World Wide Packets Lightning Edge 46 Manual Meat

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In the section we will examine what spacecraft warships will need, what they won't need, and what sort of tasks they will likely be required to perform. In the section we will examine the thorny issue of the terminiology of the various types of spacecraft. In the current 'wet' Navy, a 'Fleet' is more of an organizational fiction rather than an actual entity. A group of ships belong to a fleet. But what is generally encountered at sea is a 'Task Force.' A few ships from a fleet are 'detached' to form a task force charged with performing a specific mission. When the mission is completed, the ships of the task force are dissolved back into the fleet.

Going off of a very rough historical comparison to WW1 and earlier naval organizations try: Squadron = More than 3 ships of same type/class/mission. Flotilla = more than 1 Squadron operating independently under one commander. Division = same as a Flotilla except operating as part of a Fleet.

World Wide Packets Lightning Edge 46 Manual Meat

Fleet = Multiple Divisions. The logistical support ships, cargo, colliers, oilers, etc. Usually operated to support the battle Fleet (Flotilla etc) and could be called a Division, Squadron, or Fleet Train. Some support vessels were never organized into units at all. The US Navy still uses Squadrons, but formed units are generally called Battle Groups or Task Forces when operating alone, though they are still part of the Fleet. Pineconez' second law: Assuming a techlevel more advanced than nearfuture ( i.e. Interstellar -or- extremely cheap interplanetary travel exists), there will exist no true warship which will not ALSO be capable of single-handedly exterminating an entire continent, be it via nukes, kinetics or handwavium bombs.

World Wide Packets Lightning Edge 46 Manual Meat

Corollary: If you are able to intercept and kill another warship across a star system, you are also capable of reducing to radioactive rubble an entire planetary civilization with little effort. The brain trust that I copy from research for spacecraft combat material have developed their own private jargon. As a public service I present a small glossary so you decipher what they are talking about.

CONTROL SHIP Also called a 'Space Control Ship'. Basically a mobile control center for combat drones. It is a lightly-armed combat spacecraft carrying an enormous C4I electronics suite (communications/command/control/computers/intelligence) tasked with controlling huge numbers of remote-controlled space combat drones armed to their cute little pointy teeth. Sort of like the brain center inside a huge swarm of deadly metal space-going hornets with nuclear stingers. The idea is that the control ship and its human crew stands off at a (hopefully) safe distance from the battle, and sending in hordes of expendable drones to savage the enemy ships. Please note that the control ship probably will NOT carry and service the drones, since the control ship will have to be nimble enough beat a hasty retreat if the battle goes terribly wrong. The drones will be carried by separate spacecraft.

The control ship might contain the only live human beings in the entire swarm. KINETISTAR A combat spacecraft or weapons platform with a as its primary weapon. Since the acceleration of the projectile increases with the length of the weapon barrel, these tend to be in. Requires large amounts of electricity (advantage: missiles), but the projectile is a simple inert lump of matter (disadvantage: missiles).

KIRKLIN MINE are a defense against. They are basically huge numbers of dime-a-dozen chemical-rocket-powered kinetic-energy-weapons. It is such a good defense it could render torch missiles to be totally worthless. LANCER A is a small fighter-type combat spacecraft armed with kinetic energy weapons and/or missiles where most of the weapon kinetic energy is supplied by the spacecraft's engines. Example: imagine a fighter accelerating to 3 kilometers per second on collision course with a Blortch Empire space battlecruiser, lightly ejecting a few penetrator shells, then frantically trying to change its vector so it doesn't crash into the battlecruiser. The inert penetrator shells will continue on collision course, tearing through the battlecruiser at 3 km/s relative. Generally this is a preposterous waste of your combat dollar, unless there are.

Right off the bat the Lancer spacecraft will need at least four times the delta-V of an equivalent missile, since unlike the missile the Lancer is not on a suicide mission. A missile just has to do one burn to the target. The lancer has to burn for the target, do a counter-burn to stop, do a burn for home, and do a counter-burn to stop at home. LANCHESTERIAN that basically says whichever side has more combat units in the battle automatically wins. Science fiction authors and game designers find this to result in scenarios that are drearily boring, so they often go out of their way to try to figure out extenuating circumstances to ensure military combat in their novels is non-Lanchesterian. LASERSTAR, a 'laserstar' is a combat spacecraft with a laser cannon as its primary weapon. Requires large amounts of electricity (advantage: missiles), but since it does not launch a projectile it theoretically has an infinite number of shots (disadvantage: missiles).

Occasionally the term is used for an impressively armed combat spacecraft suitable for political use in. MISSILE A conventional missile is a rocket with a warhead for a payload and murder in its heart. This poor term is used in a variety of conflicting ways in this website. Though all of definitions refer to something that is self-propelled, as opposed to railgun shells and other gun-launched.

Since it is self-propelled, it does not require large amounts of electricity (disadvantage: laserstars and kinetistars). But each missile is an expensive precision crafted device containing its own fuel (advantage: laserstars and kinetistars). In standard military parlance, a ' missile' is guided while a ' rocket' is unguided. Rick Robinson suggests that a ' torpedo' is a missile with acceleration less than a spacecraft while a ' missile' is a missile with acceleration greater than a spacecraft (the same way a wet-navy battleship can dodge a sea-going torpedo but not a guided missile). In GURPS: Transhuman Space they refer to a missile with acceleration less than a spacecraft as an ' Autonomous Kill Vehicle' (AKV). MOTHERSHIP A is a large vehicle that leads, serves, or carries other smaller vehicles. Technically a mothership that carries smaller vehicles internally is a Sometimes spelled 'mother ship' or 'mother-ship'.

PARASITE CARRIER A is that carries internally or in blisters. The classic example is the Battlestar Galactica, a space-going fighter-aircraft carrier. But science fiction has examples of huge battleships containing a few destroyer-sized ships. For example in The Expanse, the battleship carries several Corvette Class ships like the Tachi /. PARASITE CRAFT A small spacecraft carried internally or in surface blisters on a larger spacecraft.

The classic example is parasite fighters housed inside a fighter-carrier, e.g., a Viper launched from the Battlestar Galactica. But science fiction has examples of parasite craft such as ship's boats, captain's yachts, cutters, and landing shuttles.

And the Death Star carried entire Star Destroyers. The carrier can commonly recover and service the parasites, but not always. SPINAL MOUNT A is when instead of mounting a weapon on a warship, you start with a titanic weapon and build the warship around it. Essentially the weapon becomes the backbone or spine of the warship. The advantage is the ship has the biggest possible phallic symbol weapon. Disadvantages include the difficulty supplying the monster with power, the ship savagely recoiling backward when you fire it, and having to turn the entire ship in order to aim it.

TENDER A is a small vehicle that services other larger vehicles. Basically a cut-rate that deals with larger rather than smaller ships. Obviously a tender cannot carry larger ships internally (unless it is a ). Examples from historical wet navies include,, and.

TORCH MISSILE Conventional missiles come equipped with propulsion that is high acceleration but short duration ( e.g., a few seconds). They sprint to their target, but do not have the endurance for a prolonged chase. Torch missiles, on the other hand, are equipped with propulsion giving them acceleration and delta-V comparable to the target spacecraft they are trying to kill. Which means if you do not kill the missile first, it will chase you all over entire the solar system. And it will eventually catch you because it is on a suicide mission and you are not.

The drawback is such a missile will be almost as expensive as their prey, and an order of magnitude or two more expensive than a conventional missile. It also has no special immunity from the target's. If your point-defense is ineffectual against an enemy torch missile chasing you, the expensive solution is to target it with a friendly torch missile of your own. As with most things, allowing your warships to carry large numbers of torch missiles has. The dirt-cheap solution is to kill the enemy torch missile with hordes of inexpensive. Since a spacecraft can carry a gazillion Kirklins for the price of one torch missile, this strategy could very well make torch missiles an utter waste of good military expenditure. Basic Assumptions: This paper was written using the following assumptions as a baseline.

Physical laws: The laws of physics as we know them still apply. This means that spacecraft move in a Newtonian (or Einsteinian, though this realm is outside the scope of the paper) manner, using reaction drives or other physically-plausible systems (such as solar sails) for propulsion. Thermodynamics dictate that all spacecraft must radiate waste heat, and lasers obey diffraction. The only exception is FTL, which will be included in some scenarios. Technology: The technological background is less constrained.

If a system is physically plausible, the engineering details can be ignored, or at most subject to only minor scrutiny. The paper will examine a spectrum of technology backgrounds, but will focus on near to mid-future scenarios, where the general performance and operation of the technology can be predicted with at least a little accuracy. A common term used to describe this era is PMF, which stands for Plausible Mid-Future. This term (coined by Rick Robinson) is difficult to define, but it assumes significant improvements in technologies we have today, such as nuclear-electric drives, fading into those we don’t, such as fusion torches. Environment: This paper will attempt to examine a wide variety of environments in which space combat might occur. However, it will make no attempt to examine all of them, and the scenarios described will conform to several principles. First, this is a general theory.

Any scenario that is dependent on a one-shot tactic or highly specific circumstance will likely not be included, except during the discussion of the beginnings of space warfare, or to demonstrate why it is impractical in the long run. The recommendations made are not optimal for all circumstances, nor is such a thing possible.

They are instead what the author believes would be best for a realistic military based on the likely missions and constraints. Picking highly unlikely and specific sets of circumstances under which they are not optimal is best answered with a about one such scenario, posting on the: “You need a blockade, a hijacking (innocents aboard a vessel trying to break the blockade), and a high-thrust booster on the hijacked ship. Two stretch the limits of plausibility. The third is ridiculous.

Claiming that this justifies humans [ onboard warships, see Section 2] is like claiming that because warships sometimes run aground, we should install huge external tires on all of them to help get them off.” Second, no attempt will be made to include the effects of aliens or alien technology, because to do so would be sheer uninformed speculation. Third, the default scenario, unless otherwise noted, is deep-space combat between two fleets. Other scenarios will be addressed, but will be clearly noted as such. The biggest question, of course, is what a realistic space force would look like.

This is perhaps more sensitive than anything else to the beginning tech assumptions, as it is the product of all the tech assumptions made and their interactions, but a large part of the purpose of this paper is as a reference for fiction writers, so as much will be covered as possible. First and foremost, space forces are not navies, even if they copy the rank structure and traditions of one. While the vessel type names might be the same, the vessels themselves are not. They would not be some form of navy, be it that of Trafalgar, Jutland, Midway, or today, IN SPACE!!! While a number of parallels can be drawn between space warfare and other forms of warfare, the environmental differences mean that all must be closely examined. On a broad strategic level, naval (or more accurately maritime) strategy is a good fit, but on an operational and tactical level, what parallels exist come from all forms of warfare.

The first question that must be asked is the technology available, and most specifically drives and weapons. These two, more than anything else, drive the types of ships available. The most conservative (PMF) scenario is what will be discussed in depth. The main weapons are lasers and various forms of kinetics, while drives are limited to chemfuel, nuclear-thermal, and nuclear-electric. This means that vessels in general have very limited tactical delta-V, either due to low acceleration, or due to the limited delta-V of their drives. In particular, the velocities built up by nuclear-electric craft during cruise, and the ranges involve, render any form of tactical maneuver somewhat pointless. While the exact systems chosen will vary based on the fine details of technology, history, and politics, it is possible to draw conclusions about the systems that might be used.

Vessels can be broadly divided into laser platforms, kinetic platforms, and control ships. As mentioned in Section 2, there is no reason to place humans in battle aboard either of the first two types of craft. A command ship is likely built on the same drive section as some class of warcraft, the exact one depending on the command requirements, with moderate defenses, and crew and maintenance facilities aboard. It hangs back a few light-seconds from the battle, which is generally fought at a range measured in tenths of a light-second. It has been suggested that the command ship could be a parasite attached to one of the larger combat ships, but this has a significant impact on fleet performance in most cases.

It is virtually certain that a command ship will be of non-negligible mass compared to the combat vessels, and the vessel it is attached to will suffer from significant reductions in both delta-V and acceleration. The rest of the fleet must then match this, significantly reducing strategic mobility. The alternative is to make a special class of command-carriers, but this would probably require the development of a new drive system, and leave the vessels in question with excess performance during combat. Another problem is that this arrangement automatically limits the ability of the command ship to operate independently. As discussed in Section 2, the command ship will be on a significantly different vector from the rest of the fleet. If it is a parasite, it either must be placed on such a trajectory by its carrier, which must then return to the fleet, or it must be capable of putting itself on said trajectory, undermining any savings accrued by use of this method. Also, it would probably be unable to escape if the battle goes poorly.

Dealing with these problems raises the question of why it needs to be a parasite at all. Laser platforms are not the popularly-imagined space battleships, bristling with laser turrets on all sides. Instead, they are likely to be laserstars, a ship built around a single large keel-mounted laser. Because of the nature of lasers, it is significantly more efficient to make use of a single large laser mirror then to use two mirrors of the same total area.

One key point that must be understood is that lasers are not of unlimited range. They suffer from diffraction, which sets a minimum size on the spot that the laser can place its beam in.

The spot size scales inversely with the diameter of the mirror. Thus, it makes sense to use the largest possible mirror, which can be limited by one of three factors. First, the size of the ship carrying the mirror. Second, the ability to make large mirrors. Third, jitter.

Jitter, which is the term for small vibrations in the mirror and aiming system, will also serve to limit the spot size, and can make it inefficient to enlarge a mirror past a certain point. If the first situation is the limiting factor, then the classical laserstar will be used. The second will tend to result in lasernoughts, vessels with two to four large mirrors. The third could go either way, as the amount of laser power puts a lower limit on the size of the mirror. It is possible that a vessel might use a larger-than-optimal mirror to allow a more powerful laser to be used. (For more details, see Section 7).

Laserstar is an overused term, which has been used to describe either a very large laser-armed vessel that is the political and operational equivalent of a modern CVN, or simply a vessel that has as its primary offensive armament a single large laser. The second sense is what is intended throughout the paper, unless otherwise noted. The laserstar would not be armed solely with the large laser of course.

It would also carry some form of point-defense weaponry, probably smaller lasers, and possibly some form of offensive kinetics. The form of the kinetic platforms or kinetistars will vary based on the type of kinetics it fires.

For those kinetistars that use rail/coilguns as their main armament, the purpose and general design of the vessel will be the same as that of a laserstar, with obvious changes due to the nature of the main armament. Vessels of this type might well be significantly longer than laserstars, depending on the specifics of the weapon, which would have detrimental effects on maneuverability. Those that carry missiles are generally going to be a simple rack and a drive system. It’s entirely possible that they will be considered at least semi-expendable, though recovery should not be too much of an issue under most circumstances.

The above are the main combat units of the battle fleet, or constellation. They will vary in size and design based on the operational environment, but the outline is clear. The constellation will also include various remote sensor platforms, defense parasites, and other auxiliaries. To quote Rick Robinson: “Taken as a whole you might call it a fleet.

But it more nearly resembles a mobile, distributed, and networked fortification, deploying in action into a three-dimensional array of weapon emplacements, observation posts, and patrol details, all backed up by a command and logistics center. (Armies in SPAAACE!!!) Very little of it fits our template of 'space warships,' because it is designed for space, not simply borrowed from the sea.” Of course, the battle constellation is not the entire Space Force. Patrol craft have their own role (though the actual mechanics of patrols will be covered separately.) A patrol craft is likely to resemble a naval warship far more than those previously described. A patrol mission implies that the craft will have a crew, and probably some sort of boarding team. The boarding team is generally referred to as Espatiers, derived from French in the same way as the term Marine.

The patrol craft will likely also carry various sensor drones, and possibly remote weapons drones as well. The degree of modularity in a space force is open to debate.

In space, there are no aerodynamic or hydrodynamic issues to prevent one from hooking an engine up to a modular payload and taking off. At the same time, major weapons are unlikely to be modular, as large optical trains and precision equipment are hardly plug-and-play. On the other hand, systems like point-defense lasers, missile racks, and secondary fuel tanks are very likely to be modular, and swapped out depending on the mission. These have the advantage of being generic enough to be in high demand, which avoids the problem of having to have lots of extra modules sitting around or not having enough modules for a mission.

On the other hand, it’s entirely possible that ‘modular systems’ will end up becoming permanent parts of the vessel, as has happened to similar systems on modern warships. Of course, it would be possible to construct a ship out of three types of elements: a drive, a main mission module, and some number of secondary modules. The main laser, coilgun, or command module would be the main mission module, with the secondary elements as described above.

The biggest potential challenge with this is arrangement is that all elements of a fleet will either waste part of their performance, or have to be of the same mass. Another key question in the design of a space force is the size and number of ships. A number of factors play into that decision. The most important are, of course, the amount of money available and the role the force must play. Technical considerations, such as those that drive laserstars, are also vital. The lethality of weapons must be factored in as well. Particularly if nuclear weapons are in common use, ships will look for survivability in numbers.

This obviously must be balanced against the fact that smaller vessels are less effective than larger ones, as outlined in the section on fighters. Even small Space Forces will probably field a dozen or more ‘battleships’ while larger ones might number into the hundreds. Depending on the political situation, command ships might be far larger than then battle vessels.

If both sides use drone forces, the command ships might be viewed quite like the king in chess. If its force loses or its defenses fail, the command ship in question surrenders. Both sides honor such surrenders, making warfare very bloodless. All of the above assumes a deep-space engagement.

While that is the easiest environment to analyze, it is hardly the only, or even the dominant, environment where space combat is likely to take place. The various environments for space warfare can be classified as follows: • INTRAPLANETARY WARFARE: Intraplanetary warfare is between two or more powers on the same planet. In any setting of this kind, space warfare will be a sideshow to the rest of the war. • SATELLITE WARFARE: This is the current situation. Space war will be mostly about shooting down the other guy's satellites, and it will be done from the ground (in the broadest sense). Humans in space will almost certainly be uninvolved directly in the war. There are no spacecraft shooting at each other, unless one chooses to count co-orbital ASATs.

• STATION WARFARE: Activity in space has picked up significantly. Militarily significant human concentrations are in orbit. Warfare is still mostly ground-to-orbit, but there is likely to be some orbit-to-orbit warfare as well. • CLOISTERED ORBITAL WARFARE: For whatever reason the earth-based powers aren't using surface-to-orbit weapons.

Fighting is likely mostly done by short-range ‘fighters’, which leave stations, attack, and return to their bases. Delta-V requirements are minimal. This is unlikely to occur in reality, but has interesting story potential.

• ORBITAL PATROL: This is a non-combat situation. It favors ‘fighters’ (more accurately small parasites/gunboats) even more than IC. Inspections and boarding actions are far more common than battles. Delta-V is low, as are weapon powers. All-out warfare will probably result in IB, though IC is possible. • INTRAORBITAL WARFARE: Intraorbital warfare covers battles between powers in orbit around the same body when at least one power isn't on the body. • SURFACE TO STATION WARFARE, TOTAL: An orbital population is fighting with a surface population.

This is most likely to involve the surface power shooting at the orbital power from the surface. • SURFACE TO STATION WARFARE, LIMITED: This is similar to, but it is far more likely to be space-to-space.

If the surface power has limited goals, such as capturing the orbital population, kinetics alone are unlikely to work. It overlaps with and. • STATION TO STATION WARFARE: This is a battle between two space-based powers. It will likely resemble, though unlimited kinetic warfare is a possibility. • ORBITAL PATROL: See. • INTERBODY WARFARE: This is warfare between two or more powers on different celestial bodies. This includes situations where one power is in an orbit around a separate body.

There are a broad variety of factors at work here, so this list is somewhat less organized then the other two. • INTRASYSTEM: The powers are based on celestial bodies within the same planetary system, either with one on the planet and another on the moon, or with both on separate moons. Delta-V for spacecraft will likely be low, and transit times will be on the order of days.

Fighters are on the edges of possibility, though the gunboats described in Section 1 are more likely. Battles in this scenario will variously resemble Types, and.

• INTERSYSTEM: The powers are in different planetary systems. Transit times will be on the order of months, and delta-V requirements will be high. There are several specific environments within this.

• INTERPLANETARY TRANSFER: This applies to any ships in an interplanetary transfer orbit. High delta-Vs are required, as is long endurance. Closing velocities during battles will be high, and classical “fleet battles” are unlikely. The attacking constellation will be opposed mostly by KKVs. • OUTER ORBITS: The outer orbits are orbits that are at the edge of the Hill sphere of a body. They are likely to be mostly empty except for the Lagrange points, and can be seen as relatively flat.

An attacking fleet will likely move into the outer orbits first, and probably be opposed by the defender's fleet there. For the attackers, the constellation will likely be their interplanetary vessels. The defender might have specialized vessels for this region, which will generally have lower delta-V then interplanetary vessels, but be largely the same otherwise. Encounter speeds will be low. The reason for engaging this far out is to minimize debris problems and collateral damage, which is in the interests of both sides, so long as they are relatively evenly matched. • MIDDLE ORBITS: Middle orbits are the orbits where a significant orbital curvature appears, and strategically significant objects begin to be seen, but where spacecraft are out of range of most ground-based defenses.

Ships built to fight here will probably be low delta-V (nuclear-thermal class). The defender will be at a disadvantage, as the attacker can shoot into these orbits with his outer orbit warships. It is entirely possible that a typical invasion will see little combat here. There is no reason for the defender to avoid sending all combat-capable vessels to fight in the outer orbits, leaving them nothing to engage with in this band if defeated. The attacker might move into this band later to attempt to dominate low orbits with his interplanetary craft. • LOW ORBITS: These orbits are going to be the most cluttered, as well as being in range of ground-based defenses.

Fighters and gunboats will most likely be the primary warcraft here, supported by either ground defenses or by interplanetary ships. Delta-Vs will be low, with high accelerations. Orbital curvature is highly significant, as is the presence of the body itself. Engagements will generally be short, though the chance of serious kinetic use is somewhat low, given the amount of stuff in low orbit. For more details on this, see. One point that has become obvious during the construction of this taxonomy is how likely space warfare is to be asymmetrical in the broadest sense.

Except for Type warfare, just about every scenario described does not occur between equal powers. For example, take a.

Station A is trying to take over Station B. Station B doesn't want Station A, they just want to be left alone. They can use improvised kinetics against A's assault shuttles.

A can't use kinetics because that would ruin what they are trying to attack. Any form of interplanetary warfare must be asymmetric.

It is impossible to project enough force between planets to overwhelm a defender who is within an order of magnitude economically, and the imbalance required is likely to be significantly larger, depending on the objective. The exception to this is a variant on Type when both sides are deploying forces to the objective. If the US and China decide to fight around Mars, but avoid conflict on Earth, a largely symmetrical war is possible.

This assumes that the Martian colonies themselves are evenly matched or minor compared to the forces deployed. It is impossible to wage symmetrical warfare with an equal opponent if the objective is anything but destruction. Total destruction of a roughly equal opponent is possible, but only at the gravest risk to yourself.

If the objective is anything else, then a large advantage is required. One point that is commonly brought up in the discussion of space warfare is the three-dimensional nature of space, and the need to think in three dimensions. While this is technically true, it is probably not as big of a factor as it is often portrayed to be.

First, efficient transfers will be in the ecliptic plane, which means that most of the deployments will be made in that plane, in two dimensions. Even if one side chooses an inefficient transfer to avoid this, they would have to split up their force on the way to achieve meaningful separation between its elements, throwing away any advantage of surprise it might give them. Second, ships will be generally unable to maneuver in combat (as described above), limiting the impact of any brilliant 3-D tactics, as the opponent will have plenty of time to respond. Third, humans have been fighting in a 3-D environment for almost a century, and with a little bit of training, most people do not seem to have a problem thinking in 3-D.

All but the most inexperienced officers will be familiar with the fact that space is not 2-D, and react accordingly. Many of the fleets found in modern Sci-Fi broadly follow the pattern seen in fleets since the start of the 20 th Century, with the big ships of the fleet surrounded by escorts of various types. The existence of fleet escorts is a recent development, and they are not likely to move into space. Up through the Age of Sail, fleet actions were fought by the major warships alone.

Smaller craft that travelled with the fleet were for scouting, a function that will not exist in space. The first fleet escort was the Torpedo Boat Destroyer, introduced to counter the threat of the torpedo boat. The TBD evolved into the destroyer, which during the first half of the 20 th century became a vital part of the fleet.

It was tasked with protecting the fleet from submarines, aircraft, and surface torpedo attacks, along with conducting torpedo attacks on the enemy fleet. However, none of these functions has an analogue in space. Submarines and naval aircraft rely on the fact that there are three fundamentally different environments in close proximity, a feature that does not apply to space.

Likewise, there is no reason to suppose a ‘torpedo’ would exist that is best deployed by a small escort instead of being fired from the main fleet units. This is not to say that no smaller vessels would exist. During the Age of Sail, ships below the line played an important role.

Besides scouting, they protected convoys, hunted commerce, patrolled, and showed the flag. While scouting and patrolling are not likely to have spaceborne analogues, commerce warfare and general station duties will, and smaller warships will exist to fill those roles. Weapons like particle beams and lasers may have 'unlimited ammo' if a space warship's electrical and storage system is powered by nuclear reactors, with gigawatts or more of firepower. Future ultracapacitors could have an energy density higher than 60 Wh/kg along with a power density greater than 100 kW/kg. Such is from a MIT study on ultracapacitors for future cars, implied. That would be up to 0.2+ TJ of electrical energy stored per 1000 metric-tons of ultracapacitors, able to be discharged at a rate of 0.1+ TW. For example, a 100,000-ton warship with just 5% of its mass as ultracapacitor banks could store a terajoule, then discharge it at a rate of half a terawatt.

