Agility - thoughts

[Tobias]

Where are you getting that from? Here's what that game says about missile movement:
"missiles move as if they were ships with maneuver drive-6".
And that's it.

By the way, because this is really bugging me:
(For context, I started out with Starter Traveller - to be precise, the locally published version of it - and never got to consider other versions of the basic CT rules until much, much later. Anyhow...)

In either Book 2 '77, Book 2 '81 or The Traveller Book, is it stated anywhere how a missile maneuvers? It is in Starter (which I quoted), but I can't find it in the other books through the marvelous technology of searchable PDFs. Am I just blind?

 

[infojunky]

In either Book 2 '77, Book 2 '81 or The Traveller Book, is it stated anywhere how a missile maneuvers? It is in Starter (which I quoted), but I can't find it in the other books through the marvelous technology of searchable PDFs. Am I just blind?

Heh, no you're not blind. Mayday, Starter Traveller and Special Supplement #3 are the three places it was mentioned in CT.

 

[Rupert]

T4 FF&S does, and you can design your own missiles with components that are small enough to make a very nice and capable missile under .1DT at TL 15. TL 14 and your limit appears to be about .25DT. lower than that and you are looking at multiple DT. (The power plant table rules how small the power plant can be at each tech level, even antimatter plants once you get into TL 17 through TL 19. HePlar maneuver drives require a fusion power plant to feed the drive with ionized gas to throw out the back after accellerating the ions. Think rocket exhausts that are fractional C, quite the fuel mizer for the thrust derived. If you need smaller than .1DT then you are back to chemical rockets and the relatively poor thrust/kg that entails.

RAW FF&S1/TNE HEPlaR does not require a fusion reactor to power it, and there are a number of vehicles in TNE that support that (the Grav/Raft for one). That requirement was a later addition in FF&S2.

 

[warwizard]

RAW FF&S1/TNE HEPlaR does not require a fusion reactor to power it, and there are a number of vehicles in TNE that support that (the Grav/Raft for one). That requirement was a later addition in FF&S2.

Thanks Rupert, I had missed seeing that in the TNE version, I spent a lot more years in the T4 version than the TNE one. Leads to battery powered heplar missiles, but still very limited in duration.

 

[Rupert]

This also depends on ruleset. but of course light lag is an issue in several of them. In BL/BR hexes are 30,000 km, with combat at 10-30 hexes being quite possible. In Mayday, hexes are 300,000[!] km, so obivously light lag is an issue even at 1 hex of range. In CT (Starter) combat, there is nothing to keep you from (and it may indeed be quite prudent to be) launching missiles as soon as you detect an enemy at two light-seconds, that is 600,000 km, of distance.

The extreme edge of TNE/BL/BR beam weapon rand command-guided missile range is something like 38 hexes (3.8LS) for missiles and standard RoF beams, and 40 (4LS) for RoF 100 beams, assuming a 1 million DTon target and TL15 fire control. With RoF 800 lasers and PAWS (which are legal in FF&S, but not addressed in the combat rules) the limit is 50 hexes (5LS).

As ships get smaller the max range drops by roughly 3 hexes per size modifier (so ~0.3LS per factor of ten in volume).

Semi-independent missiles with their own sensor locks don't take the massive range penalties, and so can reach out to the limit of their comms systems (generally 80 hexes, and I'd expect referee's to be unsympathetic to attempts to game this by adding 1000AU laser comms to missiles and MFDs), though in practice outside of 10 hexes the comm link becomes unreliable, beyond 20 hexes very unreliable.

Fully-independent missiles were never described, nor was how to make them. I design them using robot brains (from Vampire Fleets), and good ones (i.e. with decent sensors and skilled brains) tend to have large and expensive guidance packages, so you may as well bit a big warhead in as well, and a serious thruster (HEPlaR, etc.).

[And now I realise this is really the wrong sub-forum for this post.]

 

[Carlobrand]

If using SS3: Missiles, discretionary burns are actually lighter than other propulsion systems. You can fit a 5G10 discretionary burn, a controller, a mass sensor and an intelligent detonator, plus a 10-kg force focussing warhead into a standard 50 kg missile.

Not that I think those tiny missiles make too much sense, mind you, but going by the rules that's how things are.

You get some interesting results if you lift the 6g cap. Three of the tables are pretty straightforward to extend, but the discretionary's a beast.

 

[Carlobrand]

Many thanks to AnotherDilbert, I got my missile maker working properly. I think it's properly, anyway.

So, if you lift the 6g cap on CT SS3 - which isn't unrealistic, we had Sprint pulling 100g's as an ABM - and strip it down to a controller and a radio receiver to receive control commands from the launcher, you can come up with 23g continuous burn missiles that can go 115,000 km from a standing start in a thousand-second turn (or 230,000 km as Book 2 plays it, if I understand that correctly). No warhead, they just hit and do damage by speed, less at short range. Limited burn missiles can get 200,000 km in a turn - those confuse me. Discretionary burn missiles can reach 25g and 127,500 km in one turn. For the typical fleet vs. fleet model of two fleets being relatively static with respect to each other, they do pretty good outside of 30,000 km and emulate the same-turn business nicely (though of course that's a magic-tech fuel). Or if you want to have something with an explosive backup, your discretionary burn missile can reach 91,000 km in one turn while carrying a warhead.

Things change if you're fighting an actual running engagement but, if they're fleeing at 6g and your missile's doing 18g or 25 g, you've still got a window there in which you'll hit them and do some damage no matter what.

