Sensor Sat

[Carlobrand]

The TL15 sensor sat is a grav-thrust remotely piloted vehicle (RPV) placed in orbit to provide early detection of incoming vessels. The unit does not process sensor data. Instead, it collects and feeds data via maser link to a remote receiver - a ground base or a ship or SDB orbiting closer in; the receiver processes and interprets the data. At approximately MCr 1.3 each, 88 of these can be deployed for the cost of a single 20t strike fighter (or similar small craft with equivalent sensors and Computer-9), allowing more expensive craft to function from increased safety while the expendable RPV takes the vulnerable front-line position.

TL15 Sensor Sat, 0.5dT: 3m x 1.5m x 1.5m (6.75kL)
• Armor: 40, TL14 bonded superdense,
o UCP 0.5, streamlined cylinder airframe, = 0.7tx1x0.14x33t.=3.234t,
o 2800x(1x1.2)x1x33 = Cr110,880
• Computer: Model-0x3, 300kg, 1.5m^3, 0.003Mw, Cr180,000
• TL15 LoPen Densit. (250m.), 100 kg., 0.3 m^3, 0.08Mw, Cr205,000
o PasObjScan=Routine (7+), PasObjPin=Routine (7+),
• EMS-P-14 Interstellar, 20kg 0.20Mw, Cr400,000
• Neutrino (10 Kw) Sensor-14 x2, 95kg. 0.2Mw, Cr110,000
o PasEngScan=Simple (3+), PasEngPin=Routine (7+)
• TL15 Maser comm.: Far Orbit (500,000km) 14kg, 0.014Mw, Cr112,000
• E.M. Mask: 0.001Mw/KL 0.02m^3/KL 0.01t/KL 5000Cr/KL
• TL10 L.P. Hi-Grav, 35.2t thrust: 0.704Mw, 1.056t, 1.76 m^3, Cr70,400
• TL15 Fusion Power Plant: 1Mw, 0.66t, 0.33 m^3, Cr66,000
• Fuel, hydrogen: 3 l/hr, 2016 l (28d), 0.141t

The TL15 Sensor Sat has an operating maneuver rating of 5g and an emergency rating of 6g, achieved by shutting down the densitometer to divert power to the grav thrusters. (Emergency rating is applied only when withdrawing the satellite quickly from its assigned station, allowing it to be - hopefully - withdrawn from far orbit and landed or brought under cover of atmosphere before being spotted and fired on by intruders.) Its small size and masking renders it at least as difficult to detect as a small boat, if not harder. Passive EMS sensors provide a maximum effective detection range of 23x25=575,000 km. for capital ships, 21 for destroyer-size vessels, 19 for boats.

total:
Armor 3234kg. 6.75 m^3 Cr 110,880
Comp. 300kg. 1.5 m^3 -0.003Mw Cr 180,000
Densit. 100kg. 0.3 m^3 -0.08Mw Cr 205,000
EMS-P 20kg. 0.020 m^3 -0.20Mw Cr 400,000
Neutr. 95kg. 0.095 m^3 -0.2Mw Cr 110,000
Comm. 14kg. 0.014 m^3 -0.014Mw Cr 112,000
EMM 67.5kg. 0.135 m^3 -0.068Mw Cr 33,750
L.P. Hi-Grav.
1056kg. 1.76 m^3 -0.704Mw Cr 70,400
Pwr. Pl. 800kg. 0.40 m^3 +1.2Mw Cr 80,000
Fuel 175kg. 2.5 m^3 - -
___ ___ ___ ___
5861.5kg. 6.724 m^3 -.068Mw Cr1,302,030

(mental note: tabs don't work here.)

 

[Omnivore]

I like the idea, I've been playing around with a similar idea for a synthetic aperture thermal imaging array deployable in deep space. Rather than a single satellite, it would consist of a central signal preprocessing and communications node with numerous 'sub-munitions' as the actual sensors.

The problem I'm having is with the absurd mass and power requirements of Traveller electronics, computers, sensors, and communications gear. Later released materials (FF&S for example) are a bit improved over CT, but present day mass/power requirements are far below even TL15 devices. Also, the closest I've come to finding an equivalent of a SNAP reactor is the piezo nuclear fusion (cold-fusion) devices in FF&S alternate rules.

