Minutegirls

by George Phillies

  "Sir, apparent EU destination is Tyler," Wilmot announced. "Enemy is holding 35 effective gravities, northwest and sunwards, with Tyler in-plane." 35 effective gravities, Wilmot noted to herself, meant that they were pulling over 50 gravities not in a straight line. American forces would do little better than half that.

  "Stupid fornicators of goats," Kalinin cursed. "There's nothing on Tyler!" He glared at a planetary display. "North is temporary, because Mogadishu is more south," he announced. "Sunwards is toward Tyler and away from Teutoberger Wald." Kalinin considered his fleet disposition. The outer SLPSDF reserve flotillas were roughly screening Harding and Lincoln, both of whose orbital positions were currently east and modestly below the warp-point/Alpha Centauri line. Tyler, the outermost planet belonging solely to Alpha Centauri, was well west of that line. The current EU path was almost parallel to the plane occupied by most of his ships.

  "Panama, Mogadishu flotillas are to rotate planes of battle to face enemy, and attempt to close. Columbia flotilla is to follow enemy at best acceleration." Kalinin muttered under his breath. His reserve formations, strong enough to fight the enemy force head to head, were not placed to respond to an attack on Tyler. Someone had forgotten to allow for the detail that the enemy had miserable reconnaissance data, and might not know which planet they were supposed to attack first.

  The reserve formation closest to the EU line of flight was Albemarle. Albemarle, all thirty-two battleships, had by far the worst engines in the fleet. Worse, the reserve crews were so past commissioning that they had trained only in four-ship pyramidal flights, not in more modern eight-ship combat boxes. Crew activity since mobilization was still focused on single-ship fundamentals and equipment readiness. On the bright side, the flotilla did mass over 200 million tons, making it the largest and probably most powerful in the fleet, if it ever got up and running.

  "All other formations, accelerate primarily west and sunwards toward Tyler at best flotilla accelerations. Missile barges B to F to fall to rear of fleet and comply with our acceleration. Wilmot, see if Albemarle can get across their path -- I doubt it."

  “Confirmed, Sir. They'll get close enough to engage the rear of the enemy forces, briefly, then fall behind. And the remainder of the fleet will not close enough for effective fire. Shall I compute rapidity transitions?" asked Wilmot.

  "Compute, for jumps to Tyler, blocking, and out of plane, but don't expect us to use them. Comrade Grand Commodore Ter-Minassian risked that. Once. No, we will catch them the other way," Kalinin said. His tricursor sketched pursuit paths on the main display. "They can outrun us, but Panama and Mogadishu will hurt them enough to leave some stragglers. Do they abandon stragglers, or slow down so we can catch them?"

  "Other way?" Wilmot asked.

  "The note from Doctor Markovian says EU fusactor outputs track EU accelerations. The State of Todd Special Attack Cruiser -- Panama Flotilla -- Martingale tried engaging them with its gravlance, which had absolutely no effect. Ergo, our friends are in fact powered by fusactors, and have neither temporal screens nor are using chaos gates for power. Therefore, they have bunkerage limits. At a guess, we chase them to Tyler, to Buchanan, and finally to Harding, and then they will want to go home to refuel. We are between them and the warp point. When they head for the warp point, we execute a rapidity displacement in the safe direction, directly away from them, and stop at the warp point. They cannot copy, because they would need to perform an insane rapidity transition directly though our formation. They must then fight us to reach the warp point," Kalinin explained. "But this time we will defend on the warp point, not so far off it that they can evade our formations as they are now doing."

  "Yes, Sir," answered Wilmot. "The remaining missile barges. They have higher acceleration than EU forces are currently showing. If they were to lag our pursuit somewhat, and if the EU were to turn and fight, they could catch up, rejoining us at large Delta-Vee relative to us as they fired, shortening torpedo flight times."

  "Optimize the arrangement, and so order," Kalinin said after a little thought. The suggestion was the opposite of orthodox doctrine, which was that a good formation had everything at the same place with the same velocity. Wilmot's idea was that the barges would hide well to the rear. If a battle were forced, they would accelerate to join the fleet, arriving in position with very large positive velocities relative to the fleet. This was bad for station keeping, but just fine for the torpedoes. The larger their delta-vee relative to the enemy, the less time the enemy had to shoot them down.

