A cheer went up in Combat Information Center, and somebody shouted, “Nice shooting, Ensign. Kick ass and take names!”
The Weapons Control Officer nodded absently. He wanted to shout and cheer with the rest of them, but they couldn’t see what he could see. On the tactical display in front of him, the speed vector for the last Russian warhead continued to track across the screen. In a few brief seconds, it disappeared as the hurtling weapon passed out of the Shiloh’s engagement envelope.
It was gone, and he couldn’t do anything to stop it.
The Russian missile’s last remaining reentry vehicle dropped into the ever-thickening atmosphere of the planet below. Its cone shape and internal weight distribution made the device tail-heavy, giving it a nose-up attitude that oriented the widely rounded base into the axis of fall. The reentry vehicle effectively “backed” into the atmosphere, capitalizing on the principles of blunt body gas flow to carry away much of the fiery heat of reentry. The remaining heat load, though still nearly twice the melting temperature of steel, was absorbed and ablated by the vehicle’s pyrolytic graphite heat shield, which charred, sublimed, and then burned away in fractional layers.
The design of the heat shield was not Soviet technology, but the product of military espionage. Early in the Cold War, Soviet intelligence agents had copied the blunt body reentry shape from the work of American aeronautical engineers H. Julian Allen and Alfred J. Eggers Jr., and the ablative layering technique from America’s Mercury space program. And now that American technology was screaming back toward the nation of its birth at several times the speed of sound.
The heat shedding was critical to the vehicle’s mission, because — a few centimeters on the other side of the superheated skin — delicate circuits and mechanisms were at work. The conical device streaking toward the earth was not a decoy. It was a 200 kiloton KBS-34 series nuclear warhead, and it was in the process of arming itself for detonation.
The red arc on the wall-sized geographic display screen was almost complete now. As President Chandler watched, it flashed and grew a fraction longer.
The firing envelopes of the Army’s Patriot III missile batteries appeared on the screen as green circles. The circles were large; the Patriot system had a good effective range, but there weren’t enough of them to provide adequate coverage. And none of the Patriot batteries intersected the final flight path of the Russian warhead.
As General Gilmore had predicted, the bomb was getting a free ride on the final leg to its target.
The sequence started slowly, but built in speed as the reaction began to escalate. When the reentry vehicle fell past 50,000 meters, a relay clicked open, channeling electrical power into a ring of high-voltage capacitors that encircled the core of the weapon. With a whine like angry mosquitoes, the capacitors began to charge.
At 10,000 meters, another timed relay clicked open. Near the narrow end of the cone, a pair of electrical solenoids rammed their actuator rods downward, forcing pistons into either end of a pressurized cylinder of tritium gas. The pressure within the cylinder exceeded the failure point of a foil membrane that isolated the cylinder from a connected manifold of stainless steel capillary tubes. The foil membrane ruptured, and the pressurized tritium was forced through the manifold, into the steel tubes, and through them into the spherical void between the primary and secondary stages of the bomb.
At 3,000 meters, the ring of capacitors fired, dumping their stored electrical power into a precisely-constructed network of wires. The length of each wire was known to within a nanometer, and its electrical resistance had been calculated to nine decimal places. The attention to engineering precision paid off. The signals shooting through those wires reached their respective destinations with nearly perfect synchronicity.
Ninety-six electrical initiators fired at the same instant, detonating ninety-six trapezoidal blocks of high explosives surrounding a spherical shell of radioactive plutonium 239. The charges were carefully shaped to focus their destructive force inward, toward the center of the plutonium sphere. It was not an explosion, but an implosion.
Faced with more than a million atmospheres of external pressure, the spherical plutonium shell collapsed inward, toward the envelope of tritium gas and the secondary stage of the bomb. The plutonium, already much denser than lead, was further compressed by the converging shock wave of the implosion.
Tortured beyond the boundaries of elemental stability, the plutonium shifted from its natural process of gradual radioactive decay, to an accelerated state of induced fission. The nuclei of many of the plutonium atoms were crushed or split by the extraordinary mechanical force of the compression wave. The shattered nuclei emitted heat, photons, X radiation, gamma rays, and neutrons. The neutrons were flung out to strike adjacent atoms like randomly fired bullets, shattering previously undamaged plutonium atoms and releasing larger quantities of heat, light, radiation, and still more neutrons.
Through a process known as doubling, the chain reaction escalated. Fifty damaged atoms became a hundred. Then one hundred became two hundred, and two hundred became four hundred. In the space of a few nanoseconds, the chain reaction grew a million times more powerful than the implosion that had triggered it.
Heat, radiation, and mechanical force erupted outward in a thunderous explosion of atomic energy.
But it didn’t stop there. The mechanical force and radiation of the primary stage attacked the secondary core of depleted uranium at the heart of the bomb. Tritium atoms merged with uranium atoms, and the expanding fission reaction was magnified by nuclear fusion.
The fireball and shock wave grew, and everything they touched was obliterated. Every living creature within their hideous circle of effect was instantly incinerated.
And the telltale mushroom cloud, not seen in battle since the annihilation of Nagasaki, climbed toward the blue California sky.
Ann Roark elbowed Sheldon Miggs in the ribs. “Ask somebody, damn it!”
Ann’s eyes were glued to one of the courtesy televisions mounted high up the side of a support column in the airport departure lounge. The television was showing the feed from a Japanese news program. The images on the screen alternated between studio shots of a Japanese anchorman who looked like Ryuichi Sakamoto, and still images and video clips from some kind of breaking news story centered in California. At least it seemed to be California, as a green silhouette map of the state appeared periodically in the graphics window next to the anchorman.
The screen cut from a quick establishing shot of the White House, to archival footage of a nuclear explosion — complete with trademark mushroom cloud, to an overhead helicopter shot of a major traffic pileup on an unidentified freeway, to what looked like rioting and general pandemonium in the streets, and back to the nuclear mushroom cloud.
Something had happened. Something huge. But what was it?
The voiceovers and the on-screen text were all in Japanese, which Ann could not read or speak a word of. She glanced around at the groups of Asian travelers clustered around every visible television. Most of them stood in what appeared to be stunned silence, while a few spoke to their fellows in intense whispers.
The news feed cut back to the Ryuichi Sakamoto lookalike for a few seconds. Then it switched to a still shot of the U.S. Pentagon, jumped to footage of ambulances and paramedics helping injured people, dissolved to a still shot of a city skyline that might have been San Diego, and then returned to the nuclear explosion.
Ann looked over at Sheldon, whose attention was focused entirely on trying to get his cell phone to work.
Ann sighed. “Will you let that damned thing alone? You’re about three thousand miles outside of your cellular provider’s coverage area. You’re not going to get a signal in freaking Japan. Okay?”
Sheldon shook his head. “I upgraded my service plan to include Japan and South Korea. I’ve got a signal. That’s not the problem.” He punched several buttons and put the phone to his ear. “I need to check on my Mom and my dogs, okay?”
Ann looked back to the television screen. The Japanese news station was running a feed from CNN now. A blonde anchorwoman stood in the foreground, speaking into one of those stupidly oversized network microphones. In the distant background, the Pentagon was visible. Ann listened carefully to catch the anchorwoman’s words, but the local station was running the Japanese translation in place of the original English voice track.
A graphic window appeared beside the American news correspondent. A computer animatic of a fiery mushroom cloud blossomed above the CNN logo. The words, “NUCLEAR ATTACK” appeared over the animated image in a red diagonal banner.
Sheldon closed his cell phone with an audible thump. “Damn it. I can’t get through. The phone lines on the West Coast must be overloaded with traffic. Whatever the emergency is, it must be …”