MegaTrav Remote Sensor Drone

[Carlobrand]

The MegaTraveller space missile is a 50kg missile that seems to be able to hit a target up to a light second off, and sometimes farther, in the same turn they’re fired. (Which implies accelerations of 40g and more, but that’s another issue.) In both COACC and the CT Missile Supplement, it is presented as having a 30 kg. warhead. The CT Missile Supplement presents the option of remote sensor drones – in other words, that 30kg. payload can be sensor systems or other equipment. In space combat, it can be useful to throw a probe at someone out at the limits of detection, to gain information on what it is your facing while you still have time to react. These are examples of what such missiles might look like under MegaTrav rules.

They fall into two classes. Short-range variety are intended to identify individual targets or a group of targets close together within a given “square” (ex: a squadron flying close together); they use radio to send sensor information back to the launching ship for processing. Long-range varieties, available at TL12+, can gather information over a much wider area, allowing detection rolls to be made against entire fleets. Missiles of TL13 or less use radio to communicate sensor readings to the launching ship for processing; they may be subject to jamming. Missiles of TL14+ use laser communicators and cannot be jammed; they may be potentially "stealthy" if using passive sensors. (The surprise rules create the potential for surprised ships to be unaware of other ships firing missiles in their vicinity, making it a task to see the attack and raise the alarm.)

All are good for only one turn of active function - sometimes less, but since the sensors only draw power when they reach their assigned coordinates and the rules seem to imply it's pretty quick to detect something if you're going to detect it at all, I'm not sure whether that's an issue.

These missiles are one-shot but recoverable, barring mishap, which helps offset their high cost.

I would appreciate any comments or criticism.

TL10
TL10 Passive EMS probe: Cr. 156,563
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL10 Radio comm.: Far Orbit (500,000km) 10kg, 0.01Mw, Cr90,000
EMS Passive Array: V.Distant (50km), 2kg, 0.02Mw, Cr40,000
base roll Form (15+) +skill/ed (+3) +comp (+4) = 8 or better
Battery: 12.5 kg., 0.01 MwH (20 min.), Cr 6563

TL10 Active EMS probe: Cr. 315,250
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL10 Radio comm.: Far Orbit (500,000km) 10kg, 0.01Mw, Cr90,000
EMS Active Array: V. Distant (50km), 10kg, 0.1Mw, Cr200,000
base roll Diff (11+) +skill/ed (+3) +comp (+4) = 4 or better
Battery: 10 kg., 0.008 MwH (4.36 min.), Cr 5250

TL11
TL11 Passive EMS probe: Cr. 135,400
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL10 Radio comm.: Far Orbit (500,000km) 10kg, 0.01Mw, Cr90,000
EMS Passive Array: V. Distant (50km), 1kg, 0.01Mw, Cr20,000
base roll Form (15+) +skill/ed (+3) +comp (+5) = 7 or better
Battery: 8 kg., 0.0072 MwH (21.6 min.), Cr 5400

TL11 Active EMS probe: Cr. 278,100
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL10 Radio comm.: Far Orbit (500,000km) 10kg, 0.01Mw, Cr90,000
EMS Active Array: V. Distant (50km), 8kg, 0.08Mw, Cr160,000
base roll Diff (11+) +skill/ed (+3) +comp (+5) = 3 or better
Battery: 12 kg., 0.009 MwH (6 min.), Cr 8100

TL12
TL12 SR Passive EMS probe: Cr. 135,100
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL12 Radio comm.: Far Orbit (500,000km), 7kg, 0.007Mw, Cr90,000
EMS Passive Array: V. Distant (50km), 1kg, 0.01Mw, Cr20,000
base roll Form (15+) +skill/ed (+3) +comp (+6) = 6 or better
Battery: 6 kg., 0.006 MwH (21 min.), Cr 5100