Passive sensor arrays such as I'm envisioning should be easily deployed in sand canister form factor packages with effective aperture size increasing at higher tech levels.

 

[Carlobrand]

Okay, here's an interesting dilemma:

I am the Imperial Navy (having another one of those grandiose moments). I am defending the Spinward Marches against multiple adversaries, including one nearly as strong as me and another with a nasty taste for going a-viking. I have 7 fleets consisting of roughly 25-30 battle squadrons and 20-25 or so cruiser squadrons, an aggregate force valued at something on the rough order of 30 million megacredits. That force has to defend 272 Imperial systems with 471 gas giants.

My biggest problem is intelligence. I need to find out where the enemy is before I can apply my forces against him, or else I've spent all that money for nothing. Space is big - but he has to refuel. If I can spot him while he's refueling, and get that info back to someplace where it can do some good, then I can intercept him. At best, my information's a week old when I launch, two weeks old before I arrive, but it's better than nothing - a little deductive reasoning and a bit of luck should let me bring him to battle.

With 743 potential refueling points (actually a bit less after subtracting desert worlds with no significant starport), I put several sensor sats with supervising ships - say a small destroyer escort - in orbit around each point, and station a couple or three high-jump couriers hidden in deep space to take messages by laser comm from the DE and deliver them straight to the nearest naval base. Class A/B/C starports likely don't need anything but the couriers - those worlds will already have some sort of orbital-space monitoring going on, they just need a bit of insurance against a fleet big enough to blockade them. So, I can monitor all the likely refueling points for around 2% of the cost of my fleet (about half the cost of a single battle squadron, actually).

(And, no, don't say, "I'll just jump him before he can report." Any standard sentinel operation has the sentinel reporting in at regular intervals, and if he doesn't report, trouble is assumed. If the DE buys it, one Scout moves in to investigate while remaining in constant communication with the others and ready to jump at the drop of a hat; if that scout buys it, one of the other scouts jumps with whatever information they have, to alert the base that something is amiss.)

And the dilemma: there's no reason NOT to do this. Even if one argues the sensor sat is invalid, a DE and a few fighters do the job just as well, and the total cost is still a small fraction of my fleet investment - well spent if it helps me bring my main guns to bear against an invader. In a world governed by jump-speed communications, it's the most effective way to track the movements of enemy fleets in your space.

On the other hand, the universe just got a bit less wild. Everywhere the player goes in Imperial space, there's an Imperial warship - and it's likely the Zhodani and others would do something similar. Sure, they're Navy: they're there on a specific assignment, not to chase after itinerant tramp freighters who are behind on their payments. Still, it can make piracy more than a little tricky when there's a DE orbiting a few turns away, and the idea that you can go adventuring and have the Navy available to rescue you if you find yourself in serious trouble - or find yourself facing Navy guns if you push the legal envelope too far - definitely changes the character of the game.

Any thoughts? Design rules certainly point this way, but it does change the flavor of the game.

 

[Gray Pennell]

This comes down to a basic fleet strategy thats as old as there were fleets. Do you concentrate your forces in the hope that when you find the enemy you can over powering your enemy or do you spread it out so you can find it and get off a warning.

This problem is often answered by intelligence (not surveillance) and strategy. The biggest example I can think of at this time is the battle of Midway. Prior to that battle the Japanese had their naval forces concentrated and striking like a hammer against under strength and or unaware targets. It was US intelligence that found the Japaness were planning to strike at Midway. This allowed the US to concentrate its forces ahead of the enemy blow. It was a tie but to the defender goes most ties.

The Arch Duke did the same thing in the 5th FW where he formed the Core Fleet to attack the Zho's 40th fleet and change the 5th FW

 

[Omnivore]

This comes down to a basic fleet strategy thats as old as there were fleets. Do you concentrate your forces in the hope that when you find the enemy you can over powering your enemy or do you spread it out so you can find it and get off a warning.

Sorry, have to disagree here. This is one area where the old pre space age comparisons simply don't apply. It is a situation far more equivalent to the present day naval environment with satellite recon playing the major role in tracking unfriendly dispositions. It is a matter of economics.

Admittedly it depends on how you look at the various Traveller detection rules. I chose to err on the side of hard science and consider stealth in deep space to be impossible. There is no way to mask or hide the infrared signature of an operating power plant or a human (or human-like) crew compartment especially against observers in unknown locations.

