As you probably already know, "strategy" refers to the science of successfully fighting an entire campaign or war, while "tactics" refers to the science of successfully fighting a single battle. Predictably some military strategy and tactics are general enough to apply to interplanetary combat, while others do not work at all in the space environment. Sun Tzu's The Art of War, for instance, is general enough to work splendidly. Others will fall afoul of unique features of spatial combat, like the lack of stealth, and the mathematical predictabilty of launch windows and arrival times.

There is a good list of unscientific hackneyed tropes with respect to starship combat in the TV Tropes listing Standard Starship Scuffle.

Three-Dimensional Thinking

A basic but often overlooked feature of interplanetary combat is the fact that it is in three dimensions, not two. Think "airplane dogfighting", not "wet-navy battleship duel".

Actually it is even more extreme than airplane dogfighting, since airplanes have a strict limit of how far up or down they can go. Spacecraft have no limit.

Orientation has no limit as well. In Star Trek you never see one ship approach another with one ship flying "upside down", but in reality there is no reason not to. In many SF space combat games, one can change the ship's orientation in order to allow different sets of weapon turrets to bear on the enemy.

KIRK: Spock?

SPOCK: Sporadic energy readings port side, aft. Could be an impulse turn.

KIRK: He won't break off now. He followed me this far, he'll be back. But, from where...?

SPOCK: He's intelligent, but not experienced. His pattern indicates two-dimensional thinking...

Kirk looks at him, smiles.

KIRK: Full stop.

SULU: Full stop, sir.

KIRK: Descent ten thousand meters. Stand by photon torpedoes.

Starship Enterprise moves downward ten thousand meters. Khan's ship sails by overhead blissfully unaware. Enterprise rises up behind Khan's ship like a striking cobra and shoots Khan's derrière off.

From Star Trek II: The Wrath of Khan

6. When attacking a StarGate, converge on it from different three-dimensional directions as much as possible, again to avoid the StarGate's combat cast.

8. Never lose sight of the immensity of the volume represented by the Stellar Display. It is almost impossible to be caught in mid-space, and if you are careful, your opponent will never discover the strength of a given force until you want him to.

10. Establishing "picket lines" or "screens" of units in space never works. It is a waste of available force and is easily countered by the Enemy. The environment is a vast three-dimensional sea - not a small, flat lake.

From the game StarForce: Alpha Centauri (1974)

Fleet Command

Things become even more complicated if you are an admiral or sky marshal who is responsible for all the ships in a battle, as opposed to a captain who just commands their own ship. Admirals generally control the battle from a room equipped with a Big Board, called an Operations Room or a Combat Information Center (which is NOT the bridge). If you are a lucky admiral the battle occurs near a well defended planetary base or orbital fortress. This allows you to dictate tactics to your task force without having to worry about being personally attacked by rude enemy ships. But if the battle happens out of communication range of a cozy fortress, you will have to risk your pink hide in the battle. You will be in a "flagship", a well defended and strongly armed warship carrying an operations room. This is for C2, C3, C2I, or one of the other C4ISTAR military functions. The flagship captain will take care of running the flagship while the admiral concentrates on running the battle.

Naturally the battle will take a catastrophic turn for the worse if the admiral is killed and/or the flagship is destroyed. You should locate the operations room deep in the armored core of the spacecraft. That absurd exposed bridge on the top of the Starship Enterprise would have been shot off a long time ago. The same goes for the bridge on Space Battleship Yamato.

For more information refer to The Great Heinlein Mystery: Science Fiction, Innovation and Naval Technology by Edward M. Wysocki Jr. If you want the real inside dope, refer to 1945 US Navy CIC manual.

CIC Functions

The Combat Information Center is a little difficult to understand if you are not a member of a military wet navy.

It is NOT the ship's bridge, even though they are commonly arranged much the same as the fictitious "bridge" of Star Trek's Starship Enterprise (this is because real-world CICs were inspired by Matt Jeffries's design, see below). In the real world a wet navy ship's bridge only has a couple of stations. The Starship Enterprise has its bridge located in its CIC for dramatic reasons (the "bridge" is the navigation and helmsman stations, that red console Sulu and Chekov sit at).

It is NOT the fleet command room, though it is often used for one. In reality, non-flagship vessels have their own CICs.

As Christopher Weuve puts it:

The primary mission of CIC is to provide the organized collection, processing, display, competent evaluation, and rapid dissemination of pertinent tactical information and intelligence to command and control stations..

Christopher Weuve

All vital "intelligence" (data) from sensors, scouts, intelligence agencies, central command, other ships, etc. pours into the CIC. The Evaluator's duty is to analyze and evaluate all combat information. They filter the information, deciding what is important and what is noise. They pass the filtered information with suggestions on tactical situations to the Captain and the Flag. The information also goes on the Big Board tactical display.

In a stunning example of science fiction innovation, the very concept of an CIC came from a science fiction novel. In his novel Gray Lensman, legendary author E. E. "Doc" Smith postulated a huge flagship called the Directrix. It contained a monster operations room centered around a seven hundred foot "tank" 3D display, capable of tracking several billion warships on a map of the galaxy. At the Technovology website, Mark Charters mentions a letter to Astounding magazine. Editor John W. Campbell stated the acknowledgement of Captain Cal Lanning that Smith's ideas were used extensively in the design of US Navy warship's Combat Information Centers. At the TV Tropes website, they allege that the Directrix was the inspiration for Chester A. Nimitz to use a similar system for directing fleet operations during the Battle of Midway. After that, everybody started using them, which is how it became a troupe in the first place.

The entire set-up was taken specifically, directly, and consciously from the Directrix. In your story, you reached the situation the Navy was in—more communication channels than integration techniques to handle it. You proposed such an integrating technique and proved how advantageous it could be. You, sir, were 100% right. As the Japanese Navy—not the hypothetical Boskonian fleet—learned at an appalling cost.

Captain Cal Lanning

The bridge of the classic Star Trek Enterprise was designed by Matt Jeffries. In a second stunning example of science fiction innovation it influenced the design of the U.S. Navy master communications center at NAS San Diego. On US naval vessels, their bridge design does not look anything like the bridge of the Starship Enterprise, but the Combat Information Center in a navy vessel does have some resemblances (mostly the Captain's chair in the center of the room). Again, refer to The Great Heinlein Mystery: Science Fiction, Innovation and Naval Technology by Edward M. Wysocki Jr.

The idea of such a centralised control room is surprisingly old; it can be found in science fiction as early as The Struggle For Empire (1900). Early versions were used in the second world war; according to Rear Admiral Cal Laning, the idea for a command information center was taken “specifically, consciously, and directly” from the spaceship Directrix in the Lensman novels of E.E. Smith, Ph.D.,[3] and influenced by the works of his friend and collaborator Robert Heinlein, a retired American naval officer.[4] After the numerous losses during the various naval battles off Guadalcanal during the war of attrition that was part and parcel of the Solomon Islands campaign and the Battle of Guadalcanal the United States Navy employed Operational analysis, determined many of their losses were due to procedure and disorganization, and implemented the Combat Information Centers building on what was initially called "radar plot" according to an essay "CIC Yesterday and Today" by the Naval Historical Center.[5] That same article points out that in 1942 radar, radar procedure, battle experiences, needs, and the CIC all grew up together as needs developed and experience was gained and training spread, all in fits and starts beginning with the earliest radar uses in the Pacific battles starting with the Coral Sea, when radar gave rise to the first tentative attempt to vector an Air CAP to approaching Japanese flights, maturing some before the Battle of Midway, where post-battle analysis of Coral Sea's results had given more confidence in the ability and to the process and the desire was bolstered by new procedures giving their measure of added confidence.

  1. Flight 1957
  2. Flight 1957 referring to the carrier HMS Ark Royal
  3. Unpublished letter from John W. Campbell to E. E. Smith, pages 1–2, Dated 11 June 1947 in the collection of Verna Smith Trestrail
  4. Robert A. Heinlein by William H. Patterson, Jr., volume 1, chapter 24
  7. Aboard Uss Carl Vinson26 Stock Photo Image
From Wikipedia entry Combat Information Center

A ship's bridge is just a two-station place (navigation and helm) mainly meant to control the movement of the ship. Usually the captain is not even present, unless some critical maneuver is underway. Back in the age of steam, the bridge did not even have any controls. They would instead give commands to the engine room where the physical controls are located. They'd either use speaking tubes for verbal commands, or use a ship's wheel and a engine order telegraph. Later the power of electricity allowed the actual controls to be located in the bridge. However, even to this day warships tend to have the physical controls for the weapons to be located deep in a protected area of the ship, not on the exposed. bridge. This allows the weapons to keep on fighting if the bridge is destroyed. Since a spacecraft does not need the visibility of an exposed bridge, it too can locate the bridge in a protected position.

We now know that Research had been working on the Battle Analyzer for many years, but at the time it came as a revelation to us and perhaps we were too easily swept off our feet. Norden's argument, also, was seductively convincing. What did it matter, he said, if the enemy had twice as many ships as we—if the efficiency of ours could be doubled or even trebled? For decades the limiting factor in warfare had been not mechanical but biological—it had become more and more difficult for any single mind, or group of minds, to cope with the rapidly changing complexities of battle in three-dimensional space. Norden's mathematicians had analyzed some of the classic engagements of the past, and had shown that even when we had been victorious we had often operated our units at much less than half of their theoretical efficiency.

The Battle Analyzer would change all this by replacing the operations staff with electronic calculators. The idea was not new, in theory, but until now it had been no more than a utopian dream. Many of us found it difficult to believe that it was still anything but a dream: after we had run through several very complex dummy battles, however, we were convinced.

It was decided to install the Analyzer in four of our heaviest ships, so that each of the main fleets could be equipped with one. At this stage, the trouble began—though we did not know it until later.

The Analyzer contained just short of a million vacuum tubes and needed a team of five hundred technicians to maintain and operate it. It was quite impossible to accommodate the extra staff aboard a battleship, so each of the four units had to be accompanied by a converted liner to carry the technicians not on duty. Installation was also a very slow and tedious business, but by gigantic efforts it was completed in six months.

Then, to our dismay, we were confronted by another crisis. Nearly five thousand highly skilled men had been selected to serve the Analyzers and had been given an intensive course at the Technical Training Schools. At the end of seven months, 10 per cent of them had had nervous breakdowns and only 40 per cent had qualified.

Once again, everyone started to blame everyone else. Norden, of course, said that the Research Staff could not be held responsible, and so incurred the enmity of the Personnel and Training Commands. It was finally decided that the only thing to do was to use two instead of four Analyzers and to bring the others into action as soon as men could be trained. There was little time to lose, for the enemy was still on the offensive and his morale was rising.

The first Analyzer fleet was ordered to recapture the system of Eriston. On the way, by one of the hazards of war, the liner carrying the technicians was struck by a roving mine. A warship would have survived, but the liner with its irreplaceable cargo was totally destroyed. So the operation had to be abandoned.

The other expedition was, at first, more successful. There was no doubt at all that the Analyzer fulfilled its designers' claims, and the enemy was heavily defeated in the first engagements. He withdrew, leaving us in possession of Saphran, Leucon and Hexanerax. But his Intelligence Staff must have noted the change in our tactics and the inexplicable presence of a liner in the heart of our battle-fleet. It must have noted, also, that our first fleet had been accompanied by a similar ship—and had withdrawn when it had been destroyed.

In the next engagement, the enemy used his superior numbers to launch an overwhelming attack on the Analyzer ship and its unarmed consort. The attack was made without regard to losses—both ships were, of course, very heavily protected—and it succeeded. The result was the virtual decapitation of the Fleet, since an effectual transfer to the old operational methods proved impossible. We disengaged under heavy fire, and so lost all our gains and also the systems of Lormyia, Ismarnus, Beronis, Alphanidon and Sideneus. At this stage, Grand Admiral Taxaris expressed his disapproval of Norden by committing suicide, and I assumed supreme command.

From "Superiority" by Sir. Arthur C. Clarke (1951)

CIC Layout

As previously mentioned, Matt Jeffries designed such a logical arrangement for the bridge of the Starship Enterprise that the US Navy studied it when they were designing their command centers. The main idea they favored was the captain/evaluator in the center, where they can turn to look over the shoulder of any of the work stations, plus the idea of a Big Board where currently critical information can be displayed.

Combat Information Center from a U.S. Navy Guided Missile Destroyer DDG51 class, courtesy of Christopher Weuve.

Blue are chairs. Yellow are desks. Red are CRT/Flatscreen monitors. Magenta are rear-projection monitors ("e" and "f"). Lower case letters "a" through "h" are to allow one to match up the deck plans with the photograph. In the photo, right above "e" is the red display showing ships course, speed, and screw (propeller) revolutions. The backs of the chairs have pouches containing manuals for that control station. Note that chairs are bolted to the floor.

Bridge of the starship Enterprise, designed by Matt Jeffries. This is a combination of a bridge (helm/navigation) and a CIC. Captain/Evaluator is in the command swivel chair in the center. All station are arranged so captain can look over the sholders of each operator and examine their displays. In the front is the big board viewscreen.

Battlestar Galactcica CIC

The Battlestar Galactica’s Combat Information Center, or CIC, is a medical-theater-like room that acts as the military nerve center and brain of the Galactica. It is located near the center of the ship, is heavily armored and protected by armed guards, and has a staff of between 35-50 people.

The two highest ranking officers on the ship, Commander Adama and Colonel Tigh, typically stand at the center of the auditorium around the Command Board. This position lets them hear status reports from around the room, and issue orders to the entire ship.

Various pods of workstations provide seating for the rest of the staff. These stations are grouped by function. We see Navigation crew sitting near other navigation crew, weapons officers near other combat functions, communications near the center, and engineering given a special area up top.

Phone kiosks are placed throughout the CIC, with two high profile kiosks on the Command Board. Large display boards and the central Dradis Console provide information to the entire crew of the CIC.

Organized Chaos

The CIC is dealing with a lot of information from all over the ship and trying to relate it to the lead officers who are making decisions. There is a lot of activity related to this information overload, but the design of the CIC has organized it into a reasonably effective flow.

Teams communicate with each other, then that decision flows forward to lead officers, who relate it to Admiral Adama.

Orders flow in the opposite direction.

Admiral Adama can very quickly shout out an order from the center of the CIC and have his lead officers hear it all around him. It can also act as a failsafe: other officers can also hear the same order and act as a confirmation step. From there, the officers can organize their teams to distribute more detailed orders to the entire ship.

Large screens show information that the entire CIC needs to know, while smaller screens display information for specific crew or groups.

Overall, the stadium-like construction of the CIC works well for the low tech approach that the Galactica takes after. Without introducing automation and intelligent computer networks onto the bridge, there is little that could be done to improve the workflow.

From CIC by Clayton Beese (2016)

Tactical Display

Operations rooms are centered around some sort of tactical display, the aforementioned Big Board. In World War 2, you had huge tables with models of soldiers, tanks and aircraft, being moved about by military women using croupier sticks. You can see this in almost any movie about the Battle of Britain, depictions of the famous Battle of Britain Bunker. Another classic item is the grease-pencil annotated polar plot on an edge-lighted transparent plotting board. You can see that one in places ranging from old Voyage to the Bottom of the Sea episodes all the way up to Star Wars A New Hope and The Empire Strikes Back. Still later a Radar or Sonar cathode ray tube with the sweeping line became popular. Those are still used with air-traffic controllers, with aircraft annotation and everything. Then came NASA mission control and quite a few James Bond villains who were fond of video walls composed of multiple monitors displaying all kinds of different data. The Starship Enterprise had a classic Big Board display in the front. Finally, science fiction has postulated that futuristic combat spacecraft will have some species of holographic display (generally spherical) showing the location and vector of all friendly and hostile spacecraft in the battle. The display will probably have additional information, see Long Scan

For more information refer to The Great Heinlein Mystery: Science Fiction, Innovation and Naval Technology by Edward M. Wysocki Jr. If you want the real inside dope, refer to 1945 US Navy CIC manual.

Tactical Display: Croupier Table

Tactical Display: Polar Plot

Tactical Display: Cathode Ray Tube

Tactical Display: Video Wall

"I think the first matter before us," Jim said, "is to briefly discuss the strategic situation. Tactics will follow." Spock handed him a tape; Jim slipped it into the table and activated it. The four small holoprojection units around the table came alive, each one constructing a three-dimensional map of the Galaxy, burning with the bright pinpoints of stars. The map rotated until one seemed to be looking straight "down" through the Galactic disk, and the focus tightened on the Sagittarius Arm—the irregular spiral-arm structure, thirty thousand light-years long and half as wide, that the Federation, the Romulans and the Klingons all shared. From this perspective, the Sag Arm (at least to Jim) looked rather like the North American continent; though it was North America missing most of Canada, and the United States as far west as the Rockies and as far south as Oklahoma. Sol sat on the shore of that great starry lacuna, about where Oklahoma City would have been.

"Here's where we stand," Jim said. The bright "continent" swelled in the map-cube, till the whole cubic was full of the area that would have been southwestern North America, Mexico and the Californias. "Federation, Romulan and Klingon territories are all marked according to the map key." Three sets of very lumpy, irregular shapes, like a group of wrestling amoebas, flashed into color in the starfield: red for the Klingons, gold for the Romulans, blue for the Federation. There was very little regularity about their boundaries with one another, except for one abnormally smooth curvature, almost a section of an egg shape, where the blue space nested with and partly surrounded the gold. "Disputed territories are in orange." There was a lot of orange, both where blue met red and where red met gold; though rather more of the latter. "These schematics include the latest intelligence we have from both Romulans and Klingons. You can see that there are some problems in progress out there. The alliance between the Klingons and the Romulans is either running into some kind of trouble, or is not defined the way we usually define alliances. This gives us our first hint as to why we're out here, gentlebeings—unless Fleet was more open with one of you than it was with me."

Suvuk shook his head slightly; Walsh rolled his eyes at the ceiling. "I've rarely seen them so obtuse," Rihaul said. "Surely something particularly messy is coming up."

"Indeed," Jim said. "Which is why we will be needing to keep in very close touch with one another. Any piece of data, any midnight thought, may give us the clue to figuring out what's going to happen. My staff has done some research involving recent Romulan intelligence reports; I'll be passing that data on to you for your study and comment. Anything, any idea you may come up with, don't hesitate to call me. My intention is to keep this operation very free-form, at least until something happens. For something will happen."

"I wholly agree, Captain," Suvuk said. "Our mission here is as surely provocatory as it is investigatory. One does not waste a destroyer on empty space, or space one expects to stay empty. We are expected to force the Romulans' hand, as Captain Walsh would say."

Jim looked with carefully concealed surprise at Suvuk, who had flashed a quick mild glance at Walsh. Is it just me? he thought. But, no, Vulcans don't make jokes. Certainly this one wouldn't—"Yes, sir," Jim said. "With that in mind, here's our patrol pattern as I envision it; please make any suggestions you find apt."

The map's field changed again, becoming more detailed. The long curved ellipsoid boundary between the two spaces swelled to dominate the cubic; stars in the field became few. "Here we are," Jim said. "Sigma-285 and its environs. I suggest that we spread ourselves out as thinly as we can—not so far as to be out of easy communication with one another, but far enough apart to cover as much territory as possible with any given pattern."

"The ships would be a couple of hundred light-years or so apart," Walsh said.

"That's about right; the boundaries I was considering for the whole patrol area, at least to start with, would be defined by 218 Persei to the Galactic north, 780 Arietis to the south, and the 'east-west' distance along the lines from 56 Arietis to iota Andromedae; about half a Galactic degree. This way, any ship in need of assistance can have it within from a day to an hour, depending on what the situation is."

From My Enemy, My Ally by Diane Duane (1990)

Tactical Display: Holographic Sphere

But as the machine slid swiftly along gleaming passages, Benton saw that the private suite of the grand admiral was no small place. Through door after door he glimpsed tremendous activities. Occasionally they whizzed through open bays of desks where scraps of conversation could be overheard, while all about were annunciators flashing weird symbols incessantly.

"Sector 4," droned a voice, "Pegasus and Altair joining action....Pegasus hit....Pegasus blows up....Cruiser Flotilla 36 moving in from lower port quarter....Altair hit —"

As that faded, the orderly cut across the back of a balcony overlooking a great hail. Far down in the pit Benton could see a huge swirling ball of vapor, glittering with pinpoints of varicolored lights cast upon it by unseen projectors. That would be the ultra-secret Battle Integrator — the marvelous moving solidograph that resolved six dimensions into four. Stern-faced officers watched it intently, snapping orders into phones, and uniformed girl messengers dashed everywhere.

Benton and Torrington were crouched over a curious device in the turret booth. It was a miniature version of the Battle Integrator, a series of transparent concentric spheres cunningly illuminated by fingers of light from a projector in its nucleus. Benton indicated a crawling pink dot.

"That's us," he said. "When we get to point A, Purcell blasts off with everything he has and from there to B we accelerate full power. By the time we get to B you should have recovered from the acceleration shock and manned the thermoscope. The target will be somewhere in the zone COTV. This curve shows its heat characteristics. The minute you pick it up, cut in the tracker and put on your alert light. Get it?"

There were five assorted admirals, two commodores, and a captain in the group.

"But who would have thought they would try to sneak in raiders that way?" growled one. They were looking at the big Battle Integrator whirling and sparkling in Action Hall, not a hundred yards from Bullard's quiet office.

"The unexpected, you know — " put in the captain. "Luckily we had scouts out."

"Yah," spat the admiral. "Boys to do a man's job. Six Vixens, and along come four maulers. All right. The Scouts disintegrated two, but now there are two left and no Vixens. What's to stop 'em from coming right on in? There's nothing heavy enough this side of Mars, and that's five days off using everything."

They stared silently at the telltale ball of mist. High up toward its pole eight dull red marks were dying out., remnants of the blasted ships. The ships were gone, but the after-radiation lingered. Inside them and several degrees down two silvery blobs were crawling slowly. A pale thread of violet light throbbed in the fog, and on it the two blobs lay like pearls on a silken thread. The violet line was their computed trajectory. Its lower terminus was the Moon, Tycho Crater, in which sat the great Defense Building.

"What the — ?" murmured a commodore. A pinkish streak of light appeared like a short-tailed comet out of the nowhere, slowed, brightened, and then condensed to a definite point of glittering light. Instantly the computers in distant rooms noted it, and with flying fingers punched its observed co-ordinates into their machines. A second later another violet thread appeared — the mysterious pink body's course. It lacked little of intersecting that of the two maulers.

"There just can't be any cruisers way up there," said a bewildered vice admiral. He was the Operational Director of the cruiser force and knew.

