Fighters/PT Boats in the Traveller Universe

[warwizard]

OK OP said some other scenarios can be considered. Looking at T4 FF&S (2) I see that you can make really small pulse lasers with a 1-2 hex range, doing ONE point of penatration. This tiny laser can have a cluster of them mounted in a single turret and can be used to perform mission kills on missiles. The idea is that these tiny lasers each are tweaked to have a very high ROF and perhaps 10 or more of them per turret. It's been some 4 years since I've had access to my books, but a missile tends to have 80% of it's surface area taken up with mission critical equipment.
#1 terminal guidence sensor: knock the sensor offline and no more short range guidance, the launching ship could provide targeting data and commands, but this may be a several second decision loop for just the sensor pulse to travel to the target and back to the launcher then another time delay for the decision loop, and another delay for the command to be transmitted to the missile.
#2 Communications antenna: Command guided missiles get put into local only mode, generally mission kill in that case. Ones not command guided cannot receive detonation orders.
#3 Radiators: For missiles with internal fusion plants to power HEPLAR drives, knocking out the radiators means the fusion plant power is reduced or stopped, also it might mess up active stealth measures if extra radiators are being used to reduce signatures.
#4 Hull coatings: Well even if a weak pulse laser hits the hull and does not penetrate, it's going to make a spot hot and perhaps remove the military ultra black coating from that section of hull. Resulting in an increase in signatures given off by the missiles.
$5 Hull itself: Most missiles will not be armored, (unless it's a russian missile) the default missile hull is armor 1, and a 1 point of penatration throws hull fragments into the inner bits of the missile.

 

[Tobias]

No, Imperium doesn't even come close. What it does do is reduce all the fleet capabilities down to a couple of numbers that can be compared via a look up table and a dice roll decides outcomes. Double Star at least offers rules for fleet formations being a factor. HG79 had slightly more movement options that HG80.

Initiative, ship allocation, the range system, screening... all of these HG rules are clearly derived from Imperium. I do not own Double Star and have never played it, but fleet formations are not a factor other than line/reserve (or screened) in either HG or Imperium.

 

[AnotherDilbert]

Mike technically correct and incorrect at the same time. There's no sensor rule limiting range of detection since all ships sensors, even 10Td fighters use the same range as in CT Bk2... and the combat is abstracted enough that range is not a factor. He's twisting his wording for worst view of the ruleset.

Mike specified TNE:

HG has no sensor rules, but as soon as you move to BL or BR with sensor rules, weapon ranges...
So I am actually discussing Traveller.

He said:

The fighter is dead long before it can get into range of its own sensors, and its weapons barely have any effect on a properly designed capital.

But that is not how TNE works.

 

[mike wightman]

Unless we use FF&S2 or build bigger sensor systems.

 

[AnotherDilbert]

Unless we use FF&S2 or build bigger sensor systems.

In T4 sensor sensitivity increases at about the same rate as sensor signature, so fighters and battleships would see each other at about the same distance.

Still not:

The fighter is dead long before it can get into range of its own sensors, and its weapons barely have any effect on a properly designed capital.

But, sure, if you house rule sensors you can get any result you want.

 

[mike wightman]

Oddly enough I want them to match what happens in the real world.

The radars mounted on warships are vastly more capable than those that can be mounted on aircraft, even AWACS aircraft. A Traveller BB could have multiple arrays more capable than ground based radars rather than even warship mounted systems.

Space being empty you have antenna area and transmitted energy vs object size signature.

Better rules are needed.

 

[AnotherDilbert]

Oddly enough I want them to match what happens in the real world.

The radars mounted on warships are vastly more capable than those that can be mounted on aircraft, even AWACS aircraft. A Traveller BB could have multiple arrays more capable than ground based radars rather than even warship mounted systems.

Active sensors:
https://www.sciencedirect.com/topics/engineering/radar-equation

To get twice the range you need 2⁴ = 16 times the power and/or antenna.
To get ten times the range you need 10⁴ = 10000 times the power and/or antenna.

If a battleship has 1000 times the power and 100 times the antennae, it will have 17 times the range against the same target.

At the same time the battleship is much easier to detect. Does the battleship have more or less than 17 times the sensor cross-section of a fighter?

https://en.wikipedia.org/wiki/Radar_cross_section

• Stealth aircraft: <0.1 m² (e.g. F-117A: 0.001 m²)
• Surface-to-air-missile: ≈0.1 m²
• small combat aircraft: 2–3 m²
• large combat aircraft: 5–6 m²
• Cargo aircraft: up to 100 m²
• Coastal trading vessel (55 m length): 300–4000 m²
• Corner reflector with 1.5 m edge length: ≈20,000 m²
• Frigate (103 m length): 5000–100,000 m²

A small wet warship would have a radar cross-section of about 1000-10000 times a fighter.


In free space, without any confounding water, the fighter would see the battleship first.

 

[Tobias]

In free space, without any confounding water, the fighter would see the battleship first.

I'm not going to go into detail on this even though it used to be my field decades ago. Just a couple of three things:
a.) Surface warships vs aircraft is not the correct comparison; surface warships vs. very small surface warships is. Aircraft move in a different dimension than ships. All Traveller spacecraft move in the same dimension and medium.
b.) Comparing stealth aircraft to non-stealth ships is not particularly valid either.
c.) Most relevantly: With radar, you never see a modern warship first. If you can see them, they can definitely see you - because radar is an active sensor and they can pick up your emissions.
What they won't have by ESM alone is a range to the target. But they will definitely know you're there. (Unlike fighter aircraft, ships usually do not have major ESM/RWR blind spots.)