TL12 LR Passive EMS probe: Cr. 416,800
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL12 Radio comm.: Far Orbit (500,000km), 7kg, 0.007Mw, Cr90,000
EMS Passive Array: Interplanet. (1 AU), 15kg, 0.15Mw, Cr300,000
base roll Routine (7+) +skill/ed* (+3) +comp* (+6) = -2 or better
Battery: 8 kg., 0.008 MwH (3.06 min.), Cr 6800

TL12 Active EMS probe: Cr. 244,500
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL12 Radio comm.: Far Orbit (500,000km), 7kg, 0.007Mw, Cr90,000
TL12 EMS Active Array: V. Distant (50km), 6kg, 0.06Mw, Cr120,000
base roll Diff (11+) +skill/ed (+3) +comp (+6) = 2 or better
Battery: 17 kg., 0.017 MwH (15.22 min.), Cr 14,450

TL14
TL14 SR Passive EMS probe: Cr. 162,000
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL14 Laser comm.: Far Orbit (500,000km), 14kg, 0.014Mw, Cr112,000
EMS Passive Array: V. Distant (50km), 1kg, 0.01Mw, Cr20,000
base roll Form (15+) +skill/ed (+3) +comp (+8) = 4 or better
Battery: 2 kg., 0.008 MwH (20 min.), Cr 10,000

TL14 LR Passive EMS probe: Cr. 347,000
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL14 Laser comm.: Far Orbit (500,000km), 14kg, 0.014Mw, Cr112,000
TL14 EMS Passive Array: Interpl. (1 AU), 9kg, 0.09Mw, Cr180,000
base roll Routine (7+) +skill/ed (+3) +comp (+8) = -4 or better
Battery: 7 kg., 0.028 MwH (16 min.), Cr 35,000

TL14 Active EMS probe: Cr. 262,000
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL14 Laser comm.: Far Orbit (500,000km), 14kg, 0.014Mw, Cr112,000
TL14 EMS Active Array: V. Distant (50km), 5kg, 0.05Mw, Cr100,000
base roll Diff (11+) +skill/ed (+3) +comp (+8) = 0 or better
Battery: 6 kg., 0.024 MwH (22.5 min.), Cr 30,000

TL15
TL15 Passive EMS probe: Cr. 106,000
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL15 Laser comm.: Far Orbit (500,000km), 7kg, 0.007Mw, Cr56,000
EMS Passive Array: V. Distant (50km), 1kg, 0.01Mw, Cr20,000
base roll Form (15+) +skill/ed (+3) +comp (+9) = 3 or better
Battery: 1 kg., 0.007 MwH (24min.), Cr 10,000

TL15 Passive EMS probe: Cr. 306,000
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL15 Laser comm.: Far Orbit (500,000km), 7kg, 0.007Mw, Cr56,000
TL14 EMS Passive Array: Interpl. (1 AU), 9kg, 0.09Mw, Cr180,000
base roll Routine (7+) +skill/ed (+3) +comp (+9) = -5 or better
Battery: 5 kg., 0.035 MwH (21 min.), Cr 50,000

TL15 Active EMS probe: Cr. 186,000
Basic missile: 0.1 m^3, 50 kg., Cr20,000
TL15 Laser comm.: Far Orbit (500,000km), 7 kg, 0.007Mw, Cr56,000
TL14 EMS Active Array: V. Distant (50km), 5 kg, 0.05Mw, Cr100,000
base roll Diff (11+) +skill/ed (+3) +comp (9) = -1 or better
Battery: 1 kg., 0.007 MwH (24min.), Cr 10,000

 

[E.D.Quibell]

If you would like some independent computing capacity that is small and cheap then put in a Robot brain:

The NHR Low Function 5 Robot Brain
Designed by Ewan Quibell 2011-08-24
Updated 2011-08-24