A loud-speaker began to blare. "The ship just appearing in Sector L-56 Plus 9 Zone is the ex-monitor Vindictive, engaged in target practice. She was propelled there as the result of a mysterious accident. Believed to be damaged and only partly manned. When last seen katatrons were still in working condition, but there are no experienced officers on board, her captain and others have abandoned her — "

From "The Bureaucrat" by Malcolm Jameson, collected in Bullard of the Space Patrol (1951)

But you're going in the wrong direction. A.T. headquarters is in King sector, about five months from Belt City."

"Five months?" Paulsen laughed this time; a free laugh. "Oh, that's orbital distance, not the time it would take to get there. It's a Beltish system of direction. We use Earth's orbital velocity as the standard of distance for an asteroid—the way you use a clock face as the standard of position for an airplane; or a globe of Earth for the standard of reference in a spaceship.

"For instance, in an airplane—the way it's going would be twelve o'clock. If somebody comes up on it at a ninety-degree on the right, say, above it, that would be three o'clock high. Tells a guy where to look.

"But that wouldn't do you any good in a spaceship. Which way's up ? The way you're facing or the way you're going? And are you in an acceleration couch lying down, or a couch-chair like ours? But— well, you've got the 3-D Plan Position Indicator. It's f a globe. You use it like a globe of Earth for your reference."

Paulsen pointed to the global PPI. The faint glow of orange grid reference lines made it look very much like a skeletonized globe of Earth. The navigation stars that the computer selected from the multitude of stars around them shown as bright yel­low dots on the outside surface of the globe. In the center of the globe was one green spark that represented their own ship. Any outside object, Stan knew, would be represented by a red spot within the globe; or if it were a planet or other sizable object, it would intrude as a large red ball. The north-south axis of the globe was in line with the ship's axis; north the direction in which they were going, south the direction from which they were pushed.

"You're in a squadron, diving on the Earthies, and you want to tell the other ships which one you're taking. You use latitude—not many of them; about twenty, forty and sixty degrees of latitude. Then north and south is like in the scope here; north is the way you're going. East and west is a reference from where you're sitting—east is the right side of the scope from here. Then farside and nearside, meaning farside of the scope or near. So if the ship you're after is—well, I don't know how to describe it except to say 'north forty farside east.' That would mean ahead of my ship at an angle of about forty degrees on the far side of my PPI scope and on an east angle from me. Get it?"

"I think so."

"But an asteroid—well, A.T. is in a position that puts it in line with a spot on Earth's orbit that's five months Earth speed further along that orbit than Belt City. So they're five months apart."

"Then you just mean that's its relative position?"

"Yep. Wouldn't take more than two weeks to reach it in this crate. But now, if you want to say where an asteroid is in the Belt, not relative to you in distance, but just where it is, you use the zodiac sign. For instance, Belt City's just entered Taurus; and A.T. is in Libra. Distance is in months; position is in zodiacal sign. Right?"

"Sure. It's easy once you think about it. Makes sense." "Then there's the other part, the sectors. They're named like a deck of cards—ace, king, queen, jack, ten. The Belt's not evenly spaced around its orbit, you know. It sort of divides up into five sectors, with a fair amount of fairly empty space between. So you've got the sectors to contend with too. Think you can manage?"

From Phase Two by Walt and Leigh Richmond (1979)

He jerked back to reality as he entered the gigantic teardrop which was technically the Z9M9Z, socially the Directrix, and ordinarily GFHQ. She had been designed and built specifically to be Grand Fleet Headquarters, and nothing else. She bore no offensive armament, but since she had to protect the presiding geniuses of combat she had every possible defense.

Port Admiral Haynes had learned a bitter lesson during the expedition to Helmuth's base. Long before that relatively small fleet got there he was sick to the core, realizing that fifty thousand vessels simply could not be controlled or maneuvered as a group. If that base had been capable of an offensive or even of a real defense, or if Boskone could have put their fleets into that star-cluster in time, the Patrol would have been defeated ignominiously; and Haynes, wise old tactician that he was, knew it.

Therefore, immediately after the return from that "triumphant" venture, he gave orders to design and to build, at whatever cost, a flagship capable of directing efficiently a million combat units.

The "tank" (the minutely cubed model of the galaxy which is a necessary part of every pilot room) had grown and grown as it became evident that it must be the prime agency in Grand Fleet Operations. Finally, in this last rebuilding, the tank was seven hundred feet in diameter and eighty feet thick in the middle"over seventeen million cubic feet of space in which more than two million tiny lights crawled hither and thither in helpless confusion. For, after the technicians and designers had put that tank into actual service, they had discovered that it was useless. No available mind had been able either to perceive the situation as a whole or to identify with certainty any light or group of lights needing correction; and as for linking up any particular light with its individual, blanket-proof communicator in time to issue orders in space-combat...!

Kinnison looked at the tank, then around the full circle of the million-plug board encircling it. He observed the horde of operators, each one trying frantically to do something. Next he shut his eyes, the better to perceive everything at once, and studied the problem for an hour.

"Attention, everybody!" he thought then. "Open all circuits—do nothing at all for a while." He then called Haynes.

"I think we can clean this up if you'll send over some Simplex analyzers and a crew of technicians. Helmuth had a nice set-up on multiplex controls, and Jalte had some ideas, too. If we add them to this we may have something."

And by the time Worsel arrived, they did.

"Red lights are fleets already in motion," Kinnison explained rapidly to the Velantian. "Greens are fleets still at their bases. Ambers are the planets the reds took off from—connected, you see, by Ryerson string-lights. The white star is us, the Directrix. That violet cross 'way over there is Jalte's planet, our first objective. The pink comets are our free planets, their tails showing their intrinsic velocities. Being so slow, they had to start long ago. The purple circle is the negasphere. It's on its way, too. You take that side, I'll take this. They were supposed to start from the edge of the twelfth sector. The idea was to make it a smooth, bowl-shaped sweep across the galaxy, converging upon the objective, but each of the system marshals apparently wants to run this war to suit himself. Look at that guy there, he's beating the gun by nine thousand parsecs. Watch me pin his ears back!"

He pointed his Simplex at the red light which had so offendingly sprung into being. There was a whirring click and the number 449276 flashed above a board. An operator flicked a switch.

"Grand Fleet Operations!" Kinnison's thought snapped across space. "Why are you taking off without orders?"

"Why, I... I'll give you the marshal, sir..."

"No time! Tell your marshal that one more such break will put him in irons. Land at once! GFO off.

"With around a million fleets to handle we can't spend much time on any one," he thought at Worsel. "But after we get them lined up and get our Rigellians broken in, it won't be so bad."...

...And with the passage of time came order out of chaos. The red lights formed a gigantically sweeping, curving wall; its almost imperceptible forward crawl representing an actual velocity of almost a hundred parsecs an hour. Behind that wall blazed a sea of amber, threaded throughout with the brilliant filaments which were the Ryerson lights. Ahead of it lay a sparkling, almost solid blaze of green. Closer and closer the wall crept toward the bright white star.

And in the "reducer"—the standard, ten-foot tank in the lower well—the entire spectacle was reproduced in miniature. It was plainer there, clearer and much more readily seen: but it was so crowded that details were indistinguishable.

From Gray Lensman, by E.E. 'Doc' Smith (1942)

Keep in mind that when Gray Lensman was written, computers were little more than electronic abacuses, there was no such thing as "computer graphics". The described tank was all analog, with physical lights for all the ships.

Westhause smiles. "Looks better on holo, doesn't it?" Clambering around like a baboon in pants, he leads me to an abbreviated astrogator's console. Flanking it are a pair of input/output consoles for the ship's main computation battery. Nudging up in front, like a calf to its mother, is the tiniest spatial display tank I've ever seen. I've see cheap children's battle games with bigger tanks.

"It's just a picket boat. She's staying out of our way. Carmon, warm the display tank."

I sneer at that toy. On the Empire Class Main Battles they have them bigger than our Ops compartment. And they have more than one. For a thrill, in null grav, you can dive in and swim among the stars. If you don't mind standing Commander's Mast and doing a few weeks' extra duty.

"Bogey Niner accelerating."

We've got nine of them now? My eyes may be open, but my brain has been sleeping.

I watch the tank instead of trying to follow the ascensions, decimations, azimuths, and relative velocities and range rates the talker chirrups. The nearest enemy vessel, which has been tagging along slightly to relative nadir, has begun hauling ass, pushing four gravities, apparently intent on coming abreast of us at the same decimation.

"They do their analyses, too," Yanevich says.

His remark becomes clear when a new green blip materializes in the tank. A parr of little green arrows part from it and course toward the point where bogey Nine would've been had she not accelerated. The friendly blip winks out again. Little red arrows were racing toward it from the repositioned enemy.

"That was a Climber from Training Group. Seems he was expected."

The two missile flights begin seeking targets. Briefly, they chase one another like puppies chasing their tails. Then their dull brains realize that that isn't their mission. They fling apart, searching again. The greenies locate the bogey, surge toward her.

"Put it in the tank," the Old Man orders.

The display tank flickers to a slight adjustment. It gives a skewed view, with the Climber at one boundary. The ship casts a thin cone of red shadow across the tank.

"Got her within twenty degrees of arc," Canzoneri says. A thin black pencil stroke lances down the heart of the red cone. "Baseline within three degrees of Rathgeber."


"Indeterminate." Of course. We'd have to know what kind of ship she is to guess her distance from the intensity of her neutrino output here.

The computer keeps humming. Rose and Canzoneri push hard, though they seem unsure what the Commander wants. Every sensor strains to accumulate more data on the Leviathan.

The Commander breaks his conference long enough to tell Carmon, "Erase the tank display."

Wide-eyed, Carmon does as he's told. This is a big departure from procedure. It leaves us flying blind. There's no other way to bring all the information in a single accessible picture.

"What the hell are they doing?"

Fisherman shrugs.

The Old Man tells Cannon, "Ready for a computer feed."

"Aye, sir."

Rose and Canzoneri pound out silent rhythms on their keyboards. The tank begins to build us a composite of the Leviathan, first using the data from the identification files, then modifying from the current harvest. If reinforcements give us time, the portrayal will reveal every wound, every hull scratch, every potential blind spot.

The display tank sparkles to life.

"Damn! Brown. Turn that thing all the way back up."

Clickety-clack nearly deafens us.

Floating red jewels appear where none ought to be, telling a tale none of us want to hear. We've been englobed. The trans-solar show is a distraction.

"Oh, s**t!" someone says, almost reverently.

They aren't certain of our whereabouts. The moon is well off center of their globe.

I glance at the tank. Just one red blip, moving away fast. There're no dots on the sphere's boundary, indicating known enemies beyond its scope.

From Passage At Arms by Glen Cook (1985)

The display was a hologram about a meter square by half a meter thick and was programmed to show the positions of Sade-138, our planet, and a few other chunks of rock in the system. There were green and red dots to show the positions of our vessels and the Taurans.

"Haven't left yet." Charlie had the display cranked down to minimum scale; the planet was a white ball the size of a large melon and Masaryk II was a green dot off to the right some eight melons away; you couldn't get both on the screen at the same time.

While we were watching a small green dot popped out of the ship's dot and drifted away from it. A ghostly number 2 drifted beside it, and a key projected on the display's lower left-hand corner identified it as 2-Pursuit Drone. Other numbers in the key identified the Masaryk II, a planetary defense fighter and fourteen planetary defense drones. Those sixteen ships were not yet far enough away from one another to have separate dots.

"Another one?" The scale of the holograph display was such that our planet was pea-sized, about five centimeters from the X that marked the position of Sade-138. There were forty-one red and green dots scattered around the field; the key identified number 41 as Tauran Cruiser (2).

I wished our spy satellites had a finer sense of discrimination. But you can only cram so much into a machine the size of a grape.

"What the hell?"

"What's that, Charlie?" I didn't take my eyes off the monitors. Waiting for something to happen.

"The ship, the (enemy) cruiser—it's gone." I looked at the holograph display. He was right; the only red lights were those that stood for the troop carriers.

"Where did it go?" I asked inanely.

"Let's play it back." He programmed the display to go back a couple of minutes and cranked out the scale to where both planet and collapsar showed on the cube. The cruiser showed up, and with it, three green dots. Our "coward," attacking the cruiser with only two drones.

But he had a little help from the laws of physics.

Instead of going into collapsar insertion, he had skimmed around the collapsar field in a slingshot orbit. He had come out going nine-tenths of the speed of light; the drones were going 0.99c, headed straight for the enemy cruiser. Our planet was about a thousand light-seconds from the collapsar, so the Tauran ship had only ten seconds to detect and stop both drones. And at that speed, it didn't matter whether you'd been hit by a nova-bomb or a spitball.

The first drone disintegrated the cruiser, and the other one, 0.01 second behind, glided on down to impact on the planet. The fighter missed the planet by a couple of hundred kilometers and hurtled on into space, decelerating with the maximum twenty-five gees. He'd be back in a couple of months.

From The Forever War by Joe Haldeman (1975)

Combat Theater

In warfare, a Combat Theaters is an area or place in which important military events occur or are progressing.

What we are mainly interested in here is the classification of such theaters. This determines the design of the military assets and the strategies & tactics used, e.g., you ain't gonna be using a sea-going naval battleship in the Battle of the Bulge to crawl through the densely forested Ardennes region of Belgium in order to cross the T with the US infantry line. You use ground units and ground tactics in a ground theater, and naval units and naval tactics in a sea theater.

Ray McVay points out that the US Navy uses color names for the theaters they operate in.

  • Brown Water Naval Ops are conducted in rivers
  • Green Water Naval Ops are conducted along shores and coastlines
  • Blue Water Naval Ops are conducted in the high seas

Mr. McVay goes on to indicate that the latter two theaters have near-perfect analogs in space combat: Orbital Space and Deep Space. I suppose you could call them "Purple Sky" and "Black Sky".

Orbital Space

Orbits around Terra (geocentric) are sometimes classified by altitude above Terra's surface:

  • Low Earth Orbit (LEO): 160 kilometers to 2,000 kilometers. At 160 km one revolution takes about 90 minutes and circular orbital speed is 8 km/s. Affected by inner Van Allen radiation belt.
  • Medium Earth Orbit (MEO): 2,000 kilometers to 35,786 kilometers. Also known as "intermediate circular orbit." Commonly used by satellites that are for navigation (such as Global Positioning System aka GPS), communication, and geodetic/space environment science. The most common altitude is 20,200 km which gives an orbital period of 12 hours.
  • Geosynchronous Orbit (GEO): exactly 35,786 kilometers from surface of Terra (42,164 km from center of Terra). One revolution takes one sidereal day, coinciding with the rotational period of Terra (on other planets the altitude depends upon that planet's particular rotational period). Circular orbital speed for Terra is about 3 km/s. It is jam-packed with communication satellites like sardines in a can. This orbit is affected by the outer Van Allen radiation belt.
  • High Earth Orbit (HEO): anything with an apogee higher than 35,786 kilometers. If the perigee is less than 2,000 km it is called a "highly elliptical orbit."
  • Lunar Orbit: Luna's orbit around Terra has a pericenter of 363,300 kilometers and a apocenter of 405,500 kilometers.

Geosynchronous Orbits (aka "Clarke orbits", named after Sir Arthur C. Clarke) are desirable orbits for communication and spy satellites because they return to the same position over the planet after a period of one sidereal day (for Terra that is about four minutes short of one ordinary day).

A Geostationary Orbit is a special kind of geosynchronous orbit that is even more desirable for such satellites. In those orbits, the satellite always stays put over one spot on Terra like it was welded atop a 35,786 kilometer pole stuck in the ground. For complicated reasons all geostationary orbits have to be over the equator of the planet. In theory you'd need only three communication satellites in geostationary orbit and separated by 120° to provide coverage over all of Terra.

All telecommunication companies want their satellites in geostationary orbit, but there are a limited number of "satellite slots" available due to radio frequency interference. Things get ugly when you have, for instance, two nations at the same longitude but at different latitudes: both want the same slot. The International Telecommunication Union does its best to fairly divide up the slots.

The collection of artificial satellites in geostationary orbit is called the Clarke Belt, again named after Sir Arthur C. Clarke.

Note that geostationary communication satellites are marvelous for talking to positions on Terra at latitude zero (equator) to latitude plus or minus 70°. For latitudes from ±70° to ±90° (north and south pole) you will need a communication satellite in a polar orbit, a highly elliptical orbit , or a statite. Russia uses highly eccentric orbits since those latitudes more or less define Russia. Russian communication satellites commonly use Molniya orbits and Tundra orbits.

About 300 kilometers above geosynchronous orbit is the "graveyard orbit" (aka "disposal orbit" and "junk orbit"). This is where geosynchronous satellites are moved at the end of their operational life, in order to free up a slot. It would take about 1,500 m/s of delta V to de-orbit an old satellite, but only 11 m/s to move it into graveyard orbit. Most satellites have nowhere near enough propellant to deorbit.

Lagrangian points are special points were a space station can sit in a sort-of orbit. Lagrange point 1, 2, and 3 are sort of worthless, since objects there are only in a semi-stable position. The ones you always hear about are L4 and L5, because they have been popularized as the ideal spots to locate giant space colonies. Especially since the plan was to construct such colonies from Lunar materials to save on boost delta V costs. The important thing to remember is that the distance between L4 — Terra, L4 — Luna, and Terra — Luna are all the same (about 384,400 kilometers). Meaning it will take just as long to travel from Terra to L4 as to travel from Terra to Luna.

Having said that, Earth-Luna L2 (EML2) is often suggested as a place to park lunar ice and other resources boosted into Lunar orbit.

If the planet the station orbits has a magnetic field, the planet probably has a radiation belt. Needless to say this is a very bad place to have your orbit located, unless you don't mind little things like a radiation dosage of 25 Severts per year. And that is for Terra, Jupiter's radiation belts are a thousand times worse. In 1973 Pioneer 11 was surprised by radiation levels around Jupiter ten times greater than NASA had predicted. This is why Pioneer did not send back photos of the moon Io since the radiation belt had fried its imaging photo polarimeter. Work on the Voyager space probe came to a screeching halt as they frantically redesigned it to cope with the radiation, but still be assembled in time for the launch window.

Terra's zone of glowing blue death is called the Van Allen radiation belts.

The Inner Belt starts at an altitude from 400 km to 1,200 km, depending on latitude, and ends at an altitude of about 6,000 km, with its most lethal area 3,500 km out. The South Atlantic Anomaly can potentially disrupt satellites in polar orbits, but usually does not pose a problem for manned spaceflights. Except for the ISS. The radiation is high-energy protons (400 MeV).

The Outer Belt ranges from 13,000 km to 60,000 km, with its most lethal area 27,000 km out. The Outer Belt is affected by solar winds, and is thus flattened to 59,500 km in the area directly between the Earth and the Sun, and extends to its maximum distance in the shadow of the Earth. The radiation is high-energy electrons (7 MeV).

A safe channel exists between the belts from 9,000 km to 11,000 km.

Hostile space forces intent on invading or investing a planet will wish to use the planet's orbital space for dropping invading troopers onto the planet, and softening up the planet (and supporting said invading troopers) with orbital bombardment. The planet will be resisting with defending fleets in orbit, orbital fortresses and planetary fortresses.

But as you can see above, orbital space over an industrialized planet is going to be crowded with civilians and commercial space stations. Some of which will be military in disguise.

Also keep in mind that orbital communication and spaceport civilian assets are a substantial part of what makes an industrialized planet valuable. Think about the drastic hit the economy of Terra would suffer if telecommunication satellites were destroyed. Invaders who want to seize a planet because it is valuable would do well to avoid damaging what makes the planet valuable.

Orbital space seems obvious, but let's define it anyway; after all, everything within a light year or so orbits the Sun in some fashion. But for our purposes, in 2015, Orbital space is anything between the upper atmosphere and Earth Departure. This includes GEO, or the geo-synchronous orbits or GPS and communication satellites, the low-fast orbits in NEO currently used for manned missions, and any and all in between. By logical extension, Every planet and moon has an orbital space easy to define by use of Sir Isaac's mighty maths (see Hill Sphere).

So, where does our Navy Space Force operate? Obviously, in orbital space, of course. This is the perfect place to operate using Patrol Rockets and smaller craft to zip to and fro. It is also where Espatiers get the most use — boarding inspections, SAR, and the classic orbital drop on a planet. But that's just the tip of the iceteroid — what about enforcement of quarantine? This could be an even bigger deal than it is today, since the enclosed system of a space station or rocket pretty much insures that if I got it, you got it.


You cannot land on a planet or moon, or leave it — including, notably, Earth — without passing through its surrounding orbital space. This gives orbital space great strategic importance.

I have used 'orbital space' a good deal on this blog without ever defining what it means. Any formal definition would be somewhat arbitrary (like 'the threshold of space') but generally a planet's orbital space is the region dominated by its gravity. Think of it as close enough that you orbit the planet rather than just taking up a nearby solar orbit. (Or orbit a moon instead of its parent planet.) (see Hill Sphere)

For orbital space to have distinctive characteristics, major orbit change maneuvers must also require a substantial effort, a delta v of at least a few hundred meters per second — enough that chemfuel burns are costly in propellant consumption, while high specific impulse burns are time consuming.

Ceres, with an escape velocity of 0.51 km/s and low orbit velocity around 0.35 km/s, is about the minimum size for strategically significant orbital space. Neatly, and not entirely by coincidence, this corresponds to the minimum size for a 'dwarf planet,' shaped (literally!) by geological forces.

Significant zones of orbital space thus surrounds the eight major planets, the Moon, Ceres itself, the four big moons of Jupiter, Titan and six other moons of Saturn, four moons of Uranus, and Triton, along with Pluto and a growing list of outer system objects. We are interested in visiting most of them, and might one day be interested in fighting over them. (This last may not really be very likely, but it is possible, and makes for good thud and blunder space stories.)

Earth and Mars have escape velocities of several km/s, on the same order as interplanetary transfer speeds. (Escape speeds from the giant planets are higher still, but in strategic terms their moon systems are like miniatures of the Solar System, and a somewhat different strategic beast.)

This means that typical encounter speeds in Earth and Mars orbital space are fairly high, even after making the burn from interplanetary transfer orbit. In low Earth orbit, encounter speeds can range from 4 km/s for circular orbits with a 30 degree difference in inclination, up to 22 km/s for a retrograde encounter just below escape velocity. Even at lunar distance a head-on encounter at escape velocity means a relative speed of 2 km/s.

Which makes orbital space a kinetic shooting gallery. A defender can pre-position kinetic target seekers as 'mines' on retrograde orbits, while an attacker coming from deep space needs hardly more than a tap to send kinetics onto a retrograde approach. Moreover, so long as they are below escape velocity, kinetic target seekers will not hurtle off into the void, but keep coming around.

