perfidy

I gotta say. This isn't syncophancy, because I don't have to rely on your goodwill or largesse to live (any more, unlike when I was a basement-dweller in the Buckethead residence, thank you very much for that), but DAMN.

You think about this stuff WAY too much, and I thank you for it! I agree with you more than Den Beste on the shape of things to come, but that's not to say that SDB hasn't thought his end of things through either.

DAAAMN.

B,
I look forward to the rest of this piece. Some thoughts so far:

I understand the vast distances that might frame battlefields in space. At least, as well as any human can shoehorn such distances into a brain.

I have some questions about the warships we're considering here. If we're sticking to the plausible, and assuming warships with a nuclear, chemical, or charged particle proulsion system, I think that targeting systems can compute their way around even light-seconds of distance in order to make a killing hit; I mean, how fast can the target vessels be going?

It just seems that it would take less time for a kinetic energy munition to traverse the distance between firer and target than it would for the target to detect the round, slow down, speed up, change heading, or otherwise evade that munition. Particularly with a kinetic munition with an IR seeker and a proximity fuse.

As far as weaponry, I was thinking about this: how much energy would it take to accelerate a munition the size of a pebble, say, to a respectable fraction of C? Of course a chemical explosion won't suffice to get an object to that speed, but I've read about rings of magnets lining a gun barrel that serve, each ring in turn, to propel an object to ridiculous velocity.

No human constructed vehicle, sticking to what we agree to be plausible, will avoid an object moving at relativistic speeds. And a tiny piece of solid matter, moving at even 1/100 C, would be insanely destructive to whatever it contacts. You and the Clueless guy are way smarter at this stuff than I am, but I am considering E=mC_2_; even substituting a tiny number for the mass of the projectile, say 1 gram, and taking 1/100C, the resulting E will suffice, I daresay, to wreck a crew's day.

GL, the warships won't be moving fast - at least compared to the speed of light. However, that few seconds of delay could seriously screw with a targeting computer's head, because what the target will be doing (assuming it has the delta-v, or fuel) is jinking around its base course. Rapidly and repeatedly changing course will increase the the number of places the ship might be, and reduce the chance of a hit. Even if the course changes are relatively minor. (Of course, there will be severe limits on how long a target can dance around bullets like this, as fuel will be far from infinite - and mass will be at a premium in ship design.)

This is also a good reason why area effect weapons like nukes will be well liked by tacticians.

The problem with electromagnetic railguns, or mass accelerators, or whatever you want to call them (I prefer railgun - it has a melancholy WWI ambience) is what Clueless pointed out - energy cost. Energy=heat=lack of stealth is one equation that will be hard to wiggle out of. Also, weight limitations might factor in - a heavy nuclear fission reactor will have effects on how much the ship can accelerate (at any given moment, and overall.) That's why I liked Clueless' idea about cannon. They are low power, and in a weightless vacuum environment, could be made lightweight compared to earthly vareities.

Also keep in mind that hitting a near future spaceship with a relativistic projectile is serious overkill. Any spaceship designed around propulsion technologies we can envision right now will be severely mass constrained. We do not have powerful warp drives to haul armor around. Considering that voyages might take months, you need air, food, and water for the crew. You need weapons to kill the enemy, and you need fuel to maneuver. Armor will likely be sacrificed altogether, or limited to crucial parts of the warship. I don't think we'll see inch thick steel armor plate. A machine gun shooting flechette rounds would like shred a spaceship just as well, and would weigh far less than a railgun with all it's power supplies and whatnot.

B, I was holding off on asking those exact questions! Great minds, it seems, do think alike.

Is it perhaps a corollary to the stealth problem? To accelerate a 1 gram to 1/100C would take a massive amount of energy-- my crappy calculations give the number as 8 Billion joules, though I might be off by an order of magnitude or two. AND, that energy has to be released in such a way that the projectile and gun survive the event.

Since you cannot change the laws of physics, Jim, how do we get massive power plants into space, arm them, make them invisible, and make them repeatable?

B,
I track your response. I was advocating for relativistic projectiles, less for the considerable destructive force generated at impact than for speed in crossing interstellar distance.

But whatever the purpose of such a proposed munition: to impact, to scatter shrapnel with a proximity warhead, OR simply to get the bad guy in a timely and accurate manner over vast distances, the complexities associated with a weapon to fire it are such to render the point moot. Which is good, because now I can stop looking for my 10-year-old notes from Astronomy 104.

And now I remember some physics that AC Clarke explained in "2001", that a tiny angle between two lines emanating from a single origin but with slightly different headings will, over enough distance (say millions of miles), become a vast, insurmountable gulf between the two.

