Europa Strike

by Ian Douglas

  With a sense of history and tradition, then, Frank had suggested calling the contraption now out on the ice “The International Gun, Mark II,” and the others had adopted it with raucous good humor. No one could say, though, whether it would survive its first firing, or even whether it would be more dangerous to the Chinese or to the personnel at Cadmus.

  The IG Mark II was loaded and ready to fire, the last of the Marines who’d been prepping the gun moving away now on tractor-dragged sleds. Moments later, the surface crews reported that they were under cover.

  Not that that would help them if something went seriously wrong, and the monster mass driver cannon out there managed to score an own goal.

  “It’s your baby, Frank,” Jeff said quietly. “You want to give the word?”

  “Aye, aye, sir.” He checked the monitors a final time, then, reluctantly, touched his PAD monitor, where a firing button had been set up as a touch-screen graphic.

  Chesty Puller

  Europa

  2049 hours Zulu

  The graphic didn’t fire the gun directly, but sent a command to Chesty, who made the actual connections. A pulse of electrical energy from the base reactor surged through the superconducting cable wrapped around the twenty-meter tower like an endless strip of dark-gray ribbon. The charge created a rapidly moving magnetic field that gripped the five-kilogram round and hurled it down the length of the former microwave tower. Accelerating the package at 2,050,000 Gs, the jury-rigged railgun squirted it from the muzzle with a velocity of 28,350 meters per second.

  The railgun’s muzzle had been elevated only five degrees, just enough to clear the crater’s southwest rim.

  Kaminski’s idea had depended on Europa’s unusual environment for success. With a surface gravity of.13 G, the package, which began falling as soon as it left the railgun’s muzzle, could travel much farther—almost seven times farther, in fact—than the same impulse could have carried it on Earth. Better yet, there was no atmosphere to cause drag, no wind to buffet the projectile as it tumbled through the ice-barren night, no chaotic effects to nudge the projectile this way or that. Targeting was a simple matter of calculating solely the precise range to target, the gravity and surface curvature of Europa, and the acceleration of the projectile and the length of the firing weapon to yield muzzle velocity. At 28.35 kps, the time to target would be 35.45 seconds.

  A simple matter? That part of the equation was simple enough. Unfortunately, as Chesty was all too aware, there were still chaotic variables, which meant that actually hitting the distant target was largely a matter of chance. The complex interplay of gravitational fields between giant Jupiter and the largest Jovian moons wouldn’t affect the projectile much, but they would affect it, and in ways too essentially chaotic to predict. And, while Europa didn’t possess the masscons of Earth’s Moon, deep-buried lumps of dense nickel-iron that could tug orbiting spacecraft off course, the Jovian satellite was not entirely uniform—and the local variations in gravity, while mapped by the CWS team, were not well surveyed. And, finally, while Europa’s atmosphere measured a billionth of one standard atmosphere, there was an atmosphere of sorts, the sleeting rain of protons from Jupiter’s radiation belts, and the magnetic field of Jupiter that trapped them.

  These influences, each slight in and of itself, added up to a whole too complex to calculate, made worse by the fact that the required data were yet incomplete.

  As a result, Chesty couldn’t predict with any accuracy at all where the package would come down. Hitting anything important at all on the other end of the trajectory would require luck, a peculiarly human concept that Chesty did not, could not understand.

  Kaminski

  C-3, Ice Station Zebra, Europa

  2049 hours Zulu

  As the International Gun Mark II fired, Kaminski felt a stab of cold pain lance through his skull. The next thing he knew, he was on his back, with several Marines bending over him. “Someone get the Doc up here!” Lissa yelled.

  “Frank?” Major Warhurst said, looking worried. “Are you okay?”

  “I’m…fine…” he said. The pain was gone, but had left him feeling woozy, and a bit numb. “What happened?”

  “You fired your gun and collapsed. Just for a couple of seconds.”

