Penetrating Russian defenses will be a lot like cracking open a locked set of these dolls-within-dolls.
On Jeffrey’s order, the strike group went to silent battle stations. “Proceed with minisub release for Carter docking.”
Bell issued the orders, COB worked his console touch screens, Challenger’s hangar doors opened, and the mini began to move. It was being piloted by a chief from Carter’s crew, and co-piloted by another chief, a Navy SEAL by background, from Kurzin’s commando group. Both men, already fully qualified in the American ASDS minisub design, had come over to Challenger at the end of the previous rendezvous. Since then they’d been thoroughly checked out in operating the German mini, by Meltzer and COB. This intense extra preparation was needed, Jeffrey knew, because the German mini, vital to the mission in more ways than one, would never return to Challenger again.
The mini began to cover the modest distance across to Carter. The two full-size nuclear subs used Jeffrey’s preferred rendezvous formation. Challenger’s heading was north, and Carter’s was south, with neither ship making forward motion; each bow sphere sonar covered the other ship’s baffles, since no towed arrays were deployed. They kept just enough horizontal and vertical separation to avoid any collision hazard, and not block each other’s wide-aperture arrays on the sides where they faced. Jeffrey liked to think of this as circling the wagons.
In a split second, all calm evaporated.
“New passive sonar contact on the starboard wide-aperture array!” Chief O’Hanlon called out. “Broadband contact, submerged, intermittent, contact bearing is… zero-five-zero! Acoustic sea state too high for meaningful ranging!” Noise from the ice cap was interfering with one of the wide-aperture array’s most important functions: instantly finding the range to another submarine. “Contact not close,” O’Hanlon added after a pause to study sound-path data. “I designate the contact Master One.”
Bell acknowledged, surprised and concerned. “Fire Control, commence a target motion analysis on Master One.”
Sessions spoke with Torelli. A tracking party got busy. With enough passage of time — and if the contact wasn’t lost — Master One’s range, course, and speed could be estimated by computer analysis based solely on the way in which the bearing to the contact slowly changed.
“Sir,” Sessions reported, “Carter signals, ‘New sonar contact.’ ” Sessions read off the rest of the acoustic-link message, which made it clear that they’d detected the same vessel, Master One. “Carter asks whether to proceed with minisub docking while contact is held.”
Bell turned to Jeffrey. “Commodore?”
Jeffrey was forced to make a very difficult choice. “Anything yet on Master One’s range or speed?”
“Negative, sir,” O’Hanlon stated. “And no tonals.”
“Nothing here yet either, sir,” Torelli replied.
“He’s moving and we’re not,” Jeffrey said. “That gives us a sonar advantage.”
“Only if we put the docking on hold,” Bell warned. “Master One might pick up mechanical transients otherwise, sir.”
“If we shift the strike group’s position, and have the minisub follow along, we’ll waste its fuel and we can’t get a refill. We aren’t ready to climb up on the continental shelf, to hide from this guy that way. Deploying off-board probes to scout ahead on the shallow bottom will make mechanical transients too.”
“Hug the slope at the edge of the shelf, and wait for him to go by?” Bell asked.
“Sir,” Sessions interrupted Jeffrey’s train of thought, “Carter signals, ‘Minisub requesting clearance to dock. What are your instructions?’ ” The mini’s acoustic-link system was too weak for it to have overheard the very low power messages between Challenger and Carter. Its passive sonars were much too unsophisticated to have detected Master One on their own. The pair of chiefs in its control compartment were unaware that a third, unfriendly, nuclear submarine was so nearby.
“Master One signal strength increasing slightly,” O’Hanlon said. This suggested it was coming closer.
“Weps?” Bell asked. “Anything?”
“Bearing has shifted left, sir. Worst case is that Master One is approaching, will cross in front of our bow.”
“Can you say when?” Jeffrey asked.
“Could be twenty minutes, could be two hours.”
Sessions spoke up again. “Carter has repeated her signal.”
Jeffrey was in a real bind. None of the tactical alternatives were good.
“Carter signals, ‘Unknown submerged contact will cross my baffles within one hour.’ ”
The words were matter-of-fact, but the implied tone was insistent. A serious threat was approaching, and soon would enter the baffles zone in which Carter was totally blind.
Bell, Sessions, and Torelli kept glancing at Jeffrey, waiting for him to tell them, Harley, and the minisub what to do.
If you don’t have any good choices, pick the one which seems least bad…. And the sooner the better. That threat gets closer every second.
“Signal Carter, ‘Designate contact Master One in further messages. Warn minisub of unidentified vessel’s presence, then proceed with caution but make docking smartly. Signal flagship soonest when docking complete.’ ”
“Yes, Commodore,” Sessions typed. Though the danger hadn’t diminished, the decision to do something made the men around Jeffrey feel better. Harley acknowledged Jeffrey’s message.
“Sonar,” Jeffrey said to Finch, “monitor the mini docking for transients’ duration and signal strength. I want to know in a heartbeat if Master One could have heard anything.”
Finch turned to Chief O’Hanlon, and they conferred.
A sonarman with headphones on, assigned to monitor the minisub, visibly cringed.
“Thump and scraping,” O’Hanlon reported. “Assess as docking attempt aborted. Detection likelihood by Master One unknown.”
Jeffrey cursed to himself. The two chiefs on the mini were handling the little craft clumsily.
“Signal Carter, ‘Put docking on hold. Will match your depth to shield you acoustically from approaching contact.’ ”
Sessions sent the message; Harley acknowledged.
“Captain,” Jeffrey told Bell, “rise on autohover, make your depth seven-three-zero feet, smartly.”
Bell gave the helm order; Patel acknowledged and tapped at his keyboard and touch screen.
Jeffrey watched Challenger’s depth decrease from eight hundred fifty feet until her bulk stood between the upper part of Carter’s hull and Master One. “Signal Carter, ‘Resume docking.’ ”
Once more Sessions typed, and Harley acknowledged.
The sonarman cringed again.
“Thud and clunks,” O’Hanlon said. “Assess as mating collar lineup, and lockdown clamps engaging.”
Carter signaled that the docking had succeeded.
“Detection likelihood by Master One undetermined,” O’Hanlon said. Without knowing what class of submarine Master One was — what quality of passive sonars it carried — plus still lacking any useable data on distance, O’Hanlon and Finch had no way to calculate an enemy detection threshold for the noises just made.