(If you're really daring, you can import the Striker warheads, but that's a bit of a headache and I'm not all that confident of Striker's weight calculation for missile warheads weights, much less figuring out what a 10 kg HE or 20 kg nuke would be in Striker.)

 

[Tobias]

The thing is: AFAICT the performances in SS3, with or without a 6G limit, are flat-out impossible to achieve with chemical rockets implied in that supplement. They would have to be some kind of fusion rocket (and even that stands on shaky ground) or use the same assumed gravitic thruster technology that ships use.
But then again, I know nothing about chemistry. I would actually be interested if anyone who does could opine on whether it would somehow be possible to achieve the specific impulse of 10,000+ that SS3 missiles would need.

 

[Marcatlas]

But then again, I know nothing about chemistry. I would actually be interested if anyone who does could opine on whether it would somehow be possible to achieve the specific impulse of 10,000+ that SS3 missiles would need.

Back in the day when my uncle was still alive (USMC O6 & Ford Aerospace engineer designing AA missiles (physics and chemical engineering degrees). I asked him about the extreme Trav ship missiles. He said not possible with chemical rockets based on total energy needed for that Delta V. Maybe some advanced nuc tech could do it but not anything we could make at the time.

 

[Carlobrand]

The thing is: AFAICT the performances in SS3, with or without a 6G limit, are flat-out impossible to achieve with chemical rockets implied in that supplement. They would have to be some kind of fusion rocket (and even that stands on shaky ground) or use the same assumed gravitic thruster technology that ships use.
But then again, I know nothing about chemistry. I would actually be interested if anyone who does could opine on whether it would somehow be possible to achieve the specific impulse of 10,000+ that SS3 missiles would need.

Ion engines possibly, but that's a big engine that spits out a tiny bit of reaction mass, if I recall. If you could come up like something like that which was a lot smaller and spit out a whole lot more stuff at that efficiency, you could maybe pull it off, but I can't imagine how you'd power it.

 

[mike wightman]

Go back to the original version of the missile fuel burn in Mayday and SS6

6 (maximum acceleration) g 6 (number of burns, 1 required per g)

So a 6g6 missile has enough fuel for 1 turn at 6g.

For a true antiship missile build them as small craft.

 

[kilemall]

Go back to the original version of the missile fuel burn in Mayday and SS6

6 (maximum acceleration) g 6 (number of burns, 1 required per g)

So a 6g6 missile has enough fuel for 1 turn at 6g.

For a true antiship missile build them as small craft.

Mayday 1 turn scale is more like a 6G 6 turn burn in LBB2.

 

[mike wightman]

Mayday weapon systems are not LBB2 weapon systems.

 

[kilemall]

Mayday weapon systems are not LBB2 weapon systems.

Shrug you’re saying go back to that burn model as though they are the same. They aren’t when comparing scales, so the errata version of burn for the missile supplement is more consistent.

 

[Tobias]

Back in the day when my uncle was still alive (USMC O6 & Ford Aerospace engineer designing AA missiles (physics and chemical engineering degrees). I asked him about the extreme Trav ship missiles. He said not possible with chemical rockets based on total energy needed for that Delta V. Maybe some advanced nuc tech could do it but not anything we could make at the time.

That's what I suspected. It's too bad because I really would have liked it if there was an even remotely imaginable way of chemical sci-fi drives for the missiles.

 

[kilemall]

That's what I suspected. It's too bad because I really would have liked it if there was an even remotely imaginable way of chemical sci-fi drives for the missiles.

You could consider metallic hydrogen.

Metallic hydrogen - Wikipedia

en.m.wikipedia.org

 

[mike wightman]

Shrug you’re saying go back to that burn model as though they are the same. They aren’t when comparing scales, so the errata version of burn for the missile supplement is more consistent.

But the weapons of Mayday are vastly more powerful than LBB2 weapons.
And you can actually build the missile in the turn before you launch it.
It was the misguided fanon that called for the change in the first place.
By the way there is no mass listed for the Mayday missile but the maximum performance is 6g12, which outperforms most of the small craft.

 

[Tobias]

You could consider metallic hydrogen.

Metallic hydrogen - Wikipedia

en.m.wikipedia.org

The article mentions a maximum specific impulse of 1700 seconds, which is still about an order of magnitude too low to achieve even close to the performance of CT missiles.

 

[kilemall]

The article mentions a maximum specific impulse of 1700 seconds, which is still about an order of magnitude too low to achieve even close to the performance of CT missiles.

DioxyHandwavium it is then!

My solution is microships with a hot running minifusion plant that requires blowing through fuel to exhaust the heat.

 

[Tobias]

Something like that. The "miniature fusion generators" used in PGMP and FGMP type weapons could be an inspiration here. Use those either to power grav thruster or a small fusion rocket.
Unfortunately, that leaves little room for SS3 unless you massively rework it. I like the idea of a missile design system, but I think missiles in CT need to be re-thought completely. Also unfortunately, if you want to keep things proportional, that would mean missiles would probably cost Cr 50,000 and upwards. Then again, that could also be considered a feature. In Book 2 combat, missiles can be fairly devastating (especially against typical low-acceleration opponents).

Vague idea for IMTU is a turret missile massing 250 kg (should still be small enough to move it through spacecraft corridors if broken down into major components), costing Cr 50,000, and a bay missle ~4 times as much.