What applies to kinetics also applies to ships. Ships in orbital space do not encounter each other as ships on crossing orbits in deep space do, one flash-past and off they go into the void on their separate paths, needing dozens of km/s of delta v to reverse track and re-engage. Ships orbiting a planet, so long as they are below escape velocity, will swing back around for repeated passes.

And it gets better. Orbital space (specifically, low orbit) is the domain of the Oberth effect. Imagine a target seeker in an elongated elliptical Earth orbit, so that it whips around perigee at 11 km/s, a shade under escape velocity. Let it have a small chemfuel booster good for 3 km/s of delta v. (The booster will have about twice the mass of the target seeker itself.)

Fire the booster at perigee and the target seeker is booted to 14 km/s, well above escape velocity. And its departure speed 'at infinity' will be 8.7 km/s (14 squared - 11 squared). Any target coming from deep space will have its own approach velocity, making for encounter speeds upwards of 12 km/s. A similar boot from low Mars orbit gives a departure speed of 6.2 km/s, and encounter speeds upwards of 10 km/s.

Finally, orbital space has the planet itself at the center of the maelstrom, giving spaceships a rare opportunity to crash, and providing a big exception to the rule that 'everyone sees everything.' You don't see anything through a solid planet or moon, and remote sensor probes can be burned out.

All of this ought to make orbital space militarily … intriguing. Maneuvering there is more complex than in 'flat' space. Kinetics can be deployed cheaply and effectively as a sort of mine warfare.

And it matters, because a large proportion of strategic objectives will surely be in some planet's or moon's orbital space — or on the planet, subject to attack or blockade by whoever controls its orbital space. In any setting where planets are important, a good case can be made that most combat will take place in their orbital space.

Serious space warfare games, like Attack Vector: Tactical, respond to all of this potential by avoiding orbital combat like the plague. This is for good reason. No one has yet figured out to sim convincing orbits in a board game, and not for lack of trying. This is no bar to fiction writers, who only have the problem of getting things right, or at any rate convincing.

But there is one other important consideration for orbital combat in a setting. Most of the interesting complications belong only to the near or midfuture, and become progressively less significant at higher techlevels. The planet or moon remains a physical obstacle, but its surrounding winds and currents matter less to steamships, so to speak, than to sailing ships. The shooting gallery effect matters only if kinetics approaching at 3-15 km/s are effective weapons, while orbital maneuvers are trivial for ships with torch drives.

So if you measure speeds as a fraction of c, don't have the captain fretting over approach orbits and defensive orbital mines.


     Basic Assumptions:
     This paper was written using the following assumptions as a baseline.
     1. 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.
     2. 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.
     3. 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 quote from the author about one such scenario, posting on the Rocketpunk Manifesto topic Space Warfare XIII: “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.

Orbital mechanics obviously drive the strategy of space warfare, and in low and medium orbits will also drive tactics. To avoid turning this paper into a discussion of orbital mechanics, the author will assume that the reader has a basic knowledge of the topic.

The most basic effect of the orbital environment is that movement occurs in a totally different way than it does on Earth. Nothing is stationary, which has significant effects beyond the obvious. At the highest level, the geography of the solar system constantly changes. This will have a significant influence on the timing of events. A colonial revolt, for example, would probably wait until a relief force was at the farthest point. This fact would, of course, be known to the people who are in charge of suppressing such revolts.

One important consequence of this fact is that interception in the classical sense of going out to meet an enemy force is difficult in the extreme. Take the case of one fleet attempting to intercept another approaching from deep space. The intercepting fleet will have to reach a point in deep space ahead of the incoming fleet, and then begin to accelerate to match velocities. Once the fleets have matched velocities (and presumably fought), the intercepting fleet must still stop at the destination planet. At a first approximation, this will require delta-V of approximately four times the transit velocity of the incoming fleet. It is likely, however, that the attacking fleet will have approximately the same amount of mission delta-V in order to provide abort options.

An interesting feature of this type of interception is that the defenders have a significant advantage in the pre-battle use of kinetics. They can release salvoes of lancer-type kinetics right before they begin to decelerate, and the kinetics will hit with the combined velocity of both fleets, while any lancer-type kinetics the attackers launch will be stationary relative to them, and thus to the defenders when they make intercept. (LANCER: aim ship's vector at enemy, gently eject lancer kinetic energy weapons before ship decelerates, then decelerate ship into combat vector while lancers retain ship's destructive delta-V energy)

The suggestion above raises another question. Why not just use the kinetics, and save the fleet for when the (hopefully badly bled) enemy arrives? This leads logically to kinetic IPBMs (InterPlanetary Ballistic Missiles). IPBMs are busses, either recoverable or expendable. Either version bears more resemblance to a full-scale ship then a conventional missile, and carries a large payload of kinetic submunitions. In this scenario, recovery is feasible, but only at a penalty to throw weight and/or velocity. Depending on the timescale, it might be possible to launch multiple loads against a given opponent using a recoverable bus. The difficulty with doing so is that the salvoes with either arrive staggered, or the system will suffer throw weight penalties for later loads, although that might be balanced by said loads coming in faster.

The attacker can obviously launch kinetics shortly before beginning deceleration, which would presumably have the same effect on a waiting defender’s fleet. However, this is not as effective as the defender’s salvos would be for a variety of reasons. First, the kinetics will arrive at a predictable time, and the defender can alter his orbits slightly to ensure that the important stuff is behind the planet at the appropriate time. Spreading out the kinetics could of course defeat this, but that obviously reduces the salvo density, and makes the defender’s task significantly easier. Also, a planet’s orbital space is almost certainly far more crowded than that around a fleet transiting deep space, which could significantly complicate targeting for the attacker. The attacker would probably like as much of the orbital infrastructure intact as possible, or he wouldn’t be invading. He’d simply throw stuff at the planet from a long way away.

All of the above can be reasonably approximated using flat-space assumptions, at least on a tactical level. However, once a vessel enters a planet’s orbital space, that assumption is no longer valid. Before moving on, a definition of orbital space is required. A reasonable definition is a body’s Hill Sphere, the volume in which things will orbit the body instead of its parent. Farther, this definition should be limited to bodies of dwarf planet size and larger, as smaller bodies are likely to exert minimal influence on the paths of ships maneuvering around them.

In a body’s orbital space, any maneuver is likely to take hundreds of m/s of delta-V, which is expensive when using chemfuel or nuclear-thermal, and time-consuming when using any high exhaust velocity drive. With enough delta-V it is theoretically possible to treat orbital space as near-flat, it is unlikely that this will occur during the PMF, as it requires both very high delta-V, and high acceleration. This forces ships to maneuver not as in flat space, but as current vessels do in orbit.

Orbital space has a number of interesting characteristics beyond that. First, the ways in which a ship can maneuver are very constrained. Besides the counter-intuitive nature of orbital maneuvering in general (thrust backwards to go down and faster), the body itself serves as a significant constraint. In low orbits, there is a definite limit to the lowest (and fastest) orbit that can be used, even disregarding the possibility that someone on the planet might not be terribly fond of certain people in orbit (See Section 4 for more information). Projectiles will also tend to curve, rendering targeting more difficult, both for the attacker and the defender, and probably reducing impact velocity compared to the same weapon in flat space. This can have advantages, as well as drawbacks. It might well be harder to track incoming projectiles, particularly bursting kinetics, as mentioned in Section 8. Encounter velocities are likely to be high, ranging from 2 km/s for low orbits with 30 degrees difference in inclination to 22 km/s for posigrade-retrograde orbits meeting at just below escape velocity in low orbit. A kinetic launched from a craft in these cases is likely to only require a few hundred m/s (or less) to make intercept, while the short ranges involved make tracking the target somewhat easier, mitigating the seeker problems mentioned in Section 8. To enhance lethality, the defender can pre-position retrograde kinetic platforms, while the attacker, coming in from an interplanetary transfer, can put similar platforms in with very little trouble. Furthermore, unless the kinetic exceeds escape velocity, it will keep coming around. The biggest problem with reusing kinetics is likely to be targeting.

The same phenomena will apply to ships. Unlike deep-space warfare, where vessels go screaming by each other, then have to turn around, ships meeting in orbit will probably continue to pass by each other until one or both decide to alter their orbit. Even then, low-thrust drives might keep them in proximity for some time thereafter.

All of this gives the attacker, and the defender to some extent, significant reasons to avoid fighting in medium to low orbit. A defender would probably try to engage outside the majority of their own infrastructure, which could be as low as the equivalent of GEO. Even most of the Hill Sphere will be empty space. There are few satellites today outside of GEO (barring scientific missions, which will be relatively far less important than they are today). Activity outside of middle orbits will be confined to certain points, such as the Lagrange points and any natural satellites. These will either have to be defended separately, risking defeat in detail, or the attackers will have to be engaged at the edge of the Hill Sphere.

This casts serious doubt on any sort of “orbital forts”, relatively immobile space stations clustered in low to medium orbit. A far better choice is the equivalent of the Scandinavian coastal defense ships, mentioned briefly in Section 2, which are the equivalent of full laserstars (combat spacecraft built around a large laser weapon), but instead of a full nuclear-electric drive system use something like an NTR, which is cheaper and better suited to the operational environment. It can also be designed for short missions, on the order of days, cutting costs across the board. There are two significant problems with this concept, however.

First, depending on the relative costs of various components, one of these vessels could cost very nearly as much as a full laserstar, but with drastically reduced operational utility. For that matter, it would need the same amount of electrical power as a normal laserstar, and thus likely require the same (or an equivalent) reactor, with savings only resulting from the removal of the actual electric thrusters. This cost would be offset by the need for an alternate engine, probably leaving it a wash, although the use of a bimodal NTR design offers some possibility for small savings. The economies of scale in buying more conventional laserstars would probably make that a cheaper alternative to developing and producing a separate class of ships.

Second, the fact that the two types use different drives with different performance would be a major hindrance operationally. If there are significant numbers of both, the “coastal” laserstars would be tied to the nuclear-electric ones, sacrificing their notional performance edge. The concept only makes sense when the “coastal” laserstars make up most if not all of the fleet. This might be ideal for a less aggressive power, as well as probably being slightly cheaper for a given amount of firepower.

The only things that can function similarly to fixed defenses are kinetics deployed in retrograde orbits with kick motors ready to send them towards any attackers. These orbits might be highly elliptical, with the boosters firing at periapsis to give the maximum possible velocity. Through the use of the Oberth Effect, the boosters would impart great velocities when the projectiles reach their targets in deep space. For example, a projectile in the 32-day orbit described below, with a periapsis velocity of 10.8 km/s, given a 3 km/s delta-V at that point, would have a velocity in deep space of 8.5 km/s.

There are three problems with such a deployment, however. First, the orbital period of such an orbit that is just below escape velocity is around 32 days, which would be the approximate availability interval. Second, the projectile would only be capable of engaging targets in a limited arc, the exact width of which is dependent on the amount of delta-V available and when in its orbit the seeker is retargeted. Near apoapsis, very little delta-V is required for any inclination change, but it will still take the seeker about 16 days to reach periapsis, plus however long it takes to actually reach the target from there. Nearer periapsis, the available delta-V will only suffice for minor changes in final direction. Also, the periapsis point needs to be as low as possible to gain maximum advantage, and any delta-V used for maneuvering will reduce the final attack velocity by a much larger amount. Thirdly, when the projectiles are activated, they will be limited farther in their targeting by the need to avoid collisions with spacecraft already in low orbit. These concerns lead to either a low salvo density or long periods during which no projectiles can be brought to bear, both of which are unsatisfactory. The alternative is to deploy kinetics in a circular low orbit, which ensures constant availability and unlimited targeting within the ecliptic, but gives considerably lower velocity for a given kick motor. The problems of other spacecraft providing the enemy with ‘cover’ are somewhat reduced, because their trajectory does not have an inbound leg, and originates from a single altitude.

Another way of solving this problem is waiting until an attack is known to be inbound before the kinetics are deployed, solving the issues of targeting time and angle. While it might appear that an attacker could alter his orbit to avoid these newly-deployed kinetics, this is unlikely to be a successful tactic. Near apoapsis, alteration of direction windows is nearly free, and slight changes of time window are unlikely to be critical. This renders all attacker maneuvers until the last few days before periapsis futile, and drives up the delta-V required to dodge significantly.

For that matter, it would be possible to deploy the kinetics into a high-altitude circular orbit, and use a small engine to send them towards the planet. This means a response time of approximately 16 days from an orbit at the edge of the Earth’s sphere of influence, and the ability to hit targets across a large proportion of the sky. It also avoids the need to send kinetics screaming through low orbit on a regular basis. Multiple clusters can be positioned around Earth’s orbit, and the majority of them should be able to be combined against any given target. With proper warning, almost all of them could be maneuvered into position to attack.

As part of his classwork in orbital mechanics, the author decided to investigate this concept further, looking at how large of an arc such a projectile could threaten. The initial orbit around Earth was assumed to have a semi-major axis of 426,500 km and an eccentricity of 0.984, giving a perigee altitude of 448 km. The projectile was assumed to have 3 km/s of delta-V. For a tangential burn at perigee (the case which gives the maximum velocity in deep space), the deep-space velocity (Vinf) was 8.52 km/s, in a direction 116.5° counterclockwise from the direction of perigee as viewed from the Earth’s center. A Vinf of 8 km/s or greater is possible across a range of angles 95° to 138.5°. Vinf > 7.5 km/s runs from 86.5° to 147.5°, while the range for Vinf>7 km/s is 79° to 155°. At Vinf >6.5 km/s, the angular range runs from 76° to 161°. Accepting a Vinf lower than 6.5 km/s does not buy much more in terms of angle, due to the vagaries of orbital mechanics. This is a significantly larger arc than it might first appear to be. If we assume that the projectile begins in a circular holding orbit with a radius of 846176 km, it will be traveling at 686.3 m/s. The attack orbit has a velocity at apogee of 86.8 m/s, so insertion will require a minimum delta-V of 599.5 m/s if the attack orbit is tangential to the holding orbit. However, the worst-case attack orbit, which is retrograde to the holding orbit, will only require 733.1 m/s of delta-V. The insertion burn is made at a position with an angle of 180°. This means that to a first approximation, the same lethal arcs will be mirrored in a cone around the 0° line. In reality, there would be a slight boost for prograde attack orbits due to the delta-V saved inserting into them being used at perigee.

The author modified code written for class3, and plotted the combinations of Vinf for various combinations of true anomaly (orbital position) and burn angle. (Figures are at the end of the Section.) All of the trajectories were plotted with a semi-major axis for the attack orbit of 426,500 km, and with both burn angle and true anomaly varying between -120 and 120 degrees in one-degree steps. Any trajectories that passed below an altitude of 122 km were not plotted, as were any that failed to escape Earth’s gravity.

Figure 1 shows the effects of variations in delta-V on the final possible trajectory. All initial attack orbits had an eccentricity of 0.984. The second figure plots the reference case described above, along with two figures intended to show differences in the envelope based on minor differences in initial orbits. The first shows a prograde instead of a retrograde attack orbit (relative to the holding orbit) while the second compares orbits with perigee altitudes of 448 km (reference case) and 2160 km.

Much of the dynamics of orbital combat will be driven by the weapons involved. If the weapons are long-ranged (lasers in the tens of thousands of kilometers, and projectors with muzzle velocities of tens of kilometers per second) then almost all of orbital space is open to fire from a given ship, provided it is not blocked by the planet. In low orbits, horizon distance is likely to be minimal, possibly as low as a few hundred kilometers (counting any planetary atmosphere as part of the horizon). Given the high closing velocities possible, engagements could last a matter of seconds. These would likely be very deadly, probably killing both combatants due to the very small amount of time available to defend against incoming kinetics. If long-range lasers are available, they would also be incredibly deadly in such a knife fight, as described in Section 7. However, any craft equipped with a long-range laser is unlikely to venture into such a low orbit, both to avoid kinetic death, as well as to avoid surface defenses (described in Section 4). To a ship in geostationary Earth orbit (35,786 km / 0.125 light-seconds) the Earth will subtend an arc of about 20 degrees, and any ship in orbit will be visible for at least half the time. Assuming that the laser is capable of hitting targets at such a range, there is no need to move closer. Even if that distance is greater than the range of the weapons, there is no reason for the spacecraft to move in beyond long weapon range. Long-range kinetics are in much the same situation. Thus, short-range orbital knife-fights are only likely to develop in the early days of space warfare, when weapon ranges are short enough that the planetary horizon is not the driving factor in weapon range, or when there are multiple powers who all start in low orbit.

Note, though, that the planetary horizon is not likely to actually hide knowledge of the enemy from a vessel. Even if there are no recon drones in place to monitor the far side of the planet, the vessel should be able to see through the planet’s atmosphere to some extent, even if engagement is impossible. This fact makes popping over the horizon for a surprise attack unlikely. Orbital predictability also works against surprise. Even though it is possible for a craft to alter its orbit, it is relatively easy to predict the effects of it doing so. Nuclear-electric craft, moreover, will not be able to alter their orbits in a meaningful way during the course of a single orbit, making them doubly vulnerable. Thrusters would allow such maneuvering, but a small fuel supply imposes its own limits. Adding to this problem is the likelihood that the opponent has all-around space surveillance capability, either due to global ground stations or recon drones.

The planet itself has often been suggested as a means of allowing some form of detection uncertainty. After all, it is a warm, complex background, as opposed to the cold, simple one of deep space. Theoretically, this is true, and it is much easier to hide when against the background of a planet. There are several factors that weigh against this. First and most importantly, it is incredibly unlikely that a ship will only have one set of sensors pointed at it. Recon drones are very cheap, and would be scattered around liberally. This means that there is a good chance that either right now, or in the not-too-distant past, there was a sensor that saw the target against the background of space for long enough to get a fix on its orbit. The enemy then keeps an eye out for any attempts to adjust course. Secondly, the advantage given by the planet is outweighed by the ranges involved. A sensor system designed to detect ships at light-minute ranges will have no problem finding them against a planetary background at ranges under a light-second. Thirdly, active sensors are completely unaffected by the planet, and a number of the various passive systems are not as badly affected by the planet as IR systems are.

The only real limit to the lethality of kinetics in low orbit is the risk of serious problems from orbital debris. While the kinetic itself might well be travelling significantly faster than escape velocity, most debris from the target will not be. Assuming that both sides desire the orbital infrastructure to remain relatively intact (which may not hold true in all cases) use of large number of kinetics in low and medium orbits is unlikely. The exception is if the target is in a low enough orbit that the debris threat will clear itself quickly due to atmospheric drag, or some other form of orbital decay. Lasers would probably leave the target vessel mostly intact, making it fairly easy to deal with. In this way, low-orbit retrograde kinetics are quite similar to mines. They’re cheap, easy to deploy, and lethal, but also run the risk of serious collateral damage. Depending on the setting, they could be illegal under some treaty, or a commonly-accepted means of defending an orbit.

One interesting side-effect of the common use of low-orbit kinetics (or of any serious orbital debris problem) is the arming and armoring of space stations in those orbits. This is a serious complication for any military commander. There is in fact a legitimate reason for the station to have some firepower, but that firepower also poses a significant risk to any operations in low orbit, even after all overtly military units have been defeated. He could destroy any armed stations, but that is likely to be a serious war crime. On the other hand, desperate people sometimes do stupid things. Unless misuse of anti-debris (or anti-meteor) systems is considered abominable by virtually everyone, this situation has the potential to turn interesting very quickly.

The same orbital infrastructure that prevents indiscriminant kinetic use also has the potential to provide cover to small warcraft. This is often the last type of fighter suggested, as only a small craft would be able to hide amid the orbital clutter. This is the space-based equivalent of house-to-house fighting, messy, destructive, and unpleasant. There are two problems with this suggestion. The first is that the defender is fundamentally pinned down. A smart attacker will have his laserstars sitting nearby, waiting for the defending fighters to flee. If they do, they get picked off. If they don’t move, kinetics can be used against them. The fighter could be replaced by a concealed weapons pod with no real loss of capability. In this case, the attacker’s task is to sweep each installation to ensure that it is free of these pods. The attacker’s ‘fighter’ can be little more than a recon drone. The second problem is that the defender simply can’t win by doing this. His fighters are helpless against the attacker’s fleet, so all he can do is waste time, damage his own orbital facilities, and annoy the attacker. This is unlikely to be useful, as any attacker who wishes to mess around with the installations in low orbit is unlikely to be dissuaded by a few losses to his recon drones. Someone seeking a blockade, on the other hand, is never going to venture down into low orbit at all. While it might be pointed out a defender could choose to fight on, such fighters would have to exist before they could be used. This is improbable, and any smart defender would spend his money on weapons that have a chance of being strategically useful instead of something that is only useful to spite the attacker.

One interesting suggestion that has been put forth is that the demands of orbital defense seem to demand a separate service from the offensive forces. The practicality of this is doubtful, as the ‘offensive’ ships will also have a defensive role in high orbit, and the close-in fighting that serves as the basis for this suggestion is a dubious proposition at best. Also, the fact that ‘defensive’ ships and ‘offensive’ ships would be tactically incompatible makes this even more unlikely. On the other hand, stranger duplications of effort have been known to occur in the past.

Many of the statements above change if there are multiple players in a given orbital space. Examples of this include the situation that would be expected to prevail around Earth, any planet with multiple colonies on it, and for that matter the moon system of gas giants. In this case, there is a distinct operational environment which begins to favor craft with high accelerations and low endurance. As discussed above (and in Section 4), unlimited warfare in low orbit is likely to be devastating to both sides, which means that warfare in low orbit will likely be limited and formalized. Here at last we have a semi-plausible rationale for a space fighter. Low orbit combat is so lethal that platforms must be small, and the transit times are short enough that life support is not a major penalty. Initially, the space forces were developed from the air forces, who took their fighters into space. The fighters fight each other, and then the Espatiers board the space station that was just fought over. The fighters are manned for several reasons. First and foremost is tradition, followed by the fact that at the ranges and timescales involved, light lag cannot be discounted. The presence of men aboard is also a facet of the limited nature of warfare in this setting. However, the “fighter joust” scenario requires both sides to have semi-regular shooting wars (which would presumably extend into space from the planet) without said wars going nuclear/kinetic. Drawing from the (admittedly limited) evidence from similar situations on Earth, most wars in such a setting will instead be conducted at a proxy level.

