Session 2, Monologue 2: The Great Space Arms Race

Purpose: to determine a realistic approach to space combat.

In space, velocity is relative. There is no such thing is "maximum speed", only acceleration. Large ships tend to accelerate slower than small ones, but they all have the same top speed: just shy of the speed of light. In fact, the (theoretical) physics of FTL travel suggest that moving at warp speed is a function primarily of energy--something a large ship would have more of per unit of mass. Thus, at FTL speeds, large ships may, in fact, dominate. Forget everything Star Trek, Star Wars, EVE, and every other damned audiovisual space experience (except Babylon 5) ever showed you.

Let me just follow up on the above point. In space, Newton's laws are reality. If you accelerate, you experience G forces. When you turn off your accelerator, you stop feeling the forces. You maintain your current velocity, however, until you accelerate again, or until an outside force acts on you. Thus, everything ever pictured about space combat is wrong. Traditional dogfighting makes no sense. Even capital ships need not sluggishly saunter through space throwing potshots at each other; it is perfectly reasonable for a massive ship to rocket past another at a relative speed difference of tens, hundreds, or thousands of meters per second.

With this in mind, examine how space combat might work. Two fighters hurtle toward each other. They blast their weapons at one another; both dodge, using strafing rockets. Then, they pass each other at tremendous speed. As both turn around, they find they are opening their engagement distance very fast. In fact, never is their speed differential so high as the moment of passing. The only way to close distance, and thus increase the possibility of hitting the other, is to accelerate toward each other again; at first, it will seem they are slowing--then, they will momentarily "stop" relative to each other, then begin accelerating again.

It is unlike dogfighting in almost every way. However, it is extremely similar to something 6d20 players ought to be familiar with: jousting.

The reality of dogfighting makes low-speed projectiles almost useless. However, high-speed weapons, such as railguns or lasers, or seeking weapons such as a missile, are overwhelmingly powerful. This seems to necessitate powerful shielding, to mitigate or negate such powerful weapons. But how, then, is one to succeed? It is much like jousting--both parties point their shields at one another, endeavoring to block the other's lance whilst simultaneously attempting to strike the other despite their shield.

Jousting was intended as a showy test of skill, not an actual method of resolving combat. The winning strategy is clear: cheat. While you are heading toward your enemy, focusing your shields toward him, his 3 friends have a clear line of fire, and obliterate you. Or, your 5 friends destroy his 3, and him.

Thus is the unfortunate reality of dogfighting. Likely, future space wars will not resemble World War II dogfights in the slightest; we already have missiles which can shoot down an aircraft moving at Mach 2 a hundred miles away (seriously), and those have to contend with air friction, wind, gravity, and countermeasures. Space missiles only have to contend with the latter.

A space missile would have devastating effect. It would be near-effortless to engage at any distance. A missile could easily cross light-years if need be, first accelerating, then coasting along for however many years it takes. Total distance is no object, only total maneuvering needed. And, since we assume the ship that fired it has some exotic engine capable of long-range, high-speed maneuvering (on an interplanetary or even interstellar level) there is no reason to assume the missile lacks this.

In space, there is no fear of radioactive contamination of the environment. You might fit a ship-to-ship missile with a megaton nuclear warhead, to ensure total destruction of the target. Any excess radiation will bounce harmlessly off the shields of friendly targets, and off the magnetic shield of nearby habitable worlds. This means a missile must be evaded at long range--no tight swerves to narrowly avoid them. They'll detonate at a range of kilometers.

The only reasonable defense, even with such exotic defenses as shields and armor hardeners, is to shoot down the missile before it can shoot you down. And this is not so hard. Missiles are, by nature, smaller vehicles than that which fired them. A missile from a fighter will be rather tiny; no bigger, perhaps, than a refrigerator, on the highest estimation. Such a device would likely have minimal shielding, if any. A weapon that might bounce off your foe's fighter could destroy the missile entirely, or at least disable it's guidance systems to prevent it from engaging you. It would be relatively easy to target; it would have only AI-based evasion, and would have limited evasive capacity--every bit of evasive maneuvering comes at a cost to its total "range", and to its payload.

Of course, if countermeasures are a viable defense, then there must be a counter, and there is: missile swarms. A fighter can have only so many anti-missile countermeasures. How many missiles can it take down at once? Three? Five? Ten? Doubtful. One missile might split into four, each approaching from a different vector, and packing enough payload to finish the job on its own.

Of course, missiles equipped with sufficient fuel to engage a target, dodge its countermeasures, then split into four sub-missiles, each with independent motors and fuel sufficient to close while evading, all with enough room for a payload: these are big missiles. For a truly fire-and-forget experience, expect to pay big per missile, and not fit many onto your fighter.