In reconsidering the warships themselves, though, I'm not seeing the utility of manned versions. Why would a human crew be necessary at all? Wouldn't a sort of fire barge, a la the PTO, make more sense? That way you don't need headaches that come from care and feeding for a human crew. That cost in added mass from radiation shielding, berthing/living spaces, water, could be dispensed with.

And let me add that this line of discussion is alot more challenging -and fun- than pointing out that Star Wars fighters don't need to turn-n-bank in space; the sonic, Moog-organ munition that Jango Fett used in "Attack of the Clones" cannot work in vacuum; and don't even get me started on "Star Trek" transporters...

I'll be covering some of those points in the next piece, so hold tight.

By far the biggest problem with the idea of projectiles traveling at relativistic speeds is recoil. A tank firing its gun is sitting on the ground, and the force of recoil is transmitted to the ground via its treads. A ship in space is sitting on nothing, and momentum is conserved.

The A-10 has that problem. The GAU-8 is a scary weapon. An A-10 which wants to use its gun goes into a dive and cranks up its engines to full power, and it nonetheless decelerates as long as the gun is firing, because the recoil is so great based on volume of fire, weight of projectiles and muzzle velocity. If the pilot fires the gun for too long, the jet can stall.

A warship in space has that same problem with a rail gun firing small projectiles at preposterously high velocities. Do very much of that kind of thing without compensating, and your orbit changes. To avoid that, you have to fire the engines each time.

But there's also a really serious problem with energy yield and thus cooling. For our purposes the efficiency would be the ratio of the energy applied to the enemy target on impact compared to the energy fed into the rail gun in order to launch that projectile, and in fact the yield will not be very high at all. I don't have an exact figure but I am willing to bet it's less than 10%. That means that if the projectile is "insanely destructive" because of the energy of the impact, there's going to be 9 * insanely large energy to get rid of in the firing ship via its cooling system. That is a non-trivial problem; it may reduce the firing rate to the point of uselessness.

How would nukes be effective as area effect weapons? Isn't the shockwave from a nuke what gives it it's destructive power? The atmosphere being churned up into a massive firestorm traveling in all directions away from ground zero?

How could a nuke be effective in space if there is no atmosphere?

Wesley - the shock wave that is propagated through the atmosphere is not the only thing that would ruin your morning if you woke up in bed with a nuke. EMP and the Heat flash are also big problems. Remember - that shock wave is created by a rather large burst of radiant energy, energy which does not require an atmosphere to reach out and touch someone.

Steven, thanks for the link! Based on past experience, that will increase our traffic by two or even three orders of magnitude. Do we call that a Stevolanche, or a Cluelesslanche?

I neglected to point out (didn't think of) the recoil effects. Newton's third law insists on it, though. Happily, it reinforces my thinking that they would not be very practicable.

Regarding your point, it is worth remembering that the kids at MIT and Princeton who developed early prototypes of massdrivers and railguns back in the seventies thought of them as ways to move asteroids by ejecting some of their mass out the back, or for lifting construction material from the Moon to the LaGrange points. Silly hippies didn't think of offensive use, though Heinlein surely did, in "Moon is a Harsh Mistress."

S D Beste,
More convincing evidence to dispense with railgun thingies altogether... you and B have shown me the light. I'll save them for more classic sci-fi fare, and exclude them from the field of plausible space weaponry.

And let me add that anyone who knows his way around a GAU-8 is OK in my book.

Assuming plausible technologies I think that for the near future beam weapons aren't likely to be practical except possibly in fixed site defense. Nuclear weapons are thinkable, in fact, as I understand it, there was an unoffical, tacit understanding between the US and USSR at the time that use of tactical nuclear weapons in an anti-submarine role would not be considered an escalatory step in the sense that their use on land would have been. So a precedent of sorts is there.

With anything other than beam weapons or relativistic projectiles earth to moon represents at least an order of magnitude too great a range to deal with. I suspect that engagement ranges would more likely resemble a knife fight in a phone booth as combatants will be limited by their fire control's ability to predict the target's position at time of impact, and closer is better.

Manned vessels will be g-limited due to the fragility of the occupants and this will help simplify the targetting solution. Unmanned vessels will be limited only by structural strength and the delta-vee capability of the propulsion system.

SDB seems to believe that hauling ammo around is in the 'too hard' box and I tend to disagree on that point. He also seems to see the space combat paradigm as dueling capital ships, which would be needed for the employment of militarily-useful beam weapons as they are currently envisioned. I tend to think it more likely to be a mother ship/fighter screen kind of situation. And I suspect that for a variety of reasons the weapon of choice for these 'space fighters' would tend toward smallish-caliber autocannons, coupled with as capable a fire control system as can be afforded, probably on some sort of gimballed mount so that ship orientation doesn't affect weapon employment.

