Test of Mettle (A Captain's Crucible Book 2)

by Isaac Hooke

  The only other area more shielded than the bridge was Maxwell’s central core. The last thing the crew needed was for energetic protons to flip bits in the AI’s memory. In theory, the multiple layers of error-correction and redundancy would prevent phantom commands from executing, even if an errant particle made its way through the shielding. Incidentally, that heavily armored AI core was located right underneath the bridge.

  “Lazur, is the radiation affecting communication between the fleet?” Jonathan asked.

  “Somewhat,” the comm officer replied. “But we’re close enough together that it’s not making too much of a difference.”

  He thought he heard the subtle groan of metal coming from somewhere outside the compartment. His chair began to shake very gently.

  Jonathan addressed the Callaway’s AI: “Maxwell, please tell me you have a final update from the engineering team.”

  “I do, Captain,” Maxwell returned. “The engineering team reported in mere moments ago. They’ve completed the reinforcements to the most structurally relevant areas of the damaged hull. We still have several breaches of course, but the Callaway should survive subjection to the estimated tidal forces, as long as we keep our starboard side facing the binary suns.”

  Jonathan nodded. “Thank you, Maxwell. And what about the Marley and Maelstrom?”

  “My contemporaries aboard either vessel are reporting excellent durability thus far,” Maxwell replied.

  The structural armor on the civilian Builder Marley and the frigate Maelstrom had been the weakest in the task group. As such, the human and machine engineers of those vessels had been working as frantically as those aboard the Callaway to reinforce the hulls. The Grimm, though a civilian vessel like the Marley, was surprisingly well-armored, with exceptional hull stability—as a Harvester it was designed to operate for days on end in the extremely radioactive and gravitationally intense upper atmospheres of gas giants. Still, flying as close as Jonathan intended to the two stars would test the durability of even that ship to its limits, no doubt.

  Several minutes passed. His mind wandered, and not for the first time he questioned the wisdom of his tactics and the particular choices he had made, and planned to make. There was so little margin for error out there. One mistake, one miscalculation in a trajectory, would spell the end of the fleet. And it was literally the end: like the Avengers and missiles, no lifepods would escape the gravitational pull of those twin stars. And even if a lifepod managed to eject at the right speed and angle, the heat armor was designed for atmospheric reentry, not low solar orbit. By the time any ships could turn back to retrieve them, there would be no one left to retrieve.

  Yes, there could be no mistakes.

  Such was the burden of command.

  He stared at the flashing dot that represented the Callaway on his tactical overlay. The pulsing indicator proved calming somehow. Entrancing. For a moment he could swear he heard the phantom tone of the heart rate monitor from intensive care accompanying it. BEEP. BEEP.

  The bridge shuddered more strongly, snapping him out of his trance.

  “External temperature is now eight hundred degrees Kelvin, starboard side,” Lewis announced. “And... the combined alien fleet has closed to the five hundred thousand kilometer mark behind us.”

  He returned his attention to the positions of the ships on the tactical display, and prepared to engage in the highest stakes game of poker he had ever played.

  The first enemy task unit, fleeing the human ships, had slowed down and allowed the other unit to approach. All thirty-three ships had proceeded onward as a single task group, slowly catching up to the humans.

  The day before, six of the heat signatures had begun braking maneuvers. According to the powerful telescopic lenses, those signatures belonged to two long, cylindrical laser vessels and four dart escorts. One of the laser ships and two dart vessels halted entirely, assuming an orbit around the twin suns that was roughly sixty million kilometers behind the current position of the human fleet. The second laser ship and its two escorts had diverged on a mirror course to the human fleet that would eventually take them around the opposite side of the binary suns. It was an attempt at a pincer maneuver, Jonathan knew. The aReal labeled the stationary three as ETU-F1 behind them, and the trio engaged in the pincer maneuver as ETU-F2: Enemy Task Units Far One and Far Two.

  It had taken the remaining twenty-seven vessels a day and a half to reach their current distance of five hundred thousand kilometers. There was still a third and final laser ship with that group. In the Vega 951 battle, the enemy had deployed their laser ship at the five hundred thousand klick range, with the individual lens segments separating until there were five of them spaced a hundred thousand kilometers apart, with the closest halting one hundred thousand klicks from the human fleet before it opened fire.

  “Any signs that the laser ship has begun separation?” Jonathan asked.

  “Negative,” the ensign replied.

  “Perhaps they don’t need to separate,” Robert said from his position beside the captain. “Maybe they only did that last time out of caution. They didn’t know our weapon capabilities at that point, after all, and probably wanted to keep their main ships well out of range.”

  Jonathan nodded. Robert had been in command of the Callaway for that battle, and his intuition was probably right. “If so, that laser’s effective range is likely still one hundred thousand kilometers, regardless of whether it separates into individual lenses or not.”

  The Callaway, and the ships with her, were grouped together near the binary star. They were passing the suns in a maneuver that brought them dangerously close to the solar event horizon, that region where the gravitational pull would make it impossible to achieve escape velocity. Not to be confused with the event horizon of a black hole, which was the point at which even light could not escape.

