Darin Sunley wrote:
> What do you people think would
> be "realistic" space-based weaponry, i.e. weaponry that obeys
> the laws of physics that might reasonably be deployed from an
> interplanetary spacecraft with the goal of disabling/destroying another
> interplanetary spacecraft?
It all depends on your assumptions. As Anders pointed out, there is lots of speculation about applications of mundane technology in usenet, and they also get a lot of unlikely suggestions from guys who think they've invented perpetual motion machines and force fields. However, I haven't seen much written about the kind of future most of us expect (with nanotech, advanced biotech, AI/massive automation, and very rapid change).
The way things are going now we will probably have primitive nanotech and rather advanced biotech before anyone puts weapons on an interplanetary spacecraft. If we get real advances in AI in the same time frame the situation is going to be far to chaotic for meaningful predictions - IE and nanotech would both advance so fast that our prediction horizon would be reached within a few years. If AI and nanotech both advance at a slower rate, we might get a brief era in which space warships could be built.
That means we should assume cheap diamondoid construction, a high level of automation, amazingly good sensors and computers, and at least limited sorts of self-replication. I'm also going to assume free use of nuclear weapons and power systems, mainly because people who are squeamish about such things aren't likely to build combat spacecraft in the first place. That leaves me with the following ideas:
A warship's missile-defense lasers should be completely effect out to a range of a few thousand miles. Lasers should have an effective range of 10 to 100 times that far against other ships, depending on how fast they can dodge. That suggests ships armed with heavy lasers for close range combat, and missiles mounting bomb-pumped lasers for long-range combat. Ordinary nuclear missiles could be useful for killing kinetic energy weapons, other missiles, nanobot swarms, and other target's that don't have much missile defense.
Plasma weapons and charged particle beams probably aren't viable weapons, because they can't match the range of the lasers. Neutron beams could be very effective, if someone can figure out how to get a decent beam intensity without building a particle accelerator the size of Nebraska. If stealth technology is good you could do interesting things with mass drivers and stealthy payloads (nuclear bombs are still more effective than nanobots for anything except planetary bombardment).
For more exotic possibilities, try particle beams that use anti-matter particles. They would have a slightly shorter range than lasers, but would do far more damage to large targets. Of course, you have to carry a supply of antimatter around to use as ammo, which makes your ship a bit more vulnerable.
Overall, I would expect a trend of very rapid growth in ship size (large ships using even primitive nanotech would be very difficult to disable).
Billy Brown, MCSE+I