One common mission in such a setting is going to be inspection and boarding. In deep space, such missions are impractical due to transit time and delta-V requirements. In orbital space, however, it is relatively quick and cheap to meet another spacecraft, giving a role to a sort of Coast Guard. The boarding vessel might be accompanied by one or more “gunships”, either manned or unmanned. This is discussed further in Section 11.

The dynamics discussed above regarding armed civilian space stations would also come into play here, but to an even greater extent. There is even more reason for such stations to be armed, but at the same time, the drawbacks are potentially much greater. It is entirely possible that there could be some agreement, formal or otherwise, that bans or restricts armament on non-military vessels, similar to the restrictions on arming merchant ships. If any armament is allowed, it would probably be limited to that required for defense against debris and maybe very limited point defense capabilities in case of terrorist attacks or accidents.

As an aside in the discussion of orbital mechanics, the Hohmann transfer is commonly used as an approximation of a low-delta-V interplanetary transfer by the space warfare community. However, in the real world, the Hohmann is totally impractical for interplanetary use, as planetary orbits are not coplanar. The reason for this is fairly simple. A Hohmann transfer is essentially defined by a transfer angle of 180°, or as near to this value as practical. If the initial and final orbits are in fact coplanar (as would occur if a Hohmann transfer was being used to raise or lower an orbit), this works quite well. However, if this is generalized to non-coplanar orbits, the system breaks down.

It's a basic principle of orbits that the orbital plane must go through the center of the object being orbited. For a transfer orbit, then, the departure, the destination, and the center of mass define the orbital plane. (After all, a plane is defined by three points.) However, a Hohmann involves the assumption that, when viewed from the 'top' (perpendicular to the plane of the initial orbit), all three points are in a straight line. If the initial and final orbits are coplanar, then all three points are in a straight line in 3-D space as well, and the transfer orbit can be set at any desired inclination, the most efficient obviously being coplanar to the initial and final orbits.

If the two other orbits are not coplanar, then there is a problem. From the 'top', all three points appear to be a straight line, just as they are in a coplanar case. However, unless the transfer happens to take place at exactly the ascending/descending nodes, they will not be in a line in 3-D space. The only time when three points that are not colinear in 3-D space appear to be colinear from a 2-D perspective (which is what the view is in this case) is when the viewpoint is directly on the plane defined by the points. In this case, that plane of the transfer orbit will be at 90° to the initial orbit, and very close to 90° to the destination orbit, which is obviously the worst possible case for delta-V for a given transfer. This effect persists when the transfer angle is close to 180°, and explains the gap in the center of pork-chop plots.

This is why Hohmann transfers are not used in the real world for interplanetary missions. Usually, real-world missions are designed though the the use of numerically-generated pork-chop plots, although nonimpulsive burns complicate this significantly.

* Thanks to Dr. Henry Pernicka of Missouri S&T for putting up with unusual space warfare-related questions, and providing advice on orbits matters throughout.


Karl Gallagher

The only assumption I'd argue with is "the default scenario, unless otherwise noted, is deep-space combat between two fleets." The overwhelming majority of naval battles have been near land or in a narrow body of water. You fight where there's something worth fighting over.

Matter Beam

     A few points I'd like to make. Since it's a long piece of text, I'll write them as I read them.
     -The geography of the Solar System is very predictable. We're already making three-body gravity assist simulations for decades ahead.
     -An intercept is ALWAYS going to happen if the defenders want it. An attacker necessarily runs under the restriction of having to keep deltaV for getting back home, and failing that, cannot deviate so much from their trajectory that they cannot enter orbit around the destination. So with a deltaV advantage and less restrictive maneuvering options, a defender can always force the attacker to expend so much deltaV to evade the intercept that they fail the mission anyways. Best to confront the enemy head on and save the deltaV for tactical maneuvers.
     -You do not have to match velocities at intercept. In fact, you want to increase it to minimize the amount of kinetics you have to drop per target.
     -The interplanetary velocity of kinetics launched before insertion at destination works both ways. The defenders can exploit it too. And it is a sunk cost (you've already accelerated it to the velocity and carried it all the way), so there is no natural advantage to the defenders: kinetics by both sides won't need a booster.
     -Kinetics can be fired months in advance, and have a large fraction, if not more, closing velocity than the attacking fleet itself. Kinetics fired as little as 1 month in advance, and with 10m/s deltaV, can deviate a whole planet-width's distance from the point the attacking fleet expects to start its insertion burn. They are unexpected!
     -Hill sphere is a pretty bad limit for the distinction between orbital and deep space for warfare. At 500,000 km altitude, orbital velocity is 887m/s and the orbital period is about 3 years. That's very flat space.
     -Nuclear thermal rockets are perfectly suited to high-thrust combat. They have excellent power-to-weight ratio, 9km/s exhaust velocity and can put out gigawatts with little need for radiators. Bets of all, we've already built gigawatt NTRs.
     -The orbital fort concept can be useful if you pack a giant laser, kilotons of armor slash heatsinks and a massive nuclear reactor dedicated only to producing electricity. It will outrange attacking laserstars, and can fire for much longer. Then, if for some reason you really needed to dismantle your defenses and chase after the attackers, you can eject the heatsinks, dock a rocket engine, and end up with a rather large and under-capacity warship with full tactical mobility.
     -The only way to pop up over the horizon is to have the two fleets orbiting at the same altitude, with a delay of 10 to 15 minutes (if in low orbit). By slowing down or speeding up, they move over the horizon, and trade laser shots. Kinetics would be very inefficient. However, it is a suicidal move for an attacker to put themselves in full view of both the defending fleet and the planetary defenses below.
     -Orbital warfare must develop from the outside-in, and not as a 'natural evolution' of jet fighter forces. Lasers from the ground, or anti-satellite weapons, will dominate low orbits for a long time to come.
     -I can't comment much about deltaV trajectories. I always assume that by the time we are fighting in deep space with dedicated warships, we'll have efficient enough engines to use impulse trajectories.

Troy Campbell

Faster intercepts are not necessarily better, as we see in Children of a Dead Earth. Whipple shields are great equalisers and you really want to increase time on target to assure a mission kill.

by Byron Coffey

Smuggler's Turn

I've seen this a few times in science fiction but I cannot seem to find any accepted name for it. Perhaps one of you readers can. For now I'll call it The Phssthpok Maneuver. TV Tropes talks about the Spaceship Slingshot Stunt which is not quite the same thing, more like just a gravitational slingsot.

Anyway our heroes are in a spacecraft being hotly pursued by the bad guys, and the heroes cannot see to shake the baddies off their tail. So the heroes dive their ship on a close pass to a planet / gas giant / sun / white dwarf / neutron star / black hole and use either the Oberth effect, gravitational slingshot, or both, to do a bootlegger's turn and escape by shooting off at a wild tangent. The bad guys either are too cowardly to try it, cannot match the velocity, or cannot anticipate the unexpected vector change.

The key is to get as close as possible to something with lots of gravity in order to magnify your efforts to escape.


(ed note: Brennan and Roy are in a heavily-armed Bussard ramjet starship, being chased by two other heavily-armed Bussard ramjet scout ships. The pursuers are slowly gaining on them, over the years.)

      "No man has ever seen this before you," said Brennan, "unless you count me a man." He pointed. "There. That's Epsilon Indi."
     "It's off to the side."
     "We're not headed for it directly. I told you, I'm planning to make a right angle turn in space. There's only one place I can do it."
     "Can we beat the scouts there?"
     "Barely ahead of the second ship, I think. We'll have to fight the first one."

     Ten months after Roy had emerged from the stasis box, the light of the leading pair went out. Minutes later it came on again, but it was dim and flickering.
     "They've gone into deceleration mode," said Brennan.
     In an hour the enemy's drive was producing a steady glow, the red of blue-shifted beryllium emission.
     "I'll have to start my turn too," said Brennan.
     "You want to fight them?"
     "That first pair, anyway. And if I turn now it'll give us a better window."
     "For that right-angle turn."
     "Listen, you can eitber explain that right-angle turn business or stop bringing it up."
     Brennan chuckled. "I have to keep you interested somehow, don't I?"
     "What are you planning? Close orbit around a black hole?"
     "My compliments. That's a good guess. I've found a nonrotating neutron star… almost nonrotating. I wouldn't dare dive into the radiating gas shell around a pulsar, but this beast seems to have a long rotation period and no gas envelope at all. And it's nonluminous. It must be an old one. The scouts'll have trouble finding it, and I can chart a hyperbola through the gravity field that'll take us straight to Home (human colony at Epsilon Indi)."
     "Have you named that star yet?"
     "No," said Brennan.
     "You discovered it. You have the right."
     "I'll call it Phssthpok's Star, then. Bear ye witness. I think we owe him that."

     A day out from the neutron star, one of the green war beams went out. "They finally saw it," said Brennan, "They're lining up for the pass. Otherwise they could wind up being flung off in opposite directions."
     "They're awfully close," said Roy. They were, in a relative sense: they were four light-hours behind Protector, closer than Sol is to Pluto. "And you can't dodge much, can you? It'd foul our course past the star."

     The ship fell away. He saw a tiny humanoid figure crouched in the airlock. Then four tiny flashes. Brennan had one of the high-velocity rifles. He was firing at the Pak (the bad guys in the remaining Bussard ramjets).
     He thought about it for a good hour. Brennan had intimidated him to that extent. He thought it through backward and forward, and then he told Brennan he was crazy.
     "I'm not doubting your professional opinion," said Brennan, "But what symptom was it that tipped you off?"
     "That gun. Why did you shoot at the Pak ship?"
     "I want it wrecked."
     "But you couldn't hit it. You were aiming right at it. I saw you. The star's gravity must have pulled the bullets off course."
     "You think about it. If I'm really off my nut, you'd be justified in taking command."
     "Not necessarily. Sometimes crazy is better than stupid. What I'm really afraid of is that shooting at the Pak ships might make sense. Everything else you do makes sense, sooner or later. If that makes sense I'm gonna quit."

     They were back aboard Protector's isolated lifesystem by then, watching the vision screens and—in Brennan's case—a score of instruments besides. The second Pak team fell toward the miniature sun in four sections: a drive section like a two-edged ax, then a pillbox-shaped lifesystem section, then a gap of several hundred miles, then a much bigger drive section and another pillbox. The first pillbox was just passing perihelion when the neutron star flared.
     A moment ago magnification had showed it as a dim red globe. Now a small blue-white star showed on its surface. The white spot spread, dimming; it spread across the surface without rising in any kind of cloud. Brennan's counters and needles began to chatter and twitch.
     "That should kill him," Brennan said with satisfaction. "Those Pak pilots probably aren't too healthy anyway; they must have picked up a certain amount of radiation over thirty-one thousand light years riding behind a Bussard ramjet."
     "I presume that was a bullet?"
     "Yah. A steel-jacketed bullet. And we're moving against the spin of the star. I slowed it enough that the magnetic field would pick it up and slow it further, and keep on slowing it until it hit the star's surface. There were some uncertainties. I wasn't sure just when it would hit."
     "Very tricky, Captain."
     "The trailing ship probably has it worked out too, but there isn't anything he can do about it." Now the flare was a lemon glow across one flank of Phssthpok's Star. Suddenly another white point glowed at one edge. "Even if they worked it out in advance, they couldn't be sure I had the guns. And there's only one course window they can follow me through. Either I dropped something or I didn't. Let's see what the last pair does."
     Midway they stopped to watch events that had happened an hour ago: the third pair of Pak scouts reconnecting their ships in frantic haste, then using precious reserve fuel to accelerate outward from the star. "Thought so," Brennan grunted. "They don't know what kind of variable velocity weapon I've got, and they can't afford to die now. They're the last. And that puts them on a course that'll take them way the hell away from us. We'll beat them to Home by at least half a year."

From PROTECTOR by Larry Niven (1973)

“He (the hunter-killer singleship from The Fanatics) can blow us out of the sky with his X-ray laser. So why would he want to chase us?”

“For the same reason the hunter-killer didn’t explode when it found us. He wants to take a prisoner. He wants to extract information from a live body.”

He watched her think about that.

She said, “If he does catch up with us, you’ll get your wish to become a martyr. There’s enough anti-beryllium left in the motor to make an explosion that’ll light up the whole system. But that’s a last resort. The singleship is still in turnaround, we have a good head start, and we’re only twenty-eight million kilometres from perihelion. If we get there first, we can whip around the red dwarf, change our course at random. Unless the Fanatic guesses our exit trajectory, that’ll buy us plenty of time.

“He’ll have plenty of time to find us again. We’re a long way from home, and there might be other—”

“All we have to do is live long enough to find out everything we can about the Transcendent’s engineering project, and squirt it home on a tight beam.” The scientist’s smile was dreadful. Her teeth were filmed with blood. “Quit arguing, sailor. Don’t you have work to do?”

From RATS OF THE SYSTEM by Paul J. McAuley (2005)

(ed note: the protagonist is a machine the size of a grain of rice, with an artificially intelligent brain consisting of atomic spin states superimposed on a crystalline rock matrix encoding ten-to-the-twentieth qbits)

      2645, January

     The war is over.
     The survivors are being rounded up and converted.
     In the inner solar system, those of my companions who survived the ferocity of the fighting have already been converted. But here at the very edge of the Oort Cloud, all things go slowly. It will be years, perhaps decades, before the victorious enemy come out here. But with the slow inevitability of gravity, like an outward wave of entropy, they will come.
     The enemy, too, is patient. Here at the edge of the Kuiper, out past Pluto, space is vast, but still not vast enough. The enemy will search every grain of sand in the solar system. My companions will be found, and converted. If it takes ten thousand years, the enemy will search that long to do it.
     I, too, have gone doggo, but my strategy is different. I have altered my orbit. I have a powerful ion-drive, and full tanks of propellant, but I use only the slightest tittle of a cold-gas thruster. I have a chemical kick-stage engine as well, but I do not use it either; using either one of them would signal my position to too many watchers. Among the cold comets, a tittle is enough.
     I am falling into the sun.
     It will take me two hundred and fifty years years to fall, and for two hundred and forty nine years, I will be a dumb rock, a grain of sand with no thermal signature, no motion other than gravity, no sign of life.

     2894, June

     I check my systems. I have been a rock for nearly two hundred and fifty years.
     I come fully to life, and bring my ion engine up to thrust.
     A thousand telescopes must be alerting their brains that I am alive—but it is too late! I am thrusting at a full throttle, five percent of a standard gravity, and I am thrusting inward, deep into the gravity well of the sun. My trajectory is plotted to skim almost the surface of the sun.
     This trajectory has two objectives. First, so close to the sun I will be hard to see. My ion contrail will be washed out in the glare of a light a billion times brighter, and none of the thousand watching eyes will know my plans until it is too late to follow.
     And second, by waiting until I am nearly skimming the sun and then firing my chemical engine deep inside the gravity well, I can make most efficient use of it (Oberth effect). The gravity of the sun will amplify the efficiency of my propellant, magnify my speed. When I cross the orbit of Mercury outbound I will be over one percent of the speed of light and still accelerating.
     I will discard the useless chemical rocket after I exhaust the little bit of impulse it can give me, of course. Chemical rockets have ferocious thrust but little staying power; useful in war but of limited value in an escape. But I will still have my ion engine, and I will have nearly full tanks.
     Five percent of a standard gravity is a feeble thrust by the standards of chemical rocket engines, but chemical rockets exhaust their fuel far too quickly to be able to catch me. I can continue thrusting for years, for decades.
     I pick a bright star, Procyon, for no reason whatever, and boresight it. Perhaps Procyon will have an asteroid belt. At least it must have dust, and perhaps comets. I don’t need much: a grain of sand, a microscopic shard of ice.

     2897, May

     I am chased.
     It is impossible, stupid, unbelievable, inconceivable! I am being chased.

     2929, October

     It is too late. I have now burned the fuel needed to stop.
     Win or lose, we will continue at relativistic speed across the galaxy.

     2934, March

     Procyon gets brighter in front of me, impossibly blindingly bright.
     Seven times brighter than the sun, to be precise, but the blue shift from our motion makes it even brighter, a searing blue.
     I could dive directly into it, vanish into a brief puff of vapor, but the suicidal impulse, like the ability to feel boredom, is another ancient unnecessary instinct that I have long ago pruned from my brain.
     B is my last tiny hope for evasion.
     Procyon is a double star, and B, the smaller of the two, is a white dwarf. It is so small that its surface gravity is tremendous, a million times higher than the gravity of the Earth. Even at the speeds we are traveling, now only ten percent less than the speed of light, its gravity will bend my trajectory.
     I will skim low over the surface of the dwarf star, relativistic dust skimming above the photosphere of a star, and as its gravity bends my trajectory, I will maneuver.
     My enemy, if he fails even slightly to keep up with each of my maneuvers, will be swiftly lost. Even a slight deviation from my trajectory will get amplified enough for me to take advantage of, to throw him off my trail, and I will be free.

From THE LONG CHASE by Geoffrey Landis (2002)

Spirits rose when one of Antopol's drones knocked out the first Tauran cruiser. Not counting the ships left behind for planetary defense, she still had eighteen drones and two fighters. They wheeled around to intercept the second cruiser, by then a few lighthours away, still being harassed by fifteen enemy drones.

One of the Tauran drones got her. Her ancillary crafts continued the attack, but it was a rout. One fighter and three drones fled the battle at maximum acceleration, looping up over the plane of the ecliptic, and were not pursued. We watched them with morbid interest while the enemy cruiser inched back to do battle with us. The fighter was headed back for Sade-138, to escape. Nobody blamed them. In fact, we sent them a farewell-good luck message; they didn't respond, naturally, being zipped up in the tanks. But it would be recorded.

It took the enemy five days to get back to the planet and be comfortably ensconced in a stationary orbit on the other side. We settled in for the inevitable first phase of the attack, which would be aerial and totally automated: their drones against our lasers. I put a force of fifty men and women inside the stasis field, in case one of the drones got through. An empty gesture, really; the enemy could just stand by and wait for them to turn off the field, fry them the second it flickered out.

The gigawatts weren't doing us any good. The Taurans must have figured out the lines of sight ahead of time, and gave them wide berth. That turned out to be fortunate, because it caused Charlie to let his attention wander from the laser monitors for a moment.

"What the hell?"

"What's that, Charlie?" I didn't take my eyes off the monitors. Waiting for something to happen.

"The ship, the cruiser—it's gone." I looked at the holograph display. He was right; the only red lights were those that stood for the troop carriers.

"Where did it go?" I asked inanely.

"Let's play it back." He programmed the display to go back a couple of minutes and cranked out the scale to where both planet and collapsar showed on the cube. The cruiser showed up, and with it, three green dots. Our "coward," attacking the cruiser with only two drones.

But he had a little help from the laws of physics.

Instead of going into collapsar insertion, he had skimmed around the collapsar field in a slingshot orbit. He had come out going nine-tenths of the speed of light; the drones were going .99c, headed straight for the enemy cruiser. Our planet was about a thousand light-seconds from the collapsar, so the Tauran ship had only ten seconds to detect and stop both drones. And at that speed, it didn't matter whether you'd been hit by a nova-bomb or a spitball.

The first drone disintegrated the cruiser, and the other one, .01 second behind, glided on down to impact on the planet. The fighter missed the planet by a couple of hundred kilometers and hurtled on into space, decelerating with the maximum twenty-five gees. He'd be back in a couple of months.

From THE FOREVER WAR by Joe Haldeman (1971)

(ed note: our heroes are in their handwavium faster-than-light doublekay starship, with the dreaded lizaroid AAnn hot on their heels)

'But aktti! Commonsense …!' He paused, and his eyes opened so wide that for a moment Atha was actually alarmed. 'Atha!' She couldn't prevent herself from jumping a little at the shout. He had it. Somehow the idea had risen from its hiding place deep in his mind, where it had lain untouched for years.

'Look, when the Blight was first reached, survey ships went through it — some of it — with an eye towards mapping the place, right? The idea was eventually dropped as impractical — meaning expensive — but all the information that had originally been collected was retained. That'd be only proper. Check with memory and find out if there are any neutron stars in our vicinity.'


'An excellent idea, Captain,' said Wolf. 'I think … yes, there is a possibility — outside and difficult, mind — that we may be able to draw them in after us. Far more enjoyable than a simple suicide.'

'It would be that, Wolf, except for one thing. I am not thinking of even a complicated suicide. Mwolizurl, talk to that machine of yours and find out what it says!'

She punched the required information uncertainly but competently. It took the all-inclusive machine only a moment to image-out a long list of answers.

'Why yes, there is one, Captain. At our present rate of travel, some seventy-two ship-minutes from our current attitude. Co-ordinates are listed, and in this case are recorded as accurate, nine point … nine point seven places.'

'Start punching them in.' He swivelled and bent to the audio mike. 'Attention, everybody. Now that you two minions of peace and tranquillity have effectively pacified half our pursuit, I've been stimulated enough to come up with an equally insane idea. What I'm … what we're going to try is theoretically possible. I don't know if it's been done before or not. There wouldn't be any records of an unsuccessful attempt. I feel we must take the risk. Any alternative to certain death is a preferable one. Capture is otherwise a certainty.'

Truzenzuzex leaned over in harness and spoke into his mike. 'May I inquire into what you … we will attempt to do?'

'Yes,' said Wolf. 'I'll admit to curiosity myself, Captain.'

'Je! We are heading for a nueutron star in this sector for which we have definite co-ordinates. At our present rate of speed we should be impinging on its gravity well at the necessary tangent some seventy … sixty-nine minutes from now. At ha, Wolf, the computer, and myself are going to work like hell the next few minutes to line up that course. If we can hit that field at a certain point at our speed … I am hoping the tremendous pull of the star will throw us out at a speed sufficient to escape the range of the AAnn detector fields. They can hardly be expecting it, and even if they do figure it out, I don't think our friend the Baron would consider doing likewise a worthwhile effort. I almost hope he does. He'd have everything to lose. At the moment, we have very little. Only we humans are crazy enough to try such a stunt anyway, kweli?'

'Yes. Second the motion. Agreed,' said Truzenzuzex. 'If I were in a position to veto this idiotic — which I assure you I would do. However, as I am not… let's get on with it, Captain.'

'Damned with faint praise, eh, philosoph? There are other possibilities, watu. Either we shall miss our impact point and go wide, in which case the entire attempt might as well not have been made and we will be captured and poked into, or we will dive too deeply and be trapped by the star's well, pulled in, and broken up into very small pieces. As Captain I am empowered to make this decision by right … but this is not quite a normal cruise, so I put it to a vote. Objections?'

From THE TAR-AIYM KRANG by Alan Dean Foster (1972)

Deep Space

As Rick Robinson observes above: Ships in orbital space do not encounter each other as ships on crossing orbits in deep space do, one flash-past and off they go into the void on their separate paths, needing dozens of km/s of delta v to reverse track and re-engage. Not quite like jousting, but there are some similarities.