So in each system to be covered, a pair of scout ships augmented by cheap autonomous sensor satellites (quite probably enhanced by the use of remote sensor elements in large synthetic aperture arrays) can reliably track all ship movement through the system except very near planets.

I'd consider the total capital cost of the ships, sensor sats, and remote sensors for coverage of an average of three points in each of 272 systems to be 20 MCr per point plus 60 MCr per system or an average of 120 MCr per system. Multiplied by 272 that gives a figure of less than 33 BCr or roughly 0.1% of the fleet Carlobrand has available. Even tripling that figure for redundancy would still be a paltry sum in comparison to the fleet cost.

Sticking with stock Traveller detection rules and no provisions for synthetic aperture arrays or micro sensor clouds, the picture is a bit different. If jump signatures are ignored (iow jump is not detectable), covering the all the approaches to a large gas giant (worst case) would require coverage of between a 1x10^12 and 40x10^12 square kilometers (spherical surface area depending on desired satellite orbit). The stock standard detection range for military sensors (LBB2) is 600000km, due to planetary shadow the minimum number of sensors required would be, I believe, 4. The maximum would be 40 at about 10D orbit. Splitting the difference and being conservative, lets assume 12 satellites with military grade sensors would suffice and provide some redundancy.

Using Carlobrand's sensor satellites (12*3) along with a pair of scout ships per system the capital cost ends up even lower than the figures for the infrared deep space sensor arrays I was assuming. Admittedly there is no coverage using stock detection rules for Oort clouds, Kuiper belts, or other asteroid belt like sources of fuel.

The Achille's heel of this idea with standard Traveller detection rules is the combination of Oort cloud/Kuper belt/asteroid belt fuel sources and empty hex jumps. By sending in a refinery fleet ahead of the main fleet, stationing them in far orbit about a thousand AU's beyond the furthest body of a star, and using micro jumps for the fuel 'mining' vessels, an invasion highway could be built behind enemy lines with virtually no chance of detection.

 

[E.D.Quibell]

The Achille's heel of this idea with standard Traveller detection rules is the combination of Oort cloud/Kuper belt/asteroid belt fuel sources and empty hex jumps. By sending in a refinery fleet ahead of the main fleet, stationing them in far orbit about a thousand AU's beyond the furthest body of a star, and using micro jumps for the fuel 'mining' vessels, an invasion highway could be built behind enemy lines with virtually no chance of detection.

This is the crucks of Traveller Naval Stratergy. You can put a fleet of ships in any system you wish to and there is nothing anyone can do about it. The Zhos want to put a fleet over Capital? No problem. You just can't economically cover every fueling source with enough firepower to stop them.

Space is BIG. Space is HUGE. By the time you detect the fleet in Oort cloud/Kuper belt/asteroid belt/outer gass giant the data is at _best_ 1 jump old, and the only way to try and catch them is to out jump them and hit them at a choke point. With a Jump4 fleet these are few and far between. That's if you can guess where they are going.

The only way you can enguage the fleet is if they jump right ontop of you, and this is a millon to 1 shot.

The fleet can only be enguaged when it choises to be enguaged. And that's why they invented deep site menson planetary defence weapons.

Best regards,

Ewan

 

[77topaz]

The fleet can only be enguaged when it choises to be enguaged. And that's why they invented deep site menson planetary defence weapons.

It presume you mean deep meson sites?

 

[Gray Pennell]

SI think it is a scale question. I answered thinking of insteller coverage not system scale. System scale does allow for some interesting play. I am working on my sensor rules for my game tomorrow. The players are in a Donosev scout ship re-outfitted as a spy "trawler" equipped with Darian tech 16 sensors. So they have some role playing/die modifiers advantages.

The game runs in 4 parts.
Jump in to system, set off a meson mine posted at 100 Diamter limit of the only gas giant. It takes out the sensors, but leaves a gab in the mind field.

Players repair sensors as they burn for the gas giant.

Avoid detection of Patrol ships, refuel while spying on a mysterious new ship.

Get past a 10 fighter picket line guarding the gape left by the exploded mine.