  Beneath the solar event horizon resided the death zone, where the tidal forces between the two masses became so strong that any passing ship would be ripped apart by the competing forces.

  Six more friendly dots were located approximately four hundred thousand kilometers away. Those six had separated from the main human fleet an hour ago, and would be traveling between the two suns dangerously close to the event horizon, though well within the lower point of no return that had been computed for the more powerful engines of the enemy.

  The Callaway and her escorts were running under minimal power, letting momentum and gravity carry them on their current course. They flew close together in a long chain so that their thermal signatures overlapped and blended; thanks to the hull heating caused by their proximity to the stars, to enemy sensors it would appear they were a single vessel. That was the hope, anyway.

  In the past, the enemy had often concentrated their forces on the smaller, easier targets. But the captain felt the aliens would change that behavior, at least for the current battle, because they knew Jonathan was expecting that. As such, he was betting that the enemy would believe he had dispatched one of his vessels as a decoy—a smaller, easier target meant to draw them and lead them astray from the other six friendlies four hundred thousand kilometers away.

  He hoped at least some of the enemy forces would break formation to pursue those six signatures. With luck, the majority would. And then when the remainder came upon the so-called lone vessel, perhaps expecting an easy victory, they would discover that it was not one warship after all.

  Ten minutes later:

  “External temperature nine hundred degrees Kelvin, starboard side,” Lewis announced. “Alien fleet has closed to the four hundred fifty thousand kilometer mark. Blue main sequence star has passed below the horizon of the subgiant.”

  Jonathan glanced at the video display on his aReal. Sure enough, he could no longer see the main sequence star, but the edges of its accretion cloud were still visible near the subgiant’s corona. The interference caused by energetic protons on the video feed had worsened, however, likely due to the Callaway’s closer pro
ximity to the subgiant.

  “Radiation levels?” Jonathan asked

  “Still relatively moderate,” the ensign answered. “I’m recording the highest exposure levels in the breached mess hall two, at five mSv per minute.” Even though the entire port side was facing away from the sun, the ship would still be passing through radiation belts, allowing ionizing particles to enter through the breaches. “The rest of the ship is averaging 0.5 mSv per minute.”

  Jonathan wasn’t sure whether to call that moderate or high. For comparison, each crew member was normally exposed to 0.5 mSv per week.

  The captain focused on the tactical display.

  “Any sign of alien ships breaking away to pursue the six friendlies?” Jonathan asked.

  “Negative, sir,” the ensign responded.

  Ten more minutes:

  “External temperature nine hundred fifty degrees,” Lewis said. “Alien fleet has reached the four hundred thousand kilometer mark.”

  Jonathan stared at the display, willing at least some of the enemy vessels to divert course and give chase to the other six.

  “They’re not going to fall for it,” Miko said.

  “They will,” Jonathan said between gritted teeth. He clasped his hands and steepled the index fingers. He tapped his lips.

  They have to.

  thirty-three

  A moment later the magic moment happened. Jonathan watched as a full fifteen of the dots representing the enemy vessels began to break formation, moving toward the six friendlies.

  “Captain—” Lewis began.

  “I see it,” Jonathan interrupted.

  “Almost half the fleet. That’s better than I hoped for.” Jonathan noted with some relief that the prison ship T300 wasn’t among the group headed toward the six friendlies.

  As the minutes passed, he watched as the divergence between the alien task units became more pronounced, until the computer labeled them ETU1 and ETU2: Enemy Task Unit One and Two. ETU2 was the diverging group, while ETU1 continued after the Callaway.

  Several minutes later the first enemy task unit had reached the two hundred thousand kilometer mark behind them. Thanks to the increased acceleration provided by their current trajectory, the six friendlies were almost a million and a half kilometers away by then. The second task unit was four hundred and fifty thousand kilometers behind those friendlies, also thanks to the increased acceleration. Both were barely visible above the horizon of the nearby subgiant. The blue main sequence star was still gone, hidden behind that same horizon, though a portion of the accretion disk remained visible. From the point of view of the friendlies and enemy task unit two, however, that main sequence star would be quite visible.

  “What’s the ETA on the reactors and mortars we fired at the main sequence star ten hours ago?”

  “The debris from the reactors and mortars, you mean?” Ensign Lewis asked.

  Every warship had agreed to launch at least one of their reactor cores into the void. The process involved carefully turning the nose of each ship with the help of the AIs so that the ejected cores would follow the necessary trajectory. The slowest ships in the fleet, the Grimm and Marley, had been allowed to keep their cores, because Jonathan was unwilling to reduce the maximum speed of the group to below seventy percent. Mortars had been launched as well, to provide the raw materials necessary to attain critical mass and pressure.

  The reactors had broken up hours ago, due to the lack of heat shielding. The mortars had lasted longer, but as the rocks passed into the death zone, even they couldn’t withstand the tidal forces. However, the constituent parts had continued moving with their original speed and heading, and that was how the AI tracked them. Jonathan had hoped the incredible heat from the binary suns would mask the small thermal signatures from the enemy from launch to impact, and judging from the apparent success of the ruse, that seemed to be the case.