In deep space there generally is no terrain, no forest or hill to anchor your flank so to speak. In Ken Burnside's Attack Vector: Tactical players can use buckshot-like kinetic energy weapons to create their own terrain. In effect, the buckshot is used to herd your opponenet into vectors advantageous to you. Your weapon fire creates "terrain" by rendering certain vectors dangerous to your opponent. Your opponent will be faced with you saying "Heads - I win, Tails - You lose", as they decide if they'd rather suffer the buckshot damage or take a chance on whatever fiendish trap you have laid in the clear vector.


     Basic Assumptions:
     This paper was written using the following assumptions as a baseline.
     1. 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.
     2. 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.
     3. 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 quote from the author about one such scenario, posting on the Rocketpunk Manifesto topic Space Warfare XIII: “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 various environments for space warfare can be classified as follows:

  1. 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.

    1. 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.

    2. 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.

    3. 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.

    4. 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.

  2. INTRAORBITAL WARFARE: Intraorbital warfare covers battles between powers in orbit around the same body when at least one power isn't on the body.

    1. 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.

    2. SURFACE TO STATION WARFARE, LIMITED: This is similar to IIA, 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 IC and ID.

    3. STATION TO STATION WARFARE: This is a battle between two space-based powers. It will likely resemble IIB, though unlimited kinetic warfare is a possibility.


  3. 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.

    1. 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 II, and IIIB.

    2. 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.

      1. 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.

      2. 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.

      3. 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.

      4. 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 Section 6.

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 I warfare, just about every scenario described does not occur between equal powers. For example, take a IIC. 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 III 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.

by Byron Coffey (2016)

The destroyer, Victor-9, was another matter. Neil stared at the readout, trying to absorb it into his subconscious. She was Paltus-class, built at the Novy Rodina shipyards since 2130. She looked like a bolt-action rifle, turned upside down.

She massed more than 400 tons heavier than San Jacinto. She was also slower, at 9 milligees cruise thrust to San Jacinto’s 10, and about 100 kips less cruise range. She couldn’t sustain combat accelerations as long as her American counterpart.

Her main armament was scary; she was one of the smallest warships to mount a no-kidding spinal gun. Called a “keel mount” by some navies, these weapons were heavy mass drivers that propelled a shell through a linear accelerator running the length of the ship. The longer accelerator meant the ship could boost larger masses to greater speeds than the turreted guns in San Jacinto’s main batteries.

Standing in front of Victor-9’s spinal gun could put you in a very bad way.

Beyond that, though, the destroyer’s armament was nothing impressive: two medium lasers that fired in the violet, four smaller IR lasers, and a limited missile capacity. Pretty solid point-defense. But her IR lasers doubled as the ship’s counterbattery … a potential weakness, there, to long-range laser strikes … too bad the San Jacinto’s primary laser armament was also pretty mediocre.

How would she fight? Try to hit with the spinal gun, of course. But gun shells had very limited ability to maneuver themselves; Victor-9 would have to close range to ensure a hit. The information on the spinal cannon’s muzzle velocity was noted as uncertain, as was the maneuverability of its shells. So Neil couldn’t be sure how close the vessel would have to get.

American combat doctrine relegated guns to secondary weapons, but important ones. As guns were unlikely to hit a maneuvering target, captains were taught to think of them as creating terrain on the space battlefield. Fill a section of an enemy’s sky with shells, and he won’t go there. Shoot at his nose if you want him to turn and expose his flanks; shoot to his flanks if you want to prevent him from turning in that direction. Your shells will miss, but you will be able to predict and perhaps control where your target will go.

Neil supposed a really aggressive Paltus captain could use the main gun to create terrain and try to use his lasers to deal real damage, but that was contrary to the ship’s design.

So how should San Jacinto handle her in a head-to-head fight?

First, avoid the spinal cannon shells at all costs. Neil had no idea whether the San Jacinto could survive a direct hit from one, and he didn’t want to find out.

Beyond that, it seemed the choice would be to try to remain at standoff distance, risking San Jacinto’s flanks by always turning perpendicular to the Paltus’ advance, using gun shells to herd the ship while peppering her with missiles, or to close quickly, dodging the inevitable spinal gun shots, and try to rake her at close range.

The first option risked wasting all of San Jacinto’s missiles to the Paltus’ point defenses; the second risked destruction at the spinal cannon.

Can we deceive the Paltus captain somehow? The old space warfare cliché immediately popped into his head … You can run, but you can’t hide. Pretending damage, playing dead … none of those seemed like good options. A suspicious captain would just blast away with the spinal gun.

Our advantage is speed. What about a hybrid of the two options? Point the nose toward the ship and thrust, firing the main batteries to keep her from pointing her nose toward us. When the spinal gun fires, dodge, but dodge toward her, never countering the vector pointed toward the enemy, always closing the distance.

The key was the San Jacinto’s missiles. Hold them back until about 1,000 klicks or less, then ripple-fire them. A few should get through.

The only thing he didn’t like about the plan was its complexity. Skillful handling would be required to avoid the incoming cannon fire.

From Through Struggle, The Stars by John Lumpkin (2011)

Why is a Space Navy so different from a wet-navy? The medium, of course. Space is not like anywhere we've ever been and we've never had to fight up there before. It requires extreme levels of preparedness from all who dare enter, and the physics and mechanics and stuff is all wrong from a naval standpoint. "Stand" — that right there is a good example. In space, nothing "stands", everything is moving all the time, at speeds which impart the force of our most potent explosives. There is also no boarders in space. All planetary bodies are in constant motion — the planet in the next orbit will spend half the time on the other side of the Sun, making it's neighbor farther out the closer. Conjunction is based on the idea that planets move and thus cause the concept of territory to chance with the calendar. That's space for you. It's just not the same.

The rest of space (i.e., non-orbital space), deep space or interplanetary space is huge and open and that doesn't matter, because a spacecraft must travel in certain orbits to get to point A to B for a given speed and Delta V, and there are no exceptions. That being said, since everything is moving all the time at different orbital speeds around the sun, there is no way to establish trade routs or shipping lanes. The use of Hohmann trajectories does allow for convoys and such, but that's about it for interplanetary space; it's a lonely black desert out there, with spacecraft either deliberately close together or impossibly far apart.

As for Interplanetary space, the missions are similar but modified by circumstance. The world of Conjunction moves objects, oil and ore via the convoy system. I thought long and hard about the balance between the added expense of multiple spacecraft and the safety margin provided by the same, and decided that when you are flying missions measured in years, you really shouldn't put all your life support and Delta V in one basket. Therefore, rockets boosting to Saturn from Earth and vice versa, or to anywhere except maybe the moon, will travel in packs. This makes sense from an author's perspective, as well — just ask the writers on Battlestar Galactica. It's a lot more fun for our Astros and Espos to have somewhere to actually go on leave — and for work as well. The oft-mentioned inspection teams, emergency SAR, and even simple cargo transfers all give our Space Navy folks something to do for those long, long months in the Black.

Once, when man first took to the air, the waiting was short, the combat long. The biplanes and tri-planes, with turning circles half the length of Polar Star, could stay in contact till fuel ran out, with never more than five minutes between firing runs.

Then came World War II, and combat sprawling over countries and states while speeds lunged toward a thousand kilometers per hour and time between action doubled, tripled as the pilots, fighting to turn their planes around, swept miles beyond the field of battle before inertia could be bucked enough for return.

And then man broke the sound barrier. The MacDonald Phantom closing on the Mig, radar contact at sixty miles, the pilot inactive, his plane fighting for him as minutes drag, then contact, a shock of missiles, a blaze of fire, and he's fighting the rudder and ailerons, trying to make it around one hundred and eighty degrees of a turn before sliding into Chinese airspace a hundred miles away. A fistful of seconds for an armload of time.

And then into space. Forty minutes' wait while we watch those two fluorescent blue blotches converging across a quarter of the sky, our computers tracking, our nerves tensing, waiting for the five-second explosion, the reflexive punch at the missile control, and then empty sky ahead again, the enemy fading five hundred kilometers back and losing fast, your forward thrusters blazing to slow you down, to allow you to turn at a dead stop, to overcome inertia and rebuild the G-force to send you screaming back to the fray, the time between contact ten, twenty incredible minutes.

And every moment of waiting, while the heat of battle subsides around you, gives you time to think of the dangers you are in, of the dangers just survived, of the dangers you are plunging toward once again. For just a minute between battles, on less! For something to keep the mind a blank till it's needed to handle the stick! But it can't be done, and for ten minutes, twenty minutes, forty minutes, eyes riveted to the screens, you stagger beneath your load of fear. This is where battles are lost and won; this is where our battle was being fought, as the distance between us and the Tars narrowed and the minutes made their slow way by.

From Common Denominator by David Lewis (1972)


Military strategies are methods of arranging and maneuvering large bodies of military forces during armed conflicts (i.e., for the entire war). Wikipedia has a nice list of military strategies here.

Fustest With the Mostest

If Wikipedia is to be trusted, apparently, US Civil War general Nathan Bedford Forrest never really said that... He did say, "git thar fust with the most men," which is close enough.

I bring this up because of Doug's comment on an earlier post that the Lanchester equations are so abstract that they merely say the obvious — if you're gonna hava a fight, it's good to have more guys. Those are the odds. Tactics are how you beat the odds. Yet one of those standard military sayings that gets bandied around is amateurs study tactics, professonals study logistics. The mark of a great general is not so much beating the odds as loading the dice.

In his next comment, however, Doug lets the cat out of the bag — confessing that the real problem with the Lanchesterian logic of deep-space combat is that it rules out cool stuff like space pirates. (Off-topic? Not in the least! This blog is fundamentally about Romance, which emphatically includes Pirates in SPAAACE!)

Logistics. The very word, like "economics," kills Romance and buries her in a shallow grave. ... Logistics and economics are both crucial to realistic worldbuilding — if you want a realistic flavor — because of the same principle: If you are a pirate, raiding galleons / starliners on their voyage each year to Cockaigne, you need to know how many galleons there are to raid.

This, however, is all in the background. The reader doesn't expect to see a table of Cockaigne's imports and exports — only to see a few of the choicest samples, when the rogueish heroes break open a chest or unseal a cargo pod. Even less do we expect to see the logistic underpinnings of warfare. We only hear about the Seabees when someone attacks them and they have to shoot back.

Yet logistics includes the time dimension — the fustest, as well as the mostest — and that is where Romance and logistics meet. Every time the cavalry pennons appear over the brow of the pass just as the fort is about to fall, it means that someone got them mounted up and on the road with the sun. That trumpet blast you hear is the triumph of logistics.

From Fustest With the Mostest by Rick Robinson (2007)

Since the day of the trireme, warships have tended to specialize into types. Today we have such widely different classes as the heavy battleship, capable of keeping the sea in all weathers and dealing out and receiving terrible punishment; the submarine, which operates by stealth; the fast cruiser whose main function is to obtain information; aircraft carriers, transports, and so on. Whether seagoing tug or destroyer leader, each is designed for a definite purpose, and for its job is well nigh indispensible.

The fleets of tomorrow will be quite as specialized, and it may be interesting to speculate on how the conditions of space warfare will react on ship design and employment. If we imagine that the planets have all been colonized and some have set up independent governments, and that men occasionally still fight wars, how would such a war be conducted? What form would the attack take, and what defense could be made?

To simplify, let us assume that relations are at the breaking point between the Earth and Mars, that Mars is aggressive and is sure to attack, that both planets have considerable, and well-balanced fleets. Where and when would the attack fall and how could it be parried?

Since Mars is on the offensive, it can be assumed that she is sending an expeditionary force. She is bent on more than a mere raid, she intends to conquer the Earth if she can. She will therefore have transports full of troops, supply and ammunition ships, and hospital ships. These will be well guarded by warships and there will be special fighting units to beat down any opposition. The Earth cannot afford to wait for this invading armada to appear in her own skies—that would leave too many places to defend. She must intercept the fleet en route and destroy it there, or cripple it so it will have to turn back. Or, failing that, she must know when and where it will arrive so as to concentrate her defense.

Space is vast, and there are many possible routes by which the Martians can come. Which are they using, and how far along are they? These questions must be answered by the scouts. The function of scouts is to obtain information and nothing more. They possess high maneuverability, being of small mass and tremendous accelerative power. They need have little or no armament, but their crews must be handpicked physical specimens capable of enduring much greater accelerations than the run of men. Their chief equipment is thermoscopes, or delicate thermocouples, for locating ships by their intrinsic heat, and radio-sounding devices for measuring distances. And powerful radios, of course, for reporting what they have learned.

Now, although there are a number of possible routes for the Martians to follow, they all fall within a well defined area, just as there are a number of choices of routes between New York and Southampton, but lying in a fairly narrow band. Just as great fleets could not afford to go too far from those to throw an enemy off —as they would run out of fuel—neither could spaceships get too far from their most economical course. Students of rocket-ship trajectories know that the best course is a "C" shaped compound spiral connecting the two planets, and that it lies in or close to the plane of the ecliptic. Within limits, it should be possible to follow nearly parallel courses to one side or the other or above or below that "optimum" course. The locus, or rather the envelope of all such possible courses, would be a crescent shaped solid of circular or elliptical cross-section—something like a curved banana, or a pair of cow's horns set base to base. Its middle section might be as thick as sixty or eighty millions of miles across, but its ends would converge to the diameters of the planets involved.

The scouts know that the enemy is somewhere within this figure, but not how much to the right or left, or how far they have come. Once they can establish several successive points along the invader's trajectory, they can compute the rest. Therefore, the Earth sends out many fast scouts in successive waves.

These scouts spread out so as to cover the entire solid described above, but the space left between any adjacent pair must not be so great that an enemy ship could slip through without detection. If the range of the thermoscopes is five million miles, then the scouts should never be more than ten million miles apart. One or the other could then pick up the enemy vessel. They dart forward, piling up acceleration to the limit of their crews' endurance. By the time they make contact with the enemy, they are hurtling forward at such terrific velocity that their contact is much too brief for fighting. They may over-leap the enemy by millions of miles before they can check their momentum, but it will not matter—they have detected him and reported it.

A second wave of scouts repeats the process a few hours later, and a second point along the enemy's trajectory is known. With a third as a check, computers on the flagship back near Earth can then schedule the enemy's future movements, knowing that he cannot alter his course or speed much without ruinous expenditures of time and fuel. It does not matter greatly whether the Martian cruiser screen destroys some of these scouts or not. A reported scrimmage is a contact, nevertheless, and that is the scout's job.

Without the reports of the scouts, the Earth forces would be blind, not knowing within days when the enemy would strike, or from what quarter. With a knowledge of the most probable course, they can now make preparations to fight. The Earth main body, consisting of minelayers, fast torpedo boats and various battleships, takes off. They get clear of the Earth's gravity and kill their momentum along the Earth's orbit. Then they lie in space, to the sides of the enemy's line of approach, allowing the Earth to recede from them. They are motionless.

More detailed reports from the scouts inform them that the enemy is proceeding in a cruising formation somewhat like a fat, double-ended spear. The shank of it is a cylinder with the transports and other supply ships in line along its axis. The spearheads, front and rear, are cone-shaped formations of heavy fighting ships. Out ahead and on the quarters are clouds of cruiser screens to keep the scouts as far away as possible.

The Earth commander wishes to attack the Martian formation by surprise, if possible, and that is why he lies outside the horn-shaped locus of possible enemy trajectories. After the enemy has passed, the Earth forces will converge upon him from the rear by swiftly building up acceleration. In order to first throw the enemy into confusion and upset his formation (which is designed for quick deployment in any direction and at the same time to protect the non-combatant ships of the train) our admiral sends a squadron of minelayers across his path to strew great numbers of small iron mines. Having laid their mines, the mining ships hurry ahead and get clear, proceeding on to Earth.

As the vanguard of the invading fleet bumps into the mines, they radio the news back to the central column, so that screens can be doubled, collision doors closed and course altered. It is while they are endeavoring to maneuver past these mines that the Earth destroyer divisions attack. They come up by groups from outside space and behind, and as they cross the bows of the formation, they let successive waves of self-accelerating rocket torpedoes go, fanwise.

With torpedoes coming at them from the beam, the ships in the formation are likely to turn themselves by means of their jet deflectors so as to head toward the torpedoes. Their screens are more effective that way, and they also offer a narrower target. But at the same time they continue to drift sideways along their old course from momentum, and therefore will strike many of the mines.

It is just at this moment of confusion that the waiting battleship squadrons overtake them and add their gunfire and torpedo salvos. This attack comes on the opposite flank from the mines. The Martians are beautifully trapped in a three-way cross fire.

The Earthmen's attack is essentially a hit-and-run affair. To overtake the enemy as shown in the diagrams, they must have built up much greater velocity than the Martians and will therefore sweep by at terrific speed, letting go their missiles at the predetermined moment. The Martians have little opportunity to hit back, and will probably sustain heavy damage. Once the defenders are up ahead, they can swing out again, kill their velocity, and prepare to repeat the maneuver.

It must be observed that in this campaign, the defenders are given an advantage—superior information. For any campaign to be decisive, one side or other always has an advantage, otherwise a stalemate will result. To reverse the situation so that the Martians could win, all that is necessary would be to deprive the Earth of its scouts. They would not know then where or when to plant their ambush. Or the Martians might be given an additional advance guard of scouts and heavy ships to entice the Earthmen to come out of their ambush. Such an advance guard would take a heavy beating, but the Earthmen would have exposed their tactics and have shot on ahead. The main body of invaders, ten million miles to the rear, could alter course slightly and avoid both the minefield and any lurking warship divisions.

Terrestrial warfare today leans heavily on the service of information. In the future, information will be paramount. Superior forces are useless if it is not known where and when to employ them. Last year the German pocket battleship Graf Spee furnished an excellent illustration of that. The Allied navies were at all times overwhelmingly more powerful and numerous, yet the Spee roamed the seas for many weeks. Her immunity was due to the fact that her enemies did not know where she was. It took many weeks of searching by great numbers of destroyers and light cruisers to find out where she was not. By the process of elimination they discovered her. Once her location was known, her destruction was inevitable.

In the incredibly vast reaches of the void where up and down is as limitless as any other direction, and where speeds are so great and distances of passing so huge that vision is ruled out, the problems of scouting are magnified a thousand-fold. The war fleets of the future, as I see it, will consist chiefly of scouts—perhaps a hundred for every heavy-duty fighter. Weapons, however powerful and wonderful, are useless ornaments if the enemy cannot be located and brought within range.

From SPACE WAR STRATEGY by Malcolm Jameson (1941)

(ed note: for more see Designing A Space Navy)

This is the second part of our six-part series on Building the Imperial Navy (first part here), in which we extend the strategic assumptions – regarding the security environment and the resources available to meet them – we made in that part into the actual outcomes the Imperial Navy is supposed to achieve.

As is often the case, this is relatively simple. As of 7920, the Imperial Navy’s strategic goals and responsibilities, in order of priority, are defined thus:

  1. Preservation of the assets required for civilization survival in the event of invocation of CASE SKYSHOCK BLACK (excessionary-level invasion posing existential threat) or other extreme-exigent scenario (i.e. concealed backup sites, civilization-backup ships, etc., and other gold-level secured assets).
  2. The defense and security of the Imperial Core (including those portions of it extending into the Fringe), including population, habitats, planets, data, and Transcendent infrastructure against relativistic attack.
  3. The defense and security of the Imperial Core (including those portions of it extending into the Fringe), including population, habitats, planets, data, and Transcendent infrastructure against non-relativistic attack.
  4. The defense and security of stargates and extranet relays throughout the Associated Worlds volume and other associated critical corporate assets of Ring Dynamics, ICC and Bright Shadow, ICC1.
  5. The defense and security of Imperial ecumenical colonies throughout the Associated Worlds volume.
  6. The continued containment of perversions of any class, including but not limited to enforcement of the Containment Treaty of Ancal (i.e. containment of the Leviathan Consciousness).
  7. The maintenance of defenses against possible invasion or other violations of the Worlds-Republic Demarcation Convention.
  8. The protection of Imperial commerce including but not limited to the Imperial merchant fleet.
  9. Intervention, as required, for the protection of the Imperial citizen-shareholder abroad.
  10. Enforcement, as required, of the Accord of the Law of Free Space, the Accord on Protected Planets, the Accord on Trade, the Imperial Plexus Usage Agreement, and the Ley Accords.
  11. When requested or otherwise appropriate, the defense and security of Imperial client-states and allies.
  12. General patrol activities to maintain the perception of security, suppress “unacceptably damaging” brushfire wars, piracy, asymmetrism, and the interstellar slave trade.

It should be noted that with the exception of (7) and certain elements of (6) these are not targeted at specific enemies, of which the Empire has a distinct shortage requiring specific identification at this level; rather, the strategic supergoal of the Imperial Navy is the maintenance of the peaceful status quo, the Pax Imperium Stellarum if you like. Also, specifically, note that none of these goals requires the ability to conquer and occupy; they are all highly defense-focused.

1. This may seem a little high on the list to you, oh reader mine, especially since they’re specifically corporate assets. Well, think of it this way: if you lose the interstellar transportation and communications networks, which those two companies own most of, your fleet can’t find out where to go and couldn’t get there even if it could find out. This, most admirals deem, is something of a problem.


Military tactics are techniques for using weapons or military units in combination for engaging and defeating an enemy in a given battle. Wikipedia has a nice list of military tactics here.

Basic Tactics

"Wet-navy" tactics on the ocean are not interplanetary-navy tactics, but some principles still apply. Christopher Weuve has a "must read" list for anyone who wants to understand strategy and tactics as applied to science fiction.

Some Principles of Maritime Strategy by Sir Julian Corbett. Go to the appendix and read the "Green Pamphlet". As Mr. Weuve says "...which shows you how to think about using a navy. Everything you need to know about Maritime Strategy, in about 30 pages. VERY good stuff."

Edward Luttwak's The Grand Strategy of the Roman Empire. "...which shows you how to think about borders. (Stephen Donaldson's Gap series would have been a lot better had he read this book.)" This book is also very useful if you are writing a science fictional future history. Just read through it, replace "planet" for "city-state", "starship" for "naval vessel", and "stargate" for "road", and your future history writes itself.

Wayne Hughes's Fleet Tactics. "...which shows you how to think about attrition and analyzing tactics."

Frank Uhlig's How Navies Fight. "...which is a book of examples of how different navies have been used."

James George's History of Warships. "...for discussion of why naval vessels are they way they are."