All of this is going to require sensor rolls. I do believe in limited counter measures. I am going to have 4 different sensors: Survey, Search, Tracking, Counter Measures. Each have different ranges, capabilities and Die modifiers Its a game of who spots who first.

I ll give them to those that wish them.

 

[Omnivore]

The more I consider this, the worse the picture gets. If the Sol system is considered to be typical, as I believe it is in Traveller, then having a rather large number of iceballs orbiting at around 1 ly out from a star is the common case.

No matter what detection rules you assume, or the tech/physics basis for them, it seems to be quite possible for a fleet to travel practically anywhere unnoticed. There are no choke points!

 

[77topaz]

The more I consider this, the worse the picture gets. If the Sol system is considered to be typical, as I believe it is in Traveller, then having a rather large number of iceballs orbiting at around 1 ly out from a star is the common case.

No matter what detection rules you assume, or the tech/physics basis for them, it seems to be quite possible for a fleet to travel practically anywhere unnoticed. There are no choke points!

Looking through sector data, about two-thirds of all systems have asteroid belts, and some have very big ones (e.g. Fomalhaut's real life debris disk - but in Traveller that system has no belts (does a debris disk count as a planetoid belt?)), so you may be right...

 

[Carlobrand]

...The Achille's heel of this idea with standard Traveller detection rules is the combination of Oort cloud/Kuper belt/asteroid belt fuel sources and empty hex jumps. By sending in a refinery fleet ahead of the main fleet, stationing them in far orbit about a thousand AU's beyond the furthest body of a star, and using micro jumps for the fuel 'mining' vessels, an invasion highway could be built behind enemy lines with virtually no chance of detection.

This is the crucks of Traveller Naval Stratergy. You can put a fleet of ships in any system you wish to and there is nothing anyone can do about it. ...

Ayup, that's a problem all right. The sensor network I envision covers canon fuel sources - there's nothing I know of in canon that speaks to a ship mining fuel from an ice body. The issue isn't addressed at all in the game - FFW says you're basically stuck if you can't find a water planet or a gas giant. However, any military worth the name is going to exploit every possible alternative fuel source if it gives them a strategic advantage - and the gods know there are a LOT of alternatives. We can do it with modern tech with little difficulty; it's hard to imagine a futuristic craft dependent on hydrogen NOT carrying the equipment necessary to resort to ice sources if needed.

One could argue that it takes longer, but as Omnivore points out, there are strategies to pave the way for the battlewagons - there's nothing you could do within the scope of the the present sensor rules to counter that. Either you accept that the enemy can go anywhere he wants, any time he wants, or you envision non-canon but scientifically sound reasons for the entire system to be visible to the right kind of sensor network - and you're still likely to be a step behind a fast and clever invader.

The universe is basically hydrogen with a tiny percentage of waste products - this H2 stuff is freakin' everywhere.

 

[Selandia]

a) even if your idea work, by the time your intercept fleet jump in, the intruder fleet have jumped out... unless...

b) they wait for you to jump in before jumping out if they can't beat you. Unless you jump in with reserve fuel for a jump out, any fleet jumping in answering a call might be jumping in an ambush with only the refueled ambushers having the option to says: Ooops better leave.

c) Given enough time, caches of tanker pods may be constituted in (literally) the middle of nowhere and a fleet moved within striking distance of the most valuable target in half a dozen jump fueling in the intersideral void.

In a fleet chasing war, the best defense will the offense.

The only way I see two fleet meeting is because either, a weaker force is ambushed and cant jump out, or both forces eagerly seek battle to establish supremacy, or because a planetary invasion is taking place, forcing a protective force to cover the invasion fleet (which is another way to say they seek engagement) . Actually that invasion might be done for the sole purpose to force the enemy fleet to shows up and fight the "decisive battle" "à la Mahan". That how you find the enemy fleet, force it to show up to fight over a strategic point.

Otherwise you will be chasing, always a jump too late, a fleet that will inflict days of orbital bombardments to planet after planet after planets...jumping out just before you jump in.

I was wrong, offense is not the best defense, it is the ONLY defense

Selandia

 

[Gray Pennell]

Well I ran my first game using the modified Role Playing Space Combat system. The results the players got everything and more of what they needed and got away. Here are the highlights of the test.

