In part one of this entry I discussed the usefulness of beam weapons in far future space battles. While highly effective at short ranges their utility drops off as range increases, until they are almost useless at distances of a light hour, distances that fleets would prefer to at least initially engage at. The reason is that light beams can’t change their vectors when approaching a target that might be trying to avoid them. The farther the target the less likely they are to be where you aimed at when the beam gets there. We need something for long range that can change its vector onto the moving target. That leaves some kind of projectile weapon, a missile or a kinetic round of some kind. KE rounds, though packing a wallop, suffer from some of the same problems as particle beams. Unless they have some terminal maneuvering capability they can be dodged after they are seen. They might be hard to destroy, depending on how much mass they are carrying, but surely could be if the enemy was motivated enough to take them out. Smaller KE weapons, like cannon, might have an easier time hitting a target with a spread, but give up the hitting power of the larger KE weapon. They would again be best for close in combat, while the large KE weapon would be the ideal planetary bombardment weapon, and would be unsuited to ship to ship in most situations. Of course a terminal vector capability in larger KE rounds could have them maneuvering onto target, not inconceivable. That leaves missiles. Now if the missiles can be boosted to an appreciable fraction of light speed they become weapons due just to their speed. If not, or even if, they can be armed with massive warheads, fusion or antimatter, which can do a lot of damage. How much damage? Unfortunately for weapons tech, space is a vacuum, and any blast effect of a warhead will only consist of the mass of the weapon sent off in a sphere around the blast. Not much mass, especially as the matter is reduced as to the square of the distance. Most of the effects of the weapon would be heat and radiation, and again you need a fairly close detonation, at most a hundred kilometers, to cause much damage. Of course a direct hit could be devastating, and the target will be trying to avoid that at all costs. If the missile is traveling point nine light speed or above the warhead would almost be a useless redundancy on the weapon, as the missile would most probably shatter the target when it hit. Missiles could be sent at a target across a solar system, and would actually become more deadly the longer they boosted and built up velocity. A slow moving or close shot missiles would almost be useless, as it would be picked off by beam weapons or autocannon before they could close with the target. Of course the missiles could have all kinds of countermeasures that would be useful at a distance, holographic decoys, jamming, moving in evasive patterns, launched decoys that resemble the missiles, multiple separate warheads (MIRVS), even their own counter missiles to take out the target’s counter missiles. The speed of the missile, as mentioned, makes them deadly weapons as kinetic rounds. The faster they are traveling the harder they will be to hit, especially in a ECM loaded environment. You may only have a hundred thousandth of a second to acquire the correct target and blast it. Conversely, due to their speed they may only have the same infinitesimal time period to acquire and maneuver onto a target. And anything that gets in the way of the missile were surely take it out. On the other hand, even pieces of a destroyed missile could do immense damage to a warship. Read Niven and Pournell’s Footfall for an example of a situation where even if the closing object is vaporized the vapor will destroy the target. If the missile misses the warhead comes into play, detonating on closest approach much like AA missiles do today, and hopefully causing some worthwhile damage to the target.
Torpedoes are another weapon that is mentioned a lot in science fiction. But really a torpedo is just another name for a missile, using the connotation of ship launched weapons. Photon torpedoes from Star Trek are the most famous, though they have nothing to do with photons, and the scintillating energy around them seems at most a smoke screen, since they are nothing more than antimatter torpedoes. So what about energy torpedoes? Good question, but first we need to define what they are. Energy is simply fast moving matter (just as matter is very slow moving energy). It is a particle of some kind, electrons, protons, neutrons or something smaller. I’ve never seen a good explanation of just what they are, but maybe we’ll discover some new kind of energy that holds together over distances and makes a big flippin explosion when it hits something. It’s possible. Most engagements would probably consist of both fleets flushing masses of missiles at each other from distance as they closed to beam weapon range. Then they would fly past each other at high velocity while their beam weapons used the limited time to take each other under fire.
Now the last weapon I will talk about is plasma weapons. Just what are they? Plasma is a superheated gas, like that found in stars. Now we could probably heat gas to millions of degrees sometime in the future, but what kind of weapon would it make? Not so good, as far as I can tell. The ball of plasma would probably be very diffuse, and if not it would soon be as it spread out. Possibly it could be used as a close in weapon, but in space battles close in weapons are of limited utility. And if a hundred kilograms of superheated plasma hit a million ton warship it really wouldn’t put all that much heat into the target. It the heat was spread evenly over the ship it would cause a .1 degree rise in temperature. That’s right, .1 degree, and I think even my home AC unit could handle that. Maybe enough to cause local damage, but not ship wide. In some stories the plasma is held in a magnetic field that keeps it together and possibly even moves it to track a target. They almost never say what is generating that field though. Once it leaves the ship that source is out. Maybe if they have some kind of pod that trails the plasma it can continue generating the field, but it would also become a good target to stop the plasma. All in all it seems like a lot of work for little return. A good laser would seem to be a better investment.
Next installment will talk about possible protective strategies for these warships that are taking beam hits and being swarmed by masses of near light speed missiles.