Technology of the distant future may be superior, but the preceding is a reasonable lower limit. Energy storage is not the only limiting factor, though. (ed note: Anthony Jackson thinks that 60 Wh/kg should be considered a high end estimate, not a low end.

He further notes that 100x is approximately the theoretical limit for energy storage with chemical bonds, and as noted, 5 kilotons of capacitors hold 1 TJ.) What is the recharge rate from warship power generation? The energy content of fission, fusion, or antimatter fuel can matter less for the attainable electricity generation than engineering limits. Even before melting, metals weaken if temperatures rise from more heat transfer into them than coolant systems take away; parts deform if subject to excessive mechanical stress; etc. For example, plutonium 'fuel' in a bomb allows a power-to-mass ratio of billions of gigawatts of heat and radiation per kilogram during the fraction of a microsecond of detonation, but that of a plutonium-fueled power plant must be orders of magnitude less. A nuclear-electric concept with a MHD generator was to obtain 0.37 kg/kWe, which would be 2.7 MW/metric-ton.

For perspective, car engines of today are sometimes hundreds of kW of mechanical power per ton (i.e. 200 hp engine = 150 kW), with aircraft engines up to much higher power density.

Even with need for electricity rather than mechanical power alone, the many thousands of tons involved in a space warship would allow it to have nuclear power generation at least in the gigawatt range or higher, likely terawatts for large ships. There would also be inefficiencies. What about waste heat?

Deploying while firing weapons. Internal phase-change-material (PCM) heat sinks like ice/water might temporarily absorb heat. Actually, if the space warship has structure, armor, and individual weapons massing thousands of tons, such could absorb some gigajoules to terajoules.

But such could not sustain a high rate of fire for long without needing a 'cooling off' period, so a different system would be needed, at least as a supplement. The preferred radiator design for an armored warship is a droplet radiator, a (solid) particle radiator, or another alternative to large, vulnerable panels. Radiator mass for the weapons is going to depend much upon acceptable operating temperature. If most parts of the weapons can operate at moderately high temperature, the waste heat from high power consumption can be transferred away fast enough without excessive radiator size. One study of what is obtainable in space with merely today's technology indicates that 30 MW of heat could be dealt with by a 45 metric-ton Curie point radiator ( ) or by a 29 metric-ton liquid droplet radiator, for an average temperature of 380 degrees Celsius or 650 K.

The space warship would operate at least in the gigawatt range, with orders of magnitude greater heat rejection from its weapons, but it could afford to have orders of magnitude greater radiator system mass. And it would be more advanced, higher-performance technology. The 0.37 kg/kWe reactor described has a heat dump at 150K. That's not practical for a spaceship; you're not going to run your radiators at 150K, nor are you going to use liquid nitrogen as a heat sink. It also has an efficiency of 22%.

Using a higher temperature heat dump will reduce efficiency or power density (or both); in practice the heat dump has to operate at the same temperature as the radiator. Assuming a 10 GW reactor, it's likely going to have a heat output of 20-40 GW. Let's assume that we can get a reactor with a 1000K heat output and an efficiency of 20%, with a power density of 1 kg/kWe. A 10 GW reactor produces 40 GW of heat. A perfect blackbody at 1000K has a heat output of 56.7 kW/m 2, so we need about 18 square meters per MW, or 1.4 million square meters. A perfect blackbody could radiate from both sides, but if we're using a non-solid radiator of real materials it's not a perfect blackbody, so we'll just have a wing with an area of 1 million square meters.

Assuming our ship is 200M long, that means the radiator wing is 5 kilometers long. So much for heat radiators. Let's shift over to heat sinks. We'll use water, since it's easy to work with. This gives us a heat sink at around 400K, so we'll double our efficiency; a 10 GW reactor now produces only 15 GW of heat.

Without vaporization, cold water can hold about half a gigajoule per ton; 10,000 tons could hold 5 TJ (if we store a slurry of ice, increase by 50%). If we allow the steam to vent (which more or less requires dumping it to space; you need a phase change, which means you can't keep the water compressed) we get another 20 TJ. Now, a laser system that would make the military jump for joy would have a peak output of 1 kW/kg, an efficiency of 20%, and a duty cycle of 20%, for a mean power output of 1 kW/kg. It will produce low temperature heat, well suited to our water sinks (and nearly impossible to radiate away with our high temperature radiators).

A 10,000 ton weapon system requires a power input averaging 10 GW, and a peak power input of 50 GW. If we can fire for 15 seconds before triggering a cool down cycle, we need capacitors good for 40 GW * 15 seconds or 0.6 TJ, so 3,000 tons is all we really need.

During 1 duty cycle we produce 800 GJ of waste heat from the weapon. Generating 1 TJ produces another 1.5 TJ of waste heat, for a total of 2.3 TJ. We'll round up, and discover that we can run through 2 15-second duty cycles without venting coolant, and another 8 by venting coolant. Our combined system mass is 33,000 tons. Now, if we have some down time, we probably want to bring the coolant temperature down to near freezing, or if possible turn it into an ice slurry.

Unfortunately, that means a radiator operating at an average of about 300K, with a heat output of 0.46 kW/m2. If we figure extended radiators are 1 km long and 200m wide, they can dump heat at a rate of 180 MW, or approximately 8 hours to cool to near freezing. Generating the ice slurry would take another 6 hours or so. Also, unlike high temperature radiators, sunlight heating the radiators will interfere substantially with cooling, so we need to remain edge-on towards the sun. Let's add an intuitive illustration of the overall picture. Consider 10% of the mass of a 100,000-ton warship being a beam weapon, with the maximum energy it could fire per shot or in a second being somewhere between 0.01 TJ and 1 TJ. That proportionally corresponds to as much firepower per unit mass as a half-kilogram energy pistol firing shots between 500 J and 50 kJ of energy.

Such is equivalent to the energy pistol being able to vaporize a volume of ice between 0.7-cm and 3.3-cm in diameter per shot, like vaporizing a ball of ice between the size of a pea and a golf ball. While the whole range is conservative by sci-fi standards, one could take the low end of the range if concerned about the reliability of it being plausible. The comparison is proportional since the sample space warship's weapon masses 20,000,000 times more than the energy pistol. Big Proviso: (Sikon) is talking in terms of big ships; the example they give is a ship with mass of 100,000 tons, presumably 'Washington Treaty' mass, not including remass (propellant/reaction mass). This is roughly the size of the largest ships I think are provided for in.

It is about 10x the mass, from my impression, of the largest type (DiGleria?) in regular service in the AV:T setting. By my rule of thumb such a ship would cost (the societal equivalent of) some $100 billion.

() Mid-future colony worlds of the Ten Worlds or Human Sphere type, with populations no more than ~100 million, would be hard put to have more than a showboat or two of this class. (Sikon) speaks of fleets with thousands of such ships - so they're implicitly dealing with vast galactical-imperial scale polities. I've gone into this a bit because it makes an interesting point: scale matters.

I didn't carefully examine (Sikon's) analysis, but it gave the impression of being well thought out, and I can imagine that you could indeed get Incredible Firepower. If you can afford an Incredibly Huge And Costly Ship.

Yet the warship's shots each correspond to the equivalent of approximately between a 2500-kg high-explosive bomb and a 0.25-kiloton tactical nuke in the energy delivered. Beam weapons of such energy can have 'unlimited ammunition,' powered by the discharge of the capacitors, which are recharged by the warship's nuclear reactors to fire thousands of shots in a period of a few hours. Or smaller shots could be used for an even higher firing rate. For example, if a warship can fire a single concentrated 0.01 TJ to 1 TJ laser shot in a second, it might alternatively have weapons capable of sending out equal energy in the form of 100,000 to 10,000,000 one-hundred-kJ pulses per second over a huge shotgun-like pattern to hit a target at much greater range than would be likely otherwise.

What was optimal could depend upon factors including the type of target, but the attainable firepower is vast. For perspective, a 100-kJ vehicle-mounted laser concept is considered by the Department of Defense to be lethal against common rockets, aircraft, and light with little armor.

Yet, at the technological level implied by sci-fi interplanetary or interstellar space war, average firepower of a far larger space warship could be astronomically higher, either in the energy per shot, the number of shots fired per minute, or a combination of both. Every 0.01-TW of average weapons power corresponds to 400 million times the energy per hour. Propulsion system power could be much greater than electrical power and beam weapons power. For example, the MS Word document from researchers describes a magnetic compression pulsed fission concept with a magnetic nozzle, in which a vehicle of 1310 metric tons initial mass and 100 tons final mass could have 263 GW jet power.

That is between 0.2 GW/ton and 2.6 GW/ton, with relatively straightforward technology. For this distant-future scenario, such is just a probable lower limit. A much larger 100,000-ton space warship could be more than 1 GW/ton, corresponding to an exhaust jet power above 100 TW. As an initial beam weapons illustration, consider a space warship firing a lethal radiation beam against planetary targets including aircraft.

Against humans, on the order of 10 kJ per square meter of some types of radiation would be enough to cause enough exposure for, much above the level for slow death. The end result is a little like the effect of the radiation of a neutron bomb, for which 8000 rads or 0.08 kJ/kg-tissue (80 ) are enough to immediately incapacitate enemy soldiers like tank crewmen according to an U.S. Military, a couple orders of magnitude above the dosage usually lethal over a longer period of time (1% as many neutrons = 80 rads = 800-1600 rem in long-term). But the radiation wouldn't be neutrons. This is not an ordinary particle-beam weapon concept, being instead a wide beam with particle composition and energies chosen to equal or exceed the atmospheric propagation of penetrating natural cosmic radiation. As GeV energies are obtained in contemporary research accelerators, the preceding would be attainable by an accelerator within a large space warship.

Natural cosmic rays are 16 rem/yr in space, dropping to 0.027 rem/yr. Since natural cosmic radiation experiences such an attenuation factor of 600 going through earth's atmosphere from space to ground at sea level, assume the wide-beam radiation should have an intensity on the order of 6 MJ/m 2 before entering the atmosphere. The result is that each shot of 0.01 TJ to 1 TJ energy can deliver a pulse of quickly lethal radiation to an area around 46 meters to 460 meters in diameter. If a given intensity level is insufficient, such as firing on a relatively hardened unmanned target, making the beam more narrow by a factor of 10 would increase the intensity by a factor of 100, and so on.

But wide beams can kill ordinary tanks, aircraft, infantry, etc. The beam is unaffected by weather and sufficiently penetrates the mass shielding of the atmosphere, despite it being 10 metric tons per square meter. Unlike even neutron bombs, the beam would have no blast and just a few degrees heating effect when fired in wide beams, leaving structures unharmed aside from disruption to electronics, yet killing the occupants. Now, when talking about targeting the ground with a particle beam, it's worth noting that cosmic rays not only attenuate on hitting atmosphere, they scatter.

You can't really target a region smaller than about 100 meters radius (31,000 m 2). The attenuation length of cosmic rays at ground level is a bit over 100g/cm 2, so 1 kJ/m 2 produces a dose of about 1 gray; however, the radiation involved has a RBE of around 2, so it's about 2 Sv. Prompt incapacitation requires about 50 Sv (more vs rad-hard electronics, way way more vs bunkers), so we need at least 25 kJ/m 2, or 800 MJ at ground-level, or 500 GJ at top of atmosphere. One duty cycle from our gun above is 150 GJ (15 Sv at ground level), and we probably don't want to dump coolant on secondary targets, so we likely only fire once or twice. In practice, the lethality difference between 15 Sv and 30 Sv is negligible (in either case, nausea after 5-30 minutes, a couple days of normal activity, then delirium and death), so one shot is fine. It is also the type of thing that gets called a war crime. Lethal radiation beams may also be used against other spaceships, with effectiveness determined in part by their shielding (armor) thickness.

The extreme case is firing against a thin-hulled ship, in which case the attenuation factor of 600 for the previous scenario of firing through the 10,000 kg/m 2 mass shielding of the planetary atmosphere doesn't apply. In that case, a quickly-lethal 0.01 TJ to 1 TJ shot can be up to about 1.1-km to 11-km in diameter.

Actually, since enemy vessels can be detected, the warship might not wait but rather open fire on lightly-armored targets at such extreme range that beams hit only by being hundreds of kilometers in diameter or more. The cumulative radiation dose delivered over many shots every minute would add up to enough in time.

One potential countermeasure is or thick armor around vulnerable areas of a ship, like the battle stations for the crew and, such as with enough meters of metal to stop practically all of the radiation. Another weapon can be microwaves. Against non-hardened civilian targets, as little as a few joules per square meter or less can be enough if delivered in the right time frame, concentrated into microseconds or less. Gigantic ' pulsed microwave beams can fry ordinary electronics over up to many square kilometers per shot. EMP beams could be about the opposite of lethal radiation beams, devastating planetary infrastructure without killing any people aside from a few indirect deaths like crashing aircraft. Against more hardened targets, more focused microwaves in the form of narrow-beam MASERs might physically overheat and destroy.

The potential firepower of such a concentrated MASER beam is implied by the many-gigawatt or terawatt-level power generation of a large space warship being equivalent to a number of tons of high-explosive per second. As implied by what happens to sunlight, light from space doesn't always reach the ground well on cloudy days. Thus, lasers might be an unreliable weapon against planetary targets, unless the basic principle of could be applied with ultra-intense pulses. However, the situation is different in space against enemy warships. The of lasers compared to microwaves allows a more narrow focus at long range. During planetary attack, yet another potential weapons system for space warships is firing non-nuclear and missiles to hit air, sea, and ground targets on the planet below, impacting at hypersonic velocities. A 1977 NASA Ames study referenced determined that an earth-launched mass driver projectile going up vertically could pass through earth's atmosphere from ground level to space with a few percent of its mass being an ablative carbon shield, losing only 3% of its total mass in the transit.

Such is for a telephone-pole-shaped projectile of a metric ton mass. That means the reverse is also possible for projectiles with the right mass, dimensions, ablative shield, and trajectory.

For example, consider a similar projectile fired from space, reaching the upper atmosphere at 12 km/s velocity and going nearly straight down. It could hit a ground target at about 11 km/s, a kinetic energy equivalent to about 15 tons of TNT explosive. Projectiles and missiles fancier than the cheapest unguided shells could use small thrusters to adjust trajectory to home in on a target. Although sci-fi sensors or even remote-control communications systems might be able to operate through the plasma sheath from atmospheric passage (i.e. Using high-frequency pulses of directed radiation or particles rather than ordinary radios), the simplest solution is if it instead slows down to a lesser Mach number first. Advanced robotic missiles tracking by the right combination of infrared, visible, radar, and/or other sensors could be hard for planetary targets to evade.

Although space warships could alternatively just use their beam weapons against those targets. Large numbers of nukes may be used in planetary assault. For example, one cheap 'brute force' method of dealing with atmospheric fighters trying to avoid shells or missiles might be to have them explode with sub-kiloton to single-kiloton yield.

The equivalent isn't done by terrestrial militaries for reasons like political issues, but those do not necessarily apply so much in a sci-fi planetary assault scenario. Even in the real-world today, nukes do not have to cost more than hundreds of thousands of dollars each or less in mass-production, compared to fighters costing orders of magnitude more: tens to hundreds of millions of dollars each.

Fallout from such nukes would tend to be harmful to the planetary defenders and localized regions without making the planet unusable by the invaders. Localized radiation levels shortly after a detonation can be lethal, but such decrease over time.

The radioisotopes emitting the most initial radiation are those with the largest fraction of their atoms decaying per unit time. (The rate of radiation emission per unit time from a radioisotope is inversely proportional to half-life, to a degree such that stable elements can be thought of simply as those with infinitely long half- lives). Compared to residual radiation one hour after, radiation levels are 1% as much after 2 days and 0.1% as much after 2 weeks. The fallout of a nuclear weapon detonation of low or moderate yield can much elevate radiation levels over a limited number of square kilometers, but it can do very little overall over the half-billion square kilometer total area of a planet like earth. Historical above-ground nuclear weapon tests in the 20th century amounted to 440 megatons cumulatively, with 189 megatons fission yield. 189000 kilotons (). Total collective dosage to the world's population from such past tests corresponds to 7E6 man-Sv, for the UNSCEAR estimate for total exposure in the past plus the result of currently remaining radioisotopes projected up through.

The preceding total over the decades and centuries is less than what is received every year from natural, which is in turn orders of magnitude less than what would make an eventual death from cancer probable. Of course, from a real-world civilian perspective, any potential increased risk of cancer is undesirable, but, from the perspective of the hypothetical space invaders, the bulk of the planetary surface is not harmed enough for them to necessarily be concerned. For example, even with fission devices, if the orbiting warships are firing quarter-kiloton-yield nuclear shells or missiles against targets like enemy aircraft, it would take on the order of 800,000 warheads even just to exceed the limited radiological contamination from the 189-MT fission component of the preceding nuclear tests.

If available, pure-fusion devices would be cleaner. Sci-fi technology allows other possible ordnance, such as biological weapons genetically engineered to have a non-lethal temporary incapacitating effect or infectious nanobots.

Different attackers might use different techniques depending upon their psychology, ethics, objectives, etc. In combat between space warships, the vast firepower attainable from, combined with no particular limit on range, might make them dominate the battlefield. Or they might not, depending upon the effectiveness of missiles versus, their relative cost, and other factors in a given sci-fi scenario. With lasers destroying artillery shells becoming possible, the point defenses of distant-future space warships are not to be underestimated. As little as a 100-kJ projectile can destroy an ordinary missile. (For perspective, 100-kJ is like the kinetic energy of a 200-gram projectile going 1 km/s, although the analogy should not be taken too far since the momentum is different for a much higher velocity but far smaller projectile).

For example, if warship firepower of 0.01 TJ to 1 TJ per second is attainable as previously suggested, such could allow a mass driver or mass driver array firing a 0.01-GJ to 1-GJ shot per millisecond. If firing pellets like a shotgun, such could deliver on average a 100-kJ pellet per square meter within a 11-meter to 110-meter diameter pattern per millisecond, a thousand times as much per second, potentially destroying many different incoming missiles.

Or, to maximize engagement range, firing a whole second at one target could amount to a shotgun pattern 0.36-km to 3.6-km in diameter. Alternatively, comparable firepower to the preceding might also be obtained with another weapons system like a laser array instead.

Against such point defense firepower, ordinary missiles are at a disadvantage against warships. Still, if the missiles aren't so ordinary, there may be countermeasures to point defenses, such as faster, more armored, and/or more numerous missile swarms. One possibility could be a space missile swarm not carrying sizable nuclear warheads but rather dispersing, such as billions of grains of sand or the equivalent, too numerous for point defense weapons to hit and vaporize them all.

Point defenses might try to destroy such missiles far enough away for clouds deployed before missile destruction to subsequently miss due to the warship's changing course. Imagine two modern-day soldiers.

One is armed with a sniper rifle, while the other is armed with a pistol. If they face each other in a jungle or in dense fog with visibility not beyond several meters, either one may have a good chance of being the winner.

But now imagine them starting a kilometer apart on a featureless flat plane of solid rock with perfect visibility. Then the guy with the sniper rifle wins, as the man with the pistol can not approach close enough to hit before being shot by the sniper. Since there is typically in space, the situation for warship combat can be like perfect visibility, no horizon, and usually no cover. That makes effective weapons range particularly important. Fire control computers try to predict a target's position based on its velocity and current acceleration, but, at ranges with significant, mobility matters much against beam weapons (and possibly the missile-deployed kinetic-kill clouds described earlier).

For example, a ship doing 5g of unpredictable acceleration deviates 25-m in 1 sec, 2.5-km in 10 sec, 88-km in 1 minute, and so on. One countermeasure may be to fire many shots, but the earlier illustration of a warship firing a huge pattern of 100,000 to 10,000,000 100-kJ shots per second doesn't work well if the target has armor making 100-kJ too little.

Armor could make the enemy fire a low rate of concentrated high-energy shots, reducing the chance of any hitting at long range. Of course, good enough point defenses are also needed, or else the armor would just be penetrated by a missile with a nuclear warhead. What about space warships fighting planetary anti-space weapons? Typically the planet would be better off having space warships than planet-based weapons. Launch a missile from a planet with a regular rocket, and more than 90% of its mass is involved just getting off the planet.

Even if an advanced propulsion concept like or rockets is used instead, having such launched from a planet during a battle would make them relatively easy targets during boost phase. Craft launched from a planet may tend to be smaller and more limited than space warships. For example, a mass driver sending even just ten tons per hour to orbit could over a decade put almost a million tons up, enough to be potentially the seed of a society processing eventually billions of tons of extraterrestrial material into habitats and ships.

But, in that scenario, billions of tons of spaceships might exist without the planet necessarily being able to launch more than a proportionally minuscule amount in a day. There is likely shipment off-planet of some valuable goods and also passenger traffic, but X million people per decade going off-planet only corresponds to just 20 * X * Y tons per day needed, where Y is the ratio of total launch mass to body mass. A planet could have gigawatt to terawatt range beam weapons, but the effective range of such against space warships would tend to be less than vice versa: In a duel at up to light-minutes or greater range with light speed weapons, a space warship fleet will tend to win against a planet, as the immobile planet with zero unpredictable acceleration can be engaged at extreme range. For example, if technology allows a variant of the lethal radiation beam weapon described earlier to have 0.1 to 10 microradians divergence, the beam would diverge 0.01-m to 1-m per 100,000-km distance, hitting a spot 100-m wide at 10 million kilometers to 1 billion kilometers range. With thousands of 0.01-TJ to 1-TJ shots fired per hour with electricity from the nuclear reactors, enough hitting a planetary target sooner or later, warships could devastate appropriate parts of the planetary surface from up to light-minutes to light-hours of range. That gives the mobile warships plenty of time to evade any light speed weapons fire from the planet.

Such would arrive long after each warship has moved to another location in the vastness of space, perhaps millions of kilometers away from its previous position. If even more firepower is needed, kinetic-kill clouds might be used, i.e. Billions of particles of debris that defenses could not stop.

For example, ships with engines able to carry and send 'cargo' on the right trajectory at 100 km/s to 1000+ km/s velocity could indirectly deliver 1,200 to 120,000+ megatons of destruction per million metric tons of material carried. Optionally, the columns of fire in the atmosphere created by the preceding might 'blind' remaining defenses for critical seconds while missiles with nuclear warheads arrived right behind them. Before inefficiencies and aside from the other mass in nuclear weapons, fissioning plutonium and fusioning lithium-6 deuteride are 17 million and 64 million megatons respectively per million metric tons mass.

Of course, if the goal is to capture the planet with it still, the level of firepower used in destroying anti-space weapons from extreme range would need to be limited. Warships could afterwards move closer, into orbit, providing final fire support for an invasion. I was struck by how it assumed the space ship had amazing beam weapons capable of penetrating the atmosphere, but for some unknown reason ground defenders using that same beam weapon technology simply lose.

On, the contest between beam weapons on mobile warships vs beam weapons on planets is completely lopsided in favor of the planetary defenders. They have a stupendous advantage in heat rejection, shielding, and mobility. Ignores the heat rejection advantage and. Assumes the planetary systems can't use any shielding other than the atmosphere. He seems to assume planetary defenses must be fixed, despite the explicit example of aircraft which can literally jink all week (which, of course, spacecraft can't). Never mind about submarines, ships, or underground weaponry. And the most important one of all, (though you may be subsuming it under mobility): stealth/concealment.

A habitable-planet surface is about as cluttered an environment as you can find. Other parts of the post also seemed to blow off the problem of detecting targets on a planetary surface.

As an aside, at least 'guns' reveal themselves when they fire. Assuming you have a suitable tech for lobbing missiles out of a gravity well, a missile engagement is even more in favor of the surface, because once a missile is fired all it leaves behind is its launcher, probably of insignificant value as a target. Returning to beams, the whole sensor-blinding issue also heavily favors the planet, because finding a passive sensor on a planet surface approaches the level of trying to find a guy with binoculars somewhere on the nearside of the planet. With good enough targeting information transmitted from recon drones through a computerized system, space warships could help kill even individual vehicles or even individual enemy soldiers from orbit when possible. Such would not be their primary mission, and initially the warships would attack more valuable targets. But afterwards, a warship would still have practically unlimited ammo for its electrically-powered beam weapons running off nuclear reactors.

Using a hundred-thousand-ton warship to kill a couple enemy soldiers riding around in a truck might superficially seem wasteful, but there is next to no marginal cost in the preceding scenario. Consider a warship orbiting at 200-km low-orbit altitude for final fire support. A little like a terrestrial sniper can shoot an enemy from 0.5-km away, some beam weapons on the warship could be designed to hit precise locations on the ground below, with potential accuracy of within a meter. If there was a single person or handful of people on the warship manually trying to search for targets, aim, and fire the weapons, it would be a slow process. Yet, if there are a large number of robotic recon drones searching for enemy vehicles and soldiers, transmitting their precise coordinates, a computerized fire control system on the warship could shoot thousands of designated targets per hour, continuing for hours or days if necessary.