  “We just loosed the biggest damned EMP I’ve ever seen,” Sergeant Miller said, looking up from his PAD. “Transient effects all over the board, and that was just from the side leakage and backscatter! But it shouldn’t have affected humans!”

  Shakily, Frank allowed them to help him to his feet.

  Observation Post Iceberg

  Asterias Linea, Europa

  2049 hours Zulu

  Downer Niemeyer wished that BJ were here. Unfortunately, she’d just been given a field promotion to gunnery sergeant and put in charge of Second Platoon, which meant she was no longer as expendable as she’d been before. Since he’d had experience piloting lobbers as had she, he’d been asked to take Lance Corporal Gary Staunton with him on a jaunt a thousand kilometers southwest of the base.

  It had been a long, brutal trip, too. The idea was not to let the enemy see them coming, so the approach had been made through a series of short, low, ridge-skimming hops instead of one long, high one. The final approach had been made scant meters above the ice, slipping up to a low pressure ridge east of the enemy LZ. They’d touched down and climbed the ridge on foot in order to avoid enemy radar or lidar sweeps.

  It had worked. Four Chinese landers were visible on the western horizon, together with a radio mast and several surface buildings. Through their helmet optics, electronically magnified, they could see space-suited soldiers on sentry-go at the base of the landers, and several of the ever-present robot tanks.

  For the past three hours, they’d crouched on the ridge top, taking turns observing the base. They were far over the horizon from the CWS base, and unable to communicate; in any case, they were under orders to maintain strict EM security, with no leakage at all to tip the enemy off that they were there. Instead, they were to watch…unsure of exactly when the package would strike.

  Observe the strike, and try to get an idea of the damage, Warhurst had told them before they’d left the base nearly seven hours earlier. If we can hurt them, if we can even just scare them badly enough that they’ll back off, we have a chance for a relief expedition to make it out from Earth.

  Downer had just decided that something must have gone terribly wrong, that Kaminski’s cannon had not worked after all, when the Chinese landers were silhouetted by an intense, blinding flare of white light blossoming from the Europan horizon, a light so bright it momentarily outshone the shrunken sun, and caused Downer’s helmet visor to polarize to black.

  The shock wave reached them long seconds later, diminished by distance to a rumble felt through the ice.

  The landers remained on the horizon, apparently untouched. Through his optics, Downer could see that the radio mast was down and two of the buildings appeared to have collapsed, but there was little other obvious damage.

  Beyond the Chinese LZ, a great, frosty white cloud was seething against the night sky. Downer had seen a cloud like that before, a much smaller one—the cloud of freezing steam boiling above the Pit, back at Cadmus.

  The package had missed the enemy LZ. It had breached the ice, opening the ocean to space, but it had missed, damn it, and the shot had been wasted.

  Gary tapped his shoulder, and pointed. The second member of the OP had been monitoring a tripod-mounted EM scanner, a device designed to pick up the electromagnetic emissions of enemy troops and vehicles. It served as a kind of passive radar, one that read the electronic noise others made, without giving away its own position by broadcasting on the EM spectrum.

  Downer looked at the screen, and his eyes widened. As planned, the enemy cruiser Star Mountain was above the horizon, and if the commentary scrolling up the side of the scanner’s screen was any indication, it was changing course from an equatorial orbit to one that that would take it o
ver the CWS base.

  Downer nodded vigorously, and pointed back down the ridge. They had to warn the base, hopefully without bringing down the entire Chinese Expeditionary Force around their heads.

  By the time the Star Mountain had passed across the sky to the north and vanished again below the northeastern horizon, they’d boarded their lobber, brought the pile temperature up, and started feeding expellant into the main core tanks.

  “Kick it,” Downer said. It was the first word spoken since they’d arrived near the Chinese LZ. With a shudder, the open-top spacecraft rose, drifted a moment, then began accelerating, canting over to put some horizon between it and the enemy landers.