Guided weaponry will be limited by their propulsion systems, or more properly, their propulsion system's fuel tank. Longer range means larger, heavier, more expensive. The rocket equation applies here, too.

The GAU-8 mounted on the A10 is mentioned earlier. I'd expect to see something along those lines on larger ships, with the more fighterlike craft carrying things in the 12.7mm - 20mm range, possibly as small as 7.62mm (tradeoffs between ammo capacity, weight, penetrating ability).

As far as not being able to hide, maybe, maybe not. Use of active sensors will be 'shootme' spots and IR sensors can be spoofed relatively easily (try looking through a glass window with one...). Also, a defender would look for debris to hide in/amongst, asteroid belts are your friend if you're trying to hide. Granted, there's not a lot of it out there in useful places, but it does exist.

JS, I think that SDB was positive on the possibilities of cannon in the second part of his essay. But I agree with him on the capital ships bit. If you read further ahead in this series, I make the case that the capabilities of Orion/Nuclear Pulse drive ships will push things in that direction. They have to be big, and nothing (short of the invention of fusion or antimatter drives) will be faster.

Rapid fire cannon, or MetalStorm type electrically fired cannon, will be the rule. I think you underestimate the capabilities of targeting systems over long ranges. To be sure, hitting a target with a single round over those distances would be very difficult. But warships will launch bursts of rounds - designed to spread out, each spread covering an intersection point with one of the target's potential courses. Given limitations on d-v, ships will change course, but there's only so *much* they can change, and the job for gunners and their targeting computers will be to guess which way the target will zig, and arrange to have some bullets there to meet him. (Fighter pilots can for brief periods stand well over ten g's - that's a lot of course change in freefall. The limitation is more likely to be fuel capacity than fragile meatsacks.)

As I will be describing in the second part of my hypothetical battle, the two key difficulties for a ship commander are what intercept vector to take, and when to engage. On the one hand, you'd want to engage as early as possible, to reduce danger to your own ship. But, given the likelihood of missing at extreme ranges and the finite stores of ammo, there is a lot of pressure to be conservative. Balancing this will take nerves and very good gunners. Gunnery for space warships will be as much art, psychology and intuition as ballistic science.

Combat in orbital space would more closely resemble your knife fight description - with smaller ships at closer range.

My thoughts on SDB's original analysis were pretty similar, although I believe you articulated them better.

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Tim, your comment thingy ate my comment. So, here it is:

Tim has a good point on decoys, which could be very effective in space. A hollow balloon like object, with a small rocket could be designed to have the same IR and radar signature as a real ship. This could be very effective until someone develops an effective mass detector...

Tim's thoughts that missiles would be the primary means of offense are off base, because of the rocket equation. To engage at long distances would require prohibitively large missiles. Unless they launched, coasted, and then exploded. Which means you're better off with a cannon - you'll get more d-v per unit fuel/explosive.

I would actually expect a missiles flight to go in several stages.

Here's how I see a typical long range engagement going.
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The recoil problem is not insoluable, although it takes more energy. You launch a much heavier projectile in the opposite direction (heavier to reduce its range & possible ill effect on allies behind you). The same basic principle as a recoiless rifle. I would imagine such a "railgun" would be a remotely fired device so the heat signature would not reveal the command module. The better use of such a thing might be as a mine, similar to the seabed mines which fire a torpedo at an appropriate noise signature. They could orbit cold, firing at an "intruder" when activated. The energy considerations are a real issue -- maybe this is what asteroids were really created for. Of course, if you really want relativistic speeds, go back to the particle beam.

A few observations here since "Clueless" didn't leave a space for comments. First, the assumption that space craft would not incorporate new technology (i.e.things he did not believe in) may be hasty. For example, Aviation Week recently had a one page spread on Zero Point Energy (ZPE), that is, the energy remaining in matter at absolute zero. I don't pretend to understand the math, but the gist of the story is that someone has managed to recover some of that energy, although nowhere near breakeven yet. The potential seems to be greater than energy stored in matter by nuclear means. Considering how rapidly nuclear energy progressed from theory to both weaponry and powerplant status, ZPE may not be that far away. Second, there is real work being done on the nature of gravity, which may have potential for both powerplant use and for communications, since gravitons do not seem to be constrained by the speed of light. Finally, accepting the posited constraints, it would seem to me that the liklihood of warships in space is vanishingly small because the energy required to fight is so great compared to what is available within the constraints. Remember that you are always in orbit about something, and that the delta v available is always considerably less than the orbital velocity, so that maneuvering is likely to be a slow and tedious process. By the by, I wouldn't assume that people won't use nuc's in space. If they feel that it will give them an advantage, they'll use them. More likely they won't because nuc's are not as effective in space. Without blast and thermal effects as kill mechanisms, you are left with just radiation, and radiation falls off as one over r-cubed, meaning you have to get pretty close to avoid being stopped by ordinary shielding for interstellar radiation.