  Someday, this would all be doctrine, but missile barges were too new. He would have to determine who had originated the suggestion. He suspected there was a close collaboration between Wilmot and Junior Vice Commodore Second Class Abigail Hyde, she who had invented the barges in the first place, and needed to be sure the two women got proper credit for their ideas.

  Kalinin looked at his formation. He had urged that the fastest ships be put on the wings, but the Joint War Committee had not supported him. There were scenarios where the current formation was superior. If Albemarle and New York had switched places, New York's four battle cruiser squadrons -- 160 million tons of modern ship, making it nearly as strong as Albemarle -- would have had enough position to hurt the enemy significantly. It would not have hurt that Senior Captain, no, Junior Vice Commodore as of two weeks ago, Henderson had trained New York squadron up to her standards, which were the highest in the fleet. Meanwhile, the enemy formation was distorting from its original geometric symmetry, stretched from a spherical polyhedron to a cigar. He posed a few questions to his servile, whose analysis suggested that the enemy had put his ships with highest accelerations to the intended front of the formation. Were there subclass distinctions between various Doormouses and Dragons? It appeared so. The hind ships were distinctly lagging those in the lead, by almost ten gravities. He called the differences to the servile's attention, told it to correlate with other variables showing distinctions along those axes, and let it proceed to think.

  "Commander Bilodeau," Kalinin asked, "Are the damage reports sorting out properly now?" There had been a software glitch in the last battle. Kalinin remembered tapes of First Clarksburg, a battle so small Ter-Minassian could track damage to individual ships in detail. With more than 530 vessels possibly engaged, full lists of drives, gates, and -- God only knew -- meat lockers damaged by enemy fire would instantly swamp the comprehension of anyone listening. Momentarily, the thought of commanding the fully-mobilized fleet, with eight thousand deployed ships, came to mind.

  "Summary on workpanels 3-5, Sir," Bilodeau answered. Every simulation had tested properly. There was some difficulty with multiple reports, too close together, from a single ship, something not caught in sims that now had been fixed.

  Kalinin looked back to the main display. For all that ships were accelerating at a thousand feet per second or more, distances were so large that motions resembled schools of genegeneered fish swimming through molasses. Panama and Mogadishu flotillas would turn to face the enemy, the two planes of battle forming the jaws of a giant bear trap that would slam shut somewhat too late.

  Virginia squadron was now almost in the center of the enemy formation, evading madly and dumping decoys and flares -- torpedoes, actually, a high-yield fusion explosion doing a fine job of blinding instruments -- in all directions. Still, they were too close to the enemy for jinks to prevent xraser hits. They were going to emerge seriously damaged, if they emerged at all. The target of their attentions, the presumptive enemy flagship, had turned away from them. Hash marks suggested the FEU flagship was overscreened relative even to FEU standards, but eight Virginia-Class battlecruisers were obtaining regular burnthroughs to hull screens. Kalinin looked at the missile barges making attack runs.

  "Signal missile barges to deviate northerly, as practical, to concentrate their fire here," he designated ships in what would soon be the rear of the enemy formation, "and while the range is long, Mogadishu squadron until it closes is to concentrate xra
ser fire similarly." He paused. "We cannot solve Virginia's difficulties, but we can ease their passage." Moments after he finished speaking, a bronze point of light flashed to a violet star.

  "Georgia has blown up," reported Bilodeau. "Virginia has ordered all ahead linear." Kalinin nodded. Virginia squadron was so close to the enemy that evasive maneuvers were ineffective. Ending evasive maneuvers increased the formation's useful acceleration by forty percent.

  "Some may survive," said Kalinin. "Let's come back to the strategic level." He expanded the main display field of view. "It will be some time before there is a dramatic change. Puzzle: Why is the fleet with superior acceleration withdrawing and giving us time to unite our forces, when it would have had a reasonable chance to defeat in detail Mogadishu flotilla, while staying within the warp point though which they could always withdraw? Give that a few minutes of thought, please."

