Star Destroyers

by Tony Daniel

“Officers.” He shrugged. “Not our problem. Let’s see about getting some shinerrite.” He gave them a grin. There were advantages to not having to phrase all the directions to his techs in calm soothing tones. Sure, if they made a mistake, the ship would be lost. But there were four bright minds here working together, and they had plenty of historical data backing up their tactics.

  Attempts to communicate with the aliens had so far failed, but with shinerrite, humanity had learned to locate them. The aliens chose solar systems and played in them or did whatever it was that aliens cared to do for decades, sometimes more, and then moved on.

  His team understood what was out there. Missing ship’s captain or not, they started to track and tag contacts immediately. The ordinary diffuse plasma swirling through the interior of solar systems carried long signal waves sent out by the cleaner bots. The waves were swallowed up soundlessly by most matter, but when they hit shinerrite, the signals bounced back in a clear alien echo almost louder than the initial wave signal.

  The cleaner bot’s pitch would rise in a closing Doppler scream, roar lower after it passed, and be cut off abruptly at the target. Optical sensors would fill in the silent details later at mere light speed to show the bot crashing through everything in its way. The bot would clean and clean until all the target shinerrite was gone, and once more soft deadly pings would announce a resumed search.

  The transducers human engineers had originally built in the Centauri panic to detect cleaner bots could also pick up signals from the shinerrite itself. A few meters of lead proved to be effective shielding against those human-built detectors, so the Sol System Navy used ten meters around the cargo bay and twenty around the main drive’s power generator. Just to be sure.

  Of course Albro’s ship couldn’t actually use that drive with all the shielding in place, but every spaceship had secondary systems and they’d have to get well away undetected before they could re-engage the main drive and return to full-power operations.

  Planets and suns were good shielding too. Gas might not be the most effective shielding material, but in the amounts present in a gas giant—well, quantity had a quality all of its own. Their ship coasted into a position near the center of the system. The small inner planet of the rocky telluric type not usually favored by the aliens circled on the far side of the sun, and the gas giant loomed ever larger in their viewscreens. The hints of shinerrite they’d begun to detect from the edge of the system separated out now in three distinct masses in the gas giant’s orbit.

  Albro’s team had bearing lines plotted for two tumbling blobs of shinerrite and a confirmed datum on a third currently being consumed by a cleaner. That was the one he’d expected to be around the horizon of the gas giant by now. He’d had the speed of the combined masses orbit off by half. It would still pass around the gas giant’s horizon soon, but it would not reemerge for hours.

  A smile began to tug at the side of Albro’s face. They were on a first pass through a system with several shinerrite masses in range and no bots nearby. That other planet would almost certainly have bots on or around it, but maybe he’d get one of those rare first-pass collection opportunities. He let himself grin because there was no captain around to get nervous.

  That third deposit spun away from them in orbit around the system’s large gas giant and its bot went with it.

  “Crying shame.” Petty Officer Morales said. She had scratched notes with a light pen on the side of her trace screen, estimating the size of the deposit being consumed.

  “Not for us.” Albro corrected. “That’s too big to fit in our cargo hold.” He paused for a moment to bring up an overlay of the system bodies pulled from navigation’s computers. “Morales, how long before that deposit’s orbit puts the gas giant fully between us and the cleaner’s sensors?”

  “One minutes, thirty-eight seconds.” Morales responded immediately. “And over twelve hours before it emerges on the other side. I can calculate exactly—”

  “Belay that.” Albro turned to Rogers and Li. “After that thing slips behind the gas giant’s horizon, I’m going to have the bridge change our course to head toward it. But slowly. Work bearing solutions for me on your possible contacts after the course change. I don’t want to be headed toward it any more than fifteen minutes. Morales, keep up your dead reckon trace on the cleaner as it goes behind the planet.” He repeated himself in more formal phrasing to update the bridge.

  “Got it,” Captain Knupp acknowledged.