Steven Den Beste says that removing heat from a spaceship requires radiation.

For a warship, I can see one possible convective solution. Carry a tank of liquid nitrogen or similar cold fluid (water?), and use it to cool high-energy weapons systems, then use the hot, nitrogen gas for thrusters to make your trajectory erratic.

You can't really use this method for general ship cooling, as that would require concentrating the waste heat, which means refrigeration, which adds heat to the equation, and you can't carry enough liquid nitrogen (or water) to cool over a long time.

The thing is, there's no real place to gain or lose heat from if you do it right - have a tank of liquid nitrogen(or hydrogen/oxygen, for that matter) out back, connect it to your ship by scaffolding that's not particularly thermally conductive, and insulate it a little. It's already in a shiny metal tank inside a vacuum, think of it as a Thermos bottle of the gods. Pump the gas into your ship and cool yourself off, then use it for reaction mass and/or supply(if you're using H2 and O2). Mind you, the weight of a massive tank of liquid will NOT be negligeble, but when it serves as a combination of coolant and thrust mass, you're not doing too badly.

One question we haven't answered in these discussions yet is this: Who will be fighting whom?

Barring some breakthrough in gravitics or some other discovery that rewrites the rulebook (which is beyond the scope of the discussion), one has to assume both combatants will come from within the same planetary system. Maybe even the same planet.

If you're talking about different planets/habitats within the same system (Earth vs. The Outer Colonies or some such), there may be a role for the relativistic weapons described above...unfortunately.

I'm thinking "strategic deterrent." If you have some means (like a mass driver, though constant acceleration would seem to be required for what I'm proposing) of accelerating a sizable mass to 10 or 20 percent of C (or worse, 98-plus percent as in the "Killing Star" scenario), you don't need to target your enemy's fleet--you target his mass drivers (counterforce strategy)...

...or his homeworld (countervalue strategy). With this technology, it might be easier and cheaper to pasteurize the homeworld than to destroy the fleet. A Cold War scenario, writ large.

Your thoughts?

It would be trivial to launch a fleet of nukes to another planet with 1960s technology(toss another stage or so on an ICBM and you've got yourself an IPBM), but then you have concerns about things like enemy defences(a good-sized maser or EMP will totally ruin your day in most cases). However, your proposal to do it with inert objects is unlikely, at best. Unless you can launch a dinosaur-killer-sized rock at them(requiring one mother of a big mass driver, you'd probably have to bore through the Moon and use it), you couldn't do counterforce or countervalue worth crap unless you could get GPS-style accuracy at a billion miles.

Alex,
I think Bechtel could tunnel through the Moon for you. They did the Big Dig after all, and that turned out just fine.

As for relativistic projectiles, peek back a few entries for the link to the planet killer simulator. If it's to be trusted, it predicts the ridiculous destruction even a small mass can yield.

Of course, then you have relativity to worry about as you close in on C, what with the time slowing down and the mass increasing and all that. I know I'd sure have egg on my face when my relativity bomb struck the enemy homeworld 1000 years after the peace treaty was signed!

Nah, just plant a big frickin' "laser" on the moon and fire it downwards ;)

And by planet-killer, do you mean the meteor impact sim? If so, I picked it up from anohter site. It says that a 100m-diamater at 2/3 c is a bit bigger than Chixculub(i.e., well into "ruin your whole day" range), but that's also absurdly big. Remember that we'll probably be bombarding the outer solar system(who wants Mercury or Venus?), so we'll be firing a billion miles or more up the Sun's potential well(which is less than it sounds but is NOT negligeble), and any energy we want to have land there has to be imparted here. Multigigaton blasts don't come cheap on the energy side, even given planet-based technology and a mass driver thousands of miles long(like a Moon coring).

The problem here is that you are all designing weapons without a mission, always an exercise in futility. Certainly the first space weapons will be near-earth weaponry/sensors used to attack earth targets or counter-weaponry/sensors for same. Next will be moon-based. From there onwards it's hard to see what anyone would be wanting to do in deep space unless one imagines colonies. After all, it is people, and their politics, that are the ultimate targets. Personally I can't imagine sending people - as opposed to machinery - anywhere much beyond the moon. Not enough bang for the buck.

Interesting, but I'm still trying to wrap my little mind around this bit: "actively trying to jink and maneuver to avoid your righteous..."