It successfully ran at a scale that covered the 100 Diameter limit of a gas giant.
There was no combat but tons of sensor rolls. This is good since they are in a spy ship and non engagement is their job.
Sensor rules worked but way to many DMs I need to create a spread sheet to calculate the rolls
I managed to keep tensions high and give the ship captain a lot of role playing.
Cant wait for actual combat.

 

[Carlobrand]

Congrats, Gray, that's sounding interesting - especially the countermeasures bit. Wouldn't mind a few more details.

a) even if your idea work, by the time your intercept fleet jump in, the intruder fleet have jumped out... unless...

b) they wait for you to jump in before jumping out if they can't beat you. Unless you jump in with reserve fuel for a jump out, any fleet jumping in answering a call might be jumping in an ambush with only the refueled ambushers having the option to says: Ooops better leave. ...

Ummm, no, not exactly. If I shoot a flying bird, I don't aim where it is - I aim where I think it's going to be when my shot arrives there. Bird might veer left or right, but an experienced hunter learns to predict with fair accuracy.

In the space-war context, I've got a week old report on where the enemy was, and I'm trying to guess where the enemy will be in another week, since it will take that long for my fleet to get there. However, I can make some guesses as to his likely targets based on where he is and what places he's within striking distance of - he's certainly not invading so he can pound on unpopulated rocks. I might guess wrong, but that's the nature of war - you make the best guesses you can with what information you have. It's the fog of war.

Fifth Frontier War tried to simulate the delayed intelligence bit by implementing that 4-turn order-writing thing.

...c) Given enough time, caches of tanker pods may be constituted in (literally) the middle of nowhere and a fleet moved within striking distance of the most valuable target in half a dozen jump fueling in the intersideral void. ...

Maybe. Locating a precise jump exit point in the vastness of interstellar space with no star as referent sounds like a pretty daunting challenge, but there are workarounds that are just as effective - delivering caches of tanker pods to some obscure planetoid in the Kuiper belt, for example. So, whether it's in interstellar space or some obscure and distant point of a target system, it amounts to the same thing: a determined enemy could most likely come up with some sort of remote fueling station to support an attack if that's what he wanted to do.

...In a fleet chasing war, the best defense will the offense. ...

Not necessarily. As I said, half the game is predicting your opponent's likely actions. If you're invading, you want your effort to have a lasting effect on the enemy's will and ability to fight. Jumping around the "countryside" savaging lightly populated "villages" of little military value, while the main "cities" are left unharmed, is a waste of a good fleet's time and just gives me info on your approximate strength and location. All other things being equal, your invasion force is smaller than my defence (or else you've stripped your own defenses for this invasion and I can counter with an invasion of my own), so I might be able to bring a larger force against you if I can anticipate your movements.

Meanwhile, back at the ranch, an attacker needs to worry about supply lines - replacement warships and ships carrying reload missiles, repair parts, replacement personnel, and so forth. The deeper he goes, the longer that line is and the farther supplies have to travel to reach him. Depending on the refueling rules, it might be possible to cut that supply line. A defender mostly does not need to worry about supply lines - his supplies come straight from whatever base is closest to him.

...The only way I see two fleet meeting is because either, a weaker force is ambushed and cant jump out, or both forces eagerly seek battle to establish supremacy, or because a planetary invasion is taking place, forcing a protective force to cover the invasion fleet (which is another way to say they seek engagement). ...

That's pretty much the case in most war situations. The history of the American Revolutionary War and Civil War, the Napoleonic wars, the Wars of the Roses, the naval engagements of WW-II, and many, many other examples are basically stories of competing forces hunting and dodging until either both sides chose to engage or one side had no good choice left to it.

Random thoughts:

1. At the outset of an encounter (per MT rules) , generic markers are used. The player can neither identify nor target opposing ships until he makes a successful sensor roll - but the markers imply he knows SOMETHING is out there, somewhere in a 25-thousand kilometer region, and he can see that something moving in a vague way, because he can watch it get closer and then declare an interrupt to scan it. Or at least, that's how the rules seem to read.

Contrariwise ...

2. The game allows for "surprise" - an attacker pretty much has a free hand until surprise is lost. Thus, it is possible to be well within sensor range and yet go unnoticed, even to pepper a target with lasers and missiles and go unnoticed - assuming he does enough damage that the target itself does not have a chance to call warning, and assuming the sensor operators on the other side's other ships fail their rolls. Hard to reconcile this one with the first one - I'm thinking of calling it the "Asleep at Your Post" rule, or maybe the "Space the sensor officer" rule.