  “Zebra, Zebra, this is OP Iceberg. Stand by for encrypted transmission.”

  He was staring back at the Chinese LZ as he spoke, knowing his suit camera was picking up what he saw. From two hundred meters up, the crater punched by the railgun round was a vast, steaming black oval perhaps a half kilometer across. The round, with the destructive power of a one-to two-kiloton nuclear blast, had punched through the ice all right, but overshot the enemy LZ by a good five kilometers.

  “Iceberg, Zebra,” sounded in his headset, blasted by static. “We are reading you, but poorly. Please repeat, over.”

  “Zebra, Iceberg. Here come the goodies.” Their observations, camera records, and suit logs, as well as the data feed form their EM scanner, all compressed into a half second of tightly encrypted signal, spat at the distant base three times, the repetition designed to allow reconstructing the message if parts were garbled or lost. Another lobber had been launched above Cadmus immediately after the cannon shot, positioning itself three hundred kilometers up so that it could receive the expected signal from Iceberg.

  The signal was going out a fourth time when the rising craft was bathed in laser light, a low-power tracking beam. Seconds later, a chain of crowbars arrowed in from the northeast; the Star Mountain, detecting the lobber launch and possibly intercepting the tight-beamed signal as well, had shifted out of its nose-down attitude to bring its spinal railgun to bear on the tiny craft clawing its way up from the Europan surface.

  The first two ten-kilo crowbar flechettes whipped past, unseen; the third and fourth slammed into the lobber’s hull, shredding it with the equivalent of a detonation of two hundred kilos of HE. The blast, with little concussive effect in hard vacuum, was not instantly fatal, but flung Downer and Staunton into blackness.

  His last conscious thought was a desperate, pleading wondering if Europa’s lower gravity might spare him.

  Unfortunately, a 500-meter fall on Europa was still the equivalent of a sixty-five-meter fall on Earth. Both men died on impact, in a shower of falling debris.

  Chesty Puller

  Ice Station Zebra, Europa

  2049 hours Zulu

  Chesty engaged the bug’s engines, gentling the ungainly craft above the ice in an uncertain hover. The bug’s controls had been set for teleoperation, which meant that Chesty himself could now pilot the vehicle directly. Carefully, using inertial guidance, he aligned himself, then engaged the main thrusters, accelerating hard.

  He had heard—no, felt was the better word—the destruction of OP Iceberg, but the deaths meant little save that no more data would be coming from that source. Ample data had been received, however, reporting the failure of the cannon shot, and the course change by the Chinese cruiser.

  The five-kilometer miss by the railgun was…regrettable. The battle might have been ended immediately if three or four of the surviving seven enemy landers could have been destroyed…including the one that held, presumably, the Chinese equivalent of the E-DARES C-3 Center.

  And to have missed after so many high hopes; Chesty’s analysis of the subdued voices of the humans in C-3 told him that morale among the members of the command staff had just come crashing down. He’d tried to point out that the uncertainties, the chaotic variables of the long-range shot made pinpoint targeting a matter for chance, not skill…but he doubted that the humans had really understood this. Humans, Chesty now realized, tended to believe what they wanted to believe, and could be disappointed when the universe didn’t bend to their expectations.

  Morale had fallen even more when he reported the lobber destroyed. Again, human apprehension of the situation less than adequately reflected reality. As if such intangibles as bravery and devotion to duty could somehow coax life from a situation where the chances for death were very high indeed.

  But most of Chesty’s attention was now focused on Star Mountain. Major Warhurst had guessed that an attack on the enemy LZ would trigger an immediate response as the Chinese attempted to destroy the cannon. He’d been right; the enemy ship had shifted orbits almost immediately, and was now incoming, minutes over the horizon.

  He increased the bug’s acceleration, streaking low across the Europan surface, hugging the rills and pressure ridges to mask his approach until the last possible moment.

  The railgun attack might yet succeed, if only as a diversion designed at drawing the Star Mountain into a trap.

