Terminal Run

“Relax, Michael. I’m his stepmother — I know. When I met him he was a skinny high school kid. I watched him his plebe year at the Academy, saw him get tougher, and watched him grow into an upperclassman. He’s his own soul — there are shadows of you in him, but he’s unique. Let him go, Michael.”

“Thanks, Colleen. For being a good stepmother to him. He’s the better for having had you in his life.”

She just stared at the table for a long moment.

Back in the office, Colleen looked over his sketches.

“So, you want the full briefing?” Pacino asked.

“Tell me everything,” Colleen said.

“In theory, it’s simple. We cut the stern of the SSNX to allow inserting two dozen solid-fueled Vortex engines.” The Vortex missile was an underwater solid fueled rocket that traveled at three hundred knots and steered itself by rotating its nozzle. Although it was called a missile, some physicists called it a supercavitating torpedo, because what allowed it to go such extreme speeds was that its nose cone boiled the water to steam vapor, and the vapor bubble eventually completely enclosed the missile so that the rocket thrust could carry it through the water at the speed of a private jet. “When the con trolroom hits the switch, twenty-four large-bore rocket engines ignite and the ship gains enough thrust to get up to a hundred and fifty knots.”

“That’s not enough. The latest supercavitating torpedoes go three hundred.”

“So the ship has to eliminate skin friction. This is where it gets more complex.” Pacino riffled the pile on his desk for a sketch. “We run dry piping headers through the ship connected to the high-pressure air system and through valves to the main steam system. At first the high-pressure air banks blow plugs out of the hull surface nozzles. Air covers the skin of the ship, through these ring headers. As the air blankets the surface of the hull, the ship begins to lose skin friction. As the air banks go dry, the main steam system comes on-line to replace the air, and the boiler output dumps into the headers. That will last until the thrust is gone from the Vortex engines. According to the program, as the air banks go dry, ship velocity is up to two hundred ninety-eight knots, and as the steam takes over, we get an additional eight knots. And we maintain that for over twenty seconds, with an acceleration time-to-velocity of—”

“It won’t work.”

“—say, that’s not good, that will put internal acceleration at over ten g’s. Dammit, we’ll mangle the crew with that level of acceleration.”

“It won’t work.”

“I’ll work on the acceleration calcs—”

“You’re not listening!”

“What?” Pacino asked. “What did you say?”

“I said it won’t work.”

“I know — the acceleration’s too much.”

“That’s not why,” Colleen said, frowning. “First, the Vortex engines will melt the propulsor, the rudder, and the stern planes How will you control the thrust angle?”

“We can’t mount the engines on gimbals,” Pacino said. “It would make the system too complex. And I planned on the stern section melting away.”

“Great — so your aft ballast tank is vaporized, your control surfaces are burned away — there’s nothing to control the ship’s angle. You’ll zip to the surface and come back down, losing your speed, and get hit with the incoming torpedo, or you’ll plunge to crush depth, or worse, corkscrew through the water and kill the crew from being put into a seven-thousand ton blender.”

“We’ll control attitude with the bow planes

“It won’t work, Michael,” Colleen said, agitated. “You can’t use the gigantic hydraulics and the slow response of the bow planes to control the ship.”

Pacino nodded. “I think I see what you mean. We’ll have to lock the bow planes at zero angle, then use small trim tabs on them, or upper and lower spoilers, hooked to a dedicated pneumatic system or a separate high-pressure hydraulic mechanism. That would move fast enough to control the ship’s angle.”

Again Colleen shook her head. “The sensors and the computer control won’t have the speed to control the ship. The time constant’s too long. By the time the computer senses a down angle and sends the signals to correct for it, you’re a hundred feet deeper than crush depth.”

Pacino frowned. He had met his wife in a drydock much like the one the SSNX lay in now, laboring over the same hull, when she had come to fix the computer system installed by her company. He remembered her calm, relentless competence and the lionhearted way she had insisted on going to war in the East China Sea with the SSNX when the Cyclops battle control system was still failing. He’d listened to her then, and he would listen to her now.

“This problem’s too big to solve in a day,” Pacino said finally. “I’ll work on it tomorrow.”

“You can’t,” Colleen said, a slight smile coming to her lips. “You’re busy tomorrow.”

“Oh? What am I doing tomorrow?”