Given the firepower and capabilities possible with one space warship, imagine what a fleet of thousands of such warships (or more) could do against a planet. Space warships would initially destroy all targets they could see from space, but, for foreseeable technology, orbital surveillance might not find every last target. Deploying air and ground versions of robotic recon drones could help give further targeting information. For example, if a golf ball-sized robotic drone with a miniature jet engine flies up to the window of a building and sees enemy soldiers inside, it can transmit a signal causing the warship's computers to fry the area within a 50-meter radius with a lethal radiation beam a fraction of a second later.

Potentially very effective yet still with less collateral damage than just nuking the whole city. The preceding could be done before sending in regular armies or occupation forces in order to drastically reduce ground combat casualties, although use of expendable robots and/or whenever possible might make human or sapient casualties beyond non-sapient robots be low anyway. Even in a hard sci-fi scenario, predicting the capabilities of technology that may be centuries or millennia beyond the 21st-century is.

For example, perhaps technology would allow a million tons of raw materials to be quickly and cheaply converted to its mass-equivalence: a billion one-kilogram missiles to be dispersed at low altitude. Or there could be other weird military technologies. A little like a person from centuries ago couldn't very well predict the capabilities of modern combat, the preceding is mainly just a lower limit on what could be accomplished at the technological level commonly implied by interplanetary and interstellar wars in science fiction. I don't think there would be a huge variation in the types of warships seen. You'd have the big battleship which would dominate everything it fights, and then maybe smaller ships that could cover more area at once and engage in light combat, but wouldn't stand up to the battleships. Red called these 'frigates' in his Humanist Inheritance fiction, probably because their role is similar to the ship of the same name from the age of sail, and it is a term I like, so I will use it here.

However, note 'cruiser' may also be an applicable moniker for these ships, probably depending on its specific mission rather than its design goal. I feel these would exist due to economic efficiency rather than speed or range difference like those seen in the real sailing frigates. Let me explain.

Many of the can actually be used when talking about other capital ship classes as well. Let's look at what the roles of various naval ship classes basically were, and see if they could have an analog in space.

You had corvettes, which were small, maneuverable ships used close to shore. This role doesn't really apply in space. You might argue low orbit around a planet could be seen as a shore, but the problem is combat ranges would be rather large. If you have a stationary asset in LEO that you want to attack, you could put your battleship arbitrarily far away and attack it at will. If you have a mobile asset in you want to attack, you can still attack it from some distance away, probably around one light second, to avoid too much of your laser beams over the distance.

For comparison, the moon is about one and a half light seconds away from Earth. So, the battleship could be sitting out two thirds the distance to the moon and easily engaging the LEO target with precision and power. Corvettes being there wouldn't be of any help on defense, and the battleship can do their job on offense just as well, and at longer range. A corvette type ship might be useful to the Coast Guard for police and search and rescue work, but that is an entirely different realm than a warship. How about cruisers / frigates? The historical usage of the term referred to a small but fast warship, capable of operating on their own, and often assigned to light targets or escort duty. I do see an analog to this role in space.

A frigate would be no match for a battleship, however they would be useful in force projection, due to presumably being cheaper to produce and operate, thus more numerous. I'll be back to this in a moment. And of course, battleships would be the backbone of the war fleet, able to swat down anything that comes at them except other battleships. If it were economically feasible to build a huge fleet of battleships, I see no reason not to. Let's investigate some of their traditional disadvantages and see if they apply in space. The big one is speed: the huge battleship can take just about anything dished out to it and dish out enough to destroy nearly any other class of ship, but its huge size makes it slow.

This isn't so much of a concern in space. Allow me to elaborate. There are two things in space that are relevant when talking about 'speed': and. Delta-v is by the specific impulse (fuel efficiency) of the ship's engines and the percentage of the ship's mass that is fuel. Tonnage of the ship doesn't really matter here: it is a ratio thing.

If the specific impulse is the same and the fuel percentage to total mass the same, any size ship will eventually reach the same final speed. Thus, here, if fuel costs are ignored, small ships have no advantage over large ships. (And indeed, if you are going on a long trip, the large ship offers other advantages in how many supplies or for war, how many weapons it can carry at no cost to delta-v, again, if the ratio remains constant) So the question is how fast can they reach it, which brings me to acceleration. Acceleration is by total engine thrust and the total mass of the ship. At first glance, it seems that the smaller ship would obviously have the advantage here, but there are other factors that need be observed. One is the structural strength of the materials of which the ship is constructed.

This becomes a on insanely huge ships with larger accelerations, since the 'weight' the spaceframe must support goes up faster (it cubes) than the amount of weight it can handle (it squares). Mike talks about this on the main site when he. However, steel is strong enough that with realistic sizes and accelerations, this should not be an issue before one of the other ones are. One that is a much bigger problem is how much the human crew can handle. In the space / atmospheric fighter thread we had the week before last, Broomstick the of the human body to great accelerations. Well trained people in g-suits can handle 9 g's for a short time, but much more than this is a bad thing to just about everyone - their aorta can't handle it. In fact 5 positive g's are enough to cause most people to pass out, as she explains.

If the crew is passing out, the ship is in trouble. This problem can be lessened by the use of acceleration couches: someone laying down flat can handle it much better for longer, but even 5 g's laying down is going to be very uncomfortable, and the crew will have a hard time moving their arms. Extended trips would probably be best done at 1 g so the rocket's acceleration simulates Earth normal gravity, with peak acceleration being no more than 3-5 g's for humans in the afore mentioned couches if possible. That is probably the most significant limit on acceleration, since it is an upper limit of humans. No matter what technology exists, this cannot be avoided.

The third limitation will be based on the technical problem of generating this much thrust for the mass. This, too, can provide an upper limit, since adding more engines on to a ship will eventually give diminishing returns. The reason for that is the available surface area on the back of the ship where the engine must go increases more slowly than the mass of the ship as it grows. But, for a reasonably sized ship, this should not be a tremendous problem, especially when nuclear propulsion techniques are used, many of which have already been designed and proven feasible in the real world. Fission nuke pulse propulsion can provide 400 mega-newtons of thrust according to the on Nyrath's Atomic Rockets website (see the row for Project Orion). Three gees is about 30 metres per second squared acceleration. F = ma, so let's see what mass is possible.

4e8 / 3e1 = 1e7 kg, or about 10000 metric tonnes. Incidentally, this is the number Sikon used for his demonstrations in the. I think it a reasonable number for a battleship, so rather than repeat the benefits of this, I refer you back to that thread and the posts of GrandMasterTerwynn and Sikon on the first page, who discussed it in more depth than I am capable of. I agree with most of the views Sikon expressed in that thread. So, for these sizes, the speed argument against battleships is very much sidelined.

You also pointed this out later in your post that these advanced propulsion techniques do not necessarily scale down very well, which may also serve as a lower limit on ship size, which is probably more relevant than the upper limit it causes. You might ask if pushing for a greater peak acceleration would be worth it, and it is not, in my opinion. The reason again goes to the human limitations. Even if your warship is pulling 10 gees, it most likely won't help against a missile, which can still outperform you. An acceleration of even 1 g should be enough to throw off enemy targeting at ranges of about one light second. By the time the enemy sees what you are doing, you have already applied 10 m/s change to your velocity.

Then, if he fires back with a laser, you have another second to apply more change. This would be enough to help prevent direct, concentrated hits.

Having even five times more acceleration will offer little advantage over this in throwing off targeting or wide spread impact of lasers of particle beams, due to the ranges and the size of your warship, which is certain to measure longer than 50 metres. For missiles and coilgun projectiles, it matters even less, simply due to the time the enemy fire arrives, you have plenty of time - minutes - to have moved. 1g is plenty for that, attainable by a nuke pulse engine for sizes around 30,000 metric tonnes. Long range acceleration would again be limited to around 1 g or less due to the humans, mentioned above.

However, even at 1g constant acceleration (which would probably not be used due to fuel concerns anyway), an Earth to Mars trip could be measured in mere days. More offers little advantage there either. Lastly, there may be a question of rotation. A more massive and would have a greater moment of angular inertia than a smaller ship, thus requiring more torque to change its rate of rotation.

Again, I don't feel this will be a major concern. At the ranges involved, you again have some time to change direction. However, this does pose the problem in quick, random accelerations to throw off enemy targeting. Going with the 10,000 metric ton ship, let's assume it has an average density equal to that of water: one tonne per cubic meter. For the shape, I am going to assume a cylinder, about 10 meters in diameter (about the same as the Saturn V), with all the mass gathered at points at the end. The reason of this is to demonstrate a possible upper number for difficulty of rotation (moment of inertia), not to actually propose this is what it would look like. Actually determining an optimal realistic shape for such a ship would take much more thought.

With this, we can determine the length of the to be 10000 / (π r 2) = about 130 metres long. Now, we can estimate the moment of inertia, for which, we will assume there are two point masses of 5000 tons, each 65 meters away from the center. So moment of inertia for the turning axis (as opposed to rotating), is 2*5000 * 65^2 = about 4e10 kilogram meters squared.

Now, let's assume there are maneuvering jets on each end that would fire on opposite sides to rotate the ship. Let's further assume these have thrust about equal to that found on the space shuttle, simply because it is a realistic number that I can find: about 30 kilo-newtons. Let's determine torque, which is radius times force, so 3e4 * 65 * 2 (two thrusters) = about 4e6 newton meters.

Outstanding, now we can determine angular acceleration possible. Angular acceleration = It, where I is moment of inertia and t is torque. So, we have 4e6 / 4e10 = 1e-4 radians per second squared. This is about a meager 10th of a degree per square second. Remember this is acceleration - change in rotation rate.

Once spinning, it would tend to continue spinning. This is also a lower limit: most likely, the thrusters would be more numerous than I assumed, and probably more powerful as well, and the mass probably would be more evenly distributed. But anyway, let's see if it might be good enough. As I said when discussing linear acceleration, you would want some quick randomness to help prevent a concentrated laser beam from focusing on you, and you would want the ability to change your path within a scale of minutes to prevent long range coilgun shells from impacting. There isn't much you can do about missiles except point defense: a ship cannot hope to outmaneuver them due to limitations of the crew, if nothing else. Some unpredictable linear acceleration should be enough to do these tasks, unless the enemy can get lined up with you, in which case, you will want to change direction to prevent him from using your own acceleration against you, and blasting you head on.

So the concern is can you rotate fast enough to prevent the enemy from lining up with you. So, let's assume the enemy can change direction infinitely fast, and can thrust at 3 g's. The range will still be one light-second.

We can calculate how much of an angle he can cut into the circle per second if he attempted to circle around you. His thrust must provide the centripetal acceleration, so we can use that as our starting point. Centripetal acceleration is equal to radius times angular velocity squared, thus, sqrt(30 / 3e8) = 3e-4 radians per second. So, its angular velocity is three times that of the acceleration of the battleship.

Thus, it would take the battleship three seconds to match that rotation rate. It would also want to spin faster to make up for lost time, thus lining up on your terms again. I feel this is negligible because of two factors: if the enemy actually was orbiting like this, its position at any time would be predicable, thus vulnerable, and the battleship can probably see this coming: the enemy's tangential velocity must also be correct to do such a burn - he can not randomly change the orientation of his orbit due to his limitations on linear acceleration. This means you can see what he is doing and prepare for it with a small amount of time of him setting the terms. In this small time, he would not even move a degree on you: still easily within your armor and firing arc. (Also, weapons turrets on the battleship would surely be able to rotate at a much, much faster rate, so outrunning them is impossible anyway). Thus, I feel neither linear acceleration nor angular acceleration are significant limiting factors as size increases within this order of magnitude.

Long story short: unlike marine navies, speed is not a significant factor in space warship design, unless you are getting into obscene sizes. And, since I find it interesting, I want to finish talking about possible ship classes, so back to the comparison list. Submarines depend on stealth, and since (barring pure magic like the Romulan cloaking device), there are no submarines in space.

Destroyers operated to protect larger ships against submarines and small, fast ships, like torpedo boats. Since speed is not a significant factor and stealth impossible, there are no fast ships nor subs, meaning the destroyer has nothing to do, thus would not exist. (Though, you might chose to call what I call frigates destroyers if you prefer the name, but IMO the role is different enough that is isn't really accurate. But the US Navy somewhat does this, so it is up to you as the author.) A cruiser is simply a ship that can operate on its own.

Frigates, destroyers, and battleships can all also be called cruisers depending on their mission. A battlecruiser is a ship meant to be able to outrun anything it can't outgun - it had the speed of a lighter cruiser with the guns of a battleship. In real navies, this was usually achieved by taking armor off a battleship. However, since speed is not limited by mass in the given order of magnitude, a battleship and battlecruiser would have the same speed: the battleship would be a clearly superior vessel. Thus, no battlecruisers.

(Now, if you have FTL, then that might create a battlecruiser class, but I am trying to avoid talking about magic in this discussion, since as the author, it is entirely up to you what the magic can and cannot do.) A destroyer escort is a small, relatively slow ship used to escort merchant ships and protect them against submarines and aircraft. But, in the real world, aircraft can threaten a ship due to its superior speed and submarines due to stealth. So neither of them are there, making the destroyer escort worthless. Frigates or battleships would have to be doing the escorting, since they are the only things that can stand up to what they will be fighting: other frigates or battleships. Now, a little more on what I mean by frigate. It is basically a smaller battleship, built simply because I am presuming they will be cheaper to produce and maintain, thus allowing more of them to exist.

With more of them, they can be in more places doing more things. Cost is the only real benefit I can think of: if for some reason you could crank out and operate / maintain battleships for the same cost, I see no reason why you would not. The 10,000 ton proposal might actually be the frigate, with the battleship being larger than that, or it might be the battleship with the frigate being smaller than that. The relationship would remain the same, however. But what of vehicles intended to fight in space? As colonies and mining outposts spread throughout our solar system, there may be military value in capturing or destroying far-flung settlements -- which means there'll be military value in intercepting such missions.

The popular notion of space war today seems to follow the Dykstra images of movies and TV, where great whopping trillion-ton battleships direct fleets of parasite fighters (ed. Note: Battlestar Galactica and Star Wars).

The mother ship with its own little fleet makes lots of sense, but in sheer mass the parasites may account for much of the system, and battle craft in space may have meter-thick carapaces to withstand laser fire and nuke near-misses. Let's consider a battle craft of reasonable size and a human crew, intended to absorb laser and projectile weapons as well as some hard radiation. We'll give it reactor-powered rockets, fed with pellets of solid fuel which is exhausted as vapor.

To begin with, the best shape for the battle craft might be an elongated torus; a tall, stretched-out doughnut. In the long hole down the middle we install a crew of two -- if that many -- weapons, communication gear, life support equipment, and all the other stuff that's most vulnerable to enemy weapons. This central cavity is then domed over at both ends, with airlocks at one end and weapon pods at the other. The crew stays in the very center where protection is maximized. The fuel pellets, comprising most of the craft's mass, occupy the main cavity of the torus, surrounding the vulnerable crew like so many tons of gravel.

Why solid pellets? Because they'd be easier than fluids to recover in space after battle damage to the fuel tanks. The rocket engines are gimbaled on short arms around the waist of the torus, where they can impart spin, forward, or angular momentum, or thrust reversal. The whole craft would look like a squat cylinder twenty meters long by fifteen wide, with circular indentations at each end where the inner cavity closures meat the torus curvatures.

The battle craft doesn't seem very large but it could easily gross over 5,000 tons, fully fueled. If combat accelerations are to reach 5 g's with full tanks, the engines must produce far more thrust than anything available today.

Do we go ahead and design engines producing 25,000 tons of thrust, or do we accept far less acceleration in hopes the enemy can't do any better? Or do we redesign the cylindrical crew section so that it can eject itself from the fuel torus for combat maneuvers? This trick -- separating the crew and weapons pod as a fighting unit while the fuel supply loiters off at a distance -- greatly improves the battle craft's performance. But it also mans the crew pod must link up again very soon with the torus to replenish its on-board fuel supply.

And if the enemy zaps the fuel torus hard enough while the crew is absent, it may be a long trajectory home in cryogenic sleep. (ed note: the detachable fuel torus concept is vaguely similar to.) Presuming that a fleet of the toroidal battle craft sets out on an interplanetary mission, the fleet might start out as a group of parasite ships attached to a mother ship. It's anybody's guess how the mother ship will be laid out, so let's make a guess for the critics to lambaste. Our mother ship would be a pair of fat discs, each duplicating the other's repair functions in case one is damaged.

The discs would be separated by three compression girders and kept in tension by a long central cable. To get a mental picture of the layout, take two biscuits and run a yard long thread through the center of each. Then make three columns from soda straws, each a yard long, and poke the straw ends into the biscuits near their edges. Now the biscuits are facing each other, a yard apart, pulled toward each other by the central thread and held apart by the straw columns. If you think of the biscuits as being a hundred meters in diameter with rocket engines poking away from the ends, you have a rough idea of the mother ship. Clearly, the mother ship is two modules, upwards of a mile apart but linked by structural tension and compression members. The small battle craft might be attached to the compression girders for their long ride to battle, but if the mother ship must maneuver, their masses might pose unacceptable loads on the girders.

Better by far if the parasites nestle in between the girders to grapple onto the tension cable. In this way, a fleet could embark from planetary orbit as a single system, separating into sortie elements near the end of the trip. Since the total mass of all the battle craft is about equal to that of the unencumbered mother ship, the big ship can maneuver itself much more easily when the kids get off mama's back. The tactical advantages are that the system is redundant with fuel and repair elements; a nuke strike in space might destroy one end of the system without affecting the rest; and all elements become more flexible in their operational modes just when they need to be.

Even if mother ships someday become as massive as moons, my guess is that they'll be made up of redundant elements and separated by lots of open space. Any hopelessly damaged elements can be discarded, or maybe kept and munched up for fuel mass. MARTIAN INTERCEPTOR Description: A high thrust, high performance warship that uses drop tanks to achieve enough deltaV to intercept interplanetary fleets.

A solid-core nuclear thermal drive minimizes the need for radiators, but requires an on-board electric powerplant to power the lasers. Expendable mirror-drones are used to out-range potential targets. Datasheet: Name: Martian Interceptor Role: Intercepting interplanetary Terran fleets Dry mass: 1986.3 tons Mass percentages: 68% Armor, 32% Components Component masses: 50 ton solid-core nuclear thermal engine 100 ton nuclear-electric generator 100 ton armored radiators 38 ton Gyrotron-VECSEL laser generator 85 ton heat pumps 1 ton optics 112.5 ton mirror drones 11.4 ton life support 46 ton sensors 8.8 ton avionics 45.1 ton structure 33.6 ton tank mass Propellant mass: 3359 ton internal, 34201.4 ton inner, 253035.6 tons outer DeltaV: 5km/s internal, 15km/s inner, 25km/s outer.

Acceleration averages: 1.28G, 0.39G, 0.05G Propulsion output: 100GW Electrical output: 500MW Ammunition: 8x Long Range mirror drones, 50x Short Range mirror drones Standard laser performance factor: 5.7 Laser armor depth: 163mm, rotated, sloped. Kinetic armor depth: 400mm, 600mm Diagram: Shape is a narrow cone on top of a water cylinder. Design comments: 100GW 50 ton nuclear thermal solid-core engine. Propulsion waste heat is absorbed by 8000kg/sec mass flow. Thrust is 36MN (90% efficiency). 100 ton nuclear electric power generators produce 500MW.

At 33% efficiency, they put out 1000MW waste heat at 1500K. Power generator waste heat removed by 2000m2 of double sided radiators. Mass is 100 tons with 50kg/m2 (armored). 1000 tons of water can be boiled off in 37 minutes if radiators are damaged. Defensive gyrotron produces 333MW beam, 83MW waste heat, pushed from 500K to 1500K by 83MW heat pumps. Offensive Gyrotron-VECSEL produces 158MW beam.

Heat pumps move 170MW waste heat up to 1500K, consuming 170MW. Gyrotron masses 34 tons. VECSEL masses 4 tons.

Heat pumps mass 85 tons. Aiming is through a 1ton side beam window.

6m radius mirrors composed of 113 hexagonal 1.12m diameter segments of 1m2 each, massing 4.9 tons for the mirror, 100kg for communications, resistojet RCS and electronics. 15.8kW is absorbed from the laser. It is removed by 35g/sec of liquid hydrogen boiloff. The heat exchanger masses 13.5kg/m2, based on a microtube design.

1.53 ton exchanger. 100kg liquid hydrogen provides operation for a maximum of 1 hour of continuous shooting. Power for pumps and the rest is provided by a 1kW 200kg electrostatic-thermoionic RTG generator.

It is equipped with 12x2kg thrusters at 5 radial directions. 700kg of LOX/LH2 propellant in 10kg tank provides 500m/s deltaV. Total mass is 7.4tons. Eight mirror drones add up to 59 tons, with 0.5 ton onboard LH/OX cracker and cryo-cooler tanks. Volume is 20m3 per drone.

Closer combat mirrors of 2m radius are composed of 12x1m2 segments, massing 528kg. 100kg for control, 162kg for heat exchanger, 100kg for LH2, 60kg 300W RTG, 24kg for thrusters, 2kg tanks, 98kg propellant for 500m/s deltaV.

Total is 1.07tons. 50 of them mass 53.5 tons. Volume is 5.5m3 per drone. Comments: Long range mirrors are nine times as effective compared to a 2m radius integrated mirror, and has the flexibility of one-ship flanking of multiple opponents, along all three axis. Close combat mirrors have swarm behavior. Life support for a crew of three, with 1 month endurance. Pilot/programmer, comms/commander, engineer/teleoperator.

Separated into two control centers and an inflatable rotating habitation ring. Consumables: open-ended 180kg of oxygen (72kg) and food (108kg). Water is drawn from the propellant tanks. Water recycling and CO2 scrubbing are handled by 150kg of equipment.

Control center resembles fighter jet cockpit and masses 1050kg. Inflated habitat masses 60kg/m3 and has a radius of 6m, and is a tube ring 2m wide. Mass 7.9 tons.

Total crew mass 11.38 tons. Forward sensors are 10 degrees arc wide-angle x36 to cover the entire front arc, plus one forward facing wide-angle, plus three redundant 1 degree narrow-angle. Sides and rear are covered by three wide-angle sensors in scanning mode. Total mass 46 tons. Comments: this is a very aggressive sensor layout.

It relies on a planetary network to detect flanking threats. Multiple redundancy helps mitigate damage and blinding. Fixed positions allow for better detection of incoming stealth projectiles (zero scan delay).

Avionics represent 2% of dry mass, excluding armor. Mass 8.84tons. Comments: an arbitrarily worse figure than the Terran's 1%. Internal structure adds 10% to dry mass. Mass 45.1 tons. Total internal mass is 597.8 tons. Volume is approximately 1800m^3, based on a 0.33ton/m^3 figure, derived from modern jet fighters.

This is a cone 8.4m wide and 100m long. External mass contains armor and point defenses. The Martian Interceptor is in some ways a battering ram: no stealth, high closing velocity, no regard for force disparity. It breaks through enemy defenses and creates an opening for missiles launched by a stealthy arsenal ship. The protection of an armored nose cone is a vital element, one of the reasons it does not have a keel-firing laser.

It does not use laser point defenses, relying on kinetic PD instead to survive the one and only pass. The rotating laser armor must survive the onslaught of three standard 250MW/2m/400nm lasers from maximum to 100km range. It uses a monolithic cone of DLC. A standard laser penetrates 1mm/s of carbon armor starting from 2750km.

This can be considered maximal effective range. At 100km, it penetrates 20.9m/s. At a closing velocity of 10km/s, the MI spends 275 seconds under laser fire. If the closest approach is 500km, it accumulates 4133mm of carbon removed. If it closes to 100km, it takes 115532mm. Failing to take out any targets leads to a 24803mm penetration flyby. Taking out one target at the closest intercept reduces this to 20699mm.

An interceptor should take out at least one target before the closest intercept, and another after intercept, so 20699mm is the worst design case, and 24803 is the catastrophic failure case. We design to survive catastrophic failure.

The internal volume allows for a 2.41 degree cone. This sloping increases armor thickness by a factor 23.78, reducing requirements to 1043mm. The cone has an average circumference of 13.2m. The standard laser's spot size averages 0.347m in diameter.

An armor shell rotating twice a second can spread laser damage by a factor 76, reducing armor requirements to 13.72mm. Actual armor requirements lie between 13.72 and 1043mm. In the best case scenario, the interceptor faces a tightly clustered opponent. At worst, the opponent has set up an un-escapable flanking shot. A compromise is necessary.

If the interceptor can keep opponents within a 60 degree frontal arc, then it needs 163mm of armor. The laser armor masses 655.5kg/m^2, for a total 438 tons.

Kinetic armor consists of two armor belts and two internal bulkheads. The front bulkhead is a 40cm hemisphere 4m wide. The main belt is 40cm thick, 20m long, moving up from the base of the armor cone (437 tons). An inner cylinder with 60cm armor protects the crew (5x4m cylinder, 86.7 tons). The rear belt is 40cm thick, 8.4 m wide, 9.08m tall cone, sloped at 65 degrees. Front bulkhead is 8.18m^3 and masses 18.8 tons.

Main belt is 437 tons. Crew tube is 86.7 tons. Rear belt masses 202 tons. The reactor cap 172.4 tons. Total kinetic armor mass is 916.9 tons. Total armor mass is 1354.9 tons. Total dry mass is 1952.7 tons.