  “Yes,” Jonathan said absently. “The debris from the reactors and mortars.”

  “The lead portion should reach the accretion disk in five minutes,” Miko said. “Because of their relatively high speed, the elements should pass just above the major axis of most of the particles, drawing a swathe of plasma from the cloud along with them. A minute and a half after that, the particles should pass into the corona and chromosphere, before hitting the photosphere thirty seconds later. If successful, the resultant detonation will cause the flare to erupt microseconds after.”

  Magnetic loops, called prominences, were distributed throughout the plasma of that sun. When those loops touched, the “short circuit” caused a solar eruption that led all the way to the surface, releasing a flare. It was hoped the detonation of the geronium inside the photosphere would cause such a short circuit by shoving one of those loops into another nearby.

  “Will the second enemy task unit be close enough?” Jonathan asked.

  “Most likely,” Miko said. “The calculations predict a massive energy outburst. As I said at the conference, if we’re lucky and hit a sunspot the energy release could be upwards of sixty billion petajoules. Your question should probably be, will we be far enough away?”

  Sixty billion petajoules. In the conference, Miko had equated that to the detonation of roughly a hundred and sixty billion megatons of TNT. While it was perhaps an antiquated comparison, it suitably emphasized the incredible power of the flare.

  “I thought that magnitude of energy release was confined to the surface of the star?” Jonathan asked.

  “Well it is,” Miko agreed. “But not even Maxwell’s plasma dynamic algorithms can predict how far the resultant flare will reach, nor how much coronal mass will be ejected, if any, not with any degree of accuracy. But either way, even if those ships are hit with only a tenth of a percent of the surface energy, they’ll be vaporized.”

  Jonathan nodded. Miko had already gone through all of that at the conference, but it was good to hear it again for confirmation. The hope was that the corona and loosely bound outer layers of the subgiant would shield the main human fleet from the high-speed protons, electrons, and heavier ions that the companion star’s flare would eject in copious quantities. Maxwell predicted that the outer layers of the subgiant would experience a sudden steep rise in temperature as the energy of the particles was absorbed and radiated into space, but that was the worst of it.

  The nearer enemy task unit would be similarly spared, of course. But as for ETU2... like Miko said, they would be vaporized.

  “The decoys are breaking up!” Ensign Lewis announced.

  So the heat and tidal forces had finally proven too much. The six friendlies vanished from the display, their thermal signatures flaring out as the units broke apart in turn.

  Those “friendlies” were actually a series of six 3D-printed heat shields, each one designed to mimic the signature of a different starship in the human fleet. The engineers had placed small, battery-powered emission sources at key spots on the shields. In preparing the unmanned objects, the team had taken into account how the signatures would look when heated by the radiation from the binary stars in order to give the most realistic approximation to their starship counterparts.

  It had worked.

  Up until that moment, anyway.

  “The fifteen vessels of enemy unit two are issuing emergency deorbital burn,” Lewis stated.

  “They’ve realized the ruse,” Robert said. “They’re trying to put as much distance as they can between themselves and the suns.”

  “But they’re too late,” Jonathan said.

  “Maybe,” Miko said. “Maybe not. We won’t be certain until the geronium achieves critical mass.”

  “If it reaches critical mass,” Robert corrected.

  “It will, Commander,” Jonathan said. He had resigned himself to assuming the role of the positive one in the pair, for the moment. “And even if the geronium doesn’t, those ships won’t be a threat for at least a few days while they loop around the binary stars, trying to escape the gravity.”

  “But
the fleet will still have to face them eventually,” Robert said.

  Jonathan nodded. “And so we will.”

  He checked the display. The nearer alien task unit had closed to one hundred seventy-five thousand kilometers. At some point he would have to order the human fleet to initiate deorbital burn itself, in order to determine their final trajectory in the slingshot maneuver that would take them around the subgiant. However, before doing that it was best to wait until the flare from the main sequence companion passed: he didn’t want to risk putting the fleet in the path of the relativistic electrons, protons and heavier ions surging from it.

  “The lead portion of the debris has penetrated the accretion cloud,” Lewis said.

  Jonathan waited tensely. He thrummed his fingers impatiently on the armrest. Come on. Come on.

  The predicted minute and a half that the particles would take to reach the chromosphere passed.

  “The leading debris should be within the chromosphere,” the ensign said.

  Jonathan thrummed his fingers louder.

  The prerequisite thirty seconds the geronium should have taken to reach the photosphere transpired.

  Still nothing happened.

  “It should have reached the photosphere by now,” Robert said.

  Jonathan stopped thrumming his fingers and instead wrapped his fingers tightly around the armrest instead. Come on.

  The leading geronium would have imparted most of its velocity and angular momentum to the surrounding gases as it penetrated the photosphere. When subsequent debris struck, it would impact with slightly more energy, plowing into the leading matter. The energy of each successive wave would continue to be slightly greater, and because of the intense temperature and pressure, as more of that geronium struck, in theory the pressure would build until critical mass was achieved....

  “Maybe our calculations were off,” Miko said.