"Conventional" missiles for T:TNE

Bertil Jonell [email removed] writes:
>   Using the T2k2 demolitions rules on the yield sizes gives ...
> ... between 40 and 125 major hits worth of damage.

My reasoning was based on physics.  Assuming that the nuke was detonated
"close" to the ship (within about a shiplength or so), the hull of the
ship will intercept between a a quarter and a third of the energy output
of the explosion; probably enough to wreck the ship.  As a game
mechanic, probably about half of those hits go to the point of impact,
and the other half divided evenly between the hit locations adjacent to
the point of impact.

>   But based from the system (and the TDR discussions on space combat, agility,
> ranges, weapons and hit chanses) it would be very hard to achieve a direct
> hit with a missile. At least 2 levels of difficulty harder. And the defence
> would have a much easier time hitting it.
>   This is also a problem for missiles carrying large shape charges.

Agreed.  I was thinking about, but didn't want to post before I have
finished reading T:TNE, the following game mechanic: achieving a direct
impact hit would be 2 levels of difficulty harder, and achieving a
proximity hit would be 1 level of difficulty harder than the equivalent
detonation laser targetting task.

To even attempt an intercept, the missile should already be in the same
range band as the target, and should have more maneuver fuel available
than the thrust rating of the target's drive.  In other words, the
missile has to start it's final attack from nearby, and must be at least
as maneuverable as the target.

This assumes that the missile is using the T:TNE command guidance
system; alternative guidance systems could make it considerably easier.
The command guidance system has serious problems in co-ordinating an
intercept across distances of several light seconds.  Some example
guidance systems:

Active: Uses an active radar, ladar, or EMS sensor onboard the missile
to detect the target, and guide the missile to intercept.  Large, heavy
and expensive.  Easy to detect missile, may give away location of the
firing ship.  Makes intercept task 1 level of difficulty easier.

Semi-Active: Uses an active radar, ladar, or EMS sensor onboard the
launching vessel, and a reciever onboard the missile, to guide the
missile to intercept.  Relatively simple and cheap.  Easy to detect the
firing ship, and gives away location of the firing ship.  Makes
intercept task 1 level of difficulty easier.  If firing ship stops
operating active sensor (shuts it down, or antenna or sensor destroyed
by battle damage), the missile automatically misses.  Generally
longer-ranged than Active guidance.

Active and Semi-Active guidance can be defeated by jamming the sensor
used to guide the missile, and they can be rendered less effective by
"stealth" techniques which reduce the detection range of these sensors.

Passive: Uses a passive sensor (EMS, Neutrino, Densitometer, IR, etc) to
detect the target, and guide the missile to intercept.  Cost and Size
depend on the type of sensor.  Nearly impossible to detect, and does not
give away the location of the launching ship.  Relatively short
detection and homing range (particularly compared to Active and
Semi-Active missiles).  Makes intercept task 1 level of difficulty
easier.

Passive guidance can be defeated by jamming the sensor used to guide the
missile, or they can be rendered less effective by "stealth" techniques
which reduce the detection range of these sensors.  Passive guideance
can also be defeated by the use of decoys which mimic the passive sensor
profile of the target.

Anti-Radiation: Uses a passive sensor designed to detect specific
emissions (Radio, Radar, Active EMS, missile guidance radars or
communicators) of the target ship, and guides the missile to intercept.
This guidance system makes the intercept task two levels of difficulty
easier.  If the emission stops (is turned off, or the antenna or sensor
is destroyed by battle damage), the missile automatically misses.  If an
impact hit is made, the missile automatically hits the location
containing the antenna for the emission used to guide the missile.

Inertial: The guidance system flys the missile to a location determined
at launch time.  Intertial guidance systems cannot directly cause an
intercept.  Typically used for the first part of a missile's flight, and
then one of the other guidance systems takes over.  This guidance system
is self-comtained, and is nearly impossible to detect the missile or the
launching ship.

Command: The "Normal" T:TNE missile guidance system.  The launching ship
controls the flight of the missile via communications link (Laser,
Maser, or Radio Communicator), or through coded signals from an active
sensor (Radar or Active EMS; this type of guidance is also known as a
"Beam Rider").  The communications link may or may not give the
launching ship's location away.  Can also be used in combination with
other guidance systems.

Guidance system can be combined by specifying when each system is used.
For example, a combined guidance system might consist of Intertial,
Command, and Semi-Active guidance.  Inertial is used for the first part
of the missile's flight.  The Command system provides course corrections
to the Inertial guidance, and commands the switch-over to Semi-Active,
which guides the missile to intercept.  Another example might be a
missile with Active and Anti-Radiation guidance.  The missile is
launched on Active guidance.  If at any time the Active guidance is
successfully jammed, it switches over to Anti-Radiation (the emission it
homes in on is the jamming signal for the active guidance).  If the
Anti-Radiation guidance looses it's signal, the missile switches back to
active.  Nasty.

In all cases of multiple guidance systems, the system that handles the
final ("Terminal") guidance to intercept is used to determine the
intercept task difficulty.

>   Damage from nuclear explosions in space are mostly in the form of soft xrays
> that cause structural damage and other radiation that cause biologic damage
> and disturb electronics. None of these effects are even close to strong enough
> to affect more than one range band.

Definitely.  I've been assuming that an "Impact" (in nuclear terms,
anyway) is anything closer than a shiplength or so.  "Proximity" is
probably a couple of kilometers.  Anything outside of that is a miss.

> the damage of which is determined by how close they were. (I have
> read somehwere that the concussion induced by soft xrays are aproximately of
> the same strange at a certain range from a certain yield as the shockwave
> in air from an airburst of the same yield at the same range, but I'm not
> certain of this). I'd also inflict small scale damage (1h to 1H, say) all
> over the ship but concentrated to the side facing the explosion.

Say, 1h everywhere, and 1H on the sides facing the explosion?  In
general, your ideas sound about right to me, too.

> The cannister round replaces the nuke/laser warhead with a lot of heavy metal
> spheres and a bursting charge. At the range where a nuke/laser missile would
> detonate it spreads the spheres in a cloud which hit the target at high speed.

I'm not sure, but I've always assumed that the detonation laser's range
is tens of thousands of kilometers as a minimum.  At those ranges, the
shperes would be spread too far apart to do much damage.

On the other hand, detonated no more than a couple of kilometers away,
this coule be the basic proximity warhead.  Getting closer to the target
(an "impact" hit) would increase the number of hits, but the penetration
and damage would be about the same.

> The SFF round uses an explosive warhead that generate the 'cloud of buckshot'
> from self forging fragments (a relative of the shape charge, used in the
> experimental SADARM round).

Again, from detonation laser ranges, this will be ineffective.  However,
from a "proximity" hit, this could have the general effect of peppering
the target with buckshot.  From an "Impact" hit, all of these fragments
would go into one or two hit locations, with pretty severe results.

I like these, and I think that they could work.  Maybe Loren could
forward these comments to whomever is writing the boardgame, and also
for inclusion into the Technical architecture book?


[email removed]
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