  Albro twitched. He preferred a crisp “Very well, Senior Chief,” but the screen tore his attention away.

  Morales added a small dot on their display to show where, invisible behind the gas giant, the third deposit and the dangerous bot orbiting with it would be.

  “As I maneuver us around,” Albro continued, “you need to remind me anytime my course changes move us outside the sensor shadow of that gas giant.”

  She nodded and made adjustments to the display to show a slightly shrunken horizon line circling around the gas giant to account for the point where the gas thickness of the planet edge would stop providing sufficient shinerrite shielding. Albro nodded, pleased to not have had to remind her to do so. The captain would see it too, along with the draft courses his other two petty officers were working on.

  Albro called the bridge with the first set of accelerations, and the commanding officer executed his course change. Albro gave Rodgers and Li a full six minutes of bearing plotting time before changing to the third course. They’d need it to triangulate estimated locations for their shinerrite deposits.

  Something in the nature of shinerrite made their sensors great at line of bearing but not so accurate for range detection. When they needed extreme precision to scoop a bit of it into the cargo bay without scraping anything against the hull, using multiple precision bearing lines to calculate and recalculate their target’s location became common sense. With a fourth course change, his petty officers should be able to give him orbits and plot a retrieval course.

  The last system his previous ship had visited had been too crawling with cleaner bots for even Albro to recommend an entry. The ship’s lead shielding around their shinerrite power system only made them near invisible while coasting or on rocket power. Stealth and safety were not the same thing. The crew of a safely unlocated spaceship could starve to death waiting for an opportunity to engage shinerrite drives and leave a system with too many cleaner bots. They needed planets and suns to hide behind before engaging their drives and beginning the hopscotch home through empty systems.

  So while he checked the petty officers’ calculations and saved them in the corner of his screen, Albro also started looking for a way to get the ship out.

  And he kept an eye on that second planet. It would be having a planet rise over the sun’s horizon real soon now.

  Albro keyed his microphone to speak to the bridge and engineering. In the most bored voice he could manage he said, “Change to next course now. Expect a second bot to clear the sun’s horizon. Possibly in five minutes.”

  Rodgers, Li, and Morales gave him uniform pale-faced expressions of horror. They had some work to do before they’d be ready to run their own tactical plot teams. If Captain Knupp had been in central, he might have freaked just from their expressions. Shinerrite technicians couldn’t afford to show fear like that.

  “It’s fine,” he explained. Since there weren’t any officers around to be panicked by the details, he told them his reasoning. “Our intel says the aliens left this system only a decade ago. It’s too cleaned up to have had only one bot working on it. Behind the sun is the only place another bot could be or we would’ve been picking up its signals.”

  “But why five minutes?” Li said.

  Albro rewarded them with a broad grin. “I have no idea if there’ll be one there all. But five minutes is a little while from now. This’ll keep engineering ready if I need a quick maneuver without getting them too keyed up to react. If there’s a bot out there, it’ll probably be on or near
the system’s other planet. If it’s working on a shinerrite deposit, it’ll stay there until it finishes. If it isn’t, it’ll charge toward one of our two right here as soon as it gets a clear signal.”

  “But what if there isn’t a bot at all?” Rodgers asked.

  “I did say ‘possibly.’ Remember to always say possibly.” Albro gave them a wink.

  “It might not slow down very much before it starts consuming one of these deposits if it is there,” Morales said. She had draft courses on her screen from the rising planet’s surface and math multiplying a typical bot’s mass by the max speed of one on full shinerrite drive power. Not quite correct, but close.

  “They always slow just before impact,” Albro reminded her. “The lab tests show shinerrite will splatter if impacted like that, so that may be why their programming doesn’t allow it.”

  “Are we sure?” Li asked. “There could be another bot just in the sun’s orbit, not near the planets at all.”

  “Could be,” Albro acknowledged. “But not in this system. Our outer scans were thorough enough that we would have picked any of those up as shadows far too large to be sunspots.”