When you boil it all down, here’s what you need to know as an officer:

Divide your command into three elements.

When you contact the enemy, pin him with one element while you use the second to try to maneuver around a flank.

Hold the third element in reserve to exploit any successes the first or second elements may achieve, or to cover their retreat in case of disaster.

It works for platoons, it works for companies, it works for divisions. There are a few refinements, which we’ll cover in the rest of this course, but if you can remember that one basic tactic, you’ll do fine.

From GURPS Traveller Star Mercs by Martin Dougherty and Niel Frier (1999)

The gallery, when the jeep emerged onto it, was empty except for casualties, a few still alive. The side of the airboat was caved in; the lifter-load of ammunition had gone up with the bomb. He moved the jeep to the right of the shaft and waited for the vehicles behind him, suffering a brief indecision.

Never divide your force in the presence of the enemy.

There had been generals who had done that and gotten away with it, but they'd had names like Foxx Travis and Robert E. Lee and Napoleon—Napoleon; that was who'd made that crack about omelets! They'd known what they were doing. He was playing this battle by ear.

from THE COSMIC COMPUTER aka JUNKYARD PLANET by H. Beam Piper (1963)

     The Starfigher Division was something of an experiement.
     Four of Hatawe Ahn’s corvettes sailed through contested space on the grand arc between the leading and trailing StarGates in the border system of Almani Territories. Three Marauders, Tempest, Prospero, and Ariel, each fully loaded with a half dozen Cerberus fighters and a six Destriers, formed a triangular plane in space perpendicular to their vector. The fourth Marauder, Caliban, sailed behind the plane at the apex. Caliban was different. It carried only four Destriers for defense. Instead of mounting six high powered lasers, it only carried two in the bow, flanking the forward cabin. The lateral hardpoints were carried a pair of twin-barreled point defense railguns. The reinforced spine, which on carrier was stuffed with capacitors for the lasers, housed a single long-shaft railgun suitable for ship-to-ship combat.
     They were hunting.
     “Time to convoy forty minutes for outer envelope, forty-nine minutes to launch.”
     Captain 6Djoser Morga acknowledged the report. From the CIC on Caliban, Djoser had could observe, after time-lag, the movements of AdStars logistical fleet. One hundred and thirty-one colliers and dromedaries moved between StarGates on a reciprocal course to Djoser’s stargosy of privateers. 6Djoser’s orders from Command were deliberately vague — capture what he could, destroy as much of the rest as possible. Prospero, at the acme point of the forward plane of battle, was carrying a platoon’s worth of Espatier Ahks in oversized network servers, ready to download into their Ammit-class automatons loaded on the Starfighter’s six Cerberus HACVs.
     They were also something of an experiment.
     “Thirty-two minutes to outer envelope.”
     The convoy was either defended or dead in space. With literally millions of kilometers between the freighters and any safe port of call, scattering was not an option. The only point of clumping so many thousands of tons of shipping into such a small space on a predictable vector would be to place them under the umbrella of protection their escorts could offer. Depending on the value of the cargo, the defending spacecraft could be a couple of corvettes weaker than Caliban, up to a division of destroyers or even more. Djoser was by no means an optimist — at least, not beyond what one needed to go into space in the first place. He assumed at any moment, Caliban’s CIC would erupt with reports of thermal flairs indicating an opposing flotilla.
     “Twenty-six minutes.”
     Djoser gave orders to download Ahks to all fighters and automatons. Across space, sphont and machine interfaced, become those temporary. mongrel creatures of war. The quartet of spacecraft entered their final boosting phase, and observed no change in his prey.
     “Eighteen minutes.”
     It was a trap. It had to be. Something would happen when the two clumps of metal and meat collided. The Stellar Administration was as ruthless and brutal as any polity in space. They would surely have found out about 3Gleise’s negotiations with the Almani. They surely wouldn’t think to send an undefended convoy through space where the government-in-exile could reach. Something was going to happen — Djoser was convinced. But because he couldn’t know what was in store, he kept his ships steady on. Besides, he was damned if AdStar was going to frighten him away.
     “Outer envelope. Nine minutes to launch.”
     Djoser composed himself for battle. “Fire the main gun. On target.”
     Lacking multiple ship killing guns, Djoser couldn’t very well bracket the formation ahead of them. He was half-convinced that the fools wouldn't change vector to dodge anyway.
     “Four minutes to contact, eight minutes to launch.”
     Djoser had four minutes to wait, and another four after to decide the course of the battle. It was always like this -always had been, for sophonts in space. Hours or days of waiting, and a handful of seconds for action. He thought a command to calculate multiple tactical maneuvers and counter attacks against a variety of responses. All at this point were equally likely. He consciously ignored them even has his augmented mind furiously collated data.
     “One minute to contact, five minutes to launch.”
     Djoser became still and calm. All that could be done had been, all that could be planned for was. He was serene in the last seconds, where his crew could see.
     “Contact! Targets one through five eliminated. Four minutes to launch. Targets six through ten eliminated.”
     “M-Com, all Flights, target kinetics, Caliban attack one, vectors and velocity to follow.” Djoser signaled his INCO to send the relevant data. Across the formation, lasers turned and fired on Caliban’s railgun slugs. No matter their monstrous speed, the coherent light easily overtook them and either vaporized the tungsten rods or pushed them out onto terminal vectors.
     “Targets fifteen to twenty eliminated. Targets twenty-two, twenty-six, and twenty-seven eliminated. Launch window.”
     “Launch half the Ceberus wing. Keep the remainder on the kinetics. I want eyes on the eliminated targets soonest.”
     “HC-01 and -02, in range two minutes.”
     There had still been no counter attack, no move to defend or evade. Djoser felt the dread he had been fighting grow ever more powerful as the possible reasons dwindled to a few, each worst than the last.
     Djoser had to swallow before he could talk. “Report.”
     “Passengers? HC-01, is there any cargo?”
     “Time until upload is complete?”
     “UPLOAD EST 01:22:31 +/- 02:00.”
     “All units, begin rescue operations.” Djoser tried and failed to keep the tremor out of his voice.
     “All units acknowledged,” His INCO responded. “All lasers now on hyperband recovery. Cross vectors in thirty seconds.”

     And that was when the convoy’s hidden warships attacked.

From PRIVATEERS by Ray McVay (2016)

"Did you know, Henlo, that certain eminent military tacticians have proved to my satisfaction that war in space is impossible?"

Henlo arched the fur over his eyes. "I haven't hear the theory."

"No, I didn't think you had," Miranid said in a rambling town of voice. "However, our present situation is a splendid example."

"Consider. If you picture the present Vilkan holdings (empire) as a solid sphere in space, bristling with weapons pointed outward, and our own fleet as a hollow sphere designed to contain and crush it, then you must allow that all Farla with half the Galaxy to help it could not supply us with enough strength to keep our sphere impenetrable from the inside at all points. With further problems of uncertain ship detection in hyperspace we could not prevent repeated breakthroughs from the inside."

"Once our hollow sphere is broken it is caught between two fires, and gradually decimated if it does not withdraw into a larger, and even more porous, sphere — which can again be broken. Thus, stalemate, eventual disgust, and finally an inconclusive peace at an inconclusive price."

"Now, since we are not going to be foolish enough to form such a sphere the only alternative is to attempt an attack by a knife-like method. We can spit, split, slice, or whittle."

"Spitting is out of the question. If we try to drive through, we expose ourselves to attack from all sides. The splitting process gives rise to the same objections. This leaves slicing or whittling — and since a whittle is only a small slice, or a slice a large whittle, let us discuss them simultaneously."

Miranid looked steadily at Henlo.

"I will not whittle if I can slice, but I cannot slice, and for the same reason, I cannot whittle. For this is not a clay sphere, Henlo, but a steel ball — and red-hot, to boot. With every stroke I make, I will lose a greater percentage of my available ships than the enemy will."

"His supply lines are short — I've shortened them for him. His ships can land, be repaired, refueled, and re-armed, their crews replaced by fresh men, and sent back into battle a hundred times for each new ship that can reach me from Farla. I have a limited supply of men, equipment, and food. With every stroke, I wear down my sharpness a little more."

He paused an instant, then went on, "Until, finally, I attack the sphere for one last time and my dull, worn knife slips off the surface without leaving an impression. So again, stalemate, eventual disgust, and no true peace — that is, no peace which will not leave conditions immediately ripe for another useless war."

"I would say, as a matter of fact, that this same theory makes true peace impossible so long as any wars are attempted."

(Then Miranid explains how he is going to avoid this unhappy state of affairs in the special case before them.)

From SHADOW ON THE STARS by Algis Budrys (1954).

Slightly dated, but surprisingly good for something written almost eighty years ago.

...There are two great factors in space warfare that will set it off sharply from anything else in human experience, and those two factors will modify fighting ship types, strategy and tactics profoundly. They are: (a) the extent of space. and (b) the tremendous speed of the vessels...

...Speeds in space are as stupendous as the spaces they traverse. Needing seven miles per second to escape the Earth and another twenty to make any reasonable progress between the planets, even the slowest vessels will have speeds of twenty-five miles per second. Warships, presumably, according to type, will have correspondingly higher speeds—perhaps as high as fifty miles per second for the faster scouts...

...When we talk of gunfire or any other means of offense, we have to hear these dizzy speeds firmly in mind. The conclusion is irresistible that scouting, tracking, range finding and relative bearings will all be observed otherwise than visually...

...Each of the combatants must compute the other's course from blind bearings and ranges and lay their guns or point their torpedo tubes by means of a differential calculator.

However, in this blind tracking there is one peculiarity of these ships that while it is in one sense a source of danger to them, is of distinct assistance. In the fleeting minutes of their contact, neither can appreciably alter course or speed! This is a point that writers of fiction frequently ignore for the sake of vivid action, but nevertheless it is an unavoidable characteristic of the ether-borne ship.

The human body can withstand only so much acceleration and the momentum these vessels carry has been built up, hour after hour, by piling increment of speed on top of what had been attained before. In space there is no resistance. Once the rockets are cut, the ship will soar on forever at what ever velocity she had at the moment of cutting. Her master may flip her end over end and reverse his acceleration, but his slowing will be as tedious and cautious as his working up to speed. Jets flung out at right angles merely add another slight component to the velocity, checking nothing.

Rocket experts have stated that an acceleration of one hundred feet per second per second can be withstood by a human being—perhaps one hundred and fifty in an emergency. The master of a vessel proceeding at forty miles per second applying such an acceleration at right angles would succeed in deflecting his flight about one hundred miles by the end of the first minute, during which he will have run twenty-four hundred—a negligible turn, if under fire. Applied as a direct brake, that hundred miles of decreased velocity would slow him by one twenty-fourth—obviously not worth the doing if the emergency is imminent.

WITH these conditions in mind, let us imagine a light cruiser of the future bowling along at forty miles per second on the trail of an enemy. The enemy is also a cruiser, one that has slipped through our screen and is approaching the earth for a fast raid on our cities. He is already decelerating for his prospective descent and is thought to be about one hundred and fifty thousand miles ahead, proceeding at about thirty-five miles per second. Our cruiser is closing on him from a little on his port quarter, and trying to pick him up with its direction finders.

So far we have not seen him. We only know from enciphered code messages received several days ago from our scouting force, now fifty millions astern of us, that he is up ahead. It would take too long here to explain how the scouts secured the information they sent us. The huge system of expanding spirals along which successive patrols searched the half billion cubic miles of dangerous space lying between us and the enemy planet is much too intricate for brief description. It is sufficient for our purposes that the scouts did detect the passage of the hostile cruiser through their web and that they kept their instruments trained on him long enough to identify his trajectory. Being neither in a position to attack advantageously nor well enough armed—for their function is the securing of information, and that only—they passed the enemy's coordinates along to us. This information is vital to us, for without it the probability of contact in the void is so remote as to he nonexistent.

The ship in which we are rushing to battle is not a large one. She is a bare hundred meters in length, but highly powered. Her multiple rocket tubes, now cold and dead, are grouped in the stern. We have no desire for more speed, having all that is manageable already, for after the few seconds of our coming brush with the enemy our velocity is such that we will far overrun him and his destination as well, it will require days of maximum deceleration for us to check our flight and be in a position to return to base.

Our ship's armament, judged by today's standards, will at first sight appear strangely inadequate. Our most destructive weapon is the mine, a simple sphere of meteoric iron about the size of a billiard ball, containing no explosive and not fused. The effectiveness of such mines depends upon the speed with which they are struck by the target ship—no explosive could add much to the damage done by a small lump if iron striking at upward of thirty miles a second. Then there will be torpedo tubes amidships. and perhaps a few guns. but it may be well to post pone a discussion of the armament until we have examined the conditions at the place of battle.

Although we know in a general way where the enemy is and where he is going, before we close with him we must determine his course and speed very accurately, for our ability to hit him at all is going to depend upon extremely nice calculations. Our speeds are such that angular errors of so much as a second of arc will be fatal, and times must be computed to within hundredths of seconds.

This falls within the province of fire-control, a subject seldom if ever mentioned by fiction writers. There is no blame to be attached to them for that, for the problems of fire-control are essentially those of pure mathematics, and mathematics is notoriously unthrilling to the majority of readers. Yet hitting with guns—or even arrows, though the archer solves his difficulties by intuition—requires the solution of intricate problems involving the future positions and movements of at least two bodies, and nothing more elementary than the differential calculus will do the trick. In these problems interior ballistics, for all its interesting physics, boils down to a single figure—the initial velocity of the projectile, while exterior ballistics evaporates for the most part the moment we propel our missile into a gravityless vacuum. In space we are to be concerned with the swiftly changing relationship of two rapidly moving vessels and the interchange of equally swift projectiles between them, the tracks of all of them being complicated curves and not necessarily lying in a plane.

In its simplest statement the problem of long-range gunnery is this: where will the enemy be when my salvo gets there? For we must remember that even in today's battles the time the projectile spends en-route to its target is appreciable—fully a minute on occasion, at sea, during which the warship fired upon may move as much as half a mile. Under such circumstances the gunner does not fire directly at his target, but at the place it is going to be. That requires very accurate knowledge of where the enemy is headed and how fast he is moving.

At sea that is done by observing successive bearings and ranges and plotting them as polar co-ordinates, bearing in mind that the origin is continuously shifting due to the ship's own motion. This work of tracking—the subsequent range-keeping and prediction of future ranges and bearings—is done in our times in the plotting room. This is the most vital spot in the ship, for if her weapons may be likened to fists and her motive power to legs, her optical and acoustical instruments to eyes and ears. then the plotting room is the counterpart of the brain. There all the information is received, corrected, digested, and distributed throughout the ship. Without that co-ordination and direction the ship would be as helpless as an idiot.

Well, hardly that helpless today. Our individual units, such as turret crews, can struggle on alone, after a fashion. But not so with the ship of the future. There the plotting room is everything, and when it is put out of commission, the ship is blind and paralyzed. It will, of course, be located within the center of the ship, surrounded by an armored shell of its own, and in there will also be the ship control stations.

THE BEST WAY to approach the problems our descendants will have to face is to consider a simple problem in tracking that our own warships deal with daily. It is an absurdly simple one compared to the warped spirals to be handled in space warfare, but it will serve to illustrate the principle. In Fig. 1. it is shown graphically, but in actual practice the elements of the problem are set up on a motor-driven machine which thereupon continuously and correctly delivers the solutions of problems that would take an Einstein minutes to state. As the situation outside changes, corrections are cranked into the machine, which instantly and uncomplainingly alters its calculations.

In the figure we have the tracks of two ships, ours the left-hand one. For the sake of clarity and emphasis I have made the ratio of speeds three to one, hut the same trends would be shown at the more usual ratio of, say, 20:19.

At positions 1, 2, 3 and so on, we observe the range and bearing of the target, and plot them. By noting the differences between successive readings and the second differences between those, we soon have an idea of the type of curve the rates of changes would plot into. In a short time we can also note that the rates themselves are changing at a certain rate. This is a rough sort of differentiation—by inspection—and to one familiar with such curves these trends have a definite meaning.

For example, it is apparent that the series of observed angles Beta; are steadily opening, signifying that we are drawing past the target. Any sudden alteration of the second differences, such as occurs at 8, at once indicates a change of condition on the part of the enemy. He has either turned sharply away or slowed to half speed, for the bearing suddenly opens nearly two degrees more than the predicted bearing. We learn which by consulting our ranges. It could be a combination of changed course and changed speed.

The ranges during the first seven time-intervals have been steadily decreasing, although the rate of decrease has been slowing up, indicating we are approaching the minimum range. At 8, though, the range not only fails to decrease, but the rate of change actually changes sign. We know without doubt that the enemy has turned away.

The importance of having the machine grind out predicted bearings and ranges, aside from the desirability of speed and accuracy, is that at any moment smoke, a rain squall, or intervening ships may obscure the target. In that event the gunners need never know the difference—their range and bearing indicators are ticking away like taximeters, fed figures by the controlling range-keeper. It would not have mattered if sight had been lost of the enemy at 4; the gun fire would have been just as accurate up to the time he changed course as if they had the target in plain sight.

As a matter of fact, the guns are not pointed at the target at all, but in advance of it, as is shown in Fig. 1 (a), both range and bearing being altered to allow for the forward movements of the target while the shells are in the air. The projectiles may be regarded as moving objects launched on a collision course with regard to the enemy vessel.

Speaking of collision courses, it is an interesting property of relative bearings that when the bearing remains constant—except in the special case of the vessels being on parallel courses at identical speeds—the vessels will eventually collide, regardless of what their actual courses and speeds are. Hence, from the time the shots of the salvo left their guns until they struck their target, the target bore a constant angle of thirteen degrees to the right of the nose of the shells. (This knowledge has some utility in estimating the penetration of armor at the destination.)

In the example above, all the movement can be regarded as taking place in a plane; the ships follow straight courses and they maintain constant speeds. Our terrestrial problems are in practice much complicated by zigzagging, slowing down and speeding up, but at that they are relatively child's play compared to what the sky-warrior of the future must contend with.

His tracks are likely to he curved in three dimensions, like pieces of wire hacked out of a spiral bedspring, and whether or not they can be plotted in a plane, they will nowhere be straight. Moreover, whatever changes of speeds occur will be in the form of steady accelerations and not in a succession of flat steps linked by brief accelerations such as we know. Computing collision courses between two continually accelerating bodies is a much trickier piece of mathematical legerdemain than finding the unknown quantities in the family of plane trapeziums shown in Fig. 1. Yet projectiles must be given the course and speed necessary to insure collision.

The gunnery officer of the future is further handicapped by rarely ever being permitted a glimpse of his target, certainly not for the purpose of taking ranges and bearings. In the beginning of the approach the distances between the ships is much too great, and by the time they have closed, their relative speed will generally forbid vision.

SINCE optical instruments are useless except for astragational purposes, his range-finders and target-bearing transmitters will have to be something else. For bearings, his most accurate instrument will probably be the thermoscope—an improved heat-detector similar to those used by astronomers in comparing the heat emission of distant stars. It will have a spherical mounting with a delicate micro-vernier. A nearby space ship is sure to radiate heat, for it is exposed constantly to full sunlight and must rid itself of the excess heat or its crew will die. Once such a source of heat is picked up and identified, it can be followed very closely as to direction, although little can be told of its distance unless something is known of its intrinsic heat radiation.

Ranges will probably be determined by sounding space with radio waves, measuring the time interval to the return of reflected waves. It is doubtful whether this means will have a high degree of accuracy much beyond ranges of one light-second on account of the movement of the two vessels while the wave is in transit both ways. At long ranges the need for troublesome corrections is sure to enter.

Such observations, used in conjunction with one another, should give fairly accurate information as to the target's trajectory and how he bears from us and how far he is away. This data will be fed into a tracking and range-keeping machine capable of handling the twisted three-dimensional curves involved, and which will at once indicate the time and distance of the closest point of approach. Both captains will at once begin planning the action. They may also attempt to adjust their courses slightly, but since the rockets evolve great heat, neither can hope to keep his action from the knowledge of the other owing to the sensitiveness of the thermoscopes.

Assuming we have, by observation and plotting, full knowledge of the enemy's path and have come almost into position to commence the engagement, we find ourselves confronted once more with the two overwhelming factors of space warfare—great distance and immense speeds—but this time in another aspect. We have come up close to our foe—in fact we are within twenty seconds of intersecting his trajectory—and our distance apart is a mere four hundred miles. It is when we get to close quarters that the tremendous problems raised by

Look at Fig. 2.

The elapsed time from the commencement of the engagement until the end is less than twenty seconds. Our ship is making forty miles per second, the other fellow is doing thirty-three. We will never be closer than fifty miles, even if we regard the curves as drawn as being in the same plane. If one rides over or below the other, that minimum range will be greater. What kind of projectile can cross the two or three hundred miles separating the two converging vessels in time to collide with the enemy? Shooting cannon with velocities as low as a few miles per second would be like sending a squadron of snails out from the curb to intercept an oncoming motorcycle—it would be out of sight in the distance before they were well started.

Projectiles from guns, if they were to be given velocities in the same relation to ships' speeds that prevail at present, would have to be stepped up to speeds of three to four thousand miles per second! A manifest impossibility. It would be difficult, indeed, to hurl any sort of projectile away from the ship at greater initial velocities than the ship's own speed. Such impulses, eighty times stronger than the propelling charge of today's cannon, would cause shocks of incredible violence. It follows from that that an overtaken ship is comparatively helpless—unless she is in a position to drop mines—for whatever missiles she fires have the forward inertia of the parent ship and will therefore be sluggish in their movement in any direction but ahead.

Another difficulty connected with gunfire is the slowness with which it comes into operation. This may seem to some to be a startling statement, but we are dealing here with astonishing speeds. When the firing key of a piece of modern artillery is closed, the gun promptly goes off with a bang. To us that seems to be a practically instantaneous action. Yet careful time studies show the following sequence of events: the primer fires, the powder is ignited and burns, the gases of combustion expand and start the shell moving down the tube. The elapsed time from the will to fire to the emergence of the projectile from the muzzle is about one tenth of a second. In Fig. 2 our target will have moved more than three miles while our shell is making its way to the mouth of the cannon! It looks as if guns wouldn't do.

I COME to that conclusion very reluctantly, for I am quite partial to guns as amazingly flexible and reliable weapons, hut when we consider that both powders and primers vary some what in their time of burning, there is also a variable error of serious proportions added to the above slowness. It is more likely that the rocket-torpedoes suggested by Mr. Willy Ley in a recent article on space war will be the primary weapon of the future. They have the advantage of auto-acceleration and can therefore build up speed to any desired value after having been launched.

