Страница 112 из 207
"No doubt," Lynch agreed. "Although I trust," he continued more dryly, "that what you've just said doesn't mean you think it's going to be a good idea for a heavy cruiser to take on a superdreadnought, even with the new laser heads?"
"No, Sir. Of course not," Helen said quickly. "I guess I was just thinking about Monica, Sir. If we'd had the new laser heads there, I don't think those battlecruisers would have gotten into their effective range of us in the first place. Or, at least, if they had, they would've had a lot more of the stuffing kicked out of them first."
"Now that, Ms. Zilwicki, is a very valid observation," Lynch said.
"I also think it's bound to have at least some implications for all-up MDMs," she continued. "I mean, I don't see any reason why the same engineering can't be applied to bigger laser heads, as well."
This time, Lynch simply nodded.
There was a reason it had taken so long for the laser head to replace the contact nuclear warhead as the deep-space long-ranged weapon of choice. The basic concept for a laser head was actually quite simple, dating back to pre-Diaspora days on Old Terra. In its most basic terms, a hair-thin, cylindrical rod of some suitable material (the Royal Manticoran Navy used a Hafnium medium) was subjected to the x-ray pulse of a nuclear detonation, causing it to lase in Gamma-rays until the thermal pulse of the detonation's core expansion reached the rod and destroyed it. The problem had always been that the process was inherently extraordinarily inefficient. Under normal conditions, only a few percent of the billions of megajoules released by a megaton-range nuclear warhead would actually end up in any single x-ray laser beam, mostly because—under normal conditions—a nuclear detonation propagated in a sphere, and each rod represented only a ridiculously tiny portion of the total spherical area of the explosion and so could be subjected to only a tiny percentage of the total pulse of any detonation. Which meant the overwhelming majority of the destructive effect was completely lost.
Given the toughness of warship armor, even two or three T-centuries ago, that was simply too little to have any appreciable effect, especially since the resultant laser still had to blast its way through not just a warship's sidewalls, but also its anti-radiation shielding, just to reach the armor in question. So even though the odds of achieving what was effectively a direct hit with a contact nuke were not exactly good, most navies had opted to go with a weapon which could at least hope to inflict some damage if it actually managed to hit the target. Indeed, pre-laser head missiles had been most destructive when they achieved skin-to-skin contact as purely kinetic projectiles. That, unfortunately, had been all but impossible to achieve, even with the best sidewall penetrators, so the proximity-fused nuclear missile had become primarily a sidewall-killer. Its function was less to inflict actual hull damage than to burn out sidewall generators.
Unfortunately from the missile-firer's perspective, active missile defenses had improved to such a degree that "not exactly good" odds of scoring a direct hit had turned into "not a chance in hell," which was the real reason capital ships had gone to such massive energy batteries. Missiles might still be effective against lighter combatants, but they'd been for all intents and purposes completely ineffective against the active and passive defenses of a capital ship, so the only way to fight a battle out had been to close to the sort of eyeball-to-eyeball range at which shipboard energy mounts could get the job done.
But then, little more than a century ago, things had begun to change when some clever individual had figured out how to create what was in effect a shaped nuclear charge. The possibility had been discussed in several of the galaxy's naval journals considerably longer than that, but the technology to make it work hadn't been available. Not until improvements in the gravitic pinch effect used in modern fusion plants had been shoehorned down into something that could be fitted into the nose of a capital missile.
A ring of gravity generators, arranged in a collar behind the warhead, had been designed. When the weapon fired, the generators spun up a few milliseconds before the warhead actually detonated, which was just long enough for the layered focal points of a gravitic lens to stabilize and reshape the blast from spherical to Gaussian, directing the radiological and thermal effects forward along the warhead's axis. The result was to capture far more of the blast's total effect and focus it into the area occupied by the lasing rods. By modern standards, the original laser heads had been fairly anemic, despite their vast improvement over anything which had been possible previously, and capital ship designers had responded by further thickening the already massive armor dreadnoughts and superdreadnoughts carried. But the ancient race between armor and the gun had resumed, and by fifty or sixty T-years ago, the laser head had become a genuine danger to even the most stoutly armored vessel.
There were other factors involved in the design of a successful laser head, of course. The length and diameter of a lasing rod determined its beam divergence, with obvious implications for the percentage of energy the laser delivered at any given range. Ship-mounted energy weapons, with their powerful grav lenses, could squeeze beam divergence in a way no laser head possibly could. There was simply no way to design those lenses into something as small as a laser head which, despite many refinements in design, remained essentially a simple, expendable rod which would have been easily recognizable by any pre-Diaspora physicist.
In the current Mark 23 warhead, the laser heads (the assemblies containing the actual lasing rods) were roughly five meters in length and forty centimeters in diameter, which carried the thread-thin lasing rods suspended in a gel-like medium. The laser heads also incorporated the wolter mirrors to amplify the beampath, reaction thrusters, lots of fuel, on-board power, telemetry, and sensors. They were carried in bays on either side of the weapons bus, which ejected them once the missile had steadied down on its final attack bearing. Each of the laser heads mounted its own thrust-vectoring reaction control system, which acquired the target on its own sensors, thrust to align itself with the target's bearing, and quickly maneuvered to a position a hundred and fifty meters ahead of the missile. At which point the gravity lens came up, the warhead detonated, and the target found itself out of luck.
The critical factors were laser head rod dimensions, the yield of the detonation, and—in many ways the most critical of all—the grav lens amplification available. Which was the main reason capital missiles were so much more destructive than the smaller missiles carried aboard cruisers and destroyers. There was still a minimum mass/volume constraint on the grav lens assembly itself, and a bigger missile could simply carry both a more powerful lens and the longer—and therefore more powerful—lasing rods which gave it a longer effective standoff range from its target. That was also the reason it had been such a challenge to squeeze a laser head capable of dealing even with LACs into the new Viper anti-LAC missile. The bay for the single lasing rod was almost two thirds the length of the entire missile body, and finding a place where it could be crammed in had presented all sorts of problems.
The general Manticoran technical advantage over the Republic of Haven had made itself felt in laser head design, as well. Manticoran missile gravity generators had always been more powerful on a volume-for-volume basis, and Manticoran sensors and targeting systems had been better, as well. The Star Kingdom had been able to rely upon smaller warheads and greater lens amplification to create laser heads powerful enough for its purposes, especially since it could count on scoring more hits because of its superior fire control and seeking systems. The Republic had been forced to adopt a more brute force approach, using substantially larger warheads and heavier lasing rods, which was one of the factors that explained why Havenite missiles had always been outsized compared to their Manticoran counterparts.