  He had expected at least small shinerrite debris in heliocentric orbit in this system, but their in-system scan had yet to pick up even trace amounts of shinerrite near the sun. It was an anomaly and those always worried him. Stuff too close to a sun wasn’t recoverable by humans, but usually there was one near-melted hulk of a cleaner bot powering from one sunward bound shinerrite deposit to the next. What if there were not just one unlocated cleaner bot in this system but two?

  “Contact solution!” Li reported—finally finishing the calculations for his assigned deposit near them in the gas giant’s orbit—and he rattled off his shinerrite deposit’s details. This one would fit in the cargo hold.

  Albro held off planning to collect it until he got a good view of the other planet.

  Rodgers cursed under his breath at being second to finish his calculations, but, Albro noted with approval, he still ran his numbers three times to check them before making his own report.

  “Very well,” Albro acknowledged them both and had them plot collection courses, which he checked against his own. No errors this time, and he always appreciated extra checks.

  He didn’t usually have a choice in which deposit pickup to attempt while staying undetected; so far, either of the two petty officers’ collection courses would work if no bots waited on that inner planet. But neither collection could be accomplished before the planet came into view. The two deposits were caught by the gas giant’s gravity well but in a tumbling unstable orbit where they spun around each other.

  Some parts of the alien trash weren’t quite decomposed all the way down to shinerrite yet. That matter transition created some interesting orbital mechanics. Albro rechecked the numbers both petty officers had sent him to account for the continued wobble. The plots still worked. A little messy, maybe, but he could pull it off using the precision radar for the final approach. On a tactical scale the masses would be a challenge to collect, but not impossible. Their spins around each other had a consistent cycle and their joint decaying orbit around the gas giant spun them toward his ship.

  He tried to estimate if he could fit both deposits in the hold. From the faintness of the signal, Li’s deposit was significantly smaller, maybe only a few meters in diameter.

  “Planet rise,” Morales reported, pointing at the system’s sun on their plot and the small planet about to come out of eclipse, “in three, two—” She drew in her breath sharply and skipped straight to the more important report. “Multiple cleaner bot signals detected. Three, no, two . . .” She paused trying to figure out her screen.

  “They’re on the planet,” Albro said. “It’s got an erratic spin. It should be tidally locked, but isn’t. Maybe the aliens did something to it or maybe the decaying relics malfunctioned to cause it. Once the bots have it all cleaned up, solar gravity will eventually stop that spin, but not while we’re around to care.” He added throbbing red markers to his screen’s overlay—just in case Captain Knupp on the bridge didn’t recognize what the icons for bots in detection range of the ship looked like.

  “Surface craters.” Li bit his lip and stayed focused on his own screen. He had copied Albro and used the ship’s optics to supplement his shinerrite view to see what Morales hadn’t. “Hopefully that means they’re too broke to escape the gravity well.”

  Hope is not a plan of action. “Possible,” Albro acknowledged and looked to Morales for the rest of her report. She glanced at Li’s screen and immediately recognized the cause of the shinerrite signals blinking in and out.

  “The bots are deep in surface craters which are shielding their signals sometimes. I think there’s four of them on it,” she finished. It wasn’t standard reporting, but Albro would take it. She was giving him the information he needed and most importantly, staying calm.

  This is why a normal commanding officer would be here with them in central. Five bots in a single system with only two planets for cover far exceeded recommended safety margins, and they hadn’t known how many to expect from the outer system scans.

  He called Captain Knupp.

  “Recommend abort recovery mission and abandon this system, sir. We can reverse course and use a combination of the gas giant and system primary to cover our exit under full power.”

  “Senior Chief!” Morales interrupted.

  Two cleaner bots finished their work on the planetary surface at nearly the same time and shrieked locator pings across the system. Li and Rogers hit red-alert warning buttons in unison as both their deposits were detected.

