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