Stardate 20040419.1157

(Captain's log): So if the characteristics of ships and weapons dictate strategy and tactics used in naval encounters, then what would be the critical characteristics of space warships which would be critical?

It depends entirely on what assumptions you make. In most of science fiction, it's convenient to toss the known laws of physics out the window, to a greater or lesser extent, and once you do that the door is wide open and anything can result. My intent is to try to stay more realistic. So I will assume that space navies would still be bound by such tiresome limitations as conservation of momentum, the theory of relativity, and the laws of thermodynamics. I will assume no major changes in our understanding of the universe. That means no "faster than light" drives, no "space warp" or "inertialess" drives, no "subspace" or "hyperspace", and so on.

I will also try to reasonably extrapolate current day technology, and I won't consider anything unless I either know in general how it can be done or know enough about it to believe that it will become possible. That means no energy shields, no "leap cannon", no "high temperature superconductors", and so on.

Willing suspension of disbelief works really well for fiction, but this is not intended to be fiction, or analysis of fiction. It also isn't intended to be a technologist's wet dream, where anything which doesn't violate the laws of physics is permitted. I intend to write about what I think is possible, plausible, and feasible. [Any given reader may disagree with my judgment. Such readers are invited to write and post their own articles to their own web sites, but are not invited to send them to me.]

I also make one critical political assumption: nuclear weapons won't be used in fleet actions because of a tacit agreement by both sides, driven by a fear of escalation. If two competing powers are technologically capable of creating fleets of warships for space, both will have nuclear weapons, and deterrence will prevent their use.

So what are the consequences of such assumptions? The first is this: no "stealth". If one fleet wishes to close with another fleet in order to engage in battle, the second fleet will have ample warning that it is coming.

The primary way ships will detect other ships will be with infrared sensors. Radar and other kinds of detectors will also be used, but IR is superior. Ships will glow in IR frequencies because they will be using energy, and the Second Law of Thermodynamics will therefore force them to be warm. [Yes, it would not violate the laws of physics for a warship to carry a big tank of liquid helium and to use it to cool its entire outer skin to 4° K, but no one is going to do that. Really. It wouldn't break any law of physics, but it isn't technologically plausible, for a variety of reasons.]

IR detection is superb even here on Earth, but the main problem with it is clutter. The thing you want to track is glowing, but there's a whole lot of other stuff around and behind it which is also glowing. But space is conveniently clear of clutter nearly everywhere. Add to that the fact that IR detection is passive, and IR would be the primary sensors by which warships would watch one another. (Nor would a backdrop help; advanced computers could implement what amounted to stereo vision in IR and detect a glowing object standing in front of another. If you are between me and the Earth, I can still pick you out through parallax.)

IR detection can be foxed, but not in any way which equates to invisibility. Rather, it is subject to what amounts to active jamming. That would mean that the enemy would know something was coming and would know in general the direction it was coming from, but might not be able to identify what it was (or how numerous they were) or to figure out a location accurately enough for a weapons lock.

Defensive IR jamming involves flares; bright spots thrown every which way in hopes of distracting an IR-homing missile. But something launching flares isn't "stealthy", and flares won't confuse humans or do a very good job of disguising an attacking fleet.

For that kind of jamming, ("offensive" jamming, if you will) you use "smoke". It would be a cloud of material thrown out around an attacking fleet which would interfere with and disperse the IR signature of ships within it. The biggest disadvantage of smoke is that it blinds both sides equally, but there are ways to work around that. Unfortunately, both sides can use those ways of working around that.

An obvious workaround is sensor drones. A fleet in being would be surrounded by a loose shell of small robotic units containing sensors, engines and radio links back to the fleet. When a suspicious bogie was noticed, other sensor drones could be sent to check it out. If it's a moving cloud of smoke, sensor drones could penetrate the smoke to see what was inside. And a drone in a smoke cloud likely would detect a ship inside the cloud before the ship detected the drone and took it out.

At best an attacking fleet could try to disguise its characteristics, but could not prevent the defender from knowing that something was coming, and knowing that it was probably hostile, and there's a good chance the defender could learn a lot more than that.

I don't think "stealth" would even be possible for radar. Modern anti-radar "stealth" technology is actually rather specific. The F-117 relies strongly on the shape of the ship