  “Wait.” Albro held his breath. The cleaners’ signals also hit a moon-sized deposit in orbit around their inner planet. The bots launched together, with no synchronization and nearly clipped each other as they slammed into the moon. With a smaller target, they would have collided.

  Morales sent him the sensor analysis on that deposit. Lots of rock in it and very little shinerrite. It probably was a moon strewn liberally with alien trash rather than what it had initially appeared, and it wouldn’t hold one cleaner bot long, let alone two.

  His last commanding officer would have been screaming by now for allowing them to enter a system with five active bots. But without anyone screaming in his ear, Albro could think. He blinked at his screen. He liked that moon. And he could still see collection options. He keyed in updates to his plot.

  “Captain.” Albro double-checked the ship’s orientation and started to talk fast. “Resuming recovery mission and preparing for system exit within the hour.

  “Cargo, open recovery bay to vacuum. Prepare retrieval arms for operation. Engineering, standby for system exit at max speed.”

  Slightly too much tension showed in his voice because Albro could hear the fear in the cargo bay operator’s acknowledgement. Commander Jules answered for engineering though, and she sounded perfectly bored. The former shinerrite technician was ready to back him up.

  Lines appeared on his screen marking the future course of the two bots on the inner planet’s moon. He hadn’t drawn them, and his petty officers didn’t have the authority to push data to his master plot. Albro smiled; the executive officer still remembered her stuff. He gave the commanding officer the beginning of an update, only to be cut off.

  “Got it, Senior. Do your thing,” Captain Knupp said.

  “Recovery bay doors open,” cargo reported.

  The bot-infested planet continued to rise as its orbit brought it farther around the sun. The planet’s own spin turned the two on-surface bots away from them, but they’d be turned back again before too long.

  The gas giant’s solar orbit ran in the same ecliptic, but not as fast, and while the spin of the deposits Li and Rodgers tracked were bringing them closer to the ship, the timing was going to be tight. He sent his planned courses to the team. Morales checked them against her track for the gas giant’s hidden bot and gave him a silent thumbs up.
>
  He told the bridge the next course and they complied. Their ship, never the sleekest thing to grace the starways, scooted backward on reverse thrusters to scoop Li’s deposit into the open hold, slam shut the cargo bay doors, and jettison the now contaminated recovery arms into the back of Rodgers’s deposit.

  “Clean capture,” Albro reported to the bridge as soon as his scans showed the hull had escaped any particulate smearing.

  “Syzygy!” Rodgers breathed in admiration seeing his untouched larger deposit align with Li’s and the bot-infested planet just as they executed the recovery. If any of the bots on that planet had had a lock on it, that particular piece of shinerrite had not spontaneously vanished from their sensors. It had merely passed behind a larger chunk of shinerrite and not reemerged. The cleaner bots’ processor systems would not know it was missing until they cleaned up Rodgers’s deposit and found it hadn’t incorporated the shinerrite from Li’s deposit into its slightly increased mass.

  Albro pointed at Rodgers. “Feed the bridge continual course corrections to stay in alignment. I want your deposit between us and that inner planet. Don’t close to more than half our current distance. I don’t want any back-splattered shiny from our jettisoned arms painting the ship’s hull or any of our rocket plumes getting close enough to turn bits of shiny into vapor.”

  “Got it, Senior Chief.” The delight in Rodgers’s eyes shone.

  “Engineering, Bridge, prepare for exit course,” Albro said, reading off the route waypoints twice, “and hold for my mark, repeat hold for my mark.” Both stations acknowledged the planned course and waited.

  At the touch of a finger, Albro added Commander Jules to his private comm line with Captain Knupp.

  “We’re about to witness an impact,” he said. “I’m getting us out of here while we still can, but I think the scientists back home are going to want all the sensor data we can get.”

  “Engineering is ready,” Commander Jules replied immediately.

  “Override,” Captain Knupp said, and even Albro flinched.