Internal water tank mass is 1% of water mass. To achieve 5km/s deltaV, we need a mass ratio of 2.72. This can be achieved with 3359 tons of water propellant, requiring a tank mass of 33.6 tons and 8.4m wide, 60.6m long. Total mass is 5345.3 tons. Inner drop tanks provide 10km/s. This requires 34201.4 tons of water. The water is held in balloons 60m long, 28.2m wide.

Total mass is 39546.7 tons. Outer drop tanks provide 10km/s with 253035.6 tons of water. It is held in a balloon 42m tall and 78.5m wide.

Total mass is 292582.3 tons. MARTIAN ARSENAL SHIP Description: An unmanned missile carrier that relies on liquid hydrogen boiloff and directional stealth to stay undetected. Cold missiles are delivered by a coilgun. An efficient nuclear-electric propulsion system allows it to catch up with Interceptors and build up an intercept velocity to compensate for the missiles' low deltaV capability.

Datasheet: Name: Martian Arsenal Ship Role: Delivering missiles undetected. Dry mass: 1176.3 tons Component masses: 15 ton Pulsed Inductive Thruster engines 100 ton nuclear-electric generator 1.8 ton droplet radiators 122 ton coilgun 82.5 ton energy storage 173 ton heat pumps 354 ton missiles 9 ton sensors 6.5 ton avionics 171 ton stealth shroud 68 ton structure 73.4 ton hydrogen tank Propellant mass: 734 tons DeltaV: 24.6km/s Acceleration average: 2.1 milliG Propulsion output: 1.5GW Electrical output: 1.5MW Ammunition: 10000 stealth missiles Standard laser performance factor: 0 Laser armor depth: 1mm. Kinetic armor depth: 1mm.

Diagram: Shape is a cylinder inside a cylinder, behind a hydrogen cylinder. Design comments: Low exhaust temperature nuclear electric propulsion. 100 ton 1.5GW nuclear reactor, 15 ton PIT engines, 5000s Isp (49km/s) exhaust velocity, 30kN thrust (98% efficiency). 3030MW of waste heat is removed by four 1x5m liquid droplet radiators, using carbon-darkened tin at 1200K (emissivity 0.8, 1mm droplets). 146kg of fluid are used in operation.

Radiator mass 0.8 tons, fluid mass 1 ton. Missiles have 1km/s deltaV. They are launched by coilgun to 5km/s. Missiles are all equipped with stealth capability. The penetrator and armor is a Diamond-Like Carbon cone 40cm long, 6.6cm wide, massing 10kg. It mounts a 1kg sensor and communications package.

An 8kg, 10MPa (1450psi), 80K tank made of kevlar contains hydrogen gas for use as a propellant in a cold gas thruster, achieving an exhaust velocity of 2700m/s. Propellant density is 33kg/m^3. Thruster mass is 3kg. 9.86kg of hydrogen are required to provide 1000m/s deltaV. Launch mass is 32kg. Total length is 1.22m, width 0.82m. Missiles are delivered in 10-missile clusters massing 330kg, including a 10kg 'sabot'. Coilgun efficiency is 90%.

It requires 4.125 GJ to launch a cluster to 5km/s. The projectiles are accelerated at 2000g, reaching the muzzle velocity in 122m of acceleration. Coilgun mass is 122 tons. Energy is stored in by SMES.

Several superconducting loops with carbon bracing hold 4.125GJ in 82.5 tons. A coilgun generates waste heat too quickly to be removed directly by a radiator. It must be transferred to a heat sink first. 413MJ is released per shot. Non-corrosive liquid helium at 20K is used as the coolant fluid.

If it operates at 300K, it requires 278kg of helium gas to be flash-heated. 10 shots (one missile wave) require 2.8 tons.

The waste heat from the coilgun has to be pumped from 300K to 1200K. This can be handled by 173 tons of heat pumps. They consume 346MW. The power draw of the heat pumps reduces firing rate to one shot per 3.6 seconds. Stealth firing and moving can be performed. Waste heat is removed by boiling off liquid hydrogen propellant. The reactor operates on a temperature difference of 3000 to 20K instead of 3000 to 1200K, reducing waste heat by 40% (from 3000MW to 1812MW.

Heat exchangers increase the propellant's temperature to 100K before ejecting it, thereby removing 1575kJ/kg of hydrogen. Stealth firing consumes 1222kg/s. At the cost of 33.6 tons of liquid hydrogen, the Martian Arsenal ship can drift into position and fire a full missile wave without breaking stealth. A standard enemy fleet formation can output 750MW of laser power, and take down between 75 and 150 missiles in the terminal 100km stage. Stealth projectiles evade detection long enough for long-range laser defensive fire to not matter. A wave of stealth missiles detected at 100km range must therefore number at least 150 to get through the target's defenses. To defeat an enemy that has survived the first wave, the missiles must deplete kinetic defenses, and attack frequently enough to force lasers into operating at high temperatures.

10 waves against 3 targets requires 4500 missiles. An ammunitions load of 10000 missiles will therefore be sufficient to take out dozens of unaware targets, three aware targets, or one target in a massive simultaneous attack. This will mass 322 tons and require an ammunitions bay 30m long and 4m wide. 10% is added for storage and handling, totaling 354 tons. 9 wide-angle sensors: 3 front, 3 rear. Avionics add 2% to the dry mass, minus ammunition. Masses 6.5 tons.

The 4m wide internal cylinder is enclosed in a 30m wide, 170m long insulated tube. The far end is a radiator emitting at 1200K.

The opposite end is open and limits emissions to 10 degrees of the sky. This is Mars's diameter at 38400km. Heat removed is 74.5MW.

It allows 25MW of electricity to be generated, allowing one shot per 165 seconds, or 2.5kN thrust at 10km/s exhaust velocity. Mass is 171 tons. Structural mass adds 10%. Dry mass of the warship, minus ammunition, is 748.9 tons. With ammunition, it is 1102.9 tons.

The arsenal ship is not expected to come under laser fire. The insulated cylinder is no armor, but acts as a whipple shield.

734 tons of liquid hydrogen are kept in the nose of the ship. It is contained in a cylinder 10m long and 30m wide, massing 73.4 tons. At worst, the Arsenal ship can absorb up to 3.2MW of sunlight side-on. This requires up to 7kg of liquid hydrogen to be boiled off per second to keep the ship thermally invisible. Front-on, this is reduced to 417kW, requiring only 0.9kg/sec. TERRAN ADVANCED BATTLESHIP WITH INTERPLANETARY STAGE Description: An advanced two-stage warship that travels across the Earth-Mars distance on a large interplanetary stage, then detaches to use its high thrust open-cycle gas core engines to dodge incoming missile waves while a massive laser allows for re-usable offensive firepower. Missile complement its offensive role.

Datasheet: Name: Advanced Terran Warship Role: Destroying enemy battleships at 1000km distance. The laser is focused by a 4m wide adaptive dielectric mirror, shooting through a fused quartz conical window with to 250nm light at when shooting off-center by 5 degrees, up to 99% transparency at further diagonal angles and through the flat truncated section straight ahead. It achieves nearly 90% absorption of visible light wavelengths. It can survive a 900K temperature increase. It is 32mm thick, 4m wide and truncated at 12.5m length, sloped at a 4.5 degree angle to achieve 400mm relative thickness.

The truncated window is 2m wide. The mirror masses 0.5 tons. The cone masses 8.3 tons. The warship is equipped with 3 onboard replacement cones and mirrors. Comments: This cone serves to protect the main mirror. Acting as a blacklight, it prevents the Martians' lasers from attacking the mirror directly, while letting shorter UV wavelengths through. The 400mm straight-head thickness prevents penetrations from regular-sized kinetic impactors.

Firing diagonally is preferred, as it decreases the laser power being absorbed. The truncated window is a 3.14m^2 weakpoint. The cone can absorb up to 24MW during operation. This would bring the cone to dangerous temperatures within four minutes, with localized failure along the beam path.

A liquid hydrogen cooling system is required to absorb this heat, with a throughput peak of 8kg/s, operating between 200K and 300K. 3.45GW of waste heat is removed by tungsten tensile wire radiators operating at 1200K. The wires are 1mm thick and 10221km long, massing 154.6 tons (15.1g/m). They are extended into 100m wide loops in space. At 70m/s, they maintain a 10G centripetal force and will cool down to approximately 360K in 1.3 seconds. At 0.057m separation, they only block 0.6% of each other's radiating area.

At 3mm separation, it is 10%, but they risk touching each other. The radiator loops can be stacked 50m long, in four sets, extending 100m into space. They are mostly resistant to laser fire and kinetic damage due to their small cross-section. 200 ton replacement wire increases survivability. Anti-missile protection relies on point-defense lasers. 6x6 turrets with 60 degree traverse, massing 3.2 tons each, putting out 100MW maximum each and can take down 384 missiles.

10 Casaba-Howitzer wide-angle nuclear charges, massing a ton each, can be used to clear out a 30 degree cone of missiles at 100km range. However, this destroys the radiators. The Advanced battleship is equipped with another 10 'Silver bullet' missiles with 1200kg Casaba Howitzer 10000km range warheads, 4439kg of carbon armor (400mm thickness, angled at 30 degrees) and 10km/s deltaV with hydrolox propellant.

Each missile masses 57.3 tons, for a total of 630 tons. The crew count is 9 individuals: 1 commander, 3 tacticians, 2 mechanics and 3 programmers. They inhabit two 10-ton habitation rings rotating to provide 0.3G. Life support is fully closed-cycle, with 3 tons of equipment.

Control is through two CIC units massing 6.5 tons. Included is radiation shielding and a 20mm armored shell. The Advanced battleship has a heavy sensor suite. It has three rings of 36 narrow-angle sensors, and six lines of 10 wide-angle sensors along the flanks.

Total mass is 168 tons. Comments: Terrans fear the roving stealth missiles deployed by the Martians. They believe Martian space to be infested by thousands of smart groups of such missile. A 360 degree view sensor suite is necessary to prevent a surprise attack by cold projectiles. Avionics are 1% to the dry mass, adding 30.8 tons. Structural mass is 310.7 tons, increasing total internal dry mass to 3417.5 tons. This fits inside a cone 200m long and 14m wide.

It is sloped at 2 degrees. Comments: Battleships match orbit with their target and burn it down with their lasers. Zipping past would expose them to a cheap kinetic attack. Attack runs include closing the distance for a targeted laser strike, then pulling back on reverse thrust (to keep the armor cone pointed at the enemy).

Armor requirements are calculated based on how long the armor must survive laser fire. A standard fleet equipped with three standard lasers can remove 3mm/s of laser armor at 2750km, increasing to 60mm/s at 1000km. Based on the setting's objectives, we can set the 'time to kill' duration as 1 hour at 1000km. This leads to an armor thickness of 216000mm. The armor cone's 2 degree slope can reduce the armor required by a factor of 28.6. However, battleships with low acceleration and locked down trying to stay out of one target's weapons' effective range can easily be flanked by another target. This means that the slope cannot be relied upon.

In a typical 3 vs 1 scenario, two laser ships bracket the defender while a third rises above the plane and attacks from an angle. The Advanced battleship's cone would reduce one laser's penetration rate by 28.6, the second by 15.5 (the first two targets are 100km apart for mutual anti-missile defense) and the third by 1.006 (90 degree flanking).

The sum of their penetration rates is 21.48, leading to a thickness requirement of 78748mm. The Advanced battleship uses a nestled rotating armor scheme. Average diameter is 7m. Rotation is once per second, leading to the laser being dragged along at 22m/s. With a second shell under the first, the laser can be spread out over 44 meters of armor per second.

With a third shell, it is 66m/s. At 1000km, spot size is 0.244m in diameter. The armor rotation reduces laser effectiveness by a factor 270.

The armor thickness required is 291mm. Each shell is 97mm thick. Laser armor mass is 981.9 tons. Kinetic armor is internal. A 4m wide, 60m long 'citadel' tube protects the crew during combat, life support equipment, backup power generation and redundant avionics, as well as the vulnerable the free electron laser. It is 300mm thick and masses 520 tons. Internal dry mass is 3147.5 tons.

Armor mass is 1501.9 tons. Total dry mass is 4649.4 tons. A deltaV of 20km/s requires a mass ratio of 2.72. This requires 7997 tons of water, contained in a cylinder 14m wide and 52m long. It masses 80 tons. Actual deltaV is 19661m/s.

Launch mass is 12727 tons. The interplanetary stage permits rapid movement from Earth to Mars. It moves 4 battleships as a payload of 50908 tons. A 10000 ton 150GW nuclear electric reactor produces 300GW of waste heat.

It is removed by two 60x60m droplet radiators operating at 1200K, massing 285.7 tons. They contain 52 tons of liquid tin, and 100 tons of replacement fluid are kept onboard. For propulsion, 58km/s exhaust velocity PIT engines massing 1500 tons produce 5.17MN of thrust. The interplanetary stage's dry mass is 13151.7 tons, including avionics and structural components. It departs at 64059.7 tons. Liquid hydrogen is the propellant. 409879 tons are required, to be contained in four spheres of 132m diameter.

They mass 2000 tons. DeltaV is 116km/s. It would take it 87 days to cross the average 225 million km distance between Earth and Mars. When designing a spacecraft, certain questions inevitably arise concerning how it should be sized. Crewed spacecrafts very obviously have a lower size bound, since you can’t really miniaturize people like you can lasers or rocket engines. At the very least, your spacecraft needs to be able to fit people. However, there is no clear upper size bound.

With missiles and drones, there is no obvious lower size bound either. Let’s take a look at size limits of subsystems. Power usage is more or less the primary way to increase effectiveness of systems, and size is generally the way to reduce thermal and mechanical stresses caused by this power use. But these laws are almost never linear, and often hit ultimate limits. Take lasers, for instance. As outlined in, scaling a laser up or down in size produces very little difference in power output. However, scaling it up in size reduces the power per volume and power per area so it won’t melt when activated.

This means you often want to keep your weapons and subsystems as small as possible, but it’s physical limits that force them to grow larger. A trend with sizing of subsystems is that systems tend to work more efficiently when larger. A single 200 kN rocket thruster, for example, will perform more efficiently and be less massive than ten 20 kN thrusters. Larger singular systems distribute mass better and require fewer complex parts than many smaller systems. On the other hand, those ten lower efficiency thrusters would probably be preferred in combat to the single high efficiency thruster because of redundancy. Compare a stray shot taking out all of your thrust versus taking out only one-tenth of your thrust. Clearly, there is a balance to be struck, between redundancy and efficiency.

Similarly, crew modules come with significant overhead, such as the plumbing for the sewage and air recirculators. As a crew module expands in size, this overhead reduces proportionally to the number of people within. However, bunching all of your crew together in a single module is a major liability in combat. Alternatively, rather than making a single large spacecraft with highly redundant systems, some playtesters went the route of smaller spacecraft with no redundant systems.

In that case, the redundancy is with the spacecrafts themselves, rather than with the subsystems. Another consideration is that smaller subsystems can be manufactured more cheaply on assembly lines compared to single large subsystems. In the era of widespread, highly advanced, these benefits are less pronounced, however. There are certain minimum size limits that show up with drones and missiles, too. For instance, nuclear warheads have a minimum size. The smallest nuclear device ever made was the at about 20 kg and the size of a large suitcase. This lower limit is due to needed for fission.

Thus, for missiles, their warhead tends to determine just how small you can make the missile. If your missile has no warhead, their lower size limit is based on the rocket motor generally.

For drones, it is similarly the mass and volume of the weapons on that drone which limit the size of them. But these are all lower limits. What about upper limits? Generally, lower limits are all the rage because you want to make everything small, compact, and low mass. The smaller (volumetrically) you can make everything, the less armor you’ll need. The less massive you make everything, the greater the delta-v and thrust you’ll have.

There is actually very little stopping you from making enormous lasers or railguns, but simply making them bigger doesn’t actually improve their effectiveness or power, it only makes them deal with thermal and mechanical stress better. Essentially, you make things big because you have to, not because you want to. But suppose you don’t care about making the most effective spacecraft, you just want to go big. At this point the begins to rear its head, and that is that volume scales cubically, while surface area scales quadratically.

Without gravity, these issues are not quite as severe, but they still appear. For instance, on the positive side, larger spacecraft are more efficient about their armor-to-everything-else ratio, because armor scales by surface area, and everything else scales by volume. Large capital ships tend to be armored like tanks while smaller ships run much lighter. But on the negative side, acceleration suffers badly.

Attaching thrusters to a spacecraft scales by surface area, and the mass of spacecraft scales by volume. Thus, the larger a spacecraft becomes, the lower and lower its acceleration inevitably becomes.

As found in, thrust is hugely important, which is why only Nuclear Thermal Rockets and Combustion Rockets see major use in combat. A ship that can’t dodge is a sitting duck to all manner of weapons. Most capital ships in Children of a Dead Earth range from hundreds of milli-g’s to full g’s of acceleration, and even that affords only partial dodging usually. Dropping that acceleration further is often fatal in combat. Another negative aspect of growing in size is that the the cross sectional area of the spacecraft grows accordingly.

And having a fat targetable cross section vastly increases enemy projectile ranges against you. For combat spacecrafts, then, miniaturizing your spacecrafts is often the most ideal choice. But what about civilian crafts? Civilian crafts make a lot more sense to balloon up in size, especially for the sanity of the passengers.

The acceleration is still a problem, as if it’s too low, the spacecraft will have difficulty getting anywhere taking enormous amounts of time. But the other issues are gone. If travel time is not an issue, such as with a multi-generational colony ship, then you could try scaling up to truly enormous sizes. There is a trade off between armor, guns, and speed. Each comes at the expense of another. One method of displaying this is by a (aka ternary graph, triangle plot, simplex plot, de Finetti diagram).

It has three scales for three variables. For space warships, we will use the percentage of the ship's mass devoted to Propulsion (speed), Weapons (guns), and Defense (armor). At any point on the graph, the percentages of each variable add up to 100% (representing 100% of the ship's total mass). For example, point A is 50% weapons, 20% defense, and 30% propulsion. 20% + 50% + 30% = 100% There are specific regions on the graph: •.

This is the final graph I created. Each area is labeled with the three percentages in order of priority. For instance, all ships that are occupying the upper right dark blue area have more of their design mass devoted to propulsion than to weapons, and more of their design mass devoted to weapons than to defense. You will see it in use.

Refer to the to learn how to read the graph Defense Something with armor, that cannot move and has no guns. A foxhole or armored shell. Defense, Propulsion Unarmed ship with so much armor that it moves slowely. Defense, Weapons Stationary fortress with strong walls but few guns. Defense, Propulsion, Weapons Lightly armed ship with so much armor that it moves slowely. Defense, Weapons, Propulsion Ship with so much armor and weapons that it can barely move.

Propulsion A rocket engine or a detachable drive unit. Propulsion, Defense Unarmed ship with such light armor that it moves rapidly. Propulsion, Weapons Armed ship with no armor that moves rapidly. Propulsion, Defense, Weapons Ship with outsized engines, medium armor, and few guns. Propulsion, Weapons, Defense Ship with outsized engines, medium guns, and little armor.

Weapons A gun turret or stationary weapon platform. Weapons, Defense Stationary fortress with lots of guns but weak walls. Weapons, Propulsion Lots of weapons mounted on an engine, with no armor. Weapons, Defense, Propulsion Warship with lots of guns, good armor, but which can barely move. Weapons, Propulsion, Defense Fast warship but flimsy armor. Balance Well balanced all-around ship.

Points out that there are actually five major dimensions of ship design: armor, guns, speed, endurance (how long between refueling and re provisioning), and command & control (how large the bridge crew is, which boils down to how many different tasks can be done simultaneously). He notes that if you just look at the first three variables, one would make the erroneous prediction that the would have been an overwhelming advantage to the Germans task force. In reality, the British had the advantage because they built their ships with the endurance for long cruises and the Germans built their ships with an endurance of only two weeks. In depicting combat in space, science fiction (movies in particular) long have conveyed rather simplistic models of WWI and WWII fighting. Tiny craft, for instance, are normally depicted as faster than large ('lumbering' is frequently the adjective) ships; this is indeed true, or can be true, on Earth, where conditions force trade-offs between mass/heavy weapons and speed/maneuverability.

But conditions in space are not egalitarian. For general expectations, sub-light ship speed would be limited by the size of the engine, if the types involved are equal, and by the mechanics of relativity which demand (at near-light speeds) great increments of mass/energy for tiny increments of speed.

(There is also the problem of interstellar particles at high speeds turning the noses of ships into little atomic battlefields, to the misfortune of hull and crew.) In space, ranges are unlimited by terrain or earth curvature, visibility is absolute, and surprise probably only strategically. In such conditions, the faster ship will be the one also with bigger and better weapons; engine performance will tie directly to range and breath of energy and field weapons. Evasive maneuvers carried out by necessarily shallow curves at even 0.1c speeds will hardly challenge sophisticated fire control and titanic-aperture lasers (free of planetary weight deformations, lasers theoretically can be of any size). The next time you watch Battlestar Galactica, ask yourself how well an F-16 would fare against an energy beam with a diameter of 2000 kilometers: in space, given quality, bigger is better. GROUND SUPPORT TEAM ( tan eche, world blanket) Variable force, but averaged 55 ships with about 40,000 cortex-suspended political defenestrators, police, and communication experts.

Most effective against system defenses, but average small mass of a ship, about 30,000 tons, prevented mounting weaponry strong enough to stand up long in deep space combat. MISSILE PACK Consisted of a manned command ship accompanied by 40 to 50 multi-tubed drones which packed the missiles.

About 1000 crew, 2 million tons for complete group; main ship 1.5 kilometers, drone 0.2 kilometers. Fragile, but impressive in impact if the opposition lacked counter-fire. Very skinny command ship gave drone profile from front and back. RANGER ( vam, bully) A compromise between fully useful size and the need to defend more than one or two points. Non-situational weaponry, about as good in one sort of fight as another. Complement 2300 to 2600; mass 4.1 million tons; length 6 kilometers.

STARCRUISER ( tal des, star noble; literally master of light) The balance point between armament and mobility, a craft sized by information theory comparing system size and significant dysfunction. Completely weaponed, including exotic items like condensor clouds and linkages for demi-lunar manipulation.

Three in a team were a match for a solar system. Complement 4500; mass 10 million tons; length 9 kilometers. STARGUARD ( brev'tal bir, against the cold) The opposite of a Starcruiser, since the diffusion of thousands of discrete members initially lacks any significant target. A Starcruiser might cut for hours through this jungle of tiny ships, mines, etc., until suddenly there were more targets than fire control could handle. Once such a ship began to take damage, the Starguard units quickly stung it to death. Total spherical complement about 4 million; mass 40 million tons; length about 100 km.

There are three types of combat units Deep Space Squadrons (SQD) These are fleets of combat starships. They have the edge in space-to-space battles, but cannot attack targets on the ground without assistance from other combat unit types. Planetary Defense Forces (PDF) These are ground based army units and planetary fortresses. They have the edge in ground-to-space attacks, but are helpless if they are in space (because at that point they are in the belly of unarmed ponderous cargo transport starships). Assault Groups (AG) These are combined space and ground forces.

They have advantages when invading a hostile planet. However, since they are basically a compromise between SQDs and PDFs, they perform neither task as well as they could. COMBAT UNIT DETAILS •. Here are the in-depth details on the difference between the combat unit types. If you could care less then.

The strategic map is a 3D map of space. Each location is called a 'cell.' Certain cells contain inhabited solar systems, these are called 'system cells.' Those cells represent the solar system and orbital space over the inhabited planet.

For every planet in the game there is a specific planet map. The planet in question is divided into four regions (quadrants). This represents the ground surface of a planet. So combat units in space will occupy cells on the strategic map, combat units orbiting a planet will occupy the corresponding system cell on the strategic map, and combat units on the ground (or in the aerospace zone) of a planet will be on the corresponding planet map.

Units have a 'combat strength.' This is a measure of relative strength and is used with a die roll to determine who hurts who in any combat situation. Meaning whichever side of the combat has the highest total combat strength also has the better odds. The advantage of a SQD is a group of two or three units is stronger than the sum of their parts. A 1 SQD has a strength of 1, a 2 SQD has a strength of 3 (not 2), and a 3 SQD has a strength of 5 (not 3). The disadvantage of a SQD is it cannot occupy a region on a planet (it cannot land), and it cannot attack hostile units on a planet unless the SQDs are assisted by an equal number of friendly AGs or PDFs also on the planet.

The advantage of a PDF on a planet map is it can attack hostile units [a] in the same region, [b] in the corresponding system cell (hostiles in orbit), and [c] hostile units on the strategic map within two cells of the system cell (SQD and AG can only attack hostile units within one cell, adjacent). In addition during an attack a PDF cannot be harmed unless at least half the hostiles are also on the ground (a purely spaceborne attack cannot hurt a dug-in PDF, you have to go in after them). The disadvantage of a PDF is that if it is in space its combat value is Zero (because they are in the belly of unarmed cargo transports, remember?). They are automatically destroyed by attacks by hostile SQDs and/or AGs, unless escorted by friendly SQDs and/or AGs. PDFs in space cannot land on a planet unless both the corresponding system cell and planet map region is free of hostile units. The advantage of a AG is while its combat strength in space is 1, it is 2 while occupying any system cell or planet region. Unlike PDFs, an AG can land in a planet region that contains hostile units.