Robot ID: NHR Low Function 5 Robot Brain, TL8, Cr 5,150
UPP=xxx01x, INT=0, EDU=1
Hull: 6.1 litres, Unloaded=1.4 kg
Power: External=0.67 kw
Loco: -
Como: -
Sensors: -
Off: -
Def: -
Brain: CPU=Linear x3, Storage=Standard x11
FundLogic=LowData, FundCmd=LimitedBasic
Software=See Below
Append: -
Other: ObjSize=Small, EMLevel=None
Comment: Cost in quantity=Cr 4,120
This brain is identical at TL9, 10 and 11

The NHR low Function 5 Robot Brain provides INT 0 and EDU 1; however there is no space available to allow any skills to be run. This is the smallest and lowest functioning brain that can be installed into a robot. This robot brain has the abilities to read sensors, run communications and move robots that have tracks, wheels or legs anywhere it is commanded to go.
The Brain is a standard design used to fit into any manner of robot chassis and vehicles and the fittings have been designed to make integration into robot or vehicle chassis a simple procedure.
This brain has a CP Multiplier of 80 at TL8, 90 at TL9, 100 at TL10 and 110 at TL11.

100 CP should cover all the rockets needs.

Devide the cost of your batteries by 100 (see Errata).

Volume for TL10 is:

0.004 (PEMS)
0.0002 (Radio)
0.0125 (Batteries)
0.0061 (Brain)

0.0228 kl or 22.8 liters

The numbers on a 0.05 kl open framed hull using Crystaliron are:

Armour 1
0.05 kl
Cr 27.5
weight 0.1937 kg

Using TL7 solid rocket fuel you can get 1.08 tons of thrust in 24.1kg and 24.1 litres of space all for Cr 12,000. It burns in 0.144 seconds and provides 21.6G of acceleration.

and then just throw them all together

Best regards,

Ewan

 

[Carlobrand]

If you would like some independent computing capacity that is small and cheap then put in a Robot brain:
100 CP should cover all the rockets needs.

I'm not too familiar with bots. I'm not sure how that integrates with the MT sensor rules.

Devide the cost of your batteries by 100 (see Errata).

Thanks for that.

Volume for TL10 is:

0.004 (PEMS)
0.0002 (Radio)
0.0125 (Batteries)
0.0061 (Brain)

0.0228 kl or 22.8 liters

The numbers on a 0.05 kl open framed hull using Crystaliron are:

Armour 1
0.05 kl
Cr 27.5
weight 0.1937 kg

Using TL7 solid rocket fuel you can get 1.08 tons of thrust in 24.1kg and 24.1 litres of space all for Cr 12,000. It burns in 0.144 seconds and provides 21.6G of acceleration.

and then just throw them all together ...

Uh, what?? Correct me if I'm wrong, but a 21.6g burn for 0.144 seconds gives me a final velocity of 31.1 meters per second. This puppy's moving a bit over 37 kilometers every turn. That makes for an awful long trip out, no?

 

[aramis]

I'm not too familiar with bots. I'm not sure how that integrates with the MT sensor rules.



Thanks for that.



Uh, what?? Correct me if I'm wrong, but a 21.6g burn for 0.144 seconds gives me a final velocity of 31.1 meters per second. This puppy's moving a bit over 37 kilometers every turn. That makes for an awful long trip out, no?

216*0.144=31.104m/s using the Traveller G=10m/s/s

1 turn = 20 min = 1200s

yeah, 37324.8m/turn, 0.00149 squares per turn. WAY too slow for anything other than a deorbit burn for non-recovery deorbit.

Also, I'll point out that you need AV=8 on "disposable spacecraft" per Hard Times.

A
disposable component leaving the atmosphere must have a
hull armor rating of 8 or more.​

HT, p.83.

 

[E.D.Quibell]

ok, ok, ok ...

It was my first try at 02:00 ok?

A robot brain just replaces a computer in a vehical, and for a one shot like this they are perfect.

