Missile designs from T4 FF&S

[warwizard]

Greetings all this thread is for presenting and discussing space combat missiles designed using Marc miller's traveller Fire Fusion and Steel as well as house rules to deal with situations not covered in the official rules.

Maneuver drives for missiles:
Available for use in small missiles are chemical, Heplar, Fusion Rocket, and exotic drives (daedaelus, nuclear rocket, ion drive) Thruster plates and contragrav

The drives that do not require a seperate power system are the nuclear and fusion rockets, chemical rockets, and daedalus, all the other drives require electrical input requiring a power system

Each drive has a maximum acceleration it is capable of, as well as a fuel usage rate.

Chemical solid propellant can have over 300G's acceleration, however fuel rates makes these drives unsuitable for any but short range applications. Chemical liquid propellant drives have a lower maximum acceleration 132G's and a better fuel rate compared to the solid propellent rockets. For space combat missions the job of point defense seems the only suitable missions for chemical propellant drives perhaps also dogfighting missiles for fighters/small craft.

Fusion rockets have a maximum acceleration of 9 G's but are truly misers with the fuel making long duration missions the forte of the fusion rocket. Minimum size requirements makes for minimum of 1 Dt for missiles using this thruster.

Daedalus drives have 1.5 G max acceleration but are the best fuel use at 1/7th the rate of the fusion rocket, and can be used in smaller installations useful for long duration cruise missions sub micro sized drones and the such, hower the fusion pellet detonations make it less stealthy than an Ion drive for the stealth missions.

Other nuclear rockets can obtain maximum of 12G's but have very high fuel usage rates producing missiles that might have somewhat limited endurance, but quite suitable otherwize.

For the drives that require electrical input we have Heplar, Ion drive, Thruster plate, and contragravity.

Maximum Heplar G's is 200 G's but as you also must supply 1 M/W minimum electrical power per 200 KN so performance of Heplar systems are highly dependant on the power systems installed with higher power densities producing corespondingly better performance. long endurance Heplar systems are possiable with fusion power systems.

Ion drives are unsuitable for combat missions. Maximum G's are fractional and power needed is enormous. Used for extreame endurance missions utilizing solar panel power systems or nuclear/fusion power systems. very small systems using sub 1Kw power can be used for stealth approaches for intellegence gathering missions.

Thruster plates may not be used in some hard science campaigns but have a maximum G's of 20 G's No fuel needed and half the input power/Kn of the Heplar. Minimum thrust requirements make for fairly large missiles, however endurance is determined by that of the power system. With a fusion power plant a thruster plate missile is able to reach speed of light.

Contragravity drives are useful only within ten diamaters of a large mass. Applications that come to mind are gas giant area denial systems able to dive deep into the atomsphere and attack lurking SDBs. Within their area of use contragravity missiles can provide decent MW/Kn rates and require no fuel. Endurance is that of the power systems installed. Maximum G's are generally much less than one G and get better the stronger the grav field they are deployed in.

I'll continue this in another post if there is interest.

 

[Scott Martin]

You will note that most of your maxima are based on the drive, not the drive and other hardware - even for a KKM you will probably need at least a minimal sensor package and a fuel supply.

note also that HEPLAR *requires* a fusion plant (it's a fusion plant "afterburner" in the write-up) so your minimum missile sizes are based on minimum p-plant sizes at various tech levels. TL-13 is a very lethal "step" in the tech chain, with HEPLAR missiles in the 1/2 dTon range (nominal performance around 16 G's) and X-Ray lasers both appearing for the first time.

Somewhere I have already posted HEPLAR missiles for TL's 13-15 using FF&S-1, although I can probably track them down if you can't readily find them.

Chem-burners are useless in space combat ranges, and IMO space combat is "broken" due to the enormous scales and times.

YMMV

Scott Martin

Scott Martin

 

[warwizard]

You will note that most of your maxima are based on the drive, not the drive and other hardware - even for a KKM you will probably need at least a minimal sensor package and a fuel supply.

Yes the max acceleration is the limit as fuel, payload and everything else goes to zero, except for the chemical solid propellant rocket which has a limit of infinity. It's just a number to allow a designer to know if a particular propulson method is capable of meeting his design parameters.

note also that HEPLAR *requires* a fusion plant (it's a fusion plant "afterburner" in the write-up).

Ahh I see that now, I was using it like an advanced Ion drive that could use any electrical input. We have some advanced Ion drives today that are much more efficient than the one in the game, just look at the NASA site for them.
So per the rules the HEPlaR could not be used on missiles till TL 12. Deleting my series of battery powered HEPlaR missiles, See discussion is good!

 

[warwizard]

Ok Fusion rocket at TL 10 through TL 12, 7 G's for 31 to 42 hours 12.5 sens PEMS, 1000 AU laser Comm and 10 Kt nuclear det laser warhead, command and target seeker guidance powered envelope 29 to 60 light minutes.

TL 11 missile/sensor drone:
Volume 28 m3 (2Dt) no masking stealth or passive defenses, unstreamlined hull AF=1 rounded cylinder with moderate black coating MCr 6.0935/ MCr 4.8748 in quantity
Signatures Visual -1.5, IR -2.5 (-.5 when thrusting) Active 0. warhead laser PV36, DV 286 Battery endurance is 31 hours operating all electronics with .0032 MW used (IR sig calculation uses *2 cause half energy is delivered to load and half is used internally by the battery) mass 18.1917mt fuel 13.4375m3 LHyd (0.9598mt)
Acceleration at launch 6.81g acceleration at midpoint 6.99g, acceleration at end of run 7.19g (10.0m/s/s=1g)

Notes: Fusion rocket has minimal throttle capacity of approximatly 23% reduction from max thrust 1000 KN min/1238 KN max. Battery power can be extended by turning off the laser comm gaining 15 hours of sensors and guidance only operation for every hour the laser is not used. For safety reasons the missile is hard wired to self destruct if the battery voltage drops out. Self destruct is a conventional explosion without the concentric implosion needed to collaspe the fissile material into critical mass.

Extreme range engagements have little chance of actually hitting a maneuvering target although end of run velocities are impressively high at 7800 KPS the onboard sensors are not able to see targets far enough away to maneuver to intercept. Many captains use the missile as a sensor drone in drift mode for most of the mission, military task forces native to system can be expected to have hundreds of such missiles on modest vectors throughout the system giving them sensors that can be vectored to suspected contacts.

Variants exist where a serious attempt is given to upgrade the sensors, adding 9MCr to basic cost for PEMS sensitivity 13 at cost of -1.5G acceleration and 6 hours of endurance. A 13.5 PEMS cannot be mounted as at TL 11 it exceeds the size of the missile's hull.