On a planet an AG can move from one planet region to any other region, a PDF can only move to an adjacent region. The disadvantage of an AG is mainly it does not have the major advantages of the SQD and PDFs: [a] a group is not stronger than the sum of its parts like SQDs, [b] on the ground it can only attack hostiles in same region or in system cell, it cannot attack hostiles withing two cells like the PDFs, [c] it is harmed by a purely spaceborne attack.

POLITICAL PROBLEMS The joker in the deck is that while playing the game, a player does not have a free hand to produce whatever types of units they desire. Politics rears its ugly head. Each planet is divided into four regions. Each region has an Economic Level: Subsistence, Agriculture 1, Agriculture 2, Industrial 1, and Industrial 2. Each region is controlled by one of three political parties: the Extremists, the Reactionaries, and the Moderates.

As with most games of this type only regions with an economic level of Industrial 1 or Industrial 2 can produce more SQDs, PDFs, and/or AGs. No surprises there. Warships and army hardware are produced at factories, not at farm lands, makes perfect sense. The part that will blindside the players is that industrial regions controlled by the Extremists will only produce SQDs, controlled by Reactionaries will only produce PDFs, and controlled by Moderates will only produce AGs.

The players will find this most distressing since invariably they will be prevented from producing the combat units they desire. The three political parties are of course comic-book simplifications of any real-world party. This is for a boardgame, after all. Advocate using violence to enforce their will. So they like SQDs which are fleets of warships who go sailing into enemy space.

The best place to defend your home is on somebody else's territory. Want society to return to the.

Conservatives, in other words. They have a fortress mentality, resulting in a preference for PDFs. The best place to defend your home is along your borders. Want a middle of the road strategy. AGs are sort of a Swiss Army Knife: it can do both jobs but does neither very well. In the game it is possible to change the political party controlling a region, but it is a painful process. Basically you have to mistreat a region to the point where they are just one step away from revolt, then try to make the switch.

Half the time they will not switch, instead falling into full scale revolt. The process of changing a political party is much like using a broken beer-bottle as toilet paper: it is possible if you are very careful but sooner or later you are going to be in a world of hurt.

A century, a year, and a day ago, giants clashed across the North Sea. It was the single grand set-piece engagement of the big gun battleship era. Nothing like it was ever seen again, or probably ever will be. Battleships and their dreadnought cousins, battlecruisers, loom large in our collective imagination. They were and are inherently operatic. Space opera, in particular, emerged as a genre during the dreadnought era. And while it may often favor swords or space fighters, on some level space opera is really all about Dreadnoughts in SPAAACE!!!

If you doubt this, take a look once again at the opening scene of the original Star Wars movie. No lightsabers are to be seen, nor even a space fighter. What we see is a spaceship - no small one - in desperate flight.

To be overtaken by a truly looming, immense, unmistakable battlecruiser. We know it is a battlecruiser, rather than a battleship, because of its hunting-down role, something that would have identified without hesitation as a battlecruiser mission.

And yes, franchise canon describes this majestic ship as a 'star destroyer' but we are not fooled. Perhaps George Lucas was hazy on his 20th century naval terminology, or perhaps he felt that, in those days, battlecruiser belonged to the rival Star Trek franchise. While battlecruisers continue to have a somewhat sketchy reputation among seagoing dreadnoughts (see below), they have clearly overcome their slower if more heavily armored cousins in the battle for the stars.

Google battleship, click Images, and you get pictures of historical seagoing battleships. Google battlecruiser and you mostly get renditions of operatic spaceships, with a mere scattering of seagoing vessels. ( Battle cruiser as two words brings up a slightly different sequence of images, but equally space dominated.) It is not quite clear why, of the two dreadnought* types, battlecruisers have become so predominant in space. Perhaps, for Americans at least, Pearl Harbor looms larger than Jutland. If battleships only ever existed in order to be obsolescent sitting ducks for Japanese carrier planes, their potential as terrors of the spaceways is diminished. * Dreadnought is used inclusively here, applied to all big-gun capital ships, though the term was not often applied to new battleships once pre-dreadnoughts had faded from the scene. On the other hand, the US Navy never had any battlecruisers, or at least never admitted to having any.

Six were under construction during World War I, but under terms of the Washington Treaty two were finished as aircraft carriers while the others were scrapped before completion. The class of World War II was described officially as mere 'large cruisers', and their wartime service was brief, uneventful, and overshadowed by the much larger Iowa class 'fast battleships'. Independent of their role in science fiction, dreadnoughts have their own mythology. As recently as 1991, a book with the evocative title repeated the popular (pseudo-) contrarian argument that dreadnoughts were an inherently bad idea, impressive and expensive but with little actual fighting value.

The fact that there was only ever one grand clash of dreadnoughts - Jutland - and that it was not a classically decisive battle, is often implicitly offered as evidence of this proposition. In fact, battleships and battlecruisers mixed it up on multiple occasions in World War II, though in much smaller numbers than at Jutland. Running fights with one to three capital ships ships on a side was the usual pattern. This makes Fisher's original conception of the battlecruiser somewhat prescient. In the early 1900s he argued that the time for stately formal engagements was passing, and that future war at sea would be, in modern terms, 'kinetic' - reliant more on speed and shock than pure mass. The experience of the 1940s generally bore him out. And - again, quite apart from science fiction - battlecruisers have their own mythology, a myth that has undergone considerable evolution.

Three British battlecruisers exploded at Jutland, and went down with nearly their entire crews. These disasters were long attributed mainly to insufficient armor protection, and the whole battlecruiser concept was often denounced on this grounds. In recent times, however, much more of the. The British battlecruiser force put great emphasis on rapid fire of their main guns - which doctrine, like the ships' speed, was part of the emerging kinetic vision of war at sea. But the emphasis on rapid fire led gunners to ignore safety precautions such as properly closing anti-flash doors, so that when turrets were hit the resulting internal fires spread down to the magazines - with predictably catastrophic results.

The modern source linked above perhaps overstates the conspiratorial element in the traditional story about armor. I have 'always' known that flash protection was also lacking, so the shift is less a matter of new revelations and more a re-evaluation of what was already known. (Though perhaps it wasn't clear that flash doors were already in place, but not correctly used.) This is often how scholarship proceeds, a cycle not unlike the fashion cycle. Perhaps by the 2060s a re-re-evaluation will again say that battlecruisers blew up because they were eggshells armed with hammers. In the meanwhile, battlecruisers may well continue to rule the spaceways - as they deserve to. And readers of this blog may continue to suspect that laserstars, for all my disclaimers to the contrary, and details of armament and configuration, are still essentially Dreadnoughts in Space.

Play the, and decide for yourself. Let's talk about rocketpunk space warfare. Instead of jumping right into weapons and the primitive-tech version of purple/green, let's first enumerate the basic types of available spaceships, and then consider not how they would shoot at each other, but what underlying military missions they would perform.

I don't know how to fight you till I know what you intend to do. SHIP TYPES: Ramjet shuttles. Chemfuel, standard orbital shuttles. If refueled might reach geosynch, but not designed or suited for operation beyond LEO. Tail-lift shuttles.

Chemfuel, heavy freight shuttles. Mainly for orbit lift, but if suitably equipped and fully refueled in orbit (which takes a LOT of fuel), they can go to the Moon, land, and return, or go to Mars, land, and lift to Mars orbit. Expensive to operate, but possible military utility. Orbital ships. Chemfuel, used for movement in local orbital space. Generally small. Limited delta v.

Moon/Mars surface shuttles. Chemfuel, designed for surface-orbit operation on those planets, usable in orbital space but not suited to deep space missions. Deep-space ships, chemfuel. Available in all sizes. Many are streamlined for aerobraking at Earth and/or Mars.

Interplanetary ships differ from cislunar ships in having long-duration life support, making them somewhat more expensive. Specific impulse 320-450 seconds, suited to Hohmann orbits only. Acceleration up to several g.

Deep-space ships, nuclear-thermal. Available in larger sizes. May be streamlined for aerobraking, with retractable engine pylons.

Cislunar and interplanetary ships differ in life support as above. Specific impulse ~1000 seconds; normally use Hohmann orbits, but can use some faster ones in emergency. Acceleration around 0.1 g. Might carry chemfuel engines for a brief fast burn or two.

Deep-space ships, nuclear-electric. Available in larger sizes. Never streamlined; rely entirely on low-thrust engines with very high specific impulse, ~3000 seconds plus.

Still often use Hohmann orbits for fuel economy, but capable of faster orbits. Climb-out orbits are slow spirals, inefficient; combined with lack of aerobraking and heavy drive engines the delta v advantage of these ships is not as great as it looks. Acceleration around 1 milligee. Have ample onboard electric power, the only ships that do. MISSION TYPES: Orbital command. Complete control of a planet's orbital space.

No one leaves the surface, or at least the atmosphere, without risk of attack. Allows you to to do close-up recon, bomb the surface, or (if you have shuttles) land on the surface. Subject to attack only from deep space or by exoatmospheric fighters (Earth) or armed shuttle types (Moon/Mars).

You must have orbital command to safely perform routine space operations. Orbital interdiction. Denial of orbital command (possibly as a prelude to asserting it yourself). The target of successful orbital interdiction cannot safely carry out routine space operations. A condition of mutual interdiction might occur in which orbital space is a no man's land, and the planet may be subjected to sporadic bombing. Deep space interdiction.

'Space blockade,' exercised from very high orbit or even a nearby solar orbit. You are too far from the planet to directly attack the surface or ships in low orbit, or for them to attack you, but you can shift orbit to intercept ships departing for or arriving from deep space. Logistic requirement is demanding unless you have a nearby friendly base (e.g., the Moon, for interdiction of Earth). Deep space raid. Transient orbital interdiction — a drive-by attack executed at transfer-orbit speed, the attackers taking one passing shot before receding back into the Depths of Space. Requires less delta v than an orbital attack from deep space, but with no option to stick around even if you decisively defeat local forces.

Deep-space raiders can bomb surface targets, though aiming is difficult. Given rocketpunk sensor limitations, early warning may be limited. Deep space reconnaissance. A non-shooting drive-by in order to get a closer look at a planet's orbital space than you can get from interplanetary distances.

Flat-space warfare. This has the same basic mission types as above, but directed toward objectives with little or no local gravity gradient - bases, habitats, whatever, located at the L5 positions, or in the asteroid belt. (Ceres escape is 0.5 km/s.) Solar-orbit transfer velocities, however, are still multiple km/s, so the basic distinction remains between local operations and deep space drive-by operations. ORBITAL COMBAT: A basic tactical consequence of the above missions is that most combat is orbital.

If ships are in different orbits they have substantial crossing velocities — thus considerable kinetic punch — but must expend a lot of delta v to change or match orbits. Kinetics and debris do not usually hurtle off into the void, but remain in orbit, potentially dangerous as kinetic mines. (And the hazard is more or less permanent.) Orbits can be characterized by their velocities, and the constraints thus imposed on changing orbit.

I suggest as a handy measure ~40 percent of circular velocity [sqrt(2) - 1]: the amount of delta v needed to go from circular velocity to escape velocity, or to change circular-orbit inclination by about 23 degrees. Let's call this 'tactical velocity' — the delta v you need for a major tactical maneuver.

Some characteristic tactical velocities are: • LEO: 3.1 km/s • Mars low orbit: 1.5 km/s • Geosynch: 1.3 km/s • Lunar low orbit: 0.7 km/s • L5 orbit: 0.3 km/s • Ceres low orbit: 0.1 km/s A ship with a 50 percent combat fuel fraction (which is a lot!) has available combat delta v ranging from 2.2 to 3.1 km/s for chemfuel (multi-g), or about 6.9 km/s for nuke-thermal (~0.1 g). Nuclear-electric ships would have 21 km/s of combat delta v, but at ~1 milligee these ships have no tactical mobility to speak of; a 1 km/s burn takes a day or more. Sustained 'dogfighting' or AV:T style shoot-pivot-scoot engagements seems more or less ruled out in orbital combat, except perhaps in distant orbits, or orbiting the Moon. In most low orbits, or even Earth geosynch, an orbit change or two will use up most of your combat delta v, leaving very little for gyrating combat maneuvers. Only in nearly flat space are ships likely to drift toward fighting range at low enough relative speed for them to maneuver around each other.

Orbital combat thus looks like a matter of successive firing passes, usually an hour or more apart. I'm not sure that individual firing passes hold much tactical interest — in a game they might be, basically, a die roll and table lookup.

Manifold System 8.0.10 Ultimate Edition. The tactical interest is more likely in the overall orbital maneuvering involved, with the logical turn length perhaps being expressed in fractions of an orbit rather than a fixed time period. The low-orbit period around rocky planets is always about 1.5-2 hours, but geosynch is of course a day. Probably the most strategically important space in the rocketpunk-verse is LEO, but it is particularly difficult to fight in, with ship maneuvers highly constrained relative to the circular velocity of ~8 km/s. Kinetic impact speeds are likewise typically high, making kinetic hits more destructive. DEEP SPACE OPERATIONS: Given rocketpunk ship performance and likely weapon ranges, Earth-Moon space as a whole should be regarded as a deep space operational or even strategic theater, not a tactical theater.

Leaving LEO to attack the Moon or L5 (or vice versa) has much in common with an interplanetary expedition, except that delta v required is somewhat less, and travel times are days instead of months. Interplanetary operations are totally ruled by the solar gravity well. No torchship point-and-scoot orbits! Raiders and recon ships may take relatively fast drive-by orbits, but any force intending to spend time at its objective and then return home if necessary will have a demanding delta v requirement even using Hohmann orbits — especially if it must have combat delta v available when it reaches its objective. So, interplanetary warfare will in general follow the leisurely Hohmann timetable, with everything this implies about departure windows, threat windows, and logistics and duration of operations. WEAPONS: Kinetics.

Ship velocities and missile performance make conventional explosive warheads generally unnecessary except as bursting charges; kinetic hits will carry, typically, 1-10 ricks of impact energy. Effective range of kinetics is largely limited by problems of tracking and guidance. Most ships have limited electrical power, precluding electrically-fired lasers, though they can carry chemical lasers, with limits on ammo.

Nuke-electric ships, however, have up to hundreds of megawatts of available onboard power, so they can carry powerful lasers with unlimited zaps. (They might also carry coilguns, if these are useful.) Laser mirrors will be 5-meter absolute max (i.e., like Palomar), but 1-2 meters is much more likely, with 3-meter a very big gun.

No adaptive optics. Laser range is largely limited by problems of precision aiming and holding a spot on target. Like other missiles, effective range of nukes is limited by tracking and guidance, though of course nukes don't need to score a direct hit. Kill radius is fairly limited for physical damage, but very large against insufficiently shielded personnel.

The large fuel fractions (requiring large tanks, as well as limiting all other mass) make armor protection very hard to combine with significant mobility, tactical or strategic. Armor protection is thus very limited, except for the radiation storm cellar that all deep-space ships must carry. In general, rocketpunk space warfare is at once far more Realistic [TM] in most respects than torchship warfare, and perhaps quite difficult to either gameplay or carry out in real life. Which may be why the original rocketpunk classics had surprisingly few space battles! The necessary large size, low tactical maneuverability, and high delta-V of the nuke-electric craft seems to make them serve a role similar to deep space fortresses or aircraft carriers. They can carry unlimited zap lasers, which depending on the wavelength might give good 'reach out and touch-em' range, and can provide area defense of friendly forces by shooting down incoming missiles.

Likewise, they can afford to carry smaller 'fighter' craft - chemfuel craft with low endurance but high acceleration for tactical maneuverability. A nuke-electric fortress could park in a higher orbit and send in its fighters for orbital interdiction. The main issue here is the endurance of the fighters. Perhaps it carries a few 'patrol craft,' larger chemfuel craft with more life support and room for crew quarters that can be launched from the fortress's parking orbit into lower orbit. One tactic that may be used is for the patrol craft to expend all their delta-V in the fight, trusting that (if they win) the fortress can spiral in and pick them up later.

With this, and the use of aerobraking, the patrol craft could keep most of their delta-V for combat maneuvers. For orbital command, it eats up the long spiral time to dominate the lower orbits with its laser firepower and long endurance. The lasers also allow orbit to surface bombardment, weather permitting, without using ammo. One of these craft can also carry sufficient nukes (excuse me - atom bombs) for reducing an enemy's planetary assets from orbit. In this situation, its low acceleration makes it vulnerable, so it relies on fighters and lasers for defense. For deep space raids, interdiction, and reconnaissance, these would seem to be the craft of choice.

With a known target and lots of time to build up speed, this allows intercept and flyby courses with little use of resources. With the delta-V advantage always with the nuke-electric craft, it can pretty much dictate the closing conditions with any chemfuel or nuke-thermal craft in deep space. The only craft that could evade one of these fortresses in deep space would be another nuke-electric craft, if it knew the attack was coming.

For a single high speed pass, tactical maneuverability is not such an issue. Of course, it uses high acceleration chemfuel missiles to counter high acceleration evasive maneuvers of the target. It can also economically perform rendezvous maneuvers with chemfuel or nuke-thermal craft that it does not want to destroy, using lasers or fighters to disable the target if necessary. In fact, loitering on the edge of effective laser range is a good tactic, allowing the fortress to fire freely on the target without being in as much danger from kinetics (which will be closing at low speeds). If the other craft tries to use its superior acceleration to run, the fortress leisurely catches up to it again, and again, until the target is out of delta-V. This, of course, bleeds over to the realm of flat space warfare, with a fortress parked just in laser range and sending fighters for close-in high-G attacks. It would make sense for fortresses to operate in 'battle groups' of two or three, so they could cover each other with their lasers and deny the enemy the opportunity of presenting only the least vulnerable aspect.

It may work out to be more economical to separate the nuke-electrics into 'carriers' and 'laser fortresses,' one focusing on providing boost and transport for fighters, patrol craft, and missiles; the other focusing on high power, long range lasers. Or it may be best to combine the two roles into a single, more versatile craft. So, that's some thoughts from an armchair general.

Actual wargame scenarios could expose limits of this thinking. Now, just because I have to ask, what are the specs on the lasers? Are the chem lasers mid IR (~ 3 microns, likely DF) or near IR (~ 1 micron, possibly COIL)?

Are the electric lasers solid state devices, gas lasers (ick, far IR!), or are they 'optical klystrons' (FELs)? If solid state, what is the wavelength it lases? Is frequency doubling or tripling available?

I assume the lower wavelength limit for all lasers is given by the reflectivity of the mirrors, with nothing lower than around 0.2 microns. Do they use dielectric mirrors, or is aluminum (or silver, or gold, depending on wavelength) the only way to go? Personally, for a rocket-punky feel, I'd use COIL lasers (err, heat rays) for the chemical stuff, optical klystrons for the electrics, and only metal coatings on the mirrors.

Since optical klystrons are a development from radar technology, you could also use them for sensing, detection, and ranging ('optical radar.' Would that be vidar?

Or we could re-use lidar for a different acronym - LIght Detection And Ranging). One of the problems with figuring out how ships are going to fight in space (assuming that we have ships in space, which isn't as likely as I wish; and, that we’re still fighting when we get there, which is unfortunately more probable) is that there are a lot of maritime models to choose from. It’s also true that some of the maritime models came from very specialized sets of circumstances; and a few of them weren’t particularly good ideas even in their own time. And it’s also true that some of the writers applying the models have a better grasp of the essentials than others. That isn’t limited to writers of fiction. For example, I recall two essays which were originally published about fifty years ago in Astounding. In the first of the essays ('Space War', Astounding Science-Fiction, Aug 1939), Willy Ley, a very knowledgeable man who had been involved with the German rocket program, proved to my satisfaction that warships in space would carry guns, not missiles, because, over a certain small number of rounds, the weight of a gun and its ammunition was less than the weight of the same number of complete missiles.

The essay was illustrated with graphs of pressure curves, and was based on the actual performance of nineteenth-century British rocket artillery (“the rockets’ red glare” of Francis Scott Key). As I say, the essay was perfectly convincing until I read the by Malcolm Jameson ('Space War Tactics', Astounding Science-Fiction, Nov 1939). Jameson’s qualifications were relatively meager. Before throat cancer forced him to retire, he’d been a United States naval officer—but he was a mustang, risen from the ranks, rather than an officer with the benefit of an Annapolis education.

For that matter, Jameson had been a submariner rather than a surface-ship sailor during much of his career. That was a dangerous specialty—certainly as dangerous a career track as any in the peacetime navy—but it had limited obvious bearing on war in vacuum. Jameson’s advantage was common sense. He pointed out (very gently) that at interplanetary velocities, a target would move something on the order of three miles between the time a gun was fired and the time the projectile reached the end of the barrel. The rest of Jameson’s essay discussed tactics for missile-launching spaceships—which were possible, as the laws of physics proved gun-laying spaceships were not. Ley could have done that math just as easily.

It simply hadn’t occurred to him to ask the necessary questions. Light-swift beam weapons were a fictional staple in Jameson’s day (he used them in his stories about Bullard of the Space Patrol) and a realistic possibility in ours. And the advent of the electrically-driven railgun has brought even projectile artillery back into the realm of space warfare. Present realities don’t prevent a writer from building any number of self-consistent constructs of how space war will work, however.

At one time, and hand-to-hand combat were common notions in military science fiction (which, in the 1920s and 30s, was rather a lot of science fiction). Boarding has a long naval tradition as, at times, the heaviest available weapons were not by themselves sufficient to sink major warships. When oared warships grew sturdy enough to be equipped with rams, however, replaced boarding as the tactic of choice (This was featured in Isaac Asimov's ) Until sailing ships replaced oared warships.

Sailing ships can’t mount effective rams because their masts and rigging would come down with the shock. The guns available during the next five centuries weren’t effective ship-killers, and boarding returned. As guns became more powerful and ships were designed to mount large numbers of them along the sides, the sort of melees that characterized the Armada battles and the meeting engagements of the Anglo-Dutch Wars of the seventeenth century gave way to formal (This can be seen in the, where the handwaving propulsion systems force them to use 'wall-of-battle' tactics). Opposing fleets were expected to sail along in parallel lines, firing all their guns at one another, until something happened. Mostly, nothing much happened. A typical example is the action between the fleets of DeGrasse and Graves in 1781 in Chesapeake Bay.

This was the crucial battle that decided the fate of the British army at Yorktown—and, thus, the Revolutionary War. It was a draw, with no ships lost on either side (which tumed out to be good enough for the American rebels, of course). Nelson changed matters by what amounted to assertiveness training for the British navy. His captains were expected to close with the enemy and board if necessary, instead of staying at a reasonable range and letting noise and smoke stand in the place of doing real damage. Nelson’s opponents never beat him. In the end, they were able to kill him; but even dead he led his forces to victory. The appearance of steam and armored warships in the nineteenth century gave rise to an amazing number of theories and some of the most outlandish warships ever built.

What didn’t emerge were major battles between the new vessels. At Lissa in 1866, an Austrian fleet humiliated an Italian fleet of more modem and powerful ships, proving that competence and leadership had more to do with victory than equipment alone. (Nelson must have smiled from his grave.) Lissa proved little or nothing about the new hardware (theorists of the time thought otherwise; they were wrong).

But it was as good a test as the century provided. Ships generally mounted mixed armaments of large and mid-sized weapons.

Though there was a brief fad of equipping battleships with small numbers of very heavy guns. This was partly in the hope that a single huge shell could smash opposing armor (in the unlikely instance that such a shell hit its target); and partly because the planners wanted an easily quantifiable marker for their arms race. (The dangerous buffoons in the Pentagon and Kremlin with their “My throw weight is bigger than your throw weight” arguments had nineteenth century predecessors.) Incidentally. As soon as steam removed the necessity for masts and rigging, rams retumed as well. There were few successful examples of ramming in war. But in peacetime, rams sank almost as many friendly naval units as did.

The only real test of nineteenth century warships came in the twentieth century—1905—at the, where a Russian fleet that did nothing whatsoever right met a Japanese fleet that did nothing important wrong. The Russians were massacred. And it was heavy gunfire alone that did the butchers‘ work. An idiosyncratic genius named was running the British admiralty at the time. He came up with the first good idea in warship construction since put a turret and screw propeller on the: Cooper built the. The Dreadnought was big and fast and carried, with.

Every battleship built after the Dreadnought is more similar to her than the Dreadnought was similar to anything that came before her. Having had a brilliant idea.

Cooper went on to have a lethally bad one: the. The battle cruiser was a dreadnought (the name became generic for all-big-gun warships) which had lighter armor and more powerful engines than a battleship. And was therefore faster. The theory was that “speed is armor.” The reality was quite different, and thousands of sailors (mostly British) died in the two World Wars (the Hood was a battle cruiser) because a clever slogan can’t repeal the laws of physics.

The dreadnought brought back the concept of the line of battle. It didn’t work any better in the twentieth century than it had in the eighteenth, because both sides had to agree to play the game and the weaker side—the Germans, in this case—would inevitably lose. The German admirals of the World Wars were less than brilliant, but they weren’t stupid. Besides, the fleets of World War II were dominated by aircraft. The one major battleship-to-battleship fleet action of the war occurred at night in the.

It was a close copy of Tsu Shima, with the Japanese playing the part the Russians had forty years earlier. There is enough in actual maritime history to provide models for almost any form of space warfare a writer wants to postulate. Because there are so many possibilities, writers can find a solidly-grounded situation that suits their story, rather than forcing the story into a narrow matrix. And that, I think, makes for some very good stories. With each trailer for Star Wars: The Force Awakens, we’ve been exposed to the new Starfighter being fielded by the Rebel Alliance – now rebranded as the Resistance (go figure). The Incom T-70 is carrying the legacy of the X-Wing into a new generation, combating a likewise new model of the TIE Fighter. But each new trailer however has suggested something is lacking in the Resistance fleet – that is, a variety of other Starfighter types.