Missiles still have some purpose; a quick volley of dumb-fire missiles at close range might be useful in a jousting scenario. Missiles could bypass the enemy fighter, then explode backwards, sending the force into the ship from behind, in a sensitive area. Such missiles would be launched at the last second, in a swarm as to evade countermeasures.

Still other missiles might rely on stealth or electronic warfare to evade countermeasures. A "torpedo" missile would be aligned beforehand, like any other dumb-fire projectiel, and run silent until the last moment. Without emissions, it would be difficult to detect such a small object, especially if it had a low radar profile. At the last moment, the torpedo fires its rockets, if necessary, to make a final approach, then detonates. Such a weapon requires some skill to use, as its chance of a successful hit requires a well-placed shot and a bit of luck.

Now, there is also the small matter of lasers. Lasers take the fun out of any dogfight: they are so fast, there is almost no need to close with the enemy. They are too fast to evade, and are not made of matter to be deflected by a countermeasure. They do have a major weakness, however: they rely entirely on light to deliver their payload, and that light may be easily diverted. It seems like it would be standard practice to craft the outer lay of ship armor with highly-reflective material to easily defend against lasers. This might be somewhat effective, but such armor runs counter to all stealth practices, and implies that stealth vehicles are incredibly easy to destroy with lasers.

In the pre-shield phase of space combat, lasers may have been virtual instant-kill devices against all but the least stealthy, most reflective craft. Even massive juggernauts would be insulated with polished ceramic, for fear of easy kills via sustained laser fire.

To make space combat interesting in the age of shields, it would be convenient if lasers and other low-mass weapons were the easiest to deflect, thus ruining the fun of railguns and light plasma cannons by extension. Of course, the premise of shields as a dark matter or dark energy device seems to contradict this; such a shield would create local gravity fluctuations, which would have great effect on projectiles, but little effect on photons.

It is difficult to conjecture how such shields might work, but it would still be very nice to assure that said shields are not blatantly pseudoscientific. In sci-fi, if you do not specify the exact method by which future tech works, no one blames you if it is bizarre. If you do, however, nerds will criticize your scientific shortcomings. Thus, this is a "nice-to-have" for Homeworlds; it is, in fact, nice to have, because a sci-fi setting is greatly enriched by realistic theoretical physics.

Clearly, dark energy isn't what we want. Gravity is a terrible force for redirecting photons and very lightweight projectiles; whatever it could do to them, it would do to heavier projectiles a thousandfold. We might abandon shields altogether, focusing on armor hardeners or reflective shielding. However, a laser simply needs to be focused at the one non-reflective spot, and create intense heat which will conduct throughout the ship. Also, no reasonable amount of armor hardening could stop a super-powered laser pulse; we have already created a terajoule laser in a lab, in the 21st century. The armor that could stop such a blast would probably be invincible to all other weapons.

So, perhaps lasers work another way. In this world of warp drives, it may be possible to produce micro-warp bursts which can totally redirect even the most powerful attacks. Such a burst would draw quite a bit of power, but, if timed correctly, it could easily deflect a laser or railgun. Since such weapons typically involve a relatively long charge time (several seconds), followed by a near-instant release, a decent computer system could detect such charges and fire the micro-warp burst just after it detected the charge drop. Of course, one would need a good sensor lock, but that shouldn't be hard; the amounts of energy needed to fire meaningful laser or railgun blasts is so incredibly high that almost any sensors could see it coming a mile away.

And so, it seems there are several types of weapons:

• High-energy weapons: lasers, railguns, high-powered plasma cannons. These consume huge amounts of energy, and must be charged up before firing. The space equivalent of a standard action.
• Low-energy weapons: guns, missiles, low-powered plasma cannons. These consume small amounts of energy, and need no charge-up. They can be easily chain-fired if continuously fed ammo. Low-energy plasma cannons use a large, ready supply of plasma, such as a small fusion reactor, and accelerate them to relatively low speed (comparable to a bullet); high-powered cannons use the same ammo, but fire much faster.

There are, similarly, several types of defense:

• High-power defenses: micro-warp bursts (great vs. fast high-powered weapons) and deflector shields (great vs. high-powered explosions or heavy projectiles).
• Low-power defenses: ablative shields and armor hardeners. Both use dark matter; one condenses it in a bubble around the ship and the other uses it to reinforce existing armor.

With high-powered weapons, you need high-powered defenses and good timing to survive. The higher-skilled combatant will win. With low-powered weapons, assuming both parties have low-powered defenses, it is a battle of attrition.