Jinking? In space? I think not! Starwars was fun, yes, but none too realistic. Besides, I'm still fuming about Vader having to "dial in" his targeting system with the turn knobs on his controls. He shoulda' eyeballed the sucker and blasted him!

Yes, I'm quibbling. My way of saying thanks for contributing to the post at USS Clueless. Information is always more better.

William,

The basic missions for a space force will be similar if not identical to modern ocean navies.

1. Projection of force against the enemies targets of value (planets, colonies, space stations, refineries, etc.).

2. Interception and capture/destruction of enemy shipping.

3. Protecting your own targets of value.

4. Protecting your own shipping from capture/destruction.

Kresh,

Jinking in this context is just another way of saying dodging on in semi-random directions so that you end up in a different position than where your enemy is firing. The methods used will be different from planes (engines and thrusters instead of elevators and ailerons and rudders), but the intent and result is the same.

You are right that Star Wars isn't realistic, but I don't think anyone hear was under the assumption it was.

Tim

Tim,
I don't argue with your definition of jinking,etc, but I think it's utility in a space scenario is greatly overrated. Generally, given the chosen constraints and assumptions we've been working under, the amount of delta-v will be so small compared to orbital V that it's unlikely to be effective, except against unguided missiles or projectiles. Various kinds of countermeasures are more likely to achieve the desired results.

"Jinking" will be useful against beam weapons, if there are any useful ones. Ship-to-ship engagements will likely be at distances with a perceptible fraction of a second of light delay. With distances like that and the small visible size of ships at that distance, jinking to keep a beam weapon from doing damage will be useful.

John,

A wise defensive strategy guards against all likely attacks.

Any guided weapon in space that I can imagine requires a propulsion system that makes it easier to detect and electronics that make it vunerable to certain counter-measures.

On the other hand, beam or especially projectile weapons at a considerable distance are unguided and while they can be very difficult to detect in time (with energy weapons) or defeat with active measures (projectiles), they must directly impact in order to do damage.

At a distance of several light seconds, the image of where you target is takes several seconds to reach you, and then your beam weapons take several more seconds to reach it. If it is able to change it's position by as much as one ship width during that time, you miss (and given the heat issues den Beste describes so eloquently, you won't exactly be able to just spray-and-pray any many shots as fast as you want). With a projectile weapon, you can probably shoot more projectiles with a wider "spread" (the volume of space they cover effectively), but even assuming extremely fast projectiles, they could take several MINUTES to reach the target. Even the most leisurely rate of change in position is enough to cause you to miss.

And remember, for jinking, delta-v compared to orbital v is irrelevant. The only thing that matters is delta-v compared to the time it will take for the projectile/beam weapon to cross the intervening distance and the spread it covers when it arrives.

Most of these posts about "space war" fail to specify the most important item - who is fighting? The answer to that question determines the ranges and velocities involved, which in turn dictates nearly everything else.

There are three possibilities: Earth vs. Earth, interplanetary, and interstellar. Each leads to totally different situations.

The Earth vs. Earth situation would require a return to the days of at least two superpowers, since no one else could afford a space fleet. If the fleets are assembled in low Earth orbit, it seems like the "battle" would take place long before either side has a real "fleet", as one side attacks the other's orbital staging areas. In addition, the space war would be intimately tied to the situation on the planet. Diplomacy, conventional war, and asymmetrical war or terrorism are far more likely than a war in space. If both combatants are on the same planet, it makes little sense for them to spend a fortune to fight in space - the enemy they want to capture/threaten/destroy is on the ground.

Interplanetary war would most likely be between Earth and an upstart human colony on another planet. (No little green men on Mars, so we have to fight eah other.) It will be a _very_ long time before any such colony has the resources to build a fleet.

But _if_ such fleets exist, they will be approaching each other from hundreds of millions of kilometers, at velocities of 10-30 km/sec. That means several things:

1) The concept of two fleets or ships sitting there exchanging fire is silly. Both guns and missiles are limited to about 1-2km/sec, far less than the closing speed of the two fleets. Two convertibles racing towards each other at 100mph while the occupants throw pebbles is a more appropriate analogy - except that the "pebbles" won't hit the ground, so one that is gently tossed minutes or even hours before the two "cars" flash past each other might shatter the windshield of the other car.

2) Kinetic energy weapons will rule. Dump a bunch of cold, nearly inert "smart rocks" out the airlock on a collision course with your opponents fleet. The kinetic energy of a 1kg object at 20km/sec is equivalent to 50kg of TNT. (one ton of TNT is equal to 4.184 x 10^9 joules.)