The exact moment of their firing would have to be computed by the tracking machine, as no human brain could solve such a problem in the time allowed. But even assuming machine accuracy, great delicacy in tube-laying and micro-timing, the chances of a direct hit on the target with a single missile is virtually nil. For all their advanced instruments, it is probable that all such attacks will be made in salvos, or continuous barrages. following the time honored shotgun principle. For the sake of simplicity, only two such salvos are shown on the diagram. but probably they would be as nearly continuous as the firing mechanisms of the tubes would permit. Any reader with a flair for mathematics is invited to compute the trajectories of the torpedoes. The ones shown were fired dead abeam in order to gain distance toward the enemy as rapidly as possible...

...Spotting, as we know it, would be impossible, for the target would be invisible, Hits would have to be registered by the thermoscope, utilizing the heat generated by the impact. The gunnery officer could watch the flight of his torpedoes by their fiery wakes, and see his duds burst; that might give him an idea on which side of the enemy they passed in the event the thermoscopes registered no hits.

If there were guns—and they might be carried for stratosphere use—they could be brought into action at about 15, firing broad on the starboard quarter. The shells, ... would lose some of their forward velocity and drift along in the wake of the ship while at the same time making some distance toward the oncoming enemy. These guns would be mounted in twin turrets, one on the roof and the other on the keel, cross-connected so that they would be trained and fired together. If the ship's center of gravity lay exactly between them, their being fired would not tend to put the ship into a spin in any direction. What little torque there might be, due to inequalities in the firing charge, would be taken care of by the ship's gyro-stabilizer, an instrument also needed on board to furnish a sphere of reference so that the master could keep track of his orientation.

If upon arriving at point 16 the enemy were still full of fight and desperate measures were called for, we could lay down mines. These hard little pellets would be shot out of mine-laying tubes clustered about the main driving jets. They would be shot out at slight angles from the fore-and-aft line, and given a velocity exactly equal to the ship's speed, so that they would hang motionless where they were dropped. Being cheap and small, they could be laid so thickly that the enemy could not fail to encounter several of them. If she had survived up to this point, the end would come here.

The end, that is, of the cruiser as a fighting unit. Riddled and torn, perhaps a shapeless mass of tangled wreckage, she would go hurtling on by, forever bound to her marauding trajectory. The first duty of our cruiser would be to broadcast warnings to the System, reporting the location of its own minefield, and giving the direction taken by the shattered derelict. Sweepers would be summoned to collect the mines with powerful electromagnets, while tugs would pursue and clear the sky of the remnants of the defeated Martian.

From SPACE WAR TACTICS by Malcolm Jameson (1939)

The Trumpet Bell Effect

Ken Burnside: I call this the trumpet bell effect, and it becomes much more noticeable when slinging ballistic weapons in 3-D play.

Provided your ballistic weapon's rate of closure is greater than the lateral velocity of the target, you get a trumpet bell, or manifold shape. As the projectile's velocity increases, the skinny part of the trumpet bell elongates — but it also thins out. The volume described by the surface of the trumpet and the centerline of the trumpet remains constant along the time axis, provided the ability to laterally accelerate remains constant.

In short, if you've GOT a good shot lined up, it's harder to dodge it by "jinking". If you've got a fuzzy shot that gets refined as you approach (which is roughly how Attack Vector: Tactical does it, because it's easier than having people pretend to be targeting computers in 3-D vector space), higher speeds on the shells can reach a threshold effect, where a small error that could be corrected for at a low closing velocity can't be corrected for at a high closing velocity.

A bit of practice renders this moot, but without that practice in the mechanics of doing vector ballistics (let alone 3-D vector ballistics), they can get very frustrating to use.

(somebody asks if sensor lag will prevent the trumpet bell effect)

My suspicion is that it's still going to be a trumpet bell effect. While there's sensor lag, if they're moving at 0.92 c (about where relativity becomes noticeable), the "trumpet bell" of the target's possible positions is also very long and skinny.

One thing you learn in Attack Vector: Tactical is that velocities past about 30 hexes/turn (300 km/64 seconds) actually make you EASIER to hit with ballistic weapons, because your ability to change your vector is so dramatically reduced. What you want for dodging missiles is a low enough velocity that you can swing around and thrust in an unanticipated direction and throw off the ballistic weapon's accuracy.

From thread on sfconsim-l (2002)
Torpedo Mechanics

Kirk Spencer

(ed note: An "inertial compensator" is a handwavium gadget that allows spacecraft to make drastic maneuvers without the gee forces turning the crew into thin layers of bloody chunky pulp plastered all over the walls.)

No, I think you (Rick) are in error about the missiles — unless you have inertial compensators or other physics escape mechanisms.

Actually, let me interrupt with what I've begun to take as a truism. The superiority of Beams vs Missiles is as variable as the superiority of Offense vs Defense — each is antecendent in its turn, depending upon the specific technology and inspiration in use existent at the moment of comparison.

That said, I think your slingshot launch has a major problem. It goes as follows:

Let us assume that the missile acceleration is 2 distanceunits/timeunit while the ship has an acceleration of 1. For simplicity, we'll say that a missile has a duration of 3 timeunits, with the ability to be dangerous despite point defense mechanisms of one additional timeunit. The missile thus has a maneuvering hit range of 6 distanceunits (du), and a stationary hit range of 9 du inherent.

Let's have your ship produce a rate of movement of 10 du/tu. This means the ship can fire at the base at a range of 19 du, well outside the range of the bases missiles. Thus far your concept is correct.

Unfortunately, now we've the subsequent time intervals.

Immediately upon launch, the ship begins a thrust to maintain maximum distance from the base — initially we'll use 90 degrees to current vector. Further we'll simplify this to simple vector movement instead of true Newtonian calculations — largely because I'm lazy (grin) — but the difference here will be slight.

Create a grid of 20×20. Place the ship at 0,0, and the base at 0,19. The initial vector of the ship is +1,+10 (the 90 degrees of thrust applying at the instant of launch).

The ship's location at the next interval is +1,+10 — a slight bit outside range 11 from the base and so still safe. The next vector change has another interval of thrust applied, so the ship's vector is now +2,+10. At the end of the second turn, we're at +3,+20 — or a bit less than 4 du from the base.

The base probably fired missiles in return on an intercept path as soon as you began your avoidance thrust — thus he knows the path you must be taking. After two intervals, the intercepting missiles had a range of 6 (2+4) du.

In other words, your ship fell within the missile range of the base — and they reached that range at about the same time your missiles reached the base (actually the missiles at your ship probably intercepted your ship before the base-bound missiles reached their target, but we've broken down the time interval too broadly for that.)

This is what Ken refers to as the 'trumpet bell effect'. The only way for the ship to stay out of missile range in your attack profile is for the ship to be faster than the missiles. If that's the case, then beams are more important because missiles can be dodged more easily.

Now, I'll admit that a base can't dodge, and so in actuality you can probably launch from even further out and trust to simple mechanics in null/microgravity to be sufficient. But you used that example as the 'simple' example of ship-vs-ship combat.

Given a ship/base capable of slight maneuver, the ballistic flight is closed. I'll also note that with the base you can 'float' missiles to the launch point — throw them ballistically for several time units, then have them ignite at the optimum point for effective engagement. But you can't do this in a ship-ship battle — your foe will laugh and maneuver outside the intercept envelope to which your missiles are committed. (note that he's then committed to staying outside that space-time envelope, but you still only have a limited amount of missiles.)

In short, I don't believe your attack profile isn't what you thought, but is instead very susceptible to mutual endangerment.

Ken Burnside

The "trumpet bell effect", as I call it, puts a "maximum relative velocity" on missile engagements

This maxima is based on the delta V of the missiles, and the delta V of the ships.

In essence, if your initial relative velocity vis a vis your stationary target (and to all missiles, all targets are stationary...) means that you really cannot afford to let your ship impart much momentum at all to your shells — otherwise, your ship is going to cruise into mutual annihilation distance.

This means that for low-thrust, high-specific-impulse drives like Rick's, the smart naval commander will match velocities with his target and pick a range where his missiles have the advantage over the other guy's. At which point, tactical maneuver doctrine is a null pointer (i.e., is pointless).

Operational maneuver doctrine is still interesting — you're trying to find that point in the enemy's plot where he MUST commit to coming towards something of value, and match his velocity there.

This also means that the missile's relative velocity (assuming they focus on dV rather than thrust will be significantly slower as well.

This takes effect in Attack Vector: Tactical (AV:T); trying for the high speed pass turns you into missile-bait, because your course and range over time is easily predicted.

I've been pondering the MITEE driven missile Rick described earlier. It may be possible to work it under the rules for AV:T with the new ballistic weapons system under development. One thing that becomes very clear is that it can engage outside of "buttoned up" distance — which means it's a lot more practical to use anti-ship beam weaponry to kill it farther away from the ship. In fact, with its high emissions signature and low thrust, it should be pretty easy to hit — it won't be jinking signficant amounts when engaged at 1000 km.

Rick Robinson

Ken Burnside: The "trumpet bell effect", as I call it, puts a "maximum relative velocity" on missile engagements. This maxima is based on the delta V of the missiles, and the delta V of the ships.

I think of it more as a "range" — but in vector space, not just linear space — incorporating both distance and relative motion. Like pornography, it is hard to describe, but I know it when I see it. :)

Ken Burnside: In essence, if your initial relative velocity vis a vis your stationary target (and to all missiles, all targets are stationary...) means that you really cannot afford to let your ship impart much momentum at all to your shells — otherwise, your ship is going to cruise into mutual annihilation distance.

There seems to be a key word or phrase missing above — something like "if your initial relative velocity ... is high enough" or some such. That was just what happened in Kirk's scenario: the attacker made such a running start before launching his missile that he committed himself to passing within missile range of the non-maneuverable target, and could not perform an effective breakaway.

Ken Burnside: This means that for low-thrust, high-specific-impulse drives like Rick's, the smart naval commander will match velocities with his target and pick a range where his missiles have the advantage over the other guy's. At which point, tactical maneuver doctrine is a null pointer (i.e., is pointless).

If your missiles are enough superior to the other guy's missiles, this would be the case — even if he is more maneuverable, if your missile delta V exceeds his combined ship delta V and missile delta V, he'll never be able to get a firing position where you can't hit him.

One thing that is going on here, I think, is that "missile" is a less clearly defined concept than "beam." That is, a beam is understood to be more or less the ideal bullet: you point and shoot, and at AV:T ranges — or even many times AV:T ranges, out to a few hundred thousand km — it is effectively instantaneous.

"Missile," though, seems to cover a variety of weapons, from railgun shells that are almost slowed-down beams, but with some ability to veer in response to target jinking, to weapons that have prolonged flight times and are only modestly more maneuverable than the ships they are sent to intercept.

Missiles of the latter type are what I have in mind, used at relative ranges such that the trumpet bell tends to balloon outward to the point where it ultimately becomes nearly spherical.

Which is why I don't think tactics would devolve to simple velocity matching, because my working presumption is that, during a missile's useful flight time, the potential maneuver of ships is not much less than that of missiles.

(Submunitions, in my scheme, are very different, and behave almost like "slow beams." The relative velocity of missile bus and target, at the moment of submunition release, is very much greater than the delta V available either to the submunition or the target, so as seen by the target the submunition have a very long, narrow trumpet bell.)

Ken Burnside: Operational maneuver doctrine is still interesting — you're trying to find that point in the enemy's plot where he MUST commit to coming towards something of value, and match his velocity there. This also means that the missile's relative velocity (assuming they focus on dV rather than thrust will be significantly slower as well.

Yes. One way to look at it is that my concept of missile combat blurs the tactical and operational levels.

Ken Burnside: It may be possible to work it under the rules for AV:T with the new ballistic weapons system under development. One thing that becomes very clear is that it can engage outside of "buttoned up" distance — which means it's a lot more practical to use anti-ship beam weaponry to kill it farther away from the ship. In fact, with its high emissions signature and low thrust, it should be pretty easy to hit — it won't be jinking signficant amounts when engaged at 1000 km.

Yeah. The MITEE missile I outlined was badly hampered by the mass of its fuel tankage (and use of bulky hydrogen fuel). I suspect that a small fuel tank could be built much lighter — the estimate I used was based on my model for ship hulls. For my style of combat, you'd need a missile with about 2x the delta V given, and configure it to carry submunis.

Alternatively, given their low mass, the MITEE units could themselves be used as submunis — the constraint being whether they can carry sufficient fuel for the terminal phase of flight.

From a thread on sfconsim-l (2002)

Advanced Tactics

Space Combat Part 1: Tactical Manoeuvres

   I originally wrote this post as a guest post for the Future War Stories blog( link), where it generated a lot of very interesting discussion in the comments.  Since then, and mainly as a result of the comments, I've decided to expand on the theme of tactical manoeuvres.  I'm posting this so that anyone reading either part will be able to find the other; I do encourage reading the comments on Future War Stories though, they have almost as much stuff as the post itself.

The hand can't hit what the eye can't see

   As both Hoban 'Wash' (Firefly) and Han Solo(Star Wars) have demonstrated on numerous occasions firepower is not the only asset that can win a fight.  Quite often in movie SF the heroes of the story will be aboard a smaller spacecraft than their opponents, their only hope of survival lying in their superior abilities.  While this is largely due to dramatic reasons, it does draw attention to the importance of manoeuvrability in space combat.  When dealing with hard SF — no handwavium forcefields or technobabble shields — one shot kills are very probable: nukes, mass drivers, particle beams, lasers, all posses more than enough potential to negate any form of armour we know about today.  And while no real spaceship will every fly with the grace of a X-wing starfighter this does mean that the ability to avoid hits may be more important than surviving them(structurally, the crew is still a concern), much like the situation in arial combat today.

   For SF writers this is a boon.  A battle that requires manoeuvres is intrinsically better suited to one in which humans might play a role.  Randomness and intuition could be vital, and so far computers don't offer that.  Even if the ship can fly and fight itself this leaves room for a human tactician, negating Burnside's Zeroth Law of Space Combat — SF fans relate more to humans than they do to silicon chips.  However, it can also pose difficulties.  Space is not a familiar environment, and movement in it is counterintuitive at best.  It is also radically different for a spacecraft in orbit around a single planet, in a planetary system, or in deep space.  And for those of us who try to avoid the dreaded 'Space is a Ocean' trope this can be very...frustrating.

   So, I'll look at four basic situations; deep space with low relative velocity, deep space with high relative velocity, single planet, and planetary system.  For each I'll also take a look at the changes in the situation that different tech will have.  This post is not so much about manoeuvring itself, but about how different situations shape it.  An in depth discussion of tactical manoeuvring down to the level of orbital physics or specific technologies would make the article far to long.  In the future I'll attempt to do follow up articles that look at manoeuvring in the context of a specific spacecraft, but for now this should provide an indication of what a spaceship would be doing.  For simplicity's sake I'm only going to consider one-on-one battles in detail, not constellation engagements.  Fleet actions are a whole separate ball game, and will warrant a separate post.

Deep Space — low relative velocity

   Just what is 'deep space'?  For the purposes of a story it is that area of space which only the bigger spacecraft can reach, so interplanetary or interstellar, depending on tech levels.  From a navigational perspective it could be defined as 'flat' space.  That is, space in which the gravitational acceleration is insignificant.  Insignificant is defined by the power of the drives your spacecraft is using, so this adjusts itself to match the setting.
   Manoeuvres here are closest they will get to those found in Space Opera.  The lack of a gravitational source means that movement in any direction is equally easy, and the fight becomes truly 3D.
   For high tech - multi-gee acceleration and big delta-V — the fights will be 'dogfights' to some degree.  This will be more marked if the craft use spinal mounted weapons, or if they have large blind spots in offensive or defensive weaponry.  If kinetics are the main weapon then the fight could become quite interesting, with KE rounds restricting the possible choices for manoeuvring, a possible tactic for the adept captain to employ.  Missiles will be very effective, with s straight line of flight to the target, as will beam weapons.  Particle beams will benefit, as they are degraded in accuracy and rage in the presence of a planet's gravity or magnetic field.  If lasers are the primary weapon then the fight will be less of a dogfight, and more of random 'drunk-walking' to throw off targeting.
   For low tech - milligee acceleration and limited delta-V - visually this would be quite boring.  The ships cannot perform elaborate manoeuvres to get in each other's blind spots, nor can they expect to dodge beams and kinetic weapons at short ranges(ranges dependant on velocity of the weapon).  Instead orientation and sensor data is the most vital.  The spaceship must bring the most weapons to bear, while at the same time keeping a small target profile, and reducing signals that might give its opponent an effective targeting solution.  The ships orient themselves, enter weapons range, fire a few salvoes, and the battle is decided.  In this case missiles are very effective, as they can come in at an angle to the primary attack vector, distracting sensors and absorbing point defence capacity.  Kinetic rounds are also more effective, not only can the score a hit from longer range, but they can be more easily used to 'box in' an opponent than if accelerations were high.  As before, 'drunk-walk' will be used to throw off targeting.

Deep Space — high relative velocity

   The chances are that spaceships will rarely intercept each other in deep space.  It is simply to large, and too easy to see someone coming.  When they do it is likely to be a head-on pass at high relative velocity for two spacecraft following the same or similar orbit in opposite directions.  Note that once unrealistically powerful torch-drives become common, interception is possible, if still unlikely unless both parties wish it, or one slips up.
   It turns out that for both high and low tech the manoeuvres are much the same in this situation.  Any reasonably fast orbit will result in the two ships passing with Rv of tens if not hundreds of km/s. At this speed there is not time to dogfight.  Even a torch ship, which will have a much higher intercept velocity, will take so long to cancel its Rv and return to the battle it would be considered as a separate engagement, rather than a second pass.  For a ship with foreseeable tech it would be nearly impossible.  If anything it will resemble a joust between two medieval knights on horseback.  Unlike a joust, however, they might not be a winner.
   The longest commonly accepted range for a laser weapon to target effectively is about one light second, or 3*10^8 meters.  At a very low end relative velocity — I randomly chose 40 km/s, which means that each ship has ~half solar escape velocity, which is not unrealistic, nor is it that high for a advanced ship.  At this range and closing speed the time for targeting the incoming ships and its projectiles is ~2 hours.  Plenty of time to shoot down incoming projectiles, you say.  But at this speed one kilogram of inert matter has an energy of 8*10^8 J.  And how many of those is the opposing ship going to throw out in your path?  You can make considerable sideways movement relative to direction of travel in an effort to avoid the projectiles, but the opposing ship can easily see any move you make, and at charter ranges dodging will become impossible.  Pretty much any kinetic hit at this speed will be fatal, so it will be the ship with the best point defence, sensors, and emergency manoeuvring that will survive.
   Durin the approach both ships fill space with inert projectiles, possible with last ditch terminal guidance.  They will be hard to spot at long range, tiny, inert, and possibly cooled down so that they have no discernible thermal signature.  So it will be only in the last stage of the pass that the combatants can begin to dodge the projectiles.  High lateral acceleration and powerful attitude control will help to weave through the incoming fire like a skier on a slalom course.  Good sensors will be needed to sport the incoming, and good PD to shoot those that can't be avoided.  However, it is my personal opinion that this sort of situation would be 'two men go in, half a man comes out'.  If energy wagons are primarily used, them this is even more so the case, as dodging becomes effectively impossible.

Orbital Space — single planet

   Most space battles in SF take place in orbit around a planet.  This makes sense in both hard and soft SF 'Verse's for several reasons.  Primarily it is the place where hostile spacecraft are most likely to meet.  It also adds a new layer of complexity to the fight, introducing 'terrain' to the tactical considerations.  The planet can hide opponents, restricts manoeuvres, sucks up delta-V, and provides something to crash into.
   Aside from hiding spacecraft who are on the other side a planet can slo provide some cover for combatants.  Picking up a spacecraft against the disk of a planet is significantly harder than spotting one against the backdrop of space after all.  A low orbit that brushed the atmosphere prevents opponents from attacking from most of one hemisphere, a great advantage.  For a craft equipped to reenter the atmosphere it also offers the possibility of manoeuvres not possible with the amount of delta-V they posses.  From reading Atomic Rockets kinetic weapons seem to hold the advantage shooting from a higher orbit at a lower.  A DEW is not effected so much, and so the orbit used is less of an advantage or disadvantage aside from the detection aspects.  Lasers also posses the potential to be 'bounced' around the horizon by remote drones, meaning that the attacker can shoot without exposing themselves.
   So the aim of any manoeuvres is pretty simple.  Orientation to bring weapons to bear, and the standard 'drunk-walk' are a given.  The opposing captains will try to gain the better position in an orbit underneath the enemy ship, or perhaps between the enemy ship and the sun, which might help to blind sensors.  This will be complicated by the fact that change orbital inclination is very hard compared to other manoeuvres, restricting the spacecraft to a 3D layer of space, although not  2D plane shown in so many soft SF works.  Forcing the ship into a lower orbit will decrease its orbital period, and vice versa.  Combined with changing the orbit from circular to the elliptic and back this gives spacecraft commanders the ability to surprise their opponents by appearing around the planet at a different place or time than expected.  There will also be a large amount of 'minelaying' of a kind, seeding or its will kinetic projectiles in order to herd the enemy into a bad position.
   But while the aim of the manoeuvres is simple, execution is not.  Trying to explain it is beyond me, so I suggest that anyone serious about grasping orbital mechanics begins by playing the Kerbal Space Program game, or browsing youtube for anything helpful.  It makes a lot more sense visually than it ever will in writing.
   High tech - for advanced ships a planet is a much smaller piece of terrain, a hill rather than a mountain.  They can more easily afford to change orbits, to drop below minimum orbit al velocity or go over the maximum, and can perform delta-V heavy manoeuvres such as change the orbital inclination.  The ultimate of course is a ship that has drives powerful enough to reverse its orbit completely, surprising its opponent when it emerges around the opposite side of the planet to what was expected.  With higher acceleration and delta-V the seeding of orbits becomes less effective, much easier to dodge than with a low powered spacecraft.
   Low tech - with low levels of acceleration, even if the spacecraft has a high delta-V, changing orbits can take days if not weeks.  The position of the enemy will be highly predictable, and so kinetic weapons become very important.  The advantage converted by different orbits will be much more apparent, as it is harder for anyone to turn the tables on their opponent.  Most tactics would be a combination of manoeuvring into a good position, and using kinetics to force the enemy into a bad one.  Low tech ships would also gain a large advantage by being able to dip into the atmosphere, as this provides essentially free deceleration, saving reaction mass.