  He leaned back in his chair. His opening Academy lecture on Fleet Tactics... `The Iron Laws of Classical Mechanics' began its automatic replay. At this late date, the replay was a calming mantra, something to take him away from the action so he could notice the forest hiding in the trees.

  "...In the end, the effectiveness of all xraser-type weapons is determined by range and the maximum acceleration and jerk of your target. Once upon a time, scientifiction authors gave radiation weapons a maximum range. However, as is immediately apparent from Physics 3, a xraser beam is close to diffraction limited, so its divergence is roughly lambda/r. A battlecruiser xraser port is 3 yards across, while a typical xraser output wavelength is 10-10 yards -- you can do this in American Scientific Units if you want. That's a homework assignment. The range of angles on beam output is, oh, 10-10 radians, give or take, so the beam diameter doubles in 1010 yards, or a bit under 107 miles. Even against screened targets, the effective range is much larger, though pointing finally is challenging. The effective range of a xraser against unscreened soft targets like planets is a large multiple of this, which is why Mercury, Venus... all get planetary defense screens.

  "...However, to hurt your target, you must hit your target. An enemy ship displaces as x = 0.5 a t2, x being displacement, a being acceleration, and t being time. Time? A lidar pulse is reflected back to you; you retarget to hit the target. At one light-second range, your targeting is two seconds late. Homework: Why not three seconds, since the lidar pulses must first go from you to the target?

  "Your target has some radius R. If during t your enemy moves less than its ship radius R, then you always get to hit him. If during t your enemy moves more than R, life becomes interesting. An enemy who keeps constant acceleration might as well have parked -- constant acceleration is predictable, and that which can be predicted can be targeted. An enemy who always shoots at your start point, if you always move more that R during his t, always misses.

  "If your enemy keeps changing acceleration, he gets harder to hit. He can't see your xraser beams incoming -- he can still dodge. For example, suppose during t your enemy has randomly displaced on average through 4R. 1/16 of that 4R circle is him. The rest is empty. If you cannot predict his position 15/16 of your shots miss. There is a fine argument: if you are dodging, should you go random after each time you've displaced through your own diameter? Or is patience better? Your materials course is doing polymer properties -- look up 'wormlike chain'. Oh dear, I just gave away an exam one question, didn't I? And how does that depend on what your enemy thinks you will do?

  "After all, x goes as t2, right? No. Once you go random, you are doing Brownian motion, which is why every command officer must understand stochastic processes. For Brownian motion, x grows as the square root of t, meaning your chance to hit a distant enemy falls linearly with time and range. Double the range means double the tracking time delay means half the chance of hitting.

  "But Mister a comes in, too. The larger your a, the closer you can be to the enemy before he can hit you. Ships with larger maximum accelerations are harder to hit - unless they are so badly designed that they can't change their accelerations quickly. Constant acceleration is worthless as a defense in battle.

  "Except, except, acceleration straight at or away from your enemy doesn't affect his aim. Your motion along that axis is straight line, not random evasion, so closing or retreating, ship-on-ship, is indeed x proportional to t-squared. However, a ship that is englobed -- targeted from multiple directions -- loses this option, and in order to dodge must randomize acceleration along all three axes. Thus, being englobed is bad news, especially for an American officer whose ships are slower than his foes to start out with.

  "Let's put in some realistic numbers. A typical American ship can pull 30 gravities. An FEU battleship pulls 100. Also, R for a Villiers class is 200 yards. R for a Marco Polo Bridge class like the Large Battleship Death-to-the-Imperialist-Warmongers we are touring next week is 400 yards. The FEU ship can close to within one light-second of the American before the American's chance to hit approaches 100%, while the American can be as far out as 2-3 lightseconds while the FEU ship is still fairly certain to hit. In round numbers, for that pair of ships we must be within 50,000 leagues to be sure of hitting, while an FEU ship only needs to be within 150,000 leagues -- closer against smaller ships. At larger distances, it is harder to hit. At the 3 lightseconds at which an FEU ship is sure of hitting a Marco Polo Bridge class, our chances of hitting fall to one in three or less, so we need three times the firepower to even things up. Furthermore, FEU beams and screens are much better than ours, so in the end we want around ten times the firepower -- meaning ten times the hull weight -- to engage on even or better terms."