It would appear that, in the 30 years since the Rebel Alliance deployed an array of X-, Y-, A- and B-Wings to the Battle of Endor, they have settled on a single multi-role type across the entire fleet. With that assumption on board, it’s worthwhile considering what steps were taken over 30 years to go from a four-type Rebel Alliance fleet, to a single-type Resistance. It’s a journey to consolidation that draws some parallels to the United States Navy’s own carrier-based combat aircraft fleet. Both organisations were operating with different strategic priorities 30 years ago compared to what they are today. When Return of the Jedi hit cinemas in 1983, the Nimitz-class carriers were sailing with no less than four fixed-wing fighter/strike aircraft – the F-14 Tomcat for air superiority, the A-6 Intruder and A-7 Corsair in the strike role, and the S-3 Viking as an anti-submarine/surface warfare platform. Also operating was the EA-6B Prowler, a variation of the A-6, which was optimised for electronic attack. Likewise, the Rebel Alliance went into the Battle for Endor with its own four dedicated strike/fighter platforms, albeit with no electronic attack variant (it seemed the Empire had the upper hand in the electronic warfare spectrum that day) [Editor’s note: or that ].

Leading this charge were the T-65 X-Wing in the space superiority role, joined by fellow Yavin-veteran, the Y-Wing bomber. Also deployed were two newcomers – the high-speed A-Wing, and the B-Wing bomber, whose primary role was to attack capital ships. It’s a safe assumption that the role of a Carrier Air Wing is much like that of the Rebel Alliance’s Starfighter squadrons fighting ‘A Long Time Ago in a Galaxy Far, Far Away’.

Fundamentally, they both need to defend a home base, and are important tools for force projection in pursuit of wider campaign objectives. Fielding a variety of types that each have a dedicated role carries with it benefits. A security or technical grounding for one type will (nominally) not affect the others. Dedicated types are optimized for function, rather than compromising performance to be truly multi-role.

A Carrier Air Wing’s F-14 Tomcats can defend against high-speed bombers and provide a combat air patrol against MiGs and Sukhois. A-6 Intruders and A-7 Corsairs are optimized for striking surface combatants and hitting targets on land. The S-3 Viking – working in concert with other aircraft and vessels – can detect and defeat submarines.

For the most part, the Soviet Union spent much of the Cold War trying to defeat the force projection abilities of carriers, and at the same time protect its home shores. Whilst the Soviet Union was spending the time, resources and money on countering Carrier Battle Groups, it was not delivering comparable force projection capabilities of its own. While the Rebel Alliance faced a different strategic environment from the United States Navy, it too found itself benefiting from fielding a multi-type Starfighter fleet. It allowed them to pitch an asymmetric threat against the Empire, dictating the terms of engagements with dedicated platforms and avoid one-to-one engagements that it could not match with people, ships, or resources.

The B-Wing Starfighter was primarily for attacking capital ships. Notwithstanding its kamikaze attack on the Super Star Destroyer Executor, the A-Wing was a hit-and-run Starfighter built to raid Imperial convoys and destroy remote satellite relays, degrading logistical and communications networks, and crippling the Empire’s ability to wage its campaign. Throughout it all, the X-Wing was intended to defeat the TIE Fighter; while the Y-Wing, a relic of the Cold War Clone War, was kept in service probably because it was bloody impossible to get rid of. Striking from hidden fortresses and deployed capital ships, the Rebel Alliance’s force projection with these Starfighters would have forced the Empire to build defenses capable of defeating all forms of attack. Imperial Commanders were therefore kept guessing as to the composition of Rebel threats, and how they could attack them. Having so many different types of Starfighters and aircraft however places a significant logistical burden, whether you’re a Rebel capital ship or United States Navy aircraft carrier.

Each time a Carrier Strike Group goes to sea, it attempts to bring sufficient spares and workforce for the term of its voyage, but is otherwise reliant on C-2 Greyhound carrier on-board delivery aircraft; or port visits, which themselves are connected to a logistical pipeline supported by shore-based aircraft. Every different aircraft type in the Carrier Air Wing needs its own specially-trained workforce to operate and support, and must retain a spare parts stock for repairs. Different aircraft have different maintenance overheads, depending on their age and performance, which ultimately affects sortie generation. All of these factors determine the overall effectiveness of a Carrier Strike Wing whilst it’s at sea.

When Starfighters are embarked on a Capital Ships, we can assume their supporting constraints are almost identical to their United States Navy counterparts. There’s only so much space on the ship for hangars, spare parts storage, and workforce accommodation. Terrestrial bases for Rebel Alliance Starfighters would provide greater room, but still present similar logistical challenges in how they are sustained with spare parts and key equipment.

The one advantages the Rebel Alliance has are astromechs. An R2 or R5 unit, for example, can maintain and conduct repairs on a Starfighter without sleep, and can work across multiple types on the hangar floor without limitations. They can diagnose directly using a ship’s computer, provide accurate stocktake assessments, and receive updated technical publications instantly.

Admittedly, they do need their own spares pipeline and sustainment maintenance – but the efficiencies they deliver are worth it. The United States Navy does have the advantage of protected warehouses and factories for all its supply needs.

The Rebel Alliance likely has to disperse its equivalent facilities across the galaxy, keeping them underground to avoid the prying eyes of the Empire. Despite the range advantages of hyperspace travel, resupplying ships and bases with spare parts and personnel is a dangerous affair.

Let’s take X-Wing powerplants as an example. Building them requires de-centralised workshops to avoid detection, but also skilled workforces due to the precision construction. Once built, these components are likely kept in hidden warehouse storage until they are smuggled through the galaxy to their end user. Replicating this logistics effort across all the systems of an X-Wing gives a good impression of how hard it is to keep a Starfighter ‘spaceworthy’, especially considering how complex they are compared to their Imperial foes, which lack shields and hyperdrives.

We can assume there is little-to-no commonality in major components across Rebel Starfighters (even the Empire consolidated its TIE eye-ball across the Fighter and Interceptor variants). All of this puts Rebel Alliance at a significant logistical disadvantage during the Galactic Civil War. Which brings me to a cynical explanation for why else the Rebellion had so many different Starfighters – in all likelihood, there was more gerrymandering required from the Rebellion than the Empire, when negotiating the support of planetary systems. How many times did Mon Mothma win the support of a local star system, but only because she promised to employ local workshops and factories to build X-Wing laser canons? Or gain safe harbor in space ports for Rebel vessels, but only because she was buying squadrons of unwanted Y-Wings from the port’s governor? Tyrannical governments like the Empire are built on decrees and corruption, leaving little question that the Rebellion had to resort to financial and employment incentives to guarantee support for its cause. Over the past 30 years, there’s been significant changes to the strategic operating environment for both the United States Navy and the Rebel Alliance (now the Resistance).

These changes undoubtedly influenced their respective moves towards a consolidated fleet of strike/fighter platforms. While aircraft carriers remain an important strategic tool, the years since the end of the Cold War have largely seen their warfighting efforts concentrated on sustained force projection for overland operations in the Middle East and former Yugoslavia. The dedicated platforms operated in 1983 were retired, their roles taken on by a shrinking variety of aircraft types (or, in the case of anti-submarine warfare, shifted to shore-based and rotary-wing aircraft). Today, most Carrier Air Wings limit their fighter/strike capability to the F/A-18 Classic Hornet and Super Hornet, and the E/A-18G Growler. Carrier Air Wing Five, based in Japan, has done away with the Classic Hornet altogether, and operates the Super Hornet and the Growler from the USS Ronald Reagan.

That consolidation was not a pre-ordained path, with failed programs (the A-12 Avenger, F-14 life extensions), receding budgets, and an operating environment that emphasized reliability and multi-role performance. The move to consolidation has robbed the United States Navy of, say, an F-14’s high-speed and long-range intercept talents.

The upshot is that replacement types (in the form of the Super Hornet) are largely more reliable and efficient, and fewer types has allowed a more streamlined training and logistics pipeline. In an ideal world, this reduces operating costs and improves sortie generation rates with the same number of aircraft and personnel. The experience of the United States Navy with the Super Hornet is therefore a good clue to how the Resistance came to operate the T-70 X-Wing as its sole type (if I can indulge my imagination, I’d like to think older T-65s are still in limited frontline service as well as operated by Reserve units). Much like the Super Hornet, the T-70 is based on a widely-used predecessor, and likely performs the roles of other types that have been since retired. Anti-capital ship functions, like anti-submarine warfare, have been transferred to the Resistance’s own capital ship fleet.

While the Resistance cannot provide a dedicated type for specific roles, it can compensate through improved sortie generation rates thanks to a streamlined logistics pipeline and training model. These two factors are important when you’re fighting a sustained, 30-year conflict, as the case is suggested with The Force Awakens. All evidence in the trailers suggest that the Galactic Civil War is still happening. The Resistance is now facing off against the First Order, an Imperial remnant which is a shadow of what we saw 30 years ago. The loss of a pair of trillion-credit Death Stars, coupled with the assassination of its senior leadership, is hard to come back from. Faced with a degraded enemy, the Resistance had the freedom to reassess how it sustained its warfighting capability, and felt it was able to pair back the number of different Starfighter variants it operated. As these ships came to the end of their life-of-type, they were progressively replaced by squadrons of T-70 X-Wings.

This in turn realized significant savings that could be reinvested in a larger fleet of Starfighters, and allowed them to face the First Order on more even terms (rather than conducting a ‘counter-insurgency campaign with Starfighters’). I’d love to speculate other reasons for how the Resistance came to operate a single Starfighter type. Were there Tomcat-style Service Live Extension Programs for the B-Wings? Was a wildly ambitious replacement for the Y-Wing proposed, only to be cancelled and lead to a decades-long lawsuit?

These are the Marvel Star Wars comics that I want to read. Now, I accept the United States Navy’s wider operating environment is different in many respects from the Rebel Alliance/the Resistance. It has the wider United States Air Force, Marine Corps, and Army to jointly operate with. And the United States Navy hasn’t entirely reverted to a single combat type, either. The Northrop Grumman X-47B is plotting the Navy’s path to an Unmanned Carrier-launched Airborne Surveillance and Strike’ platform.

And very soon, the F-35C Lightning II will enter service with frontline units as a replacement for the remaining F/A-18 Classic Hornets. In keeping with the other F-35 variants, the C-model emphasizes a combination of sensor-fusion, stealth, and networked connectivity, and is intended to perform multi-role missions. The F-35C however might still have a kin-type in the Star Wars Universe. Unless JJ Abrams takes us to the planet where the Resistance has its Pax River-equivalent facility, it’s unlikely we’ll see a brand new Starfighter in The Force Awakens. But I can predict when we will see it – in 2017, with the release of Star Wars: Episode VIII.

There’s a couple of reasons to speculate this case. Without having seen The Force Awakens yet, we can expect to see a major shakeup of the power balance in the Galactic Civil War after a sustained 30-year conflict (which will take at least two more films to resolve).

The T-70 will have to soldier on, but I predict the Resistance will come into Episodes VIII and IX with a brand new Starfighter type to face this re-surging conflict. The other reason to be confident of a new Resistance type (let’s call it the T-XX) in 2017 comes down, once again, to merchandising.Disney can only sell so many models before they have to come up with something new. This year, there’s going to be a lot of T-70s underneath Christmas Trees, making it unlikely that kids will want a repackaging of ‘old’ T-70s when Episode VIII comes around. The new Resistance T-XX, much like the F-35C, is going to have big shoes to fill, and both types will affect how the Resistance and United States Navy emerge from their respective consolidated combat aircraft structure.

There’s no guarantees for what conflicts the F-35C might be called upon in the future, and as for what pressures will drive the design of the T-XX? We wont know the answer to that question until December 18. The Last Jedi promises something not seen before – a Star Wars equivalent of a strategic heavy bomber. To date, the Star Wars Universe has provided a science fiction examples to many real-life military roles (with varying degrees of artistic licence). Imperial Star Destroyers have largely stood in for the Navy, whilst the Army and Marines forces have been shown on all sides of the Galactic Civil War with armoured units, littoral forces, and even mounted elements.

The Air Force can take its pick – X-Wing fighters, Shuttle pilots, and even an Air & Space Operations Centre on Yavin. There’s one American air power staple however that’s been surprisingly missing from the eight live-action Star Wars films run (not including the two Ewok ventures) – a hulking, vulnerable, heavy-with-ordnance strategic bomber. The Last Jedi will change this in December. Both trailers for the film have shown the ‘Resistance Bomber’, a ship which appears significantly larger than your 12.48-metre-long T-70 X-Wing; but probably a touch smaller than the 126-metre-long Corellian Corvette.

That size means it doesn’t just carry a lot of bombs; it can carry all of the bombs. If the X-Wing is an F-15 or F-16 with a dozen or less hardpoints, then a Resistance Bomber is our B-52 with the capacity to carry every bomb that you own. The Resistance Bomber isn’t just unique in the Star Wars cinematic pantheon – it stands out within the 40-years of storytelling canon. Whilst real strategic bombers have (not to mention memoirs and other mediums), the Star Wars Universe doesn’t have a ship which matches something like a B-17, B-29, B-36 or B-52. That goes for the, covering computer games, novels, comics, and roleplaying guide books.

We’ve seen hundreds of different models of starfighters, but anything much larger is typically a freighter or capital ship. In the Star Wars canon, bombers have traditionally been more-or-less the same size as their starfighter escorts, and when they grew larger, they were seldom much bigger than the Millennium Falcon. We only have modest information about the Resistance Bomber, but it’s not unreasonable to suggest it is derived from Second World War heavy bombers. It carries a crew of at least one pilot and one bombardier, and likely several gunners to operate laser turrets around the ship., a naming convention which means it’s probably a distant relative of the that appeared in Return of the Jedi. The B-Wing’s background was a poor dogfighter, but equipped with a heavy weapons load intended to take down larger capital ships.

The Resistance Bomber follows this tradition, according to: Now reinforced with new combat craft, the Resistance fleet dispatches hardy bombers into battle with the First Order fleet. Escorted by swift starfighters, these munitions-laden carrier ships drop powerful proto bombers onto their Star Destroyer targets. Will use as a ‘touchstone’ for its combat scenes, and the B/SF-17 name is a nice callback to the B-17 Flying Fortresses that featured in the 1949 film. We wont know much more until The Last Jedi appears in cinemas in mid-December, coinciding with the release of the book, which is expected to explore the backstory of Resistance Bomber crews in the movie. Accompanying this will be a source book, which promises detailed schematics and liftouts the likes of which would make an Artoo unit spin its dome.

The ‘Bomber Command’ title makes for as good a segue as any to discuss what place bombers – and munitions – have in the Star Wars films. There’s two good reasons for why the Star Wars films have gone out of their way to not include any strategic bomber analogue until now – one to do with story-telling, the other to do with the real world. A good illustration of this appears in A New Hope, whose Death Star Battle is of, itself based on the May 1943 raid by Royal Air Force Avro Lancasters on the Ruhr Valley dams in Germany.

As with the X-wing’s run in the Death Star Trench, the Dam Busters had to skim along the surface to drop a ‘bouncing bomb’ with pinpoint precision to guarantee destruction of the target. A big difference difference lies is in the delivery platform. In The Dam Busters, the weapon is delivered by a Lancaster flown by a six-man crew.

In Star Wars, it’s just Luke and a busted-arse R2-D2 running along in their lone X-Wing. The story-telling reason for why we’ve seen no heavy bomber is simple – small ships in Star Wars can take the story where it needs to go. A strategic bomber requires multiple crew to operate, and the plot has characters engaging with one another on multi-crew ships like the Millennium Falcon. When it comes time to attack a Death Star, crews fly one or two-person ships because the ‘hero’s journey’ of the Star Wars plot can more easily narrow its focus on the individual. This leaves other characters to be killed off in a dramatic and explode-y fashion.

What’s more, nothing sells the ‘David and Goliath’ stakes between the Rebellion and the Empire better than a handful of starfighters firing their guided munitions at a colossal deus ex machina, all backed by a spectacular John Williams score. The real-world explanation for why we’ve yet to see a heavy bomber is the same as the story-telling reason – small ships in Star Wars can take the guided munitions where they need to go. In real life, strategic bombers have a flying range that smaller aircraft lack, by virtue of their need to carry massive bombloads (or even nuclear weapons) over oceans and continents. X-Wings on the other hand have strategic reach throughout the galaxy through the use of hyperspace, and can achieve destruction on a strategically significant scale with a limited bombload because the bad guys keep building a deus ex machina that’s vulnerable to precision attack (and, you know, the Force). Even the Empire, who you might expect to engage in a spot of terror bombing of their own, doesn’t need such a platform.

Star Destroyers carry out orbital bombardment from space, delivering destruction akin to mass area bombing raids. TIE Bombers meanwhile deliver precision bombloads where bigger ships can’t reach. If the Star Wars universe has gone 40 years with its own version of a ‘bomber gap’, why might we be seeing one in The Last Jedi? Again, there’s two likely reasons – one for story-telling, one for strategy.

Firstly, the story-telling – with so many other war films having covered strategic bombers on screen, it makes sense that Star Wars would finally adapt it for a Galaxy Far, Far Away. Starfighter combat will always feature in Star Wars films, but there’s only so many times we can see that same David and Goliath narrative play out. Bombers allow for multiple characters to crew the same ship and be forced to work together, with the dramatic tension further raised by their ship’s lack of speed or manoeuvrability as it bears down on the target. The trailers for The Last Jedi make it pretty clear that a number of Resistance Bombers are destroyed before reaching their First Order targets.

Secondly, there might be a strategy reason for why we’re seeing a Resistance Bomber. In Rogue One, a formation of Y-Wing light bombers brought down a Star Destroyer with some assistance from much larger vessels. It stands to reason that a formation of heavy bombers carrying racks and racks of guided munitions might be a valid threat to a Star Destroyer – so long as a bomber gets through. After the events of The Force Awakens, the Resistance conceivably embarked on a massive rearmament program (resourced by what was left of the New Republic), and formed squadrons of B/SF-17 Bombers to provide an immediate anti-shipping capability.

That’s a bold move to construct ship of such singular purpose – the Star Wars films reward ships that have multi-role applications throughout the saga. Whether or not the B/SF-17 will join those esteemed ranks will be seen in December 2017. • Ship classes and types from the 'Stardate: 3000' line of metal starship miniatures. This starts off with one section on the quick-n-dirty technique of cribbing one's warship types from historical naval units, then follows with a series of sections that actually study the problem and try to identify what sort of spacecraft warship types will actually exist. Several analysis note that many science fiction authors have fixated on the terminology used at the time of. Then about 1977 the first Star Wars movie dragged terminology into World War 2 as the X-wings and T.I.E. Fighters fixated the authors on aircraft carriers.

Please note the difference between a ship type and a ship class. Ships with the same type have a similarity of intended use.

Ships with the same class have a similar design. For instance, the 's ship type is nuclear aircraft carrier but it is a vessel. The Starship NCC-1701's ship type is but is is a starship. The point is that in the US Navy many ships that are all of type 'nuclear aircraft carrier' may look nothing like each other, but all of them are nuclear and can carry aircraft. But all Nimitz class vessels look almost identical. For instance, the Nimitz Class nuclear aircraft carrier is practically identical to the Nimitz Class nuclear aircraft carrier. But neither look like the Gerald R.

Ford class nuclear aircraft carrier. The minivan 'Ralph's Car' is practically identical to the Toyota Previa Class minivan 'Clarisse's Car'.

But neither look like the minivan 'Floyd's Car.' Naturally ships of the same class must be of the same type. Playing counters from by GDW, 1979. CC: Command Ship BB: Battleship BC: Battlecruiser CA: Cruiser DD: Destroyer FT: Fighting Transport TR: Transport OF: Orbital Fighter RF: Robot Fighter Numbers are Attack-Defense-Movement The easiest way for a science fiction author to create the names for the various types of spacecraft warships in their novel is to copy them from World War 1 naval vessels. The 'quick' advantage is that you will have your list of types as fast as you can copy them from Google or Wikipedia. The 'dirty' disadvantage is that many of those ship types. If this bothers you, see the sections below.

Analogies can be drawn from history, though you have to be careful. Sometimes not all the constraints are the same. For instance, examining the Naval history from World War I to World War II and reasoning by analogy into interplanetary combat, one might come to the conclusion that space war will lead to the development of a one-man fighter.

But there are that will probably prevent his. Having said that, examining Naval history might be illuminating. Form follows function and some of the functionality of a wet navy might be general enough to still be true in interplanetary space. There are two broad catagories of ships in a fleet: Battle Fleet and Independent Units.

Battle Fleet ships are always found in large groups (Task Forces), while Independent Unit ships generally operate on their own, apart from any fleet (in task forces whose size is one). There are two broad catagories of ships in Battle Fleet: Main Units and. The main units fight.

The auxiliary units assist the main units by supplying them with ammo or fuel, repairing them, giving medical attention to wounded sailors, etc. If the ship has weapons, it is a warship (self-defense weapons do not count). All Main Units are warships, no Auxiliary Units are warships, Independent Units can be either. Battle Fleet Main Units include,,,,, Escort Cruisers,,,,,,,, and Aircraft. 'Dreadnoughts' were never an official type of unit but is included here as a tribute to E.E.

'Doc' Smith, who spelled it 'Dreadnaught' Battle Fleet Auxiliary Units include,,,, Fuel Ships ( and Tankers), Supply (Logistics) Ships, Transports,,, Colliers (missile supply ships), and Ammo ships. Don't sneer at the auxiliary units. An army marches on its stomach, and a rocket ship jets with its propellant tank. The old bromide is that amateurs study military tactics but professionals study.

Independent units include Cruisers, Submarines,,, Minelayers,, Yachts, Aircraft, and assorted auxiliaries. For a list of mondern day real-world naval warships, refer to.

When translating wet navy concepts to deep space, 'continents' or the 'mainland' are Planets, 'coastal' is Planetary Orbit, 'islands' are Asteroids, and 'the high seas' are Deep Space. Instead of a 'coast guard' you would have an Orbit Guard. There was an old class of coastal defense ships called 'Monitors', these would be Orbital Fortresses.

Of course ever since the writers of classic Star Trek took the movie and re-wrote it into, everybody knows that Submarines = Ships with a. The advantage of submarines is that they are very good at hiding, and can attack while hid. In interplanetary terms, this would require a science fictional level of stealth, since by the laws of physics as currently understood interplanetary stealth is (see the entry 'CLOAKING DEVICE' in ). For a good treatment of this theme, read PASSAGE AT ARMS by Glen Cook. Early non-nuclear submarines needed sub tenders for logistical support. Nuclear submarines do not need them. Sub minelayers can lay mines without the large escorts that a surface minelayer requires.

Before the 1860s, the Battleship was the queen of the ocean. It had titanic guns capable of blowing enemy ships out of the water, and armor thick enough to bounce off enemy shells. Granted it had all the speed and turning radius of a pregnant hippo, but that didn't matter. Until some clown invented the Torpedo Boat. These little gnats could run rings around the battleships, were too agile to be targeted by the battleship's guns, and had torpedoes quite capable of sending the battleship to Davy Jone's Locker. Especially since the torpedo boats would attack in packs of twenty or more.

The battleship was much too ponderous to avoid the swarm of torpedoes the pack would launch. So the Destroyer was invented.

This name was actually short for 'Torpedo-boat Destroyer.' This was a speedy, agile warship with quick guns designed to chew up torpedo boats.

Of course this ability came at a price. The destroyer speed came at the cost of no armor, and the quick guns meant they are too light to damage anything heavier than a torpedo boat. The upshot of this is that destroyers are pathetically vulnerable to enemy battleships. So destroyers and battleships have to support each other. Destroyers protect their sister battleships from enemy torpedo boats, and battleships protect their sister destroyers from enemy battleships. What happens if you design a warship that is with regards to armor, guns, and speed?

You get a Cruiser. Since cruisers are not specialized, they are viable enough to operate independently. They can be detached from a fleet as a task force of one for missions such as convoy raiding, deep scouting, and related missions. Generally a cruiser can outrun anything it cannot outfight. Heavy cruisers have large endurance for long distance scouting. Medium cruisers are often used as raiders, on convoys and other soft targets.

Light cruisers generally operate with a fleet, scouting and repelling attack by enemy cruisers and destroyers. And as an aside, it really annoys the out of me (and agrees) when so many science fiction authors mistakenly use the term 'Destroyer' for the largest class of warship. As you can see above, 'Destroyers' are the weakest types of warship, short of a torpedo boat. This mistake happens in the otherwise excellent TV show Babylon 5, the otherwise excellent novel MY ENEMY MY ALLY by Diane Duane, and the, er, ah, Star Wars movies. Cambias is of the opinion that this is due to the perception that the word 'battleship' is old and corny and the term 'destroyer' sounds really awesome. Long ago we (Larry Niven and Jerry Pournelle) acquired a commercial model called “,” a plastic spaceship of intriguing design.

It is shaped something like a flattened pint whiskey bottle with a long neck. The “ Leif Ericson,” alas, was killed by general lack of interest in spacecraft by model buyers; a ghost of it is still marketed in hideous glow-in-the-dark color as some kind of flying saucer.