Another interesting point: the only way to time a high-powered defense against a high-powered, fast weapon is to time it right. Sensors work at the speed of light, minus a computing delay. Fast weapons travel near the speed of light, usually 90% or faster. The margin that determines how long you have to respond is the difference between the time the sensor data arrives and the time the attack arrives; the closer the attacker is, the smaller the amount of time. An aggressive opponent will get very close, in the hopes of closing the gap and making it impossible to evade his attack.

It seems EVE was right about one thing: space dogfights do not resemble earthbound ones. Rather, the faster ship chooses the engagement range, and the slower one is at his mercy. A fast ship decides if he wants to stay at long range or do a fast, tight orbit at close range. Speed, in this case, is acceleration. Engines and power have something to do with that, but inertia has much more to do with it: small ships can accelerate very easily, large ships, not so much.

This is why fighters exist. They're incredibly weak and easy to destroy by large ships. Unlike in EVE, there is no penalty for a large ship to target a small one; some large weapons may be poor at tracking small targets, but there is no reason a capital ship can't have dozens of smaller ones, each with tracking systems at least as capable as those on a fighter.

However, fighters have a tremendous speed advantage over capital ships. If they wish to hold at a great distance, they can. If they want to orbit tightly, in the hopes of evading countermeasures, they can. If they wish to open the field, it's theirs to open. Generally, once fighters or bombers are inside a capital ship's effective radius of engagement, it's a lost battle, unless the ship has fighters of its own.

An interesting note of comparison: most games with fighters and capital ships tend to have the capital ship's threat level rise as one approaches it. This is not exactly the case; outside a ship's sensitive inner "threat bubble", it can easily engage many small targets. The only way to evade its many anti-fighter weapons is to open the field. Speed won't save you when the ship fires 50 missiles at you. If you aren't attacking a capital ship, stay FAR away. Outside a few kilometers, you can probably avoid the simple stuff: guns, flak, maybe even lasers with a good tracking system. Missiles will get you at just about any range. You either need cover or stealth; range alone isn't good enough. Most missiles can outrun you unless you have a damn big head start. You need to be hiding behind another capital ship, or stealthy enough to evade detection.

Carrier groups are aware of this reality. They don't just scramble the fighters at every opportunity. They need them if there are bombers, of course, but against a capital ship, it's suicide to bring up screen fighters. However, they'll want their own bombers, in that case.

Bombers are generally very large and heavy. They devote about half their mass to defenses, half to payload, and none to maneuverability. There is little point in trying to outmaneuver fighters; even a hefty bomber can outmaneuver a capital ship, but outpacing its defenses can be very tricky. Capital ships are aware that a single bomber poses an existential threat; they will pull out all stops.

Alone, even a heavy bomber stands little chance against a capital ship's determined assault. A widely-arrayed bomber group might stand a better chance, but it's suicide for most of the pilots, and a waste of good ships. A more interesting strategy has been developed of late: bombers fly in extremely tight formation, inside one another's shield bubbles. The shield systems not only work together, but the effect is, in fact, greater than the sum of its parts.

A less sophisticated strategy has been used by desperate attackers, and was popularized by the Dekorrans. It essentially involves giving every fighter a nuke, and sending a massive cloud of them at a ship. There is no distinction between bomber and fighter--all of them support each other, all are fast, all might as well be made of paper if they get hit by the big ship. It's manpower-intensive, but relatively cheap otherwise.

Bombers are typically not used in capital-to-capital engagements where one ship clearly has the advantage. A capital ship, if not sunk, will usually survive a battle with little to no casualties; there is no reason to risk bombers and bomber pilots when dumb-fired and remote-controlled weapons work just as well.

Of course, this is all from the perspective of capital-to-capital plus fighters; there are medium-sized ships as well, and the situation is different with them.

A cruiser has decent defenses, but it can probably be bested by a wing or two of fighters. Their weapons are effective enough to pose a threat without needing bombs, and their defenses can actually take a hit or two from the cruiser. A frigate is even less of an issue; plenty of high-end military fighters are more than a match for a multi-purpose or outdated frigate. A battlecruiser, however, can be deadly to fighters, especially if well-equipped with screen modules.

All in all, fighter-class ships are quite popular, because they have a high ratio of overall effectiveness per unit of size, per unit of money, and per unit of pilots. Small installations may employ only fighters for defense. A low-end transport may require only a fighter or two for escort. Many fighters are short-range, eliminating much of the power and space needs usually eaten up by long-range drives, fuel, and support systems, making them either that much cheaper and lighter, or giving them that much more room for weapons and defenses.