the departing missiles was still faintly audible as he spoke.
The Tactical Action Officer’s reply came over the net a second later. “TAO, aye. Is there enough time to prep a second flight of birds in case we miss on some of the intercepts?”
The Weapons Control Officer keyed his mike again. “TAO — Weapons Control. That’s a negative. The inbounds are moving at about 14,000 miles an hour. We get one crack at this, sir. By the time we get off a second flight of birds, the inbounds will be outside of our missile engagement envelope.”
The reply was several seconds in coming. “TAO, aye. Let’s hope we don’t miss the first time.”
At about the time the Tactical Action Officer was releasing his mike button, the four missiles were shedding their first stage boosters, and igniting the Dual Thrust Rocket Motors of their second stage engines.
The missiles gained speed and altitude quickly, ejecting their second stage boosters as they were climbing out of the upper stratosphere and into the lower reaches of near-earth space. Three of the SM-3 missiles performed this transition perfectly. The fourth missile did not.
A pre-stressed retaining pin in the mating collar between stages failed to shear under the calculated strain of stage separation. The mating collar did not separate, and the second stage booster did not drop away as it had been designed to do.
The missile’s computer was programmed to detect many types of technical casualties, but this simple mechanical failure had not been anticipated by the weapon’s designers. Unable to sense that the second stage booster was still attached, the missile’s computer transmitted the ignition command to the third stage rocket motor on schedule. The jet of hot expanding exhaust gasses, which should have poured harmlessly into the near vacuum of space, were channeled into the small chamber between the second and third stage motors. Unable to contain the expanding pressure wave, the airframe exploded, spewing streaks of shrapnel and fire into the void of the upper stratosphere.
The Weapons Control Officer read the flashing warning message on his screen, and keyed his microphone. “TAO — Weapons Control. I’m showing a pre-intercept failure on Bird #4.”
“Weapons Control — TAO. I copy your pre-intercept failure on Bird #4. What happened?”
The Weapons Control Officer scanned his readouts for a clue to the cause of the failure. After a few seconds, he keyed his mike again. “TAO — Weapons Control. I have no idea what went wrong, sir. Bird #4 just dropped off the scope.”
“TAO, aye. How long until we find out how our other birds are doing?”
“TAO — Weapons Control. It should be any time now.”
“Weapons Control — TAO. Is there no chance at all that we can get another bird up there to replace #4?
The Weapons Control Officer looked at the converging vectors on his display screen. “TAO — Weapons Control. No chance, sir.”
He released the mike button. “No chance at all.”
Thirty seconds before impact, the Kinetic Warhead separated from the third stage booster. Unlike the EKVs of the ground-based interceptors, the Mark-142 Kinetic Warhead was equipped with onboard sensors. It detected the target immediately, and used a brief series of pulses from its maneuvering thrusters to improve its angle of approach to the intercept point.
As with the EKVs, the KW’s arrival at the intercept point had to be timed to coincide with the arrival of its target. A millisecond too soon, and the KW would pass through the intercept coordinates ahead of its quarry. A millisecond too late, and the target would blow through the intercept coordinates before the KW arrived. In either case, the Russian warhead would slip past the KW and the intercept attempt would fail. The timing had to be nearly perfect.
It was.
The Soviet-built R-29R reentry vehicle arrived at the calculated intercept point at the exact same instant as the Kinetic Warhead. Several million Newton-meters of additive linear force were spontaneously translated to thermal energy. With a blindingly bright flash that no human eye would ever see, SM-3 missile #2 obliterated its target.
The Weapons Control Officer watched his screen. “TAO — Weapons Control. Splash one!”
Before the Tactical Action Officer could acknowledge the report, the Weapons Control Officer keyed his mike again. “TAO — Weapons Control. Splash two! And splash three! I say again, three hits — three kills.”
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
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