3. While the densitometer and neutrino sensor are not given any ranges beyond those implied by the die rolls and related rules in the sensor section, the EMS Passive Array is described with ranges that far exceed their combat capabilities - up to "interstellar" range (2 parsecs).

1 and 3 taken together seem to imply that the EMS Passive Array can indeed detect ships throughout the system - just not with great accuracy. Thus, if a hostile ship or fleet jumped into, say, the Kuiper Belt region, a ship equipped with an interstellar range passive EMS would most likely know SOMETHING is out there SOMEWHERE - but not what, how many, or even precisely where beyond maybe a rough bearing and an idea that it was rather far off. Helpful, but not exactly overwhelming, and just as likely to get you in trouble if it turned out, for example, to be a decoy drawing you away from the world you're supposed to be defending. And, if the hostile landed on or hid behind some planetoid, then you'd lose the signal.

 

[Gray Pennell]

Well first I need to stress that my modifications are designed for role playing not a simulation.

1. I dont bother to describe the equipment. you can make that up. I just created three different types of sensors and counter measures.

2. Each sensor group works at different scales, and have active/passive modes.

3. My groups are Survey, Search and Tracking.
Survey sensors work on the AU scale and can get the most information.
Search sensors work in the millions of miles scale are basic navigation.
My game ran at this range and worked great for refueling at the gas giant.
Tracking sensors work at the 0-10000 km range and handle combat/docking

4. Each sensor has its own range bands. Each band has modifiers and what can be detected. Additionally there are tech level and size modifiers.

5. When Counter measures are used it becomes an opposed roll and may the best sensor op and equipment win.

6. My players with their Survey sensors spotted the enemy at the AU level and prepared for them. Instead of max refueling they settled for just 2 jumps worth of fuel and moved to the 100 D limited of the gas giant. There they warmed up the jump drives and deployed counter measures. When the enemy arrived they deployed active search and survey sensors. They got tons of intelligence and jumped out before the bad guys reacted.

7. I should have given them negative modifiers for the jump drives. But I admit I didnt think about it due to my pleasure with their plans. Oh and they didnt turn my meson mines against me though it was ruddy close. Due to this I decided to let them get out as an award. Plus it moved the plot forward.

 

[Omnivore]

Well first I need to stress that my modifications are designed for role playing not a simulation.
<snip>
3. My groups are Survey, Search and Tracking.

Though you did not intend simulation, you've done it rather well in my estimation. Your three groups correspond to the strategic, operational, and tactical realms quite nicely.

However, in the strategic realm, one must measure the usefulness of the information for the purpose. Usefulness is affected by timeliness, and there is where the outlying small bodies of ice pose a problem for strategic surveillance.

As one part of the problem consider the outer Oort cloud alone. It has a radius of approximately 1 light year and contains somewhere around 18 million bodies of 1km diameter or larger. A significant fraction of those bodies contain extractable hydrogen. Suppose pessimistically only 1.8 million are viable fuel sources. With a circumference of 6.28 ly, one can expect an average distance of 110 light seconds between each.

Assume, for a moment, that you can accept a maximum sensor latency of one week. To cover the outer Oort cloud area requires a minimum of 326 scout ships, each with a Substellar (100000AU) PEMS sensor (or better). This will have a capital cost of around 25BCr, for the outer Oort cloud area alone, per system with such a cloud. Sensor satellites don't help at all here.

Without digging into too much further detailed analysis, I'd expect that total system strategic surveillance to a one week sensor latency level maximum would cost a minimum of 100BCr in capital equipment plus operating costs.

Despite this high cost, it might well be worth paying the price to gain coverage of choke points on or beyond the border. However, total surveillance coverage of systems, even at the one week sensor lag level, would not be common.

 

[Gray Pennell]

Though you did not intend simulation, you've done it rather well in my estimation. Your three groups correspond to the strategic, operational, and tactical realms quite nicely.