The Hull
Armour 8 Open Frame Crystaliron
0.05kl
Weight 0.00155 tons or 1.5kg
Cost Cr 220

and if we go for a TL9 fusion rocket the good news is that we can kill the batteries. However to get the 0.03 Mw we need we get 2.6t of thrust, 52 kg and 0.013 kl volume and it drinks 2.66kl of liquid hydrogen an hour.

0.004 (PEMS) 2kg
0.0002 (Radio) 10kg
0.0061 (Brain) 1.4kg

0.0103 kl or 10.3 liters and 13.4kg

With the hull and the fusion rocket we have 66.9 kg weight and 23.3 l volume. This gives 36 seconds of fuel (it's weight is neglagable) and power @ 38.8 G

The only real way to improve this is to drop the power requiremetns.

If we put the batteries back we get 79.4 kg and 35.8 kl giving us 19 seconds of thrust (and power) at 32.7 G

But if we then half the fusion rocket (we don't now need the power) we get 1.3 tons 26kg 0.0065 kl and drinks 1.33 kl/h. Or 51.9 kg and 56 seconds at 25G.

You might be able to play a bit with the thrust/wieght and length of thrust, but there isn't another engine type that will give you a better power to wieght in the available space. You need to up the volume of the craft to allow for more fuel.

Best regards,

Ewan

 

[Carlobrand]

Either model gives us a final velocity in the vicinity of 14 kilometers per second. Respectable - that's 16,800 kilometers in a 20-minute turn - but still not useful for long-range probing, and they won't fit in a missile tube. No fault to you, that's the best that can be accomplished within the canon missile design rules available to us. However, that leaves the MegaTrav missile an enduring mystery - it appears to be managing 40g or better for up to 20 minutes.

Better, I think, to leave it a mystery and just deal with the payload.

 

[E.D.Quibell]

But the standard missile has far more space than that. A full 0.1kl

So the hull is:

The Hull
Armour 8 Open Frame Crystaliron
0.1kl
Weight 0.0031 tons or 3.1kg
Cost Cr 440

and we can dump the radio (missiles are fire and forget) which leaves us with:

0.004 (PEMS) 2kg
0.0061 (Brain) 1.4kg

at 0.0101 kl and 3.4kg with a 0.02Mw power draw.

1 ton thrust from a 0.0205 weight fusion rocket, taking 0.0051 kl of space and needing 1.05kl/h for fuel

Total volume is 0.0152 kl weight of 23.4kg which leaves 0.0848 for fuel or 4 minutes 50 seconds @ 42.7 G

Maybe the standard missile is infact a hitile?

Or if you put in a 26.6kg charge in 14.6 litres then you could get a 50kg missile with 4 minutes of fuel @ 21G

The launcher itself must impart some initial velocity to the missile.

Best regards,

Ewan

 

[Carlobrand]

But the standard missile has far more space than that. A full 0.1kl

So the hull is:

The Hull
Armour 8 Open Frame Crystaliron
0.1kl
Weight 0.0031 tons or 3.1kg
Cost Cr 440

and we can dump the radio (missiles are fire and forget) which leaves us with:

0.004 (PEMS) 2kg
0.0061 (Brain) 1.4kg

at 0.0101 kl and 3.4kg with a 0.02Mw power draw.

1 ton thrust from a 0.0205 weight fusion rocket, taking 0.0051 kl of space and needing 1.05kl/h for fuel

Total volume is 0.0152 kl weight of 23.4kg which leaves 0.0848 for fuel or 4 minutes 50 seconds @ 42.7 G

Maybe the standard missile is infact a hitile?

Or if you put in a 26.6kg charge in 14.6 litres then you could get a 50kg missile with 4 minutes of fuel @ 21G

The launcher itself must impart some initial velocity to the missile.

Best regards,

Ewan

Interesting. Is my math off? I thought if you applied a ton of thrust to a 23.4 kg mass, you'd get 42.7 m/s^2, not 42.7g

And, the radio/laser comm. is not optional in a sensor probe. Information is of no use unless it gets back to the fleet.