The "rocks" would have passive sensors (IR) and only small rockets for course adjustments. Small cold targets are stealthy even in space. If you drop them 8 hours before your path crosses your enemy's, you will be 500,000km away. The enemy will see your hot ships, but not your cold rocks. They might see the short rocket burns as the rocks make course adjustments, but it's hard to determine speed and heading from a 1 or 2 second rocket burn. Dodging or shooting down such small fast targets would be tough.
The "rocks" would explode a second or so before impact - not to do more damage, but to spread fragments over a large area and increase the probablility of a hit.

Finally there is interstellar war. This is really a long shot. Without some "magic" drives, the times and distances involved make the whole prospect of interstellar war (or trade, or anything else) quite unlikely. The only exception is the one DenBeste specifically excluded - wars of total destruction. If you are 10 light years away and have the technology to accelerate to 0.1C, you aren't going to invest 100 years in a partial attack. Also, at ten light years, you can't see spacecraft - your targets will be the planets themselves. Again, kinetic energy weapons are the most effective. It takes a huge amount of energy to accelerate a ship to 0.1C. Having done so, spending more energy to slow down at the target is silly - better to just ram the planet. A 100 ton ship at 0.1C has 11,000 megatons of kinetic energy. If you could accelerate at 1G for just over 1 month, you would be at 0.1C. Then shut down engines and coast. Even if your engines burn very bright and hot during the accel, from 10 light years your opponent won't see a thing. After 100 years of coasting, the opponent will be lucky to have a few minutes of advance notice before impact.

On the other hand, if you want to slow down and talk or otherwise interact with the people on the target planet, it will take a month, and you will be a brightly glowing target the entire time. If the talks go badly, news of their failure will take 10 years to reach home, and the next salvo 100 years to arrive, giving them time to launch their own attack. This leads to the chilling conclusion described in "The Killing Star". If you know somebody is out there and they are potentially hostile, logic dictates that you strike first and totally exterminate them. Anything else risks them totally destroying you.

John, even an earth-earth war has space applications, and near-earth orbit is likely to be the location for the first space war. After all, how much more effective can you be if you knock out your enemy's satellite recon, or if you can sit up in orbit and drop bombs on your enemy? How much will your enemy want to prevent that?

Anthony:
True, but this all started with DenBests's discussion of combat between space "fleets". Knocking out satelites can be done with unmanned missles from the ground. Likewise, dropping bombs on your enemy can be done easier and cheaper with ICBMs than from an orbiting platform. (Once something is in orbit, it takes significant energy to slow it down and return it to earth.) An orbital platform is a sitting duck for ground launched missiles. My conclusion is that manned "warships" in space are extremely unlikely in an Earth-Earth scenario.

Regards,

John

John and All,

Maybe we need to go back to square one and consider the situation which exists when war is contemplated. What will be the state of civilization, commerce, and technology when our assumed confrontation takes place?

One could make a case that space war on any significant scale is very unlikely anytime in the near term, say the next 100 years. Just the problems of establishing a meaningful civilization anywhere other than Earth would seem to militate against that. (I buy John's arguments about Earth-Earth struggles) A significant off-Earth infrastructure would require time to develop. That doesn't mean that a little commerce raiding by the equivalent of pirates might not occur, and maybe some punitive actions might be mounted against them, if they can be found. But that is a far cry from major fleet actions in space.

It would seem to me that major fleet actions in space would require what DenBest has preemtively ruled out, the magic drives that offer significant delta-v compared to the orbital velocity of whatever trajectory you happen to be on. This would seem to me to require a significant passage of time to occur. Granted, scientific knowledge is growing geometrically, and the time may be shorter than we think.

So, your thoughts? Time frame? Technology? Protagonists? Situations? Back to square one? This is a fascinating area and we could have a lot of fun whatever scenario we select. My objective is just to be internally consistent.

What do you think?

There are two fesable situations fo a space war that I can see. The first is that it will turn into the next level of air warfare. This is already happening to some extent - GPS and recon sattelites are pretty much the modernized equivalent of recon planes from WW1, which was, at first, their only use(until some guy took a pistol up, and it all went downhill from there...). Earth-based missiles and standard aerodynamic fighters will probably be the primary weapons in tghat, since there's no real reason I can see to lift the weapon platform instead of just the warhead. This will be fairly boring warfare, but it will happen the next time there's any sort of a war between two spacefaring nations.

Time frame: The next war between rich nations

Technology: Probably pretty similar to now, maybe add orbital or laser SDI as the only important difference.

Protagonists: China, Russia, US - pick any two.

Situations: Whatever causes those nations to fight. I think we can all spin scenarios for that one. The only relevant question will be if this is a war with good SDI(not to mention countermeasures to cruise missiles and stealth bombers), or if it's a war where we make the planet glow green for the next 50,000 years.