  The Virginia Squadron, thought Kalinin, is at pointblank range of the FEU Demon-class ship, ranges so short that both sides are firing missile volleys -- no, correct that. We are firing, and...? "Lieutenant Smythe, are you completely blanking all FEU missile traces? I see absolutely none," he asked.

  "Not deliberately, Sir. Checking. No, Sir, I'm getting no tracks on FEU missiles," she answered.

  "No reported damage from missile hits, Sir," Bilodeau added. "That datum is not very reliable."

  "Note to counterintelligence," Kalinin said to himself, "This is a clever response to our soliton torpedo upgrades -- neglect to employ torpedos. Where was the leak? How did the FEU know?"

  FLOTILLA COMMAND BRIDGE

  DIRIGIBLE PLANETARY DEFENSE BASE MONSTRATOR

  July 3, 2176, 2:07 AM LST

  Junior Vice Commodore Jane Duty Henderson glared at her bridge screen. Three weeks ago, she had been assigned to take command of the Charles Fort class Dirigible Base Monstrator and its associated flotilla, no fewer than 15 squadrons of recently-mobilized alleged warships. In some cases, the allegations were highly dubious. Monstrator was a huge spindle, albeit very light for its size, whencefrom its name. Its main dock once upon a time swallowed a squadron of battleships.

  As an afterthought, to silence a half-dozen Senior Captains who were firmly convinced that they were entitled to command the newly-formed Panama Flotilla, Henderson had been brevet-promoted three ranks. Grand Commodore Kalinin had taken her out to lunch, told her to make the best she could out of the ships she had, and promised her that failures would be blamed on her materiel. The Commander-in-Chief and Chairman of the Joint War Committee, the Honorable Senator Alphonse Humbert Meyer himself, had taken her out to dinner, and told her that he had counted the votes: If she handled the post even reasonably well, the promotion would be made permanent. Meyer's reputation was sterling. His statement was a bankable commitment from the de jure Commander in Chief of the States of Lincoln Planetary Defense Forces.

  Kalinin's line she had not believed. You might be taking a wet navy PT boat against an aircraft carrier, but if you lost the CO always got the blame. Her parents had both been American Solar Navy, father having a row of fruit salad for saving his squadron at Third Charon. She and sisters had had that lesson drilled into them from birth. You commanded; what happened was your fault. At least Dad had always kept 'commanded' and '
had highest rank' distinct. When his young daughters went to the mall, one of them 'commanded' and Goddess preserve either of the others if they disobeyed a proper command. She wished younger sister Clarissa Country had been available to help sort out some of the weirder ship types; she was very ingenious with strange weapon ideas. Older sister was more orthodox and always made the best of conventional material at hand, though older sister's sim record suggested 'Older sister has taken command, prepare to die! Victoriously!' was a propos.

  Now it was too late. She had run drill after drill, sim after sim, but two weeks had not shaken the flotilla down. At least she knew some of the more interesting weaknesses, starting with ships that only carried special-purpose weapons, effective against classes of enemy ships that the EU had apparently forgotten to invent or deploy. Then there were the ships whose brasswork gleamed, whose crew tables were gastronomic masterpieces, whose fitness and hobby facilities were absolute gems, and that on good days could Come To Quarters in an hour or two. The demisquadron of Tucson-Class Missile Cruisers could only maneuver under tow, because the Reserve Fleet Maintenance Report 'slightly incomplete repairs' had failed to emphasize 'we really should install some engines'. Those ships hovered well to the rear. At this distance from Centauri, their attitude drives were adequate for stationkeeping. Their crews were thoroughly practiced in 'abandon ship'. They packed large missile stocks. If they ever hit anything, they would do substantial damage.

  Monstrator herself was quite literally an obsolete shipyard, for some years used as a storage hulk. When Monstrator had become obsolete, someone had pointed several assembly lines in Monstrator's direction, filling vacuum graving docks with row after row of chaos gates and shield generators. The catastrophic failure blowoff shunts left much to be desired, but so long as the shields held together Monstrator was the most heavily screened ship in the SLPSDF. It was a shame the engines were so minimal. Out of her hearing, the crew's affectionate nickname for their ship was 'honorable giant war turtle'.