 

[aramis]

Interesting. Is my math off? I thought if you applied a ton of thrust to a 23.4 kg mass, you'd get 42.7 m/s^2, not 42.7g

And, the radio/laser comm. is not optional in a sensor probe. Information is of no use unless it gets back to the fleet.

Nope. it's 1000kgf, 1 kgf = 1 kg x 9.8m/s/s.

Well, technically, it's force sufficient to accelerate 1 ton at 1 G, but traditionally it was used in 2000lbf ETM units...

Traveller has, as with many units, redefined for same use but in metric, so the Traveller thrust ton is force sufficient for 1 ton-metric (1000kg) at 1 Traveller G (10m/s/s)

G=Tt/M
where G= G's, Tt= Tons Thrust, and M=mass in megagrams (=metric tons)

 

[E.D.Quibell]

And, the radio/laser comm. is not optional in a sensor probe. Information is of no use unless it gets back to the fleet.

Then you'll need to design a sensor drone from the ground up that meets requiments, becuase trying to fit in a missile by weight is not going to work.

Or you can just say that you have sensor drones that are the same size shape and performance as missiles that provide the players with the information that the GM wishes them to have, and not bother with the design sequenses at all.

Best regards,

Ewan

 

[Carlobrand]

Then you'll need to design a sensor drone from the ground up that meets requiments, becuase trying to fit in a missile by weight is not going to work. ...

... because ...?

Does the missile's drive care what the payload is?

Even if I assume the 30 kg of warhead equates to a maximum 30 liters of available space, I can certainly design something that fits in that volume - some of them already do. I can't imagine any reason the missile's drive would care what's under the nose cone - unless of course it had become emotionally attached to the warhead for some reason.

 

[E.D.Quibell]

... because ...?

Does the missile's drive care what the payload is?

Even if I assume the 30 kg of warhead equates to a maximum 30 liters of available space, I can certainly design something that fits in that volume - some of them already do. I can't imagine any reason the missile's drive would care what's under the nose cone - unless of course it had become emotionally attached to the warhead for some reason.

Because it's not posible to designe the missile drive.

You're assumptions comes under the:

"Or you can just say that you have sensor drones that are the same size shape and performance as missiles that provide the players with the information that the GM wishes them to have, and not bother with the design sequenses at all."

because you're ignoring the designe rules by abstracting the missile drive and making asumptions about the available space, so you might as well not bother.

And that's fine. There is nothing wrong with that, and there is nothing wrong with your orignal approch either.

I'm of the school of thought that if you are going to use the design rules then use them, otherwise don't bother. I can make different, but equally valid, assumptions about the missiles which you might not like and we would have to agree to disagree about the output of our equaliy valid thoughts. Using the design rules stops that.

Best regards,

Ewan

 

[Carlobrand]

Because it's not posible to designe the missile drive.

You're assumptions comes under the:

"Or you can just say that you have sensor drones that are the same size shape and performance as missiles that provide the players with the information that the GM wishes them to have, and not bother with the design sequenses at all."

because you're ignoring the designe rules by abstracting the missile drive and making asumptions about the available space, so you might as well not bother...

No, and for all that you say it's "fine", I think I'm a tad offended. It is an unfair and inaccurate characterization of what I'm doing - and, frankly, I posted this to have people criticize the designs, not to have them criticize me.

Canon provides the missiles. Canon provides the design rules. There's no element of fiat here. I'm taking canon missile design rules to modify a canon missile to explore an option that canon says exists. It's not even like I'm mixing and matching rules sets - it's all out of MegaTrav. I am not abstracting the missile drive; GDW did that.

