it self-destruct?”

  “About now,” Ensign Reichert said, just as an alert appeared on Rob’s display showing the detonation of the missile’s warhead. “Damn, I’m good.”

  “What was that, Ensign?”

  “Nothing, sir.”

  Rob called Lieutenant Commander Shen. “Do you think he’ll do it again?”

  “Maybe.”

  “‘Maybe’ isn’t a recommendation. You can get inside this guy’s head better than I can.”

  She paused, thinking, then slowly nodded. “Yes, sir, I think he will.”

  “What if he anticipates our evasion maneuver this time and fires early?”

  “He won’t do that.”

  “Why not?” Rob asked. “It’s a logical response to what we’ve been doing.”

  “Because,” Shen said, “he doesn’t have any guidance on how to do that. There’s nothing in the manual about what to do in this situation. I’ll guarantee you that he’s looking for such guidance right now and finding nothing. That leaves him only two choices. Either fire exactly when the book says to fire, or don’t.”

  Rob sat back, trying to decide if this was worth the risk. “I find it hard to believe a commander would find it that hard to think for themselves.”

  “Sir, you saw the after-action reports from the survivors of Claymore.”

  Shen didn’t add anything else. She didn’t have to. Rob recalled his disbelief as he read those reports, wondering why the commanding officer of Claymore and the Commodore had kept looking for answers in their checklists rather than doing something, anything. “All right. Lieutenant Cameron, let’s bring her around for a third pass. Ensign Reichert, as soon as we have that maneuver worked out, I want to know when he’ll fire at us.”

  Rob waited for any sign of worry or skepticism from his crew as they prepared to do the same thing for a third time. The approach vectors had been different the first two times, and would be different again this time, but it was still the same tactic. It worried him that he saw no concern in his officers as they worked. Did they trust him that much? Or was this a product of their Earth Fleet training, where doing what you were told mattered much more than the results of whatever you did?

  Once again Saber swooped in, the enemy warships repositioning in another by-the-book maneuver so they could hit her before Rob could get in any shots at the freighter. Once again, Rob waited, tense, until the maneuvering warning sounded and Saber altered vector, followed by the report of an enemy missile fired from the light cruiser. This time the enemy missile tried another radical maneuver to catch Saber, breaking into two large pieces from the stress. The front portion self-destructed, while the stern part of the missile spiraled off into space, heading “up” on a path that would take it into the endless dark between stars.

  “One more time?” Lieutenant Cameron asked.

  “Yeah,” Rob said.

  Barely ten seconds later Ensign Reichert called out, “Captain! Problem!”

  He swung to look at her. “What is it?”

  Reichert was studying something on her display, her eyes intent. “Sir, a Leader Class light cruiser carries four missiles. He’s fired three. The manual seems to say he should fire again on our next pass, but I’ve been running a simulation of the enemy cruiser alongside our own actions as a check, and a warning just popped up on it. I tagged it, and the combat manual says since the cruiser is down to one missile, it
should reserve firing it until hit probability exceeds ninety percent.”

  “Ninety percent?” Rob looked at his display, which showed the long, projected path of Saber curving toward a fourth intercept with the cruiser. “Lieutenant Cameron, what are our chances of successfully evading if he waits for a ninety percent hit probability before firing?”

  “Working it, sir.” Cameron paused, finally looking distressed. “Captain, that’d require us to hold our approach longer, making evasion harder. That leaves such a short time to change vector . . . the system is estimating something less than fifty percent chance of evading the missile.”

  “Less than fifty percent?”

  “Yes, Captain. Possibly as low as twenty percent depending on how the missile reacts.”

  Rob rested one hand over his eyes, thinking, but almost immediately lowered it. “Give me a vector to place Saber in a position above and slightly forward of the enemy formation at a distance of one light second.”

  Three hundred thousand kilometers. Close enough to menace the enemy, and to pounce if the enemy made a mistake, but far enough off that if the enemy warships suddenly turned to charge Saber he’d have time to react. Only a few minutes, but Rob had confidence that his crew could respond that quickly.

  Feeling an obligation to explain what was happening, Rob tapped the ship’s general announcing system. “All hands, this is the Captain. We’ve tricked the enemy into expending most of their missiles, but any further attempts are too likely to result in damage to Saber. Our presence here is the only thing hindering the enemy’s ability to act, so we will maintain a close watch on them, waiting for an opportunity to strike. We’ll be standing down from full combat alert, but everyone has to be prepared for action on only a few minutes’ notice. That is all.”

  This was the point, Rob Geary thought, at which his ship was supposed to charge into battle and defeat the invaders of Glenlyon, overcoming impossible odds. After all, he’d done that before.

  But that wasn’t happening this time.