The other option is something closer to a "The Moon Is A Harsh Mistress" scenario of an off-planet rebellion of some sort, or perhaps colonies of different nations on different planets that are at terrestrial war fighting it out, since those are the only likely scenarios for the first interplanetary war so far as I can see.

Time frame: Not within 50 years. The colonies will have to have actual populations and cultures - we aren't going to war with an Antarctic research station any time soon, and similarly we aren't going to war with an interstellar one. I can see one exception - if the station in question has some really appealing technology it might get raided by someone who hopes to pass off what happened as an accident. That would require an undetected launch though(to maintain deniability), so it's pretty unlikely. So you'll need real colonies on other planets, and even under the most optimistic scenarios I can't see that happening in less than 30 years. After that you'll need time for tension to build and there to be a flashpoint, so this will take quite a while.

Technology: Relevant technologies will probably include better space travel(because if we're still using Shuttle lookalikes 50 years from now, we might as well quit speculating and start mourning), although probably nothing like an Orion. Space catapaults might exist, but that's unlikely and certainly the high end of orbital technology that could happen. In general, the technology will be the same sort of stuff discussed here.

Protagonists and Situations: No real way to tell. Let your creative juices flow on this one, it's too far out to have any good idea of what's going to happen so focus on what *could* happen.

I think probably for the forseeable future (an oxymoron?) we can do worse than look at what history tells us.

Historically, colonizers, i.e. the ones that pay for it, have almost always exploited the colonies while at the same time shortchanging the colonies on the previously agreed support. For a while, the colonies are busy just surviving and exploiting the new territory.

Eventually, they reach something approaching self sufficiency and get tired of being put upon by the colonizers, and when something happens that sets them off, war happens. In our case we called it the Revolutionary War.

Perhaps the most likely colonies would be on Mars or in the Asteroid Belt. See the trilogy "Red Mars, Blue Mars, Green Mars" for a typical scenario. Mars is likely because it's a whole planet waiting to be exploited, and it doesn't need technology much beyond what we now have to be able to survive there. Still, it would take some time and some extended technology to make colonies there economically viable, and longer still to become self sufficient. Perhaps a reasonable time frame would be 200 years in the future.

The asteroids make sense because there is the equivalent of a whole planet, or more, worth of raw materials there just waiting to be harvested. If manufacturing is moved off Earth and into orbit, the asteroids become the most reasonable source of materials.

I can envision a rather roughhewn society living in something like Rama, or a Dyson sphere, or a hollowed out asteroid. Rock Jocks are not likely to take kindly having other people, like colonizers, trying to screw them. The societal needs of asteroid miners are probably going to be more difficult and technologically challenging than Mars. Just growing enough food and finding enough water to be self supporting will be more of a problem since they would be even further out from the sun and would need to learn how to make a successful closed cycle environment. Being that far away from civilization, they would have to set up at least some manufacturing capability in the Belt. Does nanotechnology make sense here? I think it does. I would guess that a Belter War would be at least 300 years away, given the challenges involved.

Technology: In the Belter case, advanced fusion rockets make sense because they need high delta v to push big asteroids into a transfer orbit, and they could use mass from the asteroids themselves for reaction mass. For personnel transport in-system or out to the asteroids, either an ion rocket or a solar sail makes sense because they could provide continuous acceleration along the transfer orbit and thus shorten the transfer time. Within the Belt, they would probably use the regular fusion rocket that they use all the time. Just grab a rock and eat it for reaction mass.

What about the ground pounding colonizers? If they follow history they will severely shortchange any military development, assuming they don't have any large scale wars (cold or hot)going on on Earth. Fat, dumb, and happy, but greedy, is probably a reasonable view. They are unlikely to be as astute in high delta v powerplants as the Belters, simply because they don't need to be. They just need shuttles to get to orbit (not necessarily like the current shuttles) and efficient solar sails or ion rockets to move stuff out of orbit to other locations. My model here is the Dutch merchants of the late days of sail.

Weapons:Belters have two ready made but makeshift weapons: planet-killer asteroids and mining lasers. Their advantage is that they have the asteroids readily available for use as reaction mass or heat sinks. Also as camouflage. Playing hide and seek in the Belt would be to their advantage. Ground pounders would likely have a variety of missile types, as well as miscellaneous manufacturing lasers and solar concentrators (for smelting ores in orbit). Missiles we can understand about how to use. Manufacturing lasers and solar concentrators we might need to think about.

A Belter War scenario sounds interesting to me.

Yeah actually, that is a cool scenario. The only question is, what will the countermeasure be to planetkillers?