Why they gave us design rules that stop short of delivering the missile the combat rules say exists, I don't know. The Hard Times fusion rocket is TL-9 equipment - maybe they intended higher-tech rockets to have better performance and never got around to publishing that, or maybe the combat rules were supposed to implement some more realistic maximum range and it got dropped in edit, or maybe the guy drafting the Hard Times rockets never actually played a Megatrav space battle - I don't know. Ask me what I'd do if I could impose my own house rules on the combat system, and you'd see missiles behaving more like Mayday missiles. However, tell me that applying Megatrav design rules to an existing Megatrav space combat missile, so it can be used in the Megatrav space combat system from which that missile originated, is ignoring the design rules - that's absurd.

There is nothing "equally valid" about this: a design works, or it does not. If you wish to criticize, I'd suggest you aim your criticism at the game designer, not the person who's applying canon rules to canon equipment to achieve ends that canon says should be achievable.

And on that note, I think I'm gonna go kick the dog.

 

[Zutroi]

Perhaps we need to 'reverse engineer' the missile's drive... And by reverse engineer, I mean rationalize the HELL out of the problem

50 kg missle, going 40G for 20 minutes, in a 20 kl drive isn't workable via any of the MT design sequences, but those design sequences never had a missile design published, IIRC.

Such a powerful, efficient drive would tend to supplant the gravitic and reactionless thrusters in the MT designs, but isn't being used for vessel design at all.

I therefore posit that the missile drive is (pick however many of these you want):

1 - Non-throttleable. It only goes full out, until it runs out of fuel (like a solid rocket motor).
2 - Dangerous to be around. Radiation, or violently corrosive exhaust gasses, or negative engram emissions make it unsuitable for use around living creatures. It may also make it unsuitable for moving around sensitive detectors... Your warheads and targeting systems don't care, they'll only be used once.
3 - Poorly scalable. 'Thrust' is proportional to the square of the exit aperature, but mass of the unit goes up as the cube... make the drive 10 times bigger and get 1/10th the usable thrust!

 

[Major B]

Even if I assume the 30 kg of warhead equates to a maximum 30 liters of available space, I can certainly design something that fits in that volume - some of them already do. I can't imagine any reason the missile's drive would care what's under the nose cone - unless of course it had become emotionally attached to the warhead for some reason.

Carlo, your assumption fits with the Striker missile design sequence. I'm not sure if you are using that resource so thought I'd mention it.

I have a spreadsheet that eases most of the design burden for making missiles using the Striker ruleset modified slightly for compatability with MT. Of course, it is for tac missiles, not ship-to-ship, but still might be useful. If you PM an address, I'd be glad to send you a copy.

 

[E.D.Quibell]

No, and for all that you say it's "fine", I think I'm a tad offended. It is an unfair and inaccurate characterization of what I'm doing - and, frankly, I posted this to have people criticize the designs, not to have them criticize me.

Appologies. It was not my intent to offend in any way. My criticisum was of the design, due to the assumptions that you have to make about the missiles.

Canon provides the missiles. Canon provides the design rules. There's no element of fiat here. I'm taking canon missile design rules to modify a canon missile to explore an option that canon says exists. It's not even like I'm mixing and matching rules sets - it's all out of MegaTrav. I am not abstracting the missile drive; GDW did that.

I agree it's all cannon, and I agree it's down to the designers. GDW did abstract the missile drive, and the missile payload, and the missile guidence systems. In fact all we have in the refs manual is a 0.1kl 50kg "black box" missile that can do significant dammage at lightsecond distances and no way of kowing how it does it. As you point out below.

Why they gave us design rules that stop short of delivering the missile the combat rules say exists, I don't know. The Hard Times fusion rocket is TL-9 equipment - maybe they intended higher-tech rockets to have better performance and never got around to publishing that, or maybe the combat rules were supposed to implement some more realistic maximum range and it got dropped in edit, or maybe the guy drafting the Hard Times rockets never actually played a Megatrav space battle - I don't know. Ask me what I'd do if I could impose my own house rules on the combat system, and you'd see missiles behaving more like Mayday missiles. However, tell me that applying Megatrav design rules to an existing Megatrav space combat missile, so it can be used in the Megatrav space combat system from which that missile originated, is ignoring the design rules - that's absurd.