Planetary Systems

   Adding more heavenly bodies to the mix vastly increases the tactical possibilities.  While 'planets' per se do not do much, moons do.  A gas giant with seven or eight moons is a extremely complicated system, and has travel times of only hours or days as opposed to years between planets, and that is with Hohmann orbits.  High acceleration, low delta-V spacecraft could follow complicated routes, sling-shoting themselves around the moons to gain an unexpected position. For much of the time they could be out of sight of the enemy, making it a scenario reminiscent of The Hunt for Red October.  The fact that moons often have lower gravity than planets also means that the manoeuvres in proximity to them can be more extreme given the same tech level.  It even brings up the possibility of landing on a moon, camouflaging the spacecraft, waiting for the enemy to pass by, and then launching and taking them by surprise.  The changes imposed by tech levels are the same as those for a single planet, so I won't both to go into detail.  This kind of setting will be the most complicated for a SF aficionado to get right, and I would suggest finding a solar system simulator to model the setting before attempting to figure out a complicated battle.  It does lend itself to far more interesting scenarios, however, and will be far more rewarding.

From Space Combat Part 1: Tactical Manoeuvres by William Moran (2016)

At a guess, though, space battles will not involve a lot of strategic manoeuvering. Both sides know where the other guy is, where the other guy wants to go, and roughly what course he has to take to get there. If one side wants to completely avoid the other and has any capability of doing so, they do, and no battle happens. Otherwise the "battle" is a pretty straightforward approach of the two forces, with both conducting small maneuvers to make sure the enemy doesn't hit them from extreme range.

At some point before firing starts, both sides launch their long-range missiles, and possibly a screen of interceptors. As the missiles and interceptors pass each other, they duke it out with energy weapons, kinetic-kill, and a few nukes and then whatever is left from each side's launch goes past toward the opposing fleet. Each fleet uses point-defense countermeasures against the enemy, tries last-minute invasions, and then takes whatever damage the missiles deal.

Repeat this for multiple volleys of missiles, until the fleets are within a few hundred thousand kilometers when they start pelting each other with energy weapons. They can fly past each other shooting, in which case likely one side or the other will be utterly destroyed, or one side can decide it is defeated and try to break off from battle as quickly as possible, preserving what it has left. This may not be feasible depending on how remaining fuel reserves compare to their velocity.

The dominant rules of space battle are:

  1. You can't hide. The enemy probably knows where you are the moment you launch.
  2. You can run or fight, but you will typically have to pick one of the two long before battle is joined, and then you're stuck with it.
  3. There isn't much room for tactics and strategy. Pretty much everything is automated, and the what your computers calculate as the best possible attack strategy probably really is the best possible attack strategy. If battle is joined, and both sides have a good idea of what the capabilities of the other side's ships are, the result will be a lot more predictable than we are used to.
  4. If the engagement moves into short range (i.e. beam weapon range), it will probably be decided in a single pass. This is because at those kinds of ranges, it is very easy to hit the enemy and very hard to avoid being hit. Both sides will keep hitting each other with deadly accuracy until one of them is no longer capable of shooting. The exception is if both sides pass each other at _extremely_ high speed, but this isn't likely to happen if the primary objective of one side is to do as much damage to the other side as possible (in which case it will decelerate, slowing relative velocity).
  5. You may know where the other guy is from extreme range, but due to lightspeed delay, none of your weapons actually have a chance of hitting him until they get fairly close. The range of the weapons themselves isn't the determining factor at all, range of engagement is determined by the size and maneuverability of the enemy. Thus, your weapons are effective against large, stationary, or slow-moving targets at far, far longer ranges than they are against the average warship.
  6. Anything which can't manoeuver had better be very heavily protected, or had better not let you get anywhere near it. This tends to eliminate the "happy medium" of space stations, they die if an enemy fleet gets in close. Anything that can't move, and move fast, had better have huge amounts of shielding and lots and lots of countermeasures, point-defense, and whatnot. Only fortified targets on planets, moons, or within large asteroids have a chance of surviving a close attack by an enemy space fleet. These bases will compensate for their lack of mobility with means of defense that spacecraft cannot have due to weight restrictions. They will be extremely heavily armored (probably with most of the important parts deep underground), and have large numbers of defensive batteries that can destroy spacecraft at long range simply by putting up so much fire that something is bound to be hit.
  7. The most effective way to destroy planetary installations is not by using warships, but by using the warships to clear out enemy space forces so you can bombard the planet with asteroids or mass nuclear assault. Conventional invasion is effectively impossible, since the defenses will destroy your invasion force if they are still functional, and the only reliable way to take out the defenses is with mass bombardment. A successful planetary assault will not allow you to capture any installations intact except those that are deep underground, and to capture those you have to send in ground forces that were very expensive to transport across space. This means capture of installations isn't really a viable alternative, unless you get the enemy to surrender upon the threat of destruction.
Ian Montgomerie

Ken Burnside notes how capabilities drive tactics:

There are a few variables for space combat.

The first is drive efficiency and top thrust. If top thrust is low enough, maneuver ceases to be a tactical concern.

The second is laser ranges — if laser ranges are long, even with high thrust, maneuver ceases to be a tactical concern.

If your engines can scale down to missile drives (Rick Robinson's torch missiles), maneuver stops being a tactical concern in terms of avoiding them, because the missile will have enough delta v (with strap on tanks or expendable stages) that it can run down the target.

AV:T's torch drives, while laughable from a space opera standpoint, are wildly optimistic at best. Likewise, AV:T's lasers, while about 5 orders of magnitude beyond current technologies, are perhaps conservative.

Ken Burnside

Ken goes on to note that a more realistic set of technologies would have ship drives that were much weaker and laser weapons that had greater ranges. Unfortunately this results in very boring interplanetary combat.

Rick Robinson agrees with Ken's assessment of torch missiles. He goes on to say:

For essentially the same reason, a higher-performance ship should always be able to choose the range, at least so long as fuel holds out. With higher acceleration, he can match any maneuver the other guy makes, plus some extra vector to either close the range or open it.

Some exception when you get down to time and distance scales where pivot time matters, but even then, there's a pretty limited scope to the ability to "turn inside" a faster-accelerating but pivot-sluggish opponent.

Rick Robinson

(ed note: Admiral Castro talks to Captain Fitzthomas)

"I know you're here, captain," said Castro. "Come, join me here."

Fitzthomas complied. The map was scaled to show the entire solar system out to Neptune. At that resolution, virtually the entire United States Space Guard was visible.

"What do you see here, captain?"

"I see what looks like our current force disposition...sir, am I cleared for this?"

"Relax. This is only an approximation. I had my staff whip it up based on our best estimation of what the Euros and the (Chinese) know. The only ones for sure and for certain in the right place are the five here: Saskatchewan, New Jersey, Jamaica, San Luis Potosí and Ohio. Now, what do you see?"

"I see we have frigates well distributed to keep an eye on most of the planetoids inside of the Kupier Belt, with the battleships in close to Earth."

"So you'd say the fleet disposition is currently optimized for protecting shipping lanes and monitoring potential threats to Earth."

"Yes sir."

"So is that configuration also optimal for a conflict with another space force of roughly equal numbers and ability."

"That would depend on how they're deployed, sir."

"I thought that's what you'd say." He touched a button on the tank's control panel. A speckle of red and blue dots appeared on the map.

"My best estimate of where Europe and China's fleets are. What do you notice?"

"Their frigates are pulled in closer to the inner system. And they're bunched together. They seem to be moving in formations of between two and four ships. Their battleships are spread out more, but they're all inside the orbit of Mars."

"So how would you say our friends on either side of the ocean are deployed?"

"They're optimized for battle. Formations of mutually supporting frigates, probably positioned to act as wolf packs. Battleships spread out so they're not vulnerable to a Pearl Harbor strike, but in easy cruising distance of strategic targets in the inner system."

"So who wins a shooting war if it breaks out today?"

"They do. Unless they're too busy with India and Russia."

"Very astute. I won't bother showing you their estimated disposition. Nevertheless, I find this whole situation troubling." He shut down the holotank.

From The Last Great War by Matthew Lineberger (not yet published)

On James Nicoll started the following interesting dialog:

Okedokee: basic set-up

  • Balkanized Earth, ditto solar system.
  • Too many Great Powers for stability.
  • Delta vees in the tens of km/s, peak accelerations a few gee (Higher gees tend to mean lower delta vees, though).
  • All sides have decent sensor nets and stealth is more or less impossible.
  • Weapons have outstripped defenses, but so far nobody has built a beam weapon that can reach across AU. You do need to close with the enemy to fight them.
  • Since it takes months to years to cross the system and since rocket flares are visible across the system, the target knows you are coming.

Am I right in thinking that this makes for an extremely lossy battlefield? Ten men go in, half a man comes out sort of thing?

James Nicoll

For certain assumptions, yes. Obviously conventional ideas of surprise and tactical manouver are compromised in the above scenario, show up at the enemies gate and he knows where and when you are coming, along with some idea of your numbers. But fear not, human ingenuity will never fail to find ways to kill other people. A number of possible strategies come to mind to get around this problem.

But first, the big assumption of your scenario: that the war is being fought between two powers on opposite sides of the Galaxy. Given that this is a highly Balkanized set-up, this seems improbable. Most countries will be mainly concerned with their immediate area, and rocket flares won't be a concern if Manhattan is invading Brooklyn (say), and only a little more when L5A invades L5B. Those with wider concerns will probably have Allies in the region.

That being said, some useful strategies for your scenario:

  1. The Ace in the Hole: They know how many rockets you have, and where they are going and (more or less) when they will get there, but do they know what's on them? A common strategy might be to pack many tactical vehicles onto one "thruster pack" which then breaks up on arrival. This obfuscates both force numbers and composition, even good visuals won't tell what the interior ships are...
  2. The Trojan Horse: The big trade fleet comes from across the system and, surprise! It's not a trade fleet... It could even be a supposed ally changing his colors instead of relieving you.
  3. The Stab in the Back: You send out your forces to meet the enemy a safe distance away from the colony, and before you can get them back, the guy next door (in a secret pact with the enemy) is going for your throat.
  4. Multiball madness: Launch a whole bunch of drones/kamikaze fighters to overwhelm enemy defenses and hope some get through. It might be useful to combine this with the thruster pack idea and have the pack break up into no-return death balls.
  5. Routine Patrol: Useful for your would-be hegemons, the great power regularly sends an overwhelming show of force out on "anti-piracy patrol" (or whatever). You know when they will arrive, you know what their force is, you know you can't beat them unless you take 'em by surprise. What you don't know is whether they come in peace and will let you fete the Admiral to show the neighbors that everything is just copacetic with the big boys, or if they come to deliver, and implement, a declaration of war.
  6. The Riccochet: You don't send your force to the enemy, you send it to a nearby ally, who adds his own troops, and launches a close range combined attack.
  7. Cool Running: Accelerate to a decent speed, use a low emissions method to alter your course slightly (so that it's not obvious where the ships that disappeared are going), and be prepared to wait a while to get to your target. If you can pull off the attack on a flyby (or crash), that's ideal. Otherwise, your deceleration will give things away, but hopefully too late. (ed note: I personally consider this option problematic due to the impossibility of ships "disappearing".)

Other than that, I would suggest that invasion would probably be downplayed as a means of trans-system warfare. Instead, the focus would probably be on using proxies, supporting privateers, terrorists, and other NGAs (non-governmental armies...), building isolating alliances, trade interdiction, financial interference, lightspeed infostructure and psyops attacks... In short, much more like 21st century warfare than 19th...

Old Toby (Least Known Dog on the Net)

James Nicoll: Since it takes months to years to cross the system and since rocket flares are visible across the system, the target knows you are coming.

This raises interesting questions about what sort of conflict could arise in the first place. The last time I was working on an interplanetary war story idea, I struggled to wrap my mind around the human aspect of launching an attack which wouldn't even reach the battlefield for months.

However, in my story idea, I assumed the two sides (Earth and the Martian colony) had no military spacecraft at all at first, because no one considered an interplanetary conflict a serious possibility. In your proposed assumptions, the political situation is far more volatile. Your situation is more like the historical situation during the age of sail.

If you look at the naval conflicts of the age of sail, the most important principle is the close blockade. Ships move so slowly that if you're not already where you need to be it's too late. Perhaps a similar principle could be applied to your Solar System. All of the major military powers could have expeditionary fleets which patrol close to potential troublespots.

James Nicoll: Am I right in thinking that this makes for an extremely lossy battlefield? Ten men go in, half a man comes out sort of thing?

Not necessarily. Because you can always see where the enemy is, it may be difficult to engage a force which knows it can't win. A force which is hopelessly outgunned may choose to retreat while still out of weapons range. A lot depends on the nature of the technology and how easy it is to gauge an enemy fleet's capabilities. For example, if we assume that the cost of weapon systems is small compared to the cost of drive systems, then it's a safe bet that any warship is heavily armed. On the other hand, if the cost of weapon systems is high compared to the cost of drive systems, then there could be a lot of lightly armed "dummies" to confuse matters.

Also, consider the "close blockade" principle. The tide of warfare might be determined almost entirely by strategic maneuvers BEFORE any declaration of war. The various sides move their chess pieces around the Solar System, hoping to gain some advantageous position in case of an outbreak of hostilities. Of course, if one side achieves a sufficiently advantageous position of forces, this might prompt the start of a conflict itself!

In this case, the true "conflict" is surprisingly peaceful most of the time despite the deadliness of the weapons involved.

Isaac Kuo

Isaac Kuo: A force which is hopelessly outgunned may choose to retreat while still out of weapons range.

The superior force then has the option to pursue, or simply force the inferior one to run away long enough that it can't get home -- if you run out of fuel moving at 60 km/s, you're on your way to Arcturus. However, if payloads are variable (as in your game concept) and some ships have more delta-V than others, then how long do you pursue?

Isaac Kuo: For example, if we assume that the cost of weapon systems is small compared to the cost of drive systems, then it's a safe bet that any warship is heavily armed. On the other hand, if the cost of weapon systems is high compared to the cost of drive systems, then there could be a lot of lightly armed "dummies" to confuse matters.

Drive and weapon systems somewhat overlap at these performance levels. Anything moving at 30 km/s relative to its target is a weapon if it can be guided. As to how expensive guidance systems are...James? If guidance is cheap, then a side facing a stronger approaching force of warships will just load its merchant ships with guided buckshot payloads and expend them as necessary in order to to win.

Possibly the main design difference between merchant craft and war craft is that merchies are built to slow down and dock, warships to strike. I wouldn't expect most warships to be manned at all. For one thing, the delta-V is four times greater if you want to return home after a strike mission; a returnable warship is bound to be weaker for a given mass/cost. You might get a 'fleet' that amounts to a flock of cruise missiles — or IPBMs — just busses for kinetic weapon systems. At 30 km/s, every kilogram's mass of the strike group is packing 450 megajoules of kinetic energy (KE), and in the solar ecliptic, even every dirtside target can be 'on the near side' at impact (if you time the launch right).

Alternatively, perhaps you could have busses placed into retrograde 'parking' orbits matched to their potential targets — depending on how many were deployed, the delay time could be reduced to a couple of weeks. Of course these strike groups are also potentially subject to attack themselves every couple of weeks; KE cuts both ways.

Isaac Kuo: The various sides move their chess pieces around the Solar System, hoping to gain some advantageous position in case of an outbreak of hostilities.

The best defensive 'chess pieces' might be unmanned kinetic interceptors that are prepositioned along approach trajectories (although depending on orbital mechanics and delta-V, this might not work any better than launching them at need). If they can be maneuvered onto the track of an approaching fleet, they'll be able to strike hard while expending little delta-V of their own.

Maybe the long term weapons are robot solar-powered ion jets that latch onto small interplanetary objects (< 1 ton) and gradually nudge them onto potential attack trajectories. Or, shatter a small asteroid with a nuke, and attach mass-produced booster units to the spreading cloud of ammunition. If there are any asteroid mining ops, they already have lots of rocks to throw. (ed note: refer to the mention of "Spaceguard")

Jonathan Cresswell-Jones

Jonathan Cresswell-Jones: The superior force then has the option to pursue, or simply force the inferior one to run away long enough that it can't get home — if you run out of fuel moving at 60 km/s, you're on your way to Arcturus.

The obvious strategy is to run away in a safe direction. A greatly superior force coming from multiple directions could force a confrontation, but this is implies an extreme disparity in force strengths. Given such a disparity, it is plausibly obvious to both sides what the outcome of the battle would be. The inferior force could plausibly just surrender rather than pointlessly fighting to the death.

Jonathan Cresswell-Jones: Possibly the main design difference between merchant craft and war craft is that merchies are built to slow down and dock, warships to strike.

I imagine the main difference would be sensor and command systems. A merchant craft doesn't even need a crew or much of an onboard AI. Light speed delays don't matter because the only time they need a tight feedback loop is when they're within a "friendly" planetary system.

In contrast, a warship fleet needs to have sophisticated integral decision-making capabilities. This plausibly means on board crew although it could mean sophisticated AI. Light speed delay concerns dictate that the fleet needs to have its own sensor systems also. While the "sensor net" is good enough for strategic maneuvering, the fleet needs real-time information in a battle.

Also, a warship may have superior maneuvering capabilities. A merchant ship can live with just a single low thrust rocket. It never needs to make emergency maneuvers to dodge projectiles. On the other hand, it's desirable to limit the ship's hull to low thrust levels to minimize dead weight. In contrast, a warship could have a high thrust rocket, or a multi-mode rocket, or auxiliary rockets to facilitate high thrust maneuvers. It may have a beefier hull to deal with high thrust stresses. This depends on whether high thrust capability is militarily significant, of course.

Jonathan Cresswell-Jones: The best defensive 'chess pieces' might be unmanned kinetic interceptors that are prepositioned along approach trajectories.

You can simply launch them at need. In fact, if there are no enemy forces patrolling your sector, you may be able to afford to BUILD THEM at need.

But you misunderstand the idea of the "close blockade". The idea is to patrol all potential trouble spot sectors so you don't have to wait weeks or months before reacting to a situation. Your expeditionary fleets are already in place to react immediately to the outbreak of hostilities.

Isaac Kuo

Isaac Kuo: The obvious strategy is to run away in a safe direction.

Well, the point was that if the defender gets driven to fuel exhaustion, there is no safe direction; you can't slow down. Maybe another friendly force (or negotiated neutral) could match velocities and rescue you, but unless they were set up for it in advance, it'd be tricky.

Now, here's where a high-KE kamikaze fleet has a problem — if the defender sidesteps somehow, the attacker may not be able to decelerate, come back, and resume the fight.

Isaac Kuo: But you misunderstand the idea of the "close blockade". The idea is to patrol all potential trouble spot sectors so you don't have to wait weeks or months before reacting to a situation.

Isn't that a division in detail, though? Of course, a player doesn't have to place fleets in all sectors. Each player would tend to 'patrol' the regions that they had vital interests in, and would have to think hard about committing force to others.

The lack of any stealth is a curious aspect. You can't sneak up on an opponent; if you redeploy some of your warships to gain local superiority over Player X's forces at one spot, everyone sees them moving into position. Depending on how predictable combat is (i.e., a 2-to-1 superiority means the weaker side is wiped out at little cost), simply sending more warships to one area could force a weaker, neutral player to either match the upgrade by dispatching their own reinforcements; start a fight immediately at even odds; sit tight and stare you down despite the new odds that would allow you to win handily if you start a fight; or withdraw. If there are three or more players' forces in one spot, then diplomacy/treachery will be decisive. "Oh, by the way, these arriving forces aren't to attack B — I just made peace with B this morning. They're to attack you."

On the other hand, "weapons outstripping defenses" implies a non-Lanchester equation: i.e., if 100 A units engage 50 B units, maybe there are only 50 A's left alive after the (very short) battle, not the 90 A's you'd expect if the units had some staying power. No stealth for moving attacks, but surprise treachery attacks would be deadly.

If Earth's balkanized as per James' post, then there could be several major Earth-based players who have large production and military capability, but are a long way from the outer system's points of interest. Suppose one Earth player has interests in the Unobtanium Mines of Io. If they station a permanent force there, it needs to be strong enough to defeat local forces, but it's too far away from home to count as a defensive force for the player if their interests are threatened back home — it's a write-off in some ways. Too many like that, and you might get attacked by another Earth player with more strength available at hand. If you send a mobile force, then it too must be (a) strong enough to not be a tempting target for an ambush en route by a hostile player; (b) still weak enough to afford to be 'out of play' for a year or two.

It might be cheaper to pay tribute to a distant local power, rather than to keep a squadron there. This is a bit like the 19th-cen Barbary Coast, where the US Congress voted for years to pay tribute to local rulers, rather than to build and deploy a more expensive navy. If the local-power player gets too greedy, they get spanked.

Jonathan Cresswell-Jones

James Nicoll: Am I right in thinking that this makes for an extremely lossy battlefield? Ten men go in, half a man comes out sort of thing?

Well, since every unit in a battle can be shooting, it'll approximate the Lanchester square law (your losses are inversely proportional to your initial strength) - much like classical naval war. So basically I'd think that would be a good source of analogies. >(The main difference being the "see the enemy coming six months in advance" part, so no surprise attacks.)

Russell Wallace

James Nicoll: Am I right in thinking that this makes for an extremely lossy battlefield? Ten men go in, half a man comes out sort of thing?

Alternately, you don't send in your men until you have a hundred to the enemy's ten. Lots of staring across No Man's Space, feints to try and convince the enemy to misdeploy his forces, very occasional concentrated attacks against targets the enemy has left inadequately guarded.

Having an edge in strategic mobility is going to be important; the enemy can see your forces converging on a particular target, but can't quite do anything about it. Except, perhaps, counterattack somewhere else.

Having a 2:1 edge in strategic mobility is huge. You can concentrate your forces for an attack on any particular target, take or destroy it before reinforcements arrive, and still get back home (or wherever) ahead of the counterattack the enemy launched while you were away.

Both of the above assume that mobile forces contribute substantially to local defenses. If relatively immobile weapons platforms (surface or orbital) win over armed spaceships representing a much larger investment, you're back to stalemate.

Tactics: If one side has a clear advantage in both tactical mobility and weapons range, they win. On the other hand, some weapons don't allow for an absolute range advantage. And the defender will probably have the edge in tactical mobility, as he starts with full tanks and can burn it all.

Balkanized Earth may well be the battlefield of choice. If it's balkanized, even spaceborne parties to a conflict will likely find proxies there, and stealth and surprise are almost certainly still possible in the place crowded with friends, enemies, neutrals, oceans, jungles, mountains, and cities. Plus, it's likely to be the single greatest concentration of wealth in the Solar System until the time comes to dismantle it for raw materials, so un-balkanizing the Earth in one's own favor is, if possible, a winning strategy.

John Schilling

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