  The trick, of course, was knowing exactly where the Xing Shan would be at any given moment. Without military observation satellite or com relays, the enemy could send an orbiting spacecraft overhead almost at will, unchallenged by the Marines on the surface.

  But with just a little sure knowledge in advance…

  Chesty had the Shan on radar now, and at almost the same instant he detected radar and lidar paints from the enemy. He applied thrust to the number one ventral thruster, bringing the bug’s nose up, and increased acceleration yet again. His trajectory was aimed just ahead of the Chinese ship; his velocity was now up to 4.8 kilometers per second. When he was certain the bug was perfectly aligned, he detonated the explosive bolts holding the securing straps on the craft’s sides and backs; the cylinders, what Major Warhurst had referred to as “shit cans,” slowly separated, their lids flying back. He decelerated sharply, and the “special munitions” hurtled ahead, maintaining their 4.8 kps velocity.

  Seconds later, a stream of crowbars slammed into the bug, crumpling its cockpit, puncturing its cargo deck, sending high-speed splinters slashing through expellant tanks and reactor.

  Seconds after that, the first Chinese missile struck, homing on the IR signature of the largest fragment of the bug and detonating in a savage, subnuclear flash. Point defense lasers began flickering invisibly across the cloud of wreckage, boiling away the larger fragments as they tumbled toward the oncoming spacecraft.

  But by that time, Chesty had already lost contact with the bug and could not report on what was happening.

  C-3, E-DARES Facility

  Ice Station Zebra, Europa

  2053 hours Zulu

  “I must protest this wanton biological desecration of this world!” Vasaliev snapped. “You had no right!…”

  Jeff looked the CWS scientist up and down. Pyotr Vasaliev was a short, stocky man with an angry shock of flyaway hair and a personality to match. His blue CWS Science Bureau jumpsuit was festooned with wearable computers and hardware on chest, sleeves, and thighs, and included a monocular headset that gave him a one-eyed HUD for accessing data no matter where he was in the base. Jeff had already come to the conclusion that he wore those high-tech trappings more as a fashion statement and as a declaration of importance than through any actual work-related need.

  “I have the right, Dr. Vasaliev, no, the responsibility to take the measures I deem necessary to fulfill my mission orders, which happen to include protecting you.”

  “You are idiot!” Vasaliev snapped. His English, usually precise despite carrying a bit of his Ukrainian accent, tended to degrade when he was excited—which was frequently. “Vandal! Philistine! Europan biosphere is…is unique, is great discovery, is important! Your actions contaminate world!”

  “Dr. Vasaliev—”

  “At least you should consult with science team! Is insufferable, is—”

  “Dr. Vasaliev, shut up!” His parade-ground bark
startled everyone in the C-3 compartment to dead silence.

  “First!” he rasped into the silence. “We had little choice. I considered loading those cans with chunks of ice, but ice tends to be friable at those temperatures. Under high acceleration, it might fragment, even melt. What we used was already neatly packaged in plastic, which keeps the mass together in a nice, neat chunk.

  “Second. Because it’s packaged, I deemed the chance of contamination to be remote. My orders, in case you didn’t realize it, do require me to take note of the unique environmental, biological, and research aspects of this place.”

  “But if any of packets should fall again to surface! They could rupture, contaminating entire Europan biosphere!”

  “The stuff is sterile,” Jeff replied. “Or it ought to be by now!”

  “No. No! We cannot know that! It was in storage on surface, yes. It was frozen solid, yes, and subjected to high levels of particulate radiation. But mandate as scientists demands we properly dispose of all organic wastes. If we contaminate local biosphere, results could be catastrophic!”

  “Doctor, think about it, please! The escape velocity for Europa is a little over 2 kilometers per second. Those packages were moving at almost five kps when they were released. The chances that any will be deflected in such a way to land on the surface again—and without being vaporized by the energy released on impact—is so small I can’t even imagine what the odds would be.