I did not do that. I said that the assumptions that you made about the missile were assumptions, and that I could make equally valid but differnet ones. Your assumptions were that the payload were 30kg and 0.03kl. The 30kg conventional focused explosive warhead is explained in COACC, but they also say that the drive is a solid fuel 6G6 sustainer motor, and the missile also has a mass ditector homing guidance package. However that missile doesn't fit with MT space combat even though COACC says it should. I could make the assumpion that the 30kg payload fits in 0.00001kl, or 0.05kl, or 0.02kl all of which could be equally valid. In which case the packegaes you propose to put in the payload might or might not fit, nor might or might not put the probe over wieght, or under weight or under of over volume etc.

There is nothing "equally valid" about this: a design works, or it does not. If you wish to criticize, I'd suggest you aim your criticism at the game designer, not the person who's applying canon rules to canon equipment to achieve ends that canon says should be achievable.

That is my critisium of the deign. You are taking an abstracted "black box" missile and trying to use the design rules on _part_ of that "black box" using assumptions that may or may not be correct, and that can't be designed using the design system. Therefore the design is not valid.

My answer to that was to either design the probe from the ground up using the design rules, or to have a "black box" probe that provides the information you wish to pass to the PCs, but not to mix the two.

It wasn't meant as a critisium of you.

And on that note, I think I'm gonna go kick the dog.

I appologies again. I don't wish for you to take your frustration with me out on your K9 companion.

Best regards,

Ewan

 

[Carlobrand]

... Your assumptions were that the payload were 30kg and 0.03kl. The 30kg conventional focused explosive warhead is explained in COACC, but they also say that the drive is a solid fuel 6G6 sustainer motor, and the missile also has a mass ditector homing guidance package. However that missile doesn't fit with MT space combat even though COACC says it should. I could make the assumpion that the 30kg payload fits in 0.00001kl, or 0.05kl, or 0.02kl all of which could be equally valid. In which case the packegaes you propose to put in the payload might or might not fit, nor might or might not put the probe over wieght, or under weight or under of over volume etc. ...

Thank you for the clarification.

I'm not seeing that mass is an issue. 30kg. is 30kg. I do agree that volume is an issue, possibly a big issue: if they're bending rules on the nature of the missile drive, they could as easily bend rules on the nature of the warhead to give the drives more room for fuel.

Before I started looking at this MegaTrav stuff, I speculated that the High Guard missile was almost nothing but drive, a kinetic kill weapon. It makes as much sense as anything GDW handed out, and given the velocities a missile would have to achieve to impact in a single turn against a target capable of up to 6g, it seemed more efficient and more likely than trying to pack in enough explosives to punch through the armor equivalent of 10 meters of steel or more while still managing room for fuel and drives, which is what Striker was suggesting was the case. In that case, there would be precious little room for anything but the engine, fuel, and a rather tiny terminal guidance package. COACC contradicts that, but this is a game system rife with contradictions, so that isn't saying much.

I am content that the designs provide a workable description of something that canon says should exist. It is an apples-and-oranges approach, but I don't see any other way to come up with a description of how the things might perform in space combat and how much they might cost. I am very interested in the Fifth Frontier War era and in the challenges faced by opponents trying to conduct a war under such significant communications and detection constraints as exist in Traveller. Given the importance of detection in this game, it seems to me that a "real" Traveller naval force would use every possible tool they could think of to improve their chances. I consider it nothing less than gross negligence on the part of GDW that it doesn't already exist in-game, right along with descriptions of an effective ground-based and satellite-based detection system - what kind of naval installation faced with the potential for war from orbit would limit itself to the kind of neutrino detectors that could fit in the hull of a ship?