It’s often easier to take a detailed construct and work within its limits than it is to have too much flexibility. For fun we tried to make the Leif Ericson work as a model for an Empire naval vessel. The exercise proved instructive. First, the model is of a big ship, and is of the wrong shape ever to be carried aboard another vessel. Second, it had fins, only useful for atmosphere flight: what purpose would be served in having atmosphere capabilities on a large ship? This dictated the class of ship: it must be a cruiser or battlecruiser.

Battleships and dreadnaughts wouldn’t ever land, and would be cylindrical or spherical to reduce surface area. Our ship was too large to be a destroyer (an expendable ship almost never employed on missions except as part of a flotilla). Cruisers and battlecruisers can be sent on independent missions. MacArthur, a General Class Battlecruiser, began to emerge. She can enter atmosphere, but rarely does so, except when long independent assignments force her to seek fuel on her own.

She can do this in either of two ways: go to a supply source, or fly into the hydrogen-rich atmosphere of a gas giant and scoop. There were scoops on the model, as it happens. She has a large pair of doors in her hull, and a spacious compartment inside: obviously a hangar deck for carrying auxiliary craft. Hangar deck is also the only large compartment in her, and therefore would be the normal place of assembly for the crew when she isn’t under battle conditions. The tower on the model looked useless, and was almost ignored, until it occurred to us that on long missions not under acceleration it would be useful to have a high-gravity area.

The ship is a bit thin to have much gravity in the “neck” without spinning her far more rapidly than you’d like; but with the tower, the forward area gets normal gravity without excessive spin rates. And on, and so forth. In the novel, Lenin was designed from scratch; and of course we did have to make some modifications in Leif Ericson before she could become INSS MacArthur (from novel The Mote in God's Eye); but it’s surprising just how much detail you can work up through having to live with the limits of a model. Ed note: so please follow my line of reasoning here. The Galactic Cruiser was originally a plastic model that came out in 1968. Larry Niven and Jerry Pournelle got a Leif Ericson plastic model. They examined it and tried to design a spacecraft based on it, the INSS MacArthur.

The MacArthur was streamlined and had scoops. This meant it was a Cruiser class, capable of independent operations. If need be, it could harvest hydrogen fuel by scooping the atmosphere of a nearby gas giant. This is what NASA calls. In 1974 Niven and Pournelle wrote the science fiction classic. It featured the INSS MacArthur. Marc Miller read The Mote in God's Eye.

He thought the fuel scooping ability of the MacArthur was a good idea. So when he wrote the in 1977, he put that into the game under the term 'wilderness refueling.' So what I am telling all you fans of the Traveller RPG is the reason there is wilderness refueling in Traveller is because of the plastic model Leif Ericson! One of the problems with figuring out how ships are going to fight in space (assuming that we have ships in space, which isn't as likely as I wish; and, that we're still fighting when we get there, which is unfortunately more probable) is that there are a lot of maritime models to choose from. It's also true that some of the maritime models came from very specialized sets of circumstances; and a few of them weren't particularly good ideas even in their own time. And it's also true that some of the writers applying the models have a better grasp of the essentials than others.

As you have probably noticed, the ships placed at our disposal correspond reasonably well to the means utilized in armies on Earth. Fast and lightly armed are our, the are our (light cavalry) and (medium cavalry). The (heavy) (Cuirassier) is replaced by heavily armored vessels, not as fast as the others.

As for the artillery, it has been replaced by missile launchers. Finally, the light with short-ranged laser-disintegrators can be compared to the infantry. It was by making use of such equivalences that I planned the battle of Usk.

CORVETTES We were interested to see that a number of “corvette” – i.e. Sub-frigate – classes of warship have emerged since our last edition, especially since the role of the frigate is already extremely limited, due to the limitations of its available mass and volume on its capacities, to wolf-pack deployments for light anti-piracy control, scouting, minor system pickets, and civilian system-security functions. On examining the three primary examples of corvette-class vessels seen in use, the Vanknir-class from Nal Kalak State Arms (we admire, incidentally, the gall of the Orsten System Navy in officially designating essentially unmodified Vanknirs as “system defense frigates”), the Auberwuth-class from Eilish Star Armories, and the General Svanek-class from the Empire’s own Islien Yards/Artifice Armaments, several key differences from frigate-class vessels, and ones which render them even more impractical as ships of war, are apparent. Specifically, the defining characteristics of these sub-frigate ships are a particularly light armament (one barely sufficient for civilian system-security functions, if that), a greater emphasis on armor and shielding (although the kinetic barriers and hull armor mounted by any corvette-class vessel would be inadequate against even lightly armed warships firing for effect), and an emphasis on technological simplicity, focusing upon ease of field repair in the absence of equivalent-technology infrastructure, often by the replacement of modular components. This is to say that the corvette appears to be designed for ease of maintenance in the low-technology field first, survivability – such as is possible at this scale – second, and warfighting ability third. In the light of these unusual features, and of its emergence after the case of, the true purpose of the corvette becomes clear. They are a political ship class, not a military one.

In other words, they are not intended to put up a practical system defense; rather, they are intended to permit a single-system polity which does not wish to bear the expense of a viable star nation’s naval establishment to claim system sovereignty – by virtue of policing their own space – using a few corvettes at a fraction of the expense of actual warships. Certainly, in the event of any serious territorial incursion, these ships could do little more than fire off a few warning shots for the honor of the flag and surrender immediately thereafter, but this may be sufficient to establish their intent to assert system sovereignty in the eyes of the legal authorities. (The name of the Islien Yards/Artifice Armaments General Svanek-class may also suggest the correctness of this analysis, the historical General Svanek Arctorran being known primarily for presiding over two surrenders in the War of Banners without any decisive battle preceding.) We await the first legal decisions on this point with considerable interest. - Naval Starships of the Associated Worlds, INI Press, Palaxias, 421 st ed. Alistair Young commented later: My rule of thumb on that is that they're sufficient to do that for values of lightly-armed equal to 'a merchant hull with some improvised weapons strapped onto it', mostly because that's helpless against anything capable of firing back, including the better class of reaction drive.

Pirates lightly-armed in typical military terms — using, say, a naval auxiliary frigate of one dubious provenance or another, on the other hand, will slice and butter a corvette unless it brought some friends to the party. And even then, not all of 'em will go home.. • Definition of the regions of the plot. Shows the ship design priorities of weapons, defense, and propulsion.

Fuller explanation. This is the results of my playing around with allocating WWII ship types on a using. Refer to the to learn how to read the graph. Briefly the graph displays what percentage of the total mass of each ship type is devoted to propulsion, weapons, and defenses. Be warned that the above classifications are totally my own invention, and are a gross simplification. Any actual Naval scholar will severely hurt themselves laughing upon viewing this. You are encouraged to make your own grid, incorporating the technological assumptions and limitations of your own SF universe.

Since making the above chart, it occurs to me that a ship ship with 50% weapons and 50% propulsion (currently marked as 'missile') is a good description of an. 'Long-range' interceptors are larger, have more endurance, but lower speed. 'Short-range' interceptors have shorter range but a much quicker response time.

The area marked 'courier' can also be 'fast scoutships', faster than the other scouts because they are totally unarmed. The entry I have as 'rocket motor' also applies to 'detachable drive' (see under 'Other Ships'). Ships with more than 75% weapons are likely, that is: less a ship with guns than it is a gun with a ship built around it. Anything with a defense of 10% or so along with a weapons of 70% or greater would be a '. If it has a defense of 0% and a weapon of 70% or greater then it is a '.

In reality, when mapping existing wet-navy ships onto the graph, there will be some holes. There are certain types of ship that are theoretically possible to build, but in reality would have no well-defined function. For instance, I used the term 'packet' to mean an armed transport (because that is how the term was used in the old Triplanetary board game). They are in the dark orange and neon green sections. In the modern wet navy, there ain't no such class of ship.

CDR Beausabre says the only use he can think of for such a ship in a science-fictional setting would be some kind of raiding ship, i.e., some sort of vessel designed for planetary raiding as an independent mission - strong enough to punch through planetary defenses, land and hold a perimeter to awhile, and then escape. Which sounds like the Nemesis from the H.

Beam Piper classic SPACE VIKING. Marko Karonen points out that packets did exist, but you have to go back to the Age of Sail to find them. They only had cargo space enough for VIPs and mail, which was of critical importance before the invention of telegraphs and wireless radio. This would make sense in a science fiction universe which lacked faster-than-light radio. Age-of-Sail packets had some weapons to defend themselves against small enemy cruisers, and to make them too costly targets for pirates. Actually, that is the main reason to make a chart like this, to find the.

When invented the periodic table of the elements, there were interesting holes in it. Mendeleev made the bold statement that these holes represented elements that had not been discovered yet, and predicted their approximate properties by analogy with the surrounding elements. He was vindicated when a couple new elements were discovered, and matched the predictions. So when you make your own ship chart, you may find holes. Examining the type of ship that would fill the hole will have you think either: [a] 'What a worthless class of ship.' Or [b] 'Wait a minute! That sort of ship could be useful.'

And some of the worthless holes might spark an idea later, say a specialized ship for a specialized mission, like the Brittania from Doc Smith's GALACTIC PATROL. Note that the graph only classifies the ships by their relative proportion of the three components. It cannot distinguish between a mini-pocket battleship with six units of weapons, three units of armor, and one unit of propulsion and a cyclopean blot-out-the-sun battleship worthy of Darth Vader with 60,000 units of weapons, 30,000 units of armor, and 10,000 units of propulsion. Both will appear on the same spot on the graph. The light blue 'A' section is labeled 'torpedo boat' but some types of destroyers will fit in the same section.

The difference is in the mass of the two ship types, which the graph doesn't handle. It is better than nothing, but use it at your own risk. So, in today’s piece of worldbuilding, have an analysis and explication of the different classes – or the different types, rather – of military starships operated by the Imperial Navy.

(The basis for the ternary plot I’m using is, of course,, so you might want to go read that first if you’re not familiar with the concept, then come back here.) Types The chart. Illustrates the differences between the various types and classes of warship in common use by the Imperial Navy by their P/D/W ratio – i.e., the relative trade-off between propulsion, defenses, and weapons (i.e.

Offensive armament): “in common use” should be read as “not counting all the weird-ass specialist ships we build for special cases”; also, it doesn’t include auxiliary vessels (oilers, hospital ships, etc.) since they’re not operated by the IN, but by the Stratarchy of Military Support and Logistics. Battleships, Dreadnoughts and Superdreadnoughts “I am an Imperial Mandate-class dreadnought, and you are within a million miles of me. Ergo, you continue to exist solely on my sufferance.” - an early experiment in AI captaincy Battleships, dreadnoughts, and superdreadnoughts (B, D, S on the chart) are capital or supercapital ships mounting heavy long-range firepower as their primary function. These types, the ships of the wall, are the kings of the outer engagement envelope, engaging each other with powerful weaponry at ranges of up to two light-minutes, and rarely closing beyond one to two light-seconds range (a zero/zero intercept at this residual range is considered a “set-piece” battle). They are the purest of all naval vessels in function, existing simply to counteract each other in the battlespace of major fleet actions, or to own the volume of space they can dominate if not opposed; the ultimate argument of star navies. The principal difference between two of the three types is simply mass and volume; doctrinally, the majority of the ships of the wall of any given time should be of battleship classes, with their larger cousins the dreadnoughts providing heavier stiffening formations to the wall and occasional nasty surprises. Because while it sure would be nice to build nothing except dreadnoughts, even nearly-post-scarcity economics doesn’t stretch to overbuilding everything just in case.

Superdreadnoughts, while sometimes referring to particularly large dreadnought classes, more typically refer to ships falling in the dreadnought type by mass, while using much of their internal volume for specialized systems: typical examples would include the command superdreadnought, the information-warfare superdreadnought, the anti-RKV superdreadnought, and so forth. Mauler Superdreadnoughts One example of this listed separately (L on the chart) since its P/D/W ratio moves it well outside the standard range is the mauler superdreadnought. In this case, the specialized systems in question are a very, very large mass driver or laser, with propulsion and defensive systems stripped back to accommodate it. Mauler superdreadnoughts are not considered ships of the wall, but rather are specialized vessels used to attack specific hardened targets. Since their low speed and weak defenses render them vulnerable “”, they are typically operated as part of a task force including close-in point-defense cruisers, and only brought up once opposing fleets and mobile defenses have been cleared away; however, in their specialty role of cracking hardened fixed bases, they’re unequalled. Hyperdreadnoughts The “hyperdreadnought” is a peculiarly unique version of the superdreadnought type, of which the Empire fields three, each unique within its class; Invictus, Imperiatrix, and God of War. In order, they are the home of Admiralty Grand Fleet Operations, the Imperial Couple’s personal flagship, and the literal embodiment of the archai/eikone of war.

Any one of them turning up in the battlespace would have implications that, by and large, no-one wants to think about thinking about. Battlecruisers and Cruisers The backbone of the fleet, battlecruisers and cruisers (C on the chart) are middle-weight combatants, more heavily armed than destroyers and frigates, and yet more maneuverable than battleships and larger ships of the wall. Most cruisers also maintain limited AKV facilities.

They are perhaps the best balanced (between operational aspects) of any of the Imperial Navy’s standard types. The distinction between cruisers and battlecruisers is simply one of mass and volume, with battlecruisers identifying the significantly larger and heavier classes of the type. In fleet operations, battlecruisers and cruisers serve as screening elements and operate on the fringes of the close-in battlespace, maneuvering aggressively for advantage.

For the most part, however, these middle-weight combatant types are intended for patrol operations and long-endurance “space control” missions, sometimes alone and sometimes in flotillas, as well as serving as the IN’s go-to types for independent missions of almost any type. In areas of heavy patrol activity, cruisers may lead destroyer or frigate flotillas into action.

Cruisers are also the type within which most variation exists, and cruiser classes may wander quite far from the indicated P/D/W ratio. So let’s talk about the layout of that mainstay of the Imperial fleet, the Drake-class frigate. (The numbers are for deck plans. My own sketches are far too horrible to publish, but well, there they are.) External Like most starships, one could conveniently divide the Drake-class into a pressure hull and a drive bus. It’s a little harder to spot the connection than it is on many ships (like, say, the ) because of the armor, but it’s still there.

The pressure hull is, essentially, the front half of the ship, a round-fronted, slightly-flattened cylinder, for the most part unbroken in its organic curves except for the few openings (stellarium, gun port, airlocks) mentioned below, for the six geodesic spheres – three on each side, arranged fore-to-aft along the mid-line – clamped to the hull, which contain redundant sensor suites, best not placed inside the armor, the four paired cheek-mounted light mass drivers to for’ard, the ship’s secondary weapons, and an antenna suite projecting from the dorsal pressure hull near its after end. Behind this, the pressure hull stops, but the armor which covers it continues on past the aftmost pressure bulkhead, broadening the hull to port and starboard even as it narrows into the starship’s stubby “wings”. (Which are of course not wings – they’re the secondary radiators; double-sided radiative striping under transparent light armor, encapsulating more bunker space. These are considered the secondary radiators because they’re designed to carry only the life-support and low-power heat load.) The armor back here serves as a cowl wrapping around the propulsion bus, which is the usual tangle of structural trusses, cryocels (for the ship’s limited supply of afterburner antiprotons), spherical and cylindrical tanks (for deuterium/He3-slush fuel and heat-sink goo), auxiliary machinery, and at the aftmost end of that (such that the bunkerage provides additional shielding for the crew), the fusion torches sticking out the open back of the cowl. (This is, of course, a weak spot in the starship’s armor, but such would the drives be wherever you put them. In practice, the argument goes, when you’re in the furball – well, million-degree drive plasma provides a poor approach vector even for a kinetic weapon, and when you’re not – well, just watch where you point your kilt, okay?) The external parts of the primary radiators sit on top of and below the cowl; they’re liquid-metal droplet radiators, which extend perpendicular to the secondaries when in use. They’re intended to support full power-and-some-more on the reactors, such that you can make a fast retreat and chill down your heat sinks at the same time.

The lowest deck extends, squared-off and flat-bottomed, a little below the main body of the pressure hull and extends back some way below the cowl; as the large doors at front and aft would indicate, it’s the landing bay. The hull itself is gorgeous in shimmering military indigo; naturally, leading edges and other salient points are highlighted in intricate swirls of embedded gold-filigree brightwork, just because the IN can and wishes to emphasize that small point.

(Close inspection will also note the apertures of attitude-control system thrusters, especially to outboard for the largest moment arms, and scattered black, glassy domes concealing the point-defense laser grid.) Internal Internally, the Drake has five decks dorsal-to-ventral. It uses the classic belly-lander arrangement because it’s considered possible to land a frigate planetside, or at least small-planet-side, or operate in atmosphere.

(In the latter case, under the “with sufficient thrust, pigs fly just fine” principle.) Frigate captains rarely want to, though. Despite that, there’s no artificial gravity on a Drake; while in space, the starship operates in microgravity. Communication between decks is provided by a pair of elevators/shafts running between decks 1 to 4, and a staircase providing access to deck 0, along with various maintenance ladderways and such (especially in engineering). The elevators don’t run under microgravity conditions; they’re only for use under gravity. Rather, the elevator car is open-topped and is locked down on deck 4 in flight, allowing the shafts to be used as any other passageways. As far as possible, auxiliary machinery, further storage tanks, etc., are wrapped around the outside of the ship, between the decks and the hull, to use as additional protection in the event of an armor-penetrating strike. Deck 0 Deck 0, “the loft” is the smallest deck, squeezed in between the ceiling of deck 1 and the hull.

Fortunately, it contains (for the most part) spaces which will be unmanned at general quarters or higher readiness states. Specifically, at the fore end, there’s (1) the captain’s cabin, including a small office and private ‘fresher, from which a central corridor runs aft past (2) and (3), VIP staterooms which include the ‘fresher but not the office, ending at (4) the auxiliary sensory and communications room (approximately beneath the antenna suite mentioned above. Outside this room, a foldaway spiral staircase (i.e. Serving as a microgravity shaft in flight) descends to the main corridor of deck 1. Deck 1 Deck 1 is the first of the three “main” decks of the pressure hull. Starting from the for’ard end, we begin with (5) the stellarium, which is literally the only room on the ship with windows, of which it has a continuous strip around the periphery and overhead. It also, being intended to entertain visitors and provide somewhere to get away from inside for a moment, comes with comfortable microgravity-adaptive seating, a few potted plants, and a wet bar.

More important for military purposes, while the windows are tough, they aren’t that tough, and as such the armor layer passes comfortably behind it, and access is through a sequential pair of spacetight doors. Naturally, it’s unmanned at general quarters or higher. Behind this, another central corridor runs aft past (6), a conference lounge to port, and (7) an office for ship’s business – usually the Flight Administrator’s domain – to starboard, reaching the for’ard entrance to (8) the bridge/CIC, which takes up the full width of the ship in the center of the deck.

The aft entrance to the bridge/CIC opens into a second central corridor, this time passing (9), the server room containing the ship’s primary “dumb” servers and avionics systems to port, and (10), the ship’s AI’s cogence core and primary mentality substrate to starboard, terminating in a five-way junction containing the access to deck 0. To port and starboard, a cross-corridor terminates at the elevators/shafts, each with a ‘fresher located adjacent; aft, a door provides access to (11) the maneuvering room, in the form of a well-insulated gallery overlooking (12) the engineering space, which spans all three main decks. (Secure backups for the cogence core and the substrate also exist buried in the middle of the propulsion bus section.) Deck 2 Deck 2 is the central deck of the ship, and to a large extent is divided into two non-communicating parts.

As a frigate, the Drake-class is built around its main gun, which occupies the axis of the ship and thus the center of the deck. While access is possible to the mass driver chamber (which can even be pressurized, with the gun port in the bow closed, for maintenance), it’s normally kept evacuated and is not, in any case, a very comfortable place to be. The mass driver runs down the center of the deck from the gun port at the bow to (13) its “breech”, which sits directly against the engineering space bulkhead. Straddling it on either side are (14), the magazines for its k-slugs, which are also kept evacuated under normal conditions for ease of autoloader operation. Starting this time from the aft end of the ship, at far port and starboard against the engineering bulkhead are the elevators/shafts and the associated adjacent ‘freshers, and the accesses directly to the engineering space. Corridors lead forward from these against the inner hull until they pass the magazines, at which point they turn inwards to reach, and proceed to the bow against, the central mass driver (for ease of accessing the driver coils for maintenance from these corridors).

On the port side, the majority of the space for’ard of this corridor is given over to (15) the medical bay, and at its for’ard end (16), the nano/cryostorage unit, used both for patients in need of return to fuller hospital facilities and doubling as the ship’s brig. (It should be noted that the medical facilities are quite limited; the nature of the space combat environment is such that the window between “fine” and “chunky salsa” is quite narrow, and as such the medical bay is oriented more toward treating illness and minor injuries among the crew than it is to handling massive combat casualties.) On the starboard side, the equivalent space is used for (17), a combined laboratory, workshop, and engineering support area. The remainder of the space for’ard of these, behind the avionics area at the bow, contains the equivalent of two small rooms on either side (18, 19, 20, 21), connected by double spacetight doors; this is the modular function area. With sufficient engineering support and at a yard, these independently-encapsulated areas are designed to be disconnected from the ship’s infrastructure and framework, pulled out as a whole – along with their associated outer-hull plate and armor – and replaced with other modular capsules of equivalent specification.

This feature permits the Drake-class to be customized for special functions – such as the electromagnetic radiation shielding we saw at the Battle of Eye-of-Night – much more flexibly than would otherwise be possible. As mentioned, main access to the (12) engineering space is on this deck, although catwalks lead up and down to the lower level and to the maneuvering room gallery. The nearer part of the engineering deck contains a variety machinery, although also housing to port and starboard the two auxiliary fusion plants used to provide power to the starship when the drive is shut down. Beyond it, a half-octagon wraps around the bulk of the vector-control core and the reaction wheels, containing in their own sections the (22) life support systems to port, and the (23) robot hotels for the ship’s mechanicals to starboard.

Amidships between these, a small airlock and external robot hotel provides access to an unpressurized maintenance crawlway running through the propulsion bus. Normally, this is only used by robots or for occasional yard maintenance; radiation levels are unhealthy back there with the drive running, to say the least, but access may be necessary in emergencies. Deck 3 Deck 3 is primarily the crew deck. At the for’ard end, along the centerline, is the (24) mindcast receiving room, allowing visitors received as infomorphs to borrow one of the ship’s spare bodies for the duration of their visit; aft of that, a cross-corridor links the (25) port and (26) starboard airlocks, each of which is accompanied by a small conning station (usually disabled) for use while docking. Aft of that, another small room serves as a quarterdeck/reception area and security post. From there, a central corridor leads aft through the (27) crew quarters – the corridor itself is lined with access hatches to what are, in effect, double-sized personnel capsules – to the (28) comfortably furnished mess deck, which incorporates a (29) standing galley to port, and the (30) ship’s locker to starboard. Beyond the mess deck, hatches to port and starboard – a design choice permitting a large screen to be mounted on the mess deck’s after bulkhead – lead through inner-hull-hugging corridors past the (31) accumulator room to port, and the (32) auxiliary control room and (33) a small gymnasium to starboard, to another cross-corridor against the engineering bulkhead, providing access to the elevators/shafts and the ‘freshers on this level.

However, there is no routine access to the engineering space on this deck. Deck 4 Deck four, slung beneath the ship, is primarily its (33) landing bay; one large space, extending fore to aft. Space is reserved at port for the (34) armory, used to equip shore parties if necessary, and at starboard for a (35) second workshop space.

These are each located for’ard of the elevators/shafts which open into a small hallway offering access both to these, and to an airlock opening into the landing bay. There are no associated ‘freshers on this deck. A Drake-class frigate is typically equipped with a single cutter, an interface vehicle, or both; the relatively large landing bay permits it to also store the frigate’s complement of drones, and to serve as a cargo bay to such extent as space permits.

Overhead manipulators permit vehicles to be moved to engage with either the fore or aft mass catapult for launching, reshuffling of the cargo, or retasking of the cutter, as desired. Flight operations are handled from the bridge/CIC.

The bay can be pressurized with both doors closed, but at general quarters or higher readiness states operates unpressurized to expedite operations and avoid unnecessary risks. (For those paying attention to the implications: yes, the very same vector control tech that lets you make kinetic barriers lets you make nice air curtains that would hold air in even with the door open, while still letting you fly in and out. [Well, mostly: for molecular statistical reasons, they leak, but it’s manageable.] Some civilian ships use those for the convenience.

Military ships prefer not to have unexpected depressurization incidents when someone gets a lucky shot in on the emitters when they don’t have to. Sure, it’s a pain to have to wear a skinsuit all the time, but you’re in the Navy now! Also, you’re less likely to get brained by a flying spanner if there were to be a curtain oops.).

We've come a long way in our discussions about forces and the thereof. At this point, we can start actually designing some spacecraft, or at least start focusing in on the specific needs our space forces will have to address when designing spacecraft. First off, and remember that in the case of Conjunction, this is the most important, is the fact that the UN Space Force is not a military in the conventional sense. It is a law-enforcement body primarily and a search and rescue service secondarily. Military action, as will occur in the dark years of the Great Conjunction War (or whatever they decide to call it) are all new and uncomfortable roles forced onto the majority of the commanders, mission planners and spacecraft designers of the future. That last part brings up an interesting point, however: Spacecraft have a horrendous amount design time, and spacecraft as big and complex as the ones in Conjunction can easily take years to develop and build. This fact, along with the multi-year travel times from the Inner System to the, will make it all to likely that the spacecraft developed for the Conjunction War will not be available until the war is over.