 

[AnotherDilbert]

I'm not going to go into detail on this even though it used to be my field decades ago.

Then you know this much better than I do.

Just a couple of three things:
a.) Surface warships vs aircraft is not the correct comparison; surface warships vs. very small surface warships is. Aircraft move in a different dimension than ships. All Traveller spacecraft move in the same dimension and medium.

Compared to free space, small aircraft vs. large aircraft would be better?
Ships have a water surface and a horizon to confound the matter?

b.) Comparing stealth aircraft to non-stealth ships is not particularly valid either.

I didn't; I compared non-stealth combat aircraft (2-6 m²) vs non-stealth warship (5000-100000 m²).

c.) Most relevantly: With radar, you never see a modern warship first. If you can see them, they can definitely see you - because radar is an active sensor and they can pick up your emissions.
What they won't have by ESM alone is a range to the target. But they will definitely know you're there. (Unlike fighter aircraft, ships usually do not have major ESM/RWR blind spots.)

Sure, and both can go passive. Or rely on a third part going active.


What do you think will happen if both go active and hang in free space? Who will get a direct fire targeting solution first?

 

[mike wightman]

Then you are into the realm of EW - ECM, ECCM

 

[McPerth]

even AWACS aircraft

IIRC the advantage of the AWAC is that, being higher, they avoid the effect of Earth curvature that shinders the surface radars.

Nothing similar applies in Space, I guess...

 

[Tobias]

Compared to free space, small aircraft vs. large aircraft would be better?
Ships have a water surface and a horizon to confound the matter?

Size differences between similar types of aircraft are not that great, but if they were, it would be more appropriate.

It's relatively simple: For two craft with the same level of RCS reduction, the relation of their RCSs will be roughly equal to that of their respective surface areas. Since Traveller warships function on the same technical principles whether they are fighters or battleships, there is no reason that they should not have the same level of RCS reduction.
The power available to the radar, on the other hand, under the assumption that both vessels use the same percentage of their tonnage for this purpose, is proportional to the tonnage of the vessel. Square-cube law; the larger vessel will have relatively more powerful sensors.

I didn't; I compared non-stealth combat aircraft (2-6 m²) vs non-stealth warship (5000-100000 m²).

These values are not to be taken at... errr... face value.
2-6 m³ is very much already in reduced RCS territory. The gigantic RCS value for the frigate is from a 1970s study I cannot access at the moment, but I feel comfortable in saying: These values are not for two objects with anywhere near the same level of RCS reduction.

Sure, and both can go passive. Or rely on a third part going active.

The idea of a third party, i.e. a dedicated picket ship, providing sensor data to nearby fighters would work. Of course that ship would become the primary target.

 

[Tobias]

What do you think will happen if both go active and hang in free space? Who will get a direct fire targeting solution first?

That is a different question which I have separated into this reply.
Firstly I think because of the effect of the square-cube law as mentioned above, if both rely on active sensors, the larger vessel, all other things being equal, will gain an accurate (past) position of the smaller vessel first.
But IMHO that will not equal a "targeting solution". Detection by active sensors requires you to emit energy at a space target; damaging it, especially if armored, is essentially the same process but likely requires a lot more energy. Thus I think (beam) weapon ranges will generally be much shorter than active sensor ranges.

 

[Condottiere]

Triangulation seems likely, as opposed to a single sensor.

 

[Carlobrand]

MegaTraveller was a bit confusing on the subject of sensors. On the one hand, you bought sensors, their specifics deciding your sensor roll. On the other, you could get additional sensor rolls by foregoing attack rolls on a 1-for-1 basis, implying the batteries themselves had sensors. On that basis though bigger ships would have better sensors, since they have more batteries, ergo more opportunities.

The issue with MT (and by extension CTHG) was the damage table which made it impossible to damage a heavily armored craft. Even if we assume the weapons and sensors are operating behind heavily armored shutters that open and close, there's a chance a hit will get through and claim a weapon (and by extension a sensor roll) since these had to be exposed briefly to function. Table would be better to end at -1 (or 21+ for CTHG).

 

[Tobias]

I couldn't edit my earlier post anymore.

Just to clear one thing up, because I see that should be more clear: Radar transmittor power and RCS influence range in the same manner; i.e. both are subject to the relation (to the fourth power of differences in range) AnotherDilbert mentioned in his first post. You need to increase power by a factor of 16 to double the range. Similarly, you need to reduce RCS by a factor of 16 to halve the range.

 

[Condottiere]

Sensor hand offs seems likely, from command and control spacecraft, if not from the local swarm.

 

[Tobias]

That can work, but only if they are in relatively close proximity. If not, the required communications link adds another source of light lag.

I don't know if that was an optional rule somewhere, or if I had just toyed with the idea before, but IMHO a fighter squadron (of 10 vessels) should be allowed to add together its weapons as a single battery.

 

[McPerth]

Well, so we agree a figher has little to do agains a battleship, but fighters don't act alone, but in swarms...

 

[Tobias]

Well, so we agree a figher has little to do agains a battleship, but fighters don't act alone, but in swarms...

The problem with that is that a swarm of fighters doing 0 damage each still is zero damage in total.

I don't know that fighters should be effective against battleships. If they could perform other roles (missile defense, picking off more lightly armored cruisers) effectively, that would be quite enough IMHO.