As I said, 30 kg. is 30 kg. You're right, it might not be a 30kg warhead - it's actually much easier to assume the missile is 48 kilos of engine and fuel tipped with a small homing package and a 1-kilo DU penetrator - but its the only crumb of a clue they've left that might make a sensor drone practical in game terms. We can avoid the volume difficulty entirely by declaring that they can not be fired from missile launchers but require a dedicated launcher designed for them - in essence a single 1-ton turret designed to launch probes.

Better would be to rewrite the whole blessed thing, come up with a COACC space-missile design system that didn't leave the missiles coasting like spent bullets before they left the ship's hex, while simultaneously coming up with a Megatrav space combat system with more realistic missile range limits so that it didn't require god-missiles to make it emulate High Guard. But, there, I dream.

 

[Carlobrand]

An idle mind is the devil's playground.

I was tossing through some ideas on a completely unrelated matter, glancing through the Hard Times rocket rules, when it occurred to me: the fusion rocket generates a lot of excess power. The 1-dTon 4000kg model for example puts out 3.9 Mw of power while delivering 200 tons of thrust and consuming 205 kiloliters per hour (or 68 kiloliters per 20 minute game turn. That weighs 4.76 t.). That caused me to reflect on E.D.'s valiant effort to create a workable missile within canon.

Now, if we assume that 50kg missile with a 30kg warhead/payload, we have 20kg to work with. Not much. If we want the puppy to pull, say, 40g (400m/s^2 accel, or the ability to cover ~300,000 km in a single 20 minute game turn) we need 20 tons of thrust - a 400kg engine on a missile that masses 50kg total. That's clearly unworkable. Best I can manage is maybe 0.45 tons of thrust, allowing for the fuel space. Gets me a bit under 1g for 20 minutes - faster with more drive and less fuel, but for shorter durations.

... Unless ...

... unless there were some way to put that extra power to work. There isn't - not in canon. There's nothing described in Hard Times or elsewhere that I can use to take the excess energy and apply it directly to the fusion rocket exhaust. However, if there WERE - if I could imagine some sort of reasonably sized add-on afterthruster, as yet undescribed, that could add that power back in to the fusion exhaust, then I think that megawattage could increase the thrust output by a factor of 10 to 20 for the same quantity of fuel. At that point, I've got a missile that can do 10 to 20 g for 20 minutes - and it begins to look a lot more like the High Guard/Megatrav missile. Dump the warhead and assume the thing's a kinetic kill weapon, in other words mostly fuel and engine (20+ g's for 20 minutes whips up some ferocious impact velocities) around maybe a 1 kg Depleted Uranium penetrator and a small guidance package, and I can bring it to 20-40 g or more - and it's covering up to 300,000 km in a single turn, just like our mysterious High Guard/Megatrav missile. I just need that "afterburner".

Just some idle speculation.

 

[E.D.Quibell]

You could try a low power L Grav unit. 0.03 vol, 0.01 power, 0.02 weight costs 0.3 Mcr but would provide 20g for a 50kg missile for as long as you can power it.

These would be TL12 + missiles though.

Best Regards,

Ewan

 

[Carlobrand]

You could try a low power L Grav unit. 0.03 vol, 0.01 power, 0.02 weight costs 0.3 Mcr but would provide 20g for a 50kg missile for as long as you can power it.

These would be TL12 + missiles though.

Best Regards,

Ewan

Interesting thought. I tried playing around with a low-L, but it only delivers a ton of thrust for every 20kg weight, which is the same as the performance of the fusion rocket. I'm topping out at 4g, and I can maintain it for a lot longer - a definite improvement - but it's still low by a factor of 5 to 10 from what the game's implying.

If I stretch the rules and apply the fusion power plant tech level advances to the fusion rocket, I can come up with a TL15 fusion-rocket 50kg missile that hits 20g - but that's TL15 and a bit of rule-bending.