The sonar set for the active search went through a self-check, and when it showed all circuits and systems nominal, it lit up the active pinger, seeking forward for the submarine target. In case the target were closer, the weapon would detonate upon driving up to a close range of a hundred meters. If not, and there were no submarine target detected, the unit would proceed to the aim point. If there were no target in the sonar seeker window by the time it approached the far side ice wall, the unit would execute what was called a default detonation, the logic behind it that a one megaton blast didn’t need to get close to destroy a target.
But the sonar seeker, instead of hearing a pulse return from a target, heard a ping at a much higher frequency from something else. It was faint at first, but then louder as it got closer. The weapon was confused. It had no protocol for hearing this oddly insistent pinging sound.
At a distance from launching point of two miles, that pinging sound got extremely loud and a sudden impact cut the Gigantskiy torpedo in two, and an explosion started from aft of the warhead and the computer controls. There was a protocol for something like this happening. When the accelerometers registered over one G in any direction, a default detonation command would be programmed, the thinking that a countermeasure torpedo would not prevent the weapon from exploding. Rather, it would just explode early.
The low explosives lit off as the back half of the Gigantskiy vaporized in the explosion of the Mark 48 ADCAP countermeasure torpedo, and the high explosives detonated, compressing the plutonium fragments into a sphere, and nanoseconds later, the plutonium exploded, its plasma sphere engulfing the heavy water canisters, which started the fusion reaction, and the full one megaton yield of the torpedo lit the previously coal mine darkness under the ice into bright daylight. The explosion blew upward into thick ice, but the ten meter thickness of the ice canopy was unequal to the tremendous force of the explosion, the entire ice canopy blowing into splinters and shards and flying upward for a radius of three hundred meters, the violent expulsion of water vapor of the explosion rising to over a mile over the surface. The pressure wave from the blast hit the bottom and reflected upward, the shock wave becoming a cylinder around the blast zone and traveling away at sonic speed in all directions, until it encountered an ice wall to the west, blowing the ice wall to fragments.
On the other side of the ice wall was the huge hull of the launching ship, the Belgorod, and the deep-diver submarine, the Losharik. Belgorod was at a depth of 150 meters, with Losharik bottomed out at 470 meters. The shock wave slammed into Belgorod like the punch of a fist, but it passed over Losharik, only rolling the deep-diver submarine over. The flooding of the Belgorod started immediately after the impact.
25
Tomahawk SUBROC unit one, in tube eleven of the aft Virginia Payload Tube, lay snug in its waterproof capsule, nestled in the vertical tube. It was connected to the BSY-1 battlecontrol system by a signal wire leading to the flank of the capsule and penetrating it and connected to the weapon’s electronics. The target location was programmed in and accepted, as well as the present position of the weapon. The warhead yield was dialed in at maximum, 250 kilotons of thermonuclear power. The signal wire from the battlecontrol system disconnected. The missile was on its own now, its battery keeping it alive until the turbine could start up in the near future.
The weapon felt the sudden intense acceleration upward as the launching system ejected it, a rocket motor directed into a reservoir of pure water at the base of the tube, flashing the water to high-pressure steam that acted like the gunpowder explosion of a cannon ejecting a cannonball. The cannister flew out of the tube, accelerating more as it rose out of the tube, but as the stern of the capsule cleared the tube, the pressure of the steam eased and the acceleration became negative as the weapon slowed. The steam created a bubble around the capsule and the steam and the cannister rose quickly toward the surface a hundred feet above, to the open water of the polynya formed by the first Gigantskiy detonation.
The weapon continued rising until the nosecone of it broached into the cold arctic air. As it did, a wet-dry sensor at the tip of the cannister detected dry air, and it activated twenty-four explosive bolts around the circumference of the cannister, blowing the nosecone cleanly off, the fiberglass of it tumbling end over end high in the air. As the nosecone reached the apex of its flight and started falling back toward the water, the missile’s first stage rocket engine ignited, and the missile roared out of the waterproof cannister and blasted out of the water, rising vertically up over the icy landscape. Behind it, the polynya grew smaller as the rocket motor roared, lifting the missile to a height of a thousand feet.
As suddenly as it had begun, the rocket thrust stopped, the solid rocket fuel exhausted. By then, an air inlet scoop had popped out, the scoop sucking in air. Another two dozen explosive bolts blew the rocket motor off the aft end of the weapon, the first stage tumbling back down toward the polynya, and as it did, the explosive blast of steam could be seen below as a second missile’s cannister broached into the open water.
The missile’s winglets popped out into the airflow and directed the missile to dive downward straight toward the ice below. As the missile flew downward in a glide, its speed rising as it fell, the air coming in through the scoop spun the turbomachinery, the compressor on the forward end and the turbine on the aft end beginning to spool up to operating speed, and as the compressor blades rotated, they compressed the incoming cold air and the pressure in the combustion chamber rose, as well as the temperature, until the combustion chamber was super-pressurized and red hot. The missile’s computer opened the valve to the pressurized fuel tank and jet fuel flowed into the combustion chamber and the spark plugs lit the atomized fuel and air mixture, the chemical reaction causing temperature and pressure to soar far over what they’d been to start. The hot combustion gases sought the relief of a lower pressure and first blasted through the turbine blades, some of their energy going to spinning the turbine harder and faster, which kept the compressor spinning up forward. The remainder of the hot, high-energy gases flowed aft through the missile’s exhaust nozzle, the thrust of them propelling the missile, but by then, the missile was approaching the solid ice below.
At an altitude of seven meters above the ice, the winglets pulled the missile out of the dive and it flew west-northwest toward the aim point, hugging the terrain of the ice, following the rises and valleys, until it was a mere thousand feet from the aim point.
Behind the missile, the second-launched unit was climbing to the height of its rocket-driven flight, jettisoning the rocket motor stage and diving for the ice canopy. The first-launched unit rotated its winglets and climbed vertically in its pop-up maneuver, until at a thousand feet over the ice, it again arced over and down until the nosecone was pointed straight down at the aim point. The time for powered flight was ended, and explosive bolts blew the payload module away from the missile body, which pulled away, flew on to the north and then self-destructed.