However, in the strategic realm, one must measure the usefulness of the information for the purpose. Usefulness is affected by timeliness, and there is where the outlying small bodies of ice pose a problem for strategic surveillance. <snip>

I must tell you I assumed these would be sensors found on Scout Ships with limited space to install large equipment. I put the max range of these sensors at 32 AU, thats just short of Pluto and in effective range to take action. Additionally size mods and tech mods make spotting a small ship at 25 AUs nearly impossible, When you consider most action takes place in a few AUs with combat in the 1000 Km range than OC distance becomes a grand Strategic scale and really can be ignored for operational planning.

The invader can hide there but to close in for an attack they have to move into the AU scale. To do things like refuel and deploy for battle you have operational scale than engage at the tactical. A good defender would watch GGs with a picket line and keep a ready reaction force that can reach the picket line in maybe a day or two.

 

[Omnivore]

I must tell you I assumed these would be sensors found on Scout Ships with limited space to install large equipment. I put the max range of these sensors at 32 AU, thats just short of Pluto and in effective range to take action. Additionally size mods and tech mods make spotting a small ship at 25 AUs nearly impossible, When you consider most action takes place in a few AUs with combat in the 1000 Km range than OC distance becomes a grand Strategic scale and really can be ignored for operational planning.

I'd be tempted to mix MT, FF&S, and house rules to get a synthetic aperture PEMS array using drones on a max jump scout design with max computer (max for TL). The design goal would be to have a detection range (for strategic purposes - not combat) of 1 light week (1216AU). Effective target size for detection would be quite large since we're talking about enough auxiliary tonnage to refuel a main battle fleet or at least a moderately large raiding fleet. The resultant design would probably be three to four times the cost of a normal type S.

Of course I'm one of those who refuse to accept stealth in deep space as a possibility. A tactical environment with decoys, jamming, nuclear detonations, etc is another story. So the idea of drastically different ranges for strategic, operational, and tactical environments is quite logical and realistic from my point of view.

As far as extracting fuel from ice, while OTU canon does not specifically state it is possible, realistically it is hard to deny. However, I'd use house rules to require mining equipment beyond the normal fuel purification plants and fuel scoops/hoses. So in order to use the Oort/Kuiper refueling strategy, you'd need a fleet of mining vessels in addition to the normal fuel purification support. Supporting a TCS would require a rather large operation at each pit stop.

 

[Gray Pennell]

Ha Ha go for it you will have a flying dish. I built in a few general constraints into the system because, I want more close quater combats thats just me.

I consider counter measures being any action and technique one can do to hide. Again I dont get into the level of detail of naming absolutes. Absolutes lead to canon and canon leads to debates about .1C rocks. Flexibility is the key in a rpg non simulator system.

As for refueling out there I thought about it after my posting. I would allow mining but it would as you said have to big, complex, time consuming, and dangerous. This leads it open to a defense fleet jumping to the Oort belt and engaging. If the defender dosent engage there then the attacker has to either leave or move in to engage the defender

 

[Selandia]

That is indeed a better way to use information. Nonetheless I prefer to lets him try to figure out were I am going, rather than having to guess where he is going. His nuisance operation does not concern unpopulated rock, just destroy starports, orbital installation of large world, key industrial complexes to cause significant economic disruptions. The japanese disregard for submarine war on shipping when compared to german an USN operation is an example of underestimating economic warfare


So we agree as to the possibility of penetration, (the interstellar void was extreme example)

All other things being equal, your invasion force is smaller than my defence (or else you've stripped your own defenses for this invasion and I can counter with an invasion of my own), so I might be able to bring a larger force against you if I can anticipate your movements.

That is my point, attacking is likely a better attitude that chasing around with a larger force, even if you chose intelligently.

Meanwhile, back at the ranch, an attacker needs to worry about supply lines - replacement warships and ships carrying reload missiles, repair parts, replacement personnel, and so forth. The deeper he goes, the longer that line is and the farther supplies have to travel to reach him. Depending on the refueling rules, it might be possible to cut that supply line. A defender mostly does not need to worry about supply lines - his supplies come straight from whatever base is closest to him.

Well stated the classical advantage of defense. But will you win a war without going on the offense at one point, just relying on the other exhausting himself into submission? Counter-attacking an overextended exhausted enemy is a classical strategy, but it still require that you master the problem of the attack, as you just stated it. Therefore, I guess you know how to make winning attack.

Selandia