Yeah Alex,
It's probably pretty difficult. On the other hand, self sufficient doesn't necessarily mean comfortable or luxurious, so the Belters might be loath to use that option and destroy the source of whatever they can't make or grow themselves. Then too, many of them are likely to still have family and friends groundside, so that weapon may be more of a threat than a real weapon, or else a doomsday weapon: "If we can't survive, neither will you!" Depending on skill and a little luck, though, they could take out orbiting facilities such as ship graving docks or manufacturing plants without impacting Earth proper.

There are probably other weapons available to both sides, I can't claim to have exclusive knowledge. Another area that needs to be fleshed out is sensor systems and communications. Last I knew RADAR, for example, had not reached farther than the Moon, and then only after days of processing to pull a known signal out of the noise. Most orbital surveillance systems tend to be optical rather than electronic, although they do do computer frame subtraction to find moving objects in near real time. It would seem to me that general space surveillance would suffer from humongous amounts of clutter. I don't doubt that 300 years of development would improve sensor systems, but how, and how much? Any sensor experts out there?

In the kind of scenario I put up, it would seem to me that ship to ship actions would be rare, and that something similar to space amphibious landings might be more likely. That said, a space rock could ruin a troop carrier, too! Maybe the Rock Jocks would be smart to let the Earthies come to them and play a little hide and seek? I'm inclined to think that most actions are going to be at fairly close range.

We also need to decide who and what starts this melee.

Alex,
After I had finished my last post it occurred to me that the Earthies would need pushers (or more correctly catchers) to intercept and slow incoming rocks, and then put them into the right orbit to be used as raw materials. As a routine operation the Belters would probably (1)transmit a "departure message" providing transfer orbit parameters for each rock sent in-system, and (2) they would also install some form of homing beacon on each rock to help in acquiring it in a timely way, for intercept. The transfer orbits would probably be offset so that if the rock failed to be caught it would not endanger Earth.

I envision the pushers/catchers as looking something like a three-legged Eiffel Tower. Each leg would have a pad with an electronically controlled adhesive to attach to, and release from, the asteroid. In the central core there would be an extendable tube that would incorporate mining lasers to vaporize the rocks and something like magnetohydrodynamic (MHD) thrusters to ionize and accelerate the vaporized material aft to achieve forward thrust. Power would come from either fusion or fission in the form of electricity. Deflector plates in the discharge end of the tubes would allow the operator to align the thrust through the center of mass of the rock, minimizing the necessity to align the pusher/catcher exactly on the rock. A fairly robust OMS would be needed to maneuver to attach to the rock, and to nudge the rock to maneuver the thrust axis, once attached.

Just some additional thoughts...

Some thoughts from a profesional WSA. Stealth IS TOTALY WORTHLESS in space. Current sensors can distinguish between the back ground radiation left over from the big bang and LH2 cooling the facing side of your ship. Radar can track and range on targets without disclosing it self to units ajaisent to the target but separated my a few miliradians of angle.

Weapons are so totaly overmatched to ANY CONCIEVABLE DEFFENSE that all ships are equaly vulnerable. A .22LR machine gun or EM Rail gun shooting BB's would totaly destroy any ship.

Got to dash, will write more later.

Sincerely, Stewart.

I enjoyed your analysis and thoughts very much, but your ignorance of the facts concerning physics and real space flight doom this piece to insignificance.

Again, there is no stealth in space! The basic premice of your stealth argument betrays total ignorance of the subject. There is no prospect of getting stealth in the future and infact the future is certain to make stealth advances even more impossable than they are now.

Construction of space ships that are required to opperate with rocket technology as we know and envision it in the future, can be destroyed with a BB gun! Close examination of current and future ships/craft reveal that the skins are no thicker than "BEER CANS"!

Current weapons and other systems are so totaly overpowering as to make combat in space imposable! Period!!!!!

That space is such a forbidding environment that maneuver is impossable! No space craft using current or future technology that does not flaunt the laws of physics as we know them, could possably cary enough reaction mass to maneuver as many think! The "JINKING" about the base course maneuver that all think will allow space craft to "DODGE" bullets will amount to at most a few micro-radians of displacement. Not nearly enough to foil a BB machine gun little own a laser or any other beam weapon.

EMP is not and never will be that damaging a weapon. It is very easy to "HARDEN" electronic devices against it while still letting them function.

The persistance of thease idiotic ideas ( combat, maneuver and stealth.) persist because no one has forced the holders to do the math that goes with them!

Space combat with the technology we possess now or any time in the near future is impossable!

What I would like to see, really see, is your thoughts on how combat might work in a fantacy based context, like star trek or wars. By side stepping physics, we can have some fun and get a game together. Without that crevat, it is all over.