This leads to our first design consideration, one mentioned by in the past: The weapons of this war were designed to win the last war. Specific to Conjunction, the weapons of this war weren't made for war at all, but police actions and purely theoretical combat scenarios that our ornery Jovians have no moral requirement to follow. Hilarity ensues. So, what would the UNSF have available, at the start of the war, and what would they have in the slips or on the drawing board? As far as what the UN have available, it's mostly Patrol Rockets like the Class-A, little utility rockets like the Cygnus, and the big, trans-Chronian transports. The Class-A and the Cygnus have been before — just click on the link for a reminder. The big transports need a few words, as these classes of spacecraft will have been well established prior to the war and really are the backbone of not only the UNSF, but of all space travel in Conjunction.

Annie and Chris mention the Mekong in the, as the ship the two will have share for the two year trip to Saturn. This is a River-class logistical ship, of a kind similar to the ones Rick Robinson describes in his. However, the Mekong is not a military ship; it is a civilian-run transport that is heavily subsidized by the UN in exchange for ferrying personnel and patrol craft across the black.

This kind of compromise is to be expected, given that the UNSF is not a military, is not at war, and is only mandated to keep the peace. It also has to do this in a sphere of operations roughly a billion kilometers in diameter, They can't have a large number of purely peacekeeper spacecraft of this size, It isn't cost effective.

That being said, there are a lot of convoys moving between Titan and Terra in a constant stream of methane, and, so each convoy needs some escort, and that escort needs the delta-v and the life support to move across a large chunk of interplanetary space. Therefore, I postulate the creation of a logistical carrier and a stripped-down variant made for civilian use. The UN Carrier — call it the Gagarin class and name it after astronauts, will be armored and armed with large defensive lasers, carry a half-dozen patrol rockets a dozen or so Cygnus rockets, and two crews for itself and each rocket it carries. That's a lot of people, but a spacecraft of this type is more starbase than spaceship anyway.

In addition, the Gagarins will need large repair spaces for the patrol craft, a fleet reserve of propellant, and space to carry any kinetic vehicles that will be used in combat. The civilian version — our River-class — will only carry a pair of patrol rockets, maybe for utility craft, a correspondingly smaller propellant reserve, and most likely no kinetics for deployment during travel. Weather or not they carry kinetics as cargo depends on how easy it is to manufacture KKVs at Saturn and weather or not the UN wants it's colony to make its own WMDs or not.

How do these behemoths move between the worlds? Chemical rockets — or even nuclear ones — are right out as they are too inefficient.

A nuclear electric drive, delivering constant boost at minimal acceleration, is the best option. The disadvantage to such a drive is that minimal acceleration thing. To alleviate this, the logistical craft could have NTRs — after all, they got the reactors anyway — and thus be able to hit the gas when needed. In fact, there is even a way, albeit a very expensive and inefficient one, for our logistical craft to move from the inner system to a hot spot in the outer worlds much faster than normal.

This involves the technique upon which naval legend Chester Nimitz credits the American victory over the Japanese in the Pacific — underway replenishment. To perform underway replenishment, we need another class of spacecraft: The Tanker. This need not be too complicated, as ice is a more effective medium for transporting hydrogen than hydrogen is. As a purely practical matter, the propellant tanks of the interplanetary ships will have to be full of water anyway, as you. So our tanker will basically be a gigantic plug of water ice with a nuke at one end and an electrolyzer at the other. The heat from the nuke serves to melt the ice for conversion into propellant. The logistical craft and the tanker will have to dock nose-to-nose in order to prevent irradiating one another, and will spin around their common access to make enough force to let the propellant pump in between the two.

I'm not a hundred percent on this, but I don't think the pair of craft could dock nose-to-nose under acceleration, seeing as their rumps would be at cross-purposes. It goes without saying that the logistical craft have spin gravity. This is in the form of two rings, spinning in opposite directions to cancel the gyroscopic effect.

I imagine that the rings will sit inside a huge, globular water tank — that fleet reserve I mentioned — as a way of making the propellant do double duty as cosmic radiation shielding. Because the ship will sometimes spin end-over-end while taking on reaction mass, the logistical craft must either halt spin on the gravity rings — a pain in the butt — or use a species of Winchell Chung's If this looks like it could be a maintenance nightmare, let me reassure you — yes, yes it is. Any spin-gravity system is high maintenance, and one that must spin along two axes is high maintenance squared. However, with a large number of crew, literally half of which will be out rotated out at a time, lengthy and complex maintenance cycles are a feature, not a bug. So, we have patrol rockets, utility craft, logistical carriers, and tanker already available for the UNSF at to play around with.

What about what is on drawing board? Mission planners and saber-rattlers are all too aware that the Great Conjunction will come and put the UN&Cs most troubling possession in between the oil-hungry masses of the inner system and the oil-rich oceans of Saturn's moon, Titan. They must have made some plans ahead for the eventuality that Jupiter, which in our scenario is self-sufficient in terms of power and many other commodities, is ready to go its own way. What have the UN developed to counter this? Even for Conjuction, my Laserstar concept is an oddity in the annals of space combat. Usually the biggest, most heavily armed and armored ship is the 'battleship' right? In this case our about combat and the thereof make the Laserstar the opposite of that: The ultimate defensive system in our arsenal.

It boasts a Violet wavelength laser with a twenty meter mirror on the nose and six ten-meter mirrors on its flanks. These monsters are uncrewed, controlled by on-board AI, and nuclear powered. They are named after the native countries of the first astronauts and cosmonauts, with The Union of Soviet Socialist Republics being the flag ship. The Laserstar's purpose is to provide cover fire for the logistical craft it is assigned to defend. With the number of lasers on these leviathans, the goal is to make a successful kinetic attack impossible. That's a lot of ships.

A lot of different ships. And given the nature of space and its peculiarities, how they come together as a cohesive fighting unit will be equally peculiar. There's a decent functional space to discuss here. Most navies really have three sizes of ship. • Small ships • Medium sized ships • Capital ships Most navies have two roles that ships are designed for: • Independent patrol • Main battle fleet Independent patrol sacrifices firepower (and sometimes protection) for cruise endurance and multi-mission capabilities.

Main battle fleet requires ships to be 'honed to the bone' - anything that doesn't make the ship more capable in a fight is usually a luxury. History hasn't been kind to independent patrol capital ships. They're generally too expensive for the benefit they give the navy (something that eats independent cruisers for lunch and can do commerce raiding. Jackie Fisher's Battlecruisers in WWI and the German pocket battleships are two examples.

So this leaves: • Frigate (Small ship, independent patrol) • Destroyer (Small ship, main battle line) • Cruiser (Medium ship, independent patrol) • Armored Cruiser (Medium ship, battle line) • Battlecruiser (Capital ship, independent patrol) • Battleship (Capital ship, battle-line) Within each role, you have specific missions, and you'll have different sizes of ships within each niche, depending on what specific navies did with their doctrines. The frigate is the smallest thing that can be armed with guns capable of doing shore bombardment. The destroyer may have less armament than a frigate; it's job is to shoot down threats to the bigger ships in the battle fleet. The cruiser is a frigate that's generally got more armament, more armor, and more survivability. It usually has greater endurance. The armored cruiser trades endurance for enough armor to maybe survive a hit from a capital ship's gun without being mission killed, and usually has the same number of guns as the cruiser with heavier throw weights.

The capital ship has Massive Firepower and the armor to stand up to it. Endurance is usually traded off somewhere. It's a common trope in sci-fi that [WARNING - TV TROPES LINK], and so when we talk about spacecraft classification, naval terminology creeps into our work. I think some of this is unavoidable. For one, the Space is an Ocean meme is a powerful one, and it's been heavily reinforced over decades of use. The other is that while I personally expect any future space forces to evolve from the Space Commands of existing Air Forces, once you get the ability to build large space-going warships and send them days or weeks out of contact from home, the Navy's organizational model starts making more sense over the Air Force model ( pace, SG Universe.) But that's not what I want to write about.

I think this 'creep' has extended so far that we've forgotten (or just didn't know), what all of those ship classifications even mean, or haven't taken a good look at whether a particular wet navy ship type even makes sense in space. The term 'destroyer' is perhaps the worst offender.

We get destroyers in sci-fi that range from small escorts to titanic capital ships. (I'm looking at you, George.) Since sci-fi Space is an Ocean models invariably build upon conventions established for such recent events as the, the rock-paper-scissors paradigm of naval combat that dominated in that period may have been lost, and with it, just what exactly made a destroyer what it was and why. Battleships rule the waves, with armor that only another battleship could defeat, and large bore cannons which could in theory strike their targets over the horizon. If you wanted your Navy to compete, you needed to build battleships, which were crushingly expensive burdens.

(Look back to the period for commentary on how the naval arms race prior to WW1 was driving countries to ruin for examples of this.) Then along came the torpedo, a powerful, relatively cheap weapon that could sink one of these behemoths, and could be deployed by relatively tiny, fast, and cheap swarms of torpedo boats. The Battleship, especially the post-Dreadnought models of the type, could not effectively engage torpedo boats with their big guns.

Thus entered the Destroyer, short for Torpedo Boat Destroyer. It was much smaller and cheaper to build than a ship of the line, was fast enough to chase after its quarry, and had lighter guns that could track and sink the torpedo boats. Battleships sink Destroyers and other Battleships, Torpedo Boats sink Battleships, and Destroyers sink Torpedo Boats.. The Destroyer had a specific purpose, otherwise it would have never existed. Submarines being torpedo boats that could go underwater just meant that the Destroyer still had a reason to be as naval warfare technology moved on. Does your Destroyer have such a purpose?

It's something to think about. A Destroyer in a space setting could be a 'Fighter, Drone, and Missile' Destroyer, heavy on the point defense systems and acting as a consort to a larger and more important vessel. That makes perfect sense and justifies the class. If your Destroyer can stand in the line of battle, with a primary anti-ship armament and good protection, and even carry a few of its own fighters or troops along for the ride, you might want to reconsider its classification. Make it a cruiser, or, if it really is just a battleship in destroyer clothing, call it something that reflects that role. I think one of the reasons why the trope has been so enduring is that audiences can relate to them easily.

'Battleship' is fairly clear in peoples' minds, so a battleship in space is an easy mental gearshift for them. For better or worse, so too 'Destroyer.' People can relate to a 'battleship' or 'carrier' in a way that a 'system control ship' or 'parasite (craft) tender' do not relate. For one thing, there is a certain elegance to the wet navy terms that the clunkier if more apt 'system control ship' and 'parasite tender' are clearly lacking. And let's face it, frigate commands were romantic and exciting in the days of Wooden Ships and Iron Men, more so in the sea-romances written about them, and if you're going to write a sci-fi romance in the days of Alumo-Titanium Ships and Diamondoid Men, they probably have a place there, too.

As creative types, we love the worlds we create. We love our fluff. I'm no exception to that. What I find disturbing, even objectionable, is when I find so little consideration put into the fluff. I think the caveat of applies, but as someone who enjoys sci-fi games, books, movies and TV shows as much for their fluff as their primary contributions to the visual and literary media, a well reasoned and internally consistent fluff is a signifier to me that the creative person behind their works actually cares about what they are doing, is as interested as me in the genre, and isn't just doing this because this is how they earn their daily crust.

For my own setting, I've adopted naval ship classes that seem to have a purpose. Here's a list and the reasons for their existence. Battleship Space Control ship. Heavy armament and stout protection. If you don't have anything that can stand up to it available, you have to concede the space it can control. Thus, Battleships can take control of orbital spaces, or even entire solar systems without firing a shot if the defenders don't have a comparable amount of tonnage and throw-weight to resist them and the willingness to do so. Carrier Interface Fighter and Strike Craft mothership.

In my setting, there is nothing a Space Fighter can do that a drone missile carrier can't do better, but when it comes to planetary real estate, a fighter that can operate in low orbit as well as within the deep atmosphere has greater utility. They can be Johnny-On-The-Spot for close air support, ISR, and air superiority in a way that orbiting warships providing for these roles cannot. For one thing, in low orbit, a warship will only pass over a given location on the ground for about 10 or 15 minutes, maybe 4 or 5 times a day depending on the latitude and the inclination of the orbit. Because Interface Fighters and Strike Craft have a reason to be, so too the Carrier, to bring them to low orbit, recover them after their mission, and return them to service. Cruiser A cruiser is more or less a scaled down Battleship. Battleships are expensive to build, man, and maintain, and if your setting has lots of places to go, the amount of space you can actually control will be limited by your ability to put something there that can take care of itself. The Cruiser, being smaller, is less expensive to build, man, and maintain, so you can build more of them to control more space, reserving the Battleships for the really important locations and to keep them available to mass for a decisive engagement.

Wet Navy cruisers tended to be faster than battleships, but in a Newtonian physics based space setting like my own, one's 'speed' in the end comes down to propellant fractions, which can be the same for any given size or class of spacecraft. Instead, a Cruiser is built for long endurance independent operations, trading a little firepower and protection for the ability to maintain a presence somewhere and control space where a Battleship isn't worth sending instead.

Assault Ship A troop carrier. Their job is to transport ground based combat power to target worlds and deliver them with organic interface craft. They may carry interface fighters and strike craft as well as landers, they may even have their own space to surface weaponry for fire support, but most of their displacement is given over to housing troops, their vehicles, their gear, and their supplies. Tanker Just what it says on the tin. The Tanker carries reserves of propellant and reactor fuel to replenish the fleet.

Since propulsion within a system is by reaction drive, massive quantities of reaction mass get consumed, and it is the Tanker's job to keep the fleet fueled. Tankers usually carry harvesting craft to find sources of hydrogen, deuterium, and helium-3 and have their own processing plants to turn raw materials harvested into useable propellants/reactants. An army marches on its stomach, and so too a fleet maneuvers on what is in its tankers. Logistics Ship A military version of a freighter, usually identical to existing civilian merchant classes, with perhaps a slight upgrade to armament, communications, and protection. Warships need spare parts, replacement missiles and other expendable stores, water, and food. Tender A repair ship.

These carry fabrication plants, raw materials, and technical shops to maintain, repair, and in some cases even rebuild parts of spacecraft to keep the fleet in the fight away from their home stations. Frigate A scaled down Cruiser. You can build and operate 2 or 3 frigates for the same expense as a Cruiser, so you can at least 'show the flag' in more places, and in remote systems even control them. Most Frigates have a small organic troop contingent embarked on board as well as small landers to transport them, allowing them to occupy or provide security for outposts and small colonies. The Frigate is the Swiss Army Knife of the fleet. It doesn't do any particular job very well, but it can do a little of everything, and because you can build lots of them for the same price as a Battleship, your ability to at least influence large volumes of space is much greater than a powerful warship that can only be in one place at a time.

Destroyer Also called an Escort. The purpose of the Destroyer is to eliminate any missiles or small craft which threaten its consort, usually a Battleship, Carrier, Assault Ship, Tanker, Tender, or Logistics Ship. It does not have an appreciable anti-ship armament, and would be helpless against even a Frigate.

They have to be fairly agile in order to provide coverage, or if necessary, position themselves to eat an anti-ship missile instead of letting their charge get hit. Corvette/System Defense Boat A scaled down Frigate, usually optimized for an anti-ship role. Since a corvette/SDB is unlikely to have a direct fire armament that can seriously threaten larger warships, they typically incorporate a significant fraction of their weapons displacement as anti-ship missiles and will engage in packs.

This gives them limited combat endurance, but offers a cheap way to punch well above their weight in an engagement. Think of them as the wet navy Torpedo Boat. (Ironically, Destroyers are not built to engage them, but a Frigate or another Corvette/SDB would serve admirably in this role.) Corvettes and SDBs may also be assigned to convoy escort duties, sometimes led by a Frigate or a Destroyer. Their job is to intercept commerce raiders away from the convoy, and destroy them with salvos of anti-ship missiles. The original wet navy Corvette was meant to operate in home waters in a patrol role, and with a fairly strong for its displacement anti-ship capability. A System Defense Boat is simply a Corvette without an FTL system, making them more in line with the original wet navy concept.

I don't think there would be a huge variation in the types of warships seen. You'd have the big battleship which would dominate everything it fights, and then maybe smaller ships that could cover more area at once and engage in light combat, but wouldn't stand up to the battleships. Red called these 'frigates' in his Humanist Inheritance fiction, probably because their role is similar to the ship of the same name from the age of sail, and it is a term I like, so I will use it here. However, note 'cruiser' may also be an applicable moniker for these ships, probably depending on its specific mission rather than its design goal. I feel these would exist due to economic efficiency rather than speed or range difference like those seen in the real sailing frigates.

Let me explain. Many of the can actually be used when talking about other capital ship classes as well. Let's look at what the roles of various naval ship classes basically were, and see if they could have an analog in space. You had corvettes, which were small, maneuverable ships used close to shore. This role doesn't really apply in space. You might argue low orbit around a planet could be seen as a shore, but the problem is combat ranges would be rather large. If you have a stationary asset in LEO that you want to attack, you could put your battleship arbitrarily far away and attack it at will.

If you have a mobile asset in you want to attack, you can still attack it from some distance away, probably around one light second, to avoid too much of your laser beams over the distance. For comparison, the moon is about one and a half light seconds away from Earth. So, the battleship could be sitting out two thirds the distance to the moon and easily engaging the LEO target with precision and power.

3dmark06 1 1 Keygenguru. Corvettes being there wouldn't be of any help on defense, and the battleship can do their job on offense just as well, and at longer range. A corvette type ship might be useful to the Coast Guard for police and search and rescue work, but that is an entirely different realm than a warship. How about cruisers / frigates? The historical usage of the term referred to a small but fast warship, capable of operating on their own, and often assigned to light targets or escort duty. I do see an analog to this role in space. A frigate would be no match for a battleship, however they would be useful in force projection, due to presumably being cheaper to produce and operate, thus more numerous. I'll be back to this in a moment.

And of course, battleships would be the backbone of the war fleet, able to swat down anything that comes at them except other battleships. If it were economically feasible to build a huge fleet of battleships, I see no reason not to. Let's investigate some of their traditional disadvantages and see if they apply in space. The big one is speed: the huge battleship can take just about anything dished out to it and dish out enough to destroy nearly any other class of ship, but its huge size makes it slow. This isn't so much of a concern in space. Allow me to elaborate. There are two things in space that are relevant when talking about 'speed': and.

Delta-v is by the specific impulse (fuel efficiency) of the ship's engines and the percentage of the ship's mass that is fuel. Tonnage of the ship doesn't really matter here: it is a ratio thing.

If the specific impulse is the same and the fuel percentage to total mass the same, any size ship will eventually reach the same final speed. Thus, here, if fuel costs are ignored, small ships have no advantage over large ships. (And indeed, if you are going on a long trip, the large ship offers other advantages in how many supplies or for war, how many weapons it can carry at no cost to delta-v, again, if the ratio remains constant) So the question is how fast can they reach it, which brings me to acceleration. Acceleration is by total engine thrust and the total mass of the ship. At first glance, it seems that the smaller ship would obviously have the advantage here, but there are other factors that need be observed. One is the structural strength of the materials of which the ship is constructed.

This becomes a on insanely huge ships with larger accelerations, since the 'weight' the spaceframe must support goes up faster (it cubes) than the amount of weight it can handle (it squares). Mike talks about this on the main site when he.

However, steel is strong enough that with realistic sizes and accelerations, this should not be an issue before one of the other ones are. One that is a much bigger problem is how much the human crew can handle. In the space / atmospheric fighter thread we had the week before last, Broomstick the of the human body to great accelerations. Well trained people in g-suits can handle 9 g's for a short time, but much more than this is a bad thing to just about everyone - their aorta can't handle it. In fact 5 positive g's are enough to cause most people to pass out, as she explains. If the crew is passing out, the ship is in trouble.

This problem can be lessened by the use of acceleration couches: someone laying down flat can handle it much better for longer, but even 5 g's laying down is going to be very uncomfortable, and the crew will have a hard time moving their arms. Extended trips would probably be best done at 1 g so the rocket's acceleration simulates Earth normal gravity, with peak acceleration being no more than 3-5 g's for humans in the afore mentioned couches if possible. That is probably the most significant limit on acceleration, since it is an upper limit of humans. No matter what technology exists, this cannot be avoided. The third limitation will be based on the technical problem of generating this much thrust for the mass. This, too, can provide an upper limit, since adding more engines on to a ship will eventually give diminishing returns. The reason for that is the available surface area on the back of the ship where the engine must go increases more slowly than the mass of the ship as it grows.

But, for a reasonably sized ship, this should not be a tremendous problem, especially when nuclear propulsion techniques are used, many of which have already been designed and proven feasible in the real world. Fission nuke pulse propulsion can provide 400 mega-newtons of thrust according to the on Nyrath's Atomic Rockets website (see the row for Project Orion). Three gees is about 30 metres per second squared acceleration. F = ma, so let's see what mass is possible. 4e8 / 3e1 = 1e7 kg, or about 10000 metric tonnes. Incidentally, this is the number Sikon used for his demonstrations in the.

I think it a reasonable number for a battleship, so rather than repeat the benefits of this, I refer you back to that thread and the posts of GrandMasterTerwynn and Sikon on the first page, who discussed it in more depth than I am capable of. I agree with most of the views Sikon expressed in that thread. So, for these sizes, the speed argument against battleships is very much sidelined. You also pointed this out later in your post that these advanced propulsion techniques do not necessarily scale down very well, which may also serve as a lower limit on ship size, which is probably more relevant than the upper limit it causes. You might ask if pushing for a greater peak acceleration would be worth it, and it is not, in my opinion. The reason again goes to the human limitations.

Even if your warship is pulling 10 gees, it most likely won't help against a missile, which can still outperform you. An acceleration of even 1 g should be enough to throw off enemy targeting at ranges of about one light second. By the time the enemy sees what you are doing, you have already applied 10 m/s change to your velocity.

Then, if he fires back with a laser, you have another second to apply more change. This would be enough to help prevent direct, concentrated hits. Having even five times more acceleration will offer little advantage over this in throwing off targeting or wide spread impact of lasers of particle beams, due to the ranges and the size of your warship, which is certain to measure longer than 50 metres. For missiles and coilgun projectiles, it matters even less, simply due to the time the enemy fire arrives, you have plenty of time - minutes - to have moved. 1g is plenty for that, attainable by a nuke pulse engine for sizes around 30,000 metric tonnes. Long range acceleration would again be limited to around 1 g or less due to the humans, mentioned above. However, even at 1g constant acceleration (which would probably not be used due to fuel concerns anyway), an Earth to Mars trip could be measured in mere days.

More offers little advantage there either. Lastly, there may be a question of rotation. A more massive and would have a greater moment of angular inertia than a smaller ship, thus requiring more torque to change its rate of rotation. Again, I don't feel this will be a major concern. At the ranges involved, you again have some time to change direction. However, this does pose the problem in quick, random accelerations to throw off enemy targeting.

Going with the 10,000 metric ton ship, let's assume it has an average density equal to that of water: one tonne per cubic meter. For the shape, I am going to assume a cylinder, about 10 meters in diameter (about the same as the Saturn V), with all the mass gathered at points at the end. The reason of this is to demonstrate a possible upper number for difficulty of rotation (moment of inertia), not to actually propose this is what it would look like. Actually determining an optimal realistic shape for such a ship would take much more thought. With this, we can determine the length of the to be 10000 / (π r 2) = about 130 metres long. Now, we can estimate the moment of inertia, for which, we will assume there are two point masses of 5000 tons, each 65 meters away from the center. So moment of inertia for the turning axis (as opposed to rotating), is 2*5000 * 65^2 = about 4e10 kilogram meters squared.

Now, let's assume there are maneuvering jets on each end that would fire on opposite sides to rotate the ship. Let's further assume these have thrust about equal to that found on the space shuttle, simply because it is a realistic number that I can find: about 30 kilo-newtons.

Let's determine torque, which is radius times force, so 3e4 * 65 * 2 (two thrusters) = about 4e6 newton meters. Outstanding, now we can determine angular acceleration possible. Angular acceleration = It, where I is moment of inertia and t is torque. So, we have 4e6 / 4e10 = 1e-4 radians per second squared.

This is about a meager 10th of a degree per square second. Remember this is acceleration - change in rotation rate.

Once spinning, it would tend to continue spinning. This is also a lower limit: most likely, the thrusters would be more numerous than I assumed, and probably more powerful as well, and the mass probably would be more evenly distributed. But anyway, let's see if it might be good enough. As I said when discussing linear acceleration, you would want some quick randomness to help prevent a concentrated laser beam from focusing on you, and you would want the ability to change your path within a scale of minutes to prevent long range coilgun shells from impacting. There isn't much you can do about missiles except point defense: a ship cannot hope to outmaneuver them due to limitations of the crew, if nothing else.

Some unpredictable linear acceleration should be enough to do these tasks, unless the enemy can get lined up with you, in which case, you will want to change direction to prevent him from using your own acceleration against you, and blasting you head on. So the concern is can you rotate fast enough to prevent the enemy from lining up with you. So, let's assume the enemy can change direction infinitely fast, and can thrust at 3 g's.

The range will still be one light-second.