RE: Planetary Defenses & missiles

As far as planetary defenses go, I think a lot of it will be determined
by 
the particular tech/background you are using.  Traveller has deep-sited 
meson guns, Starfire has some beams & missiles, Star Wars has full 
planetary shields and surface-to-orbit cannons, etc.  So, for this, I'll

stick to general ideas and the GZG background.

Planets have some advantages over spacecraft; they're messy, so you can 
hide things on/in them pretty well, armor is practically free, power is 
pretty easy (geothermal tap, etc), they're really big, with lots of
places 
to hide.  Some disadvantages are that they're messy, with lots of
obscuring 
atmosphere to shoot/launch through, they're non-maneuvering (except in a

Lensman universe...), so they cannot choose the time & place of a battle

with as much freedom as a ship, and they've usually got things on them
that 
you don't want blown up.  This may sound strange; who wants their ships'

bridge blasted?  Nobody, but if you lose a ship, you've lost a bit of an

investment, probably recoupable.  If you start losing cities 
(infrastructure), you're losing the base upon which everything else is 
built.

By the time an invading fleet has destroyed the orbital
defenses/defending 
fleet (or if there never were any), the planet is in trouble.  The 
attackers could drag a rock over and drop it from well out of PD range,
and 
score a pretty good, predictable hit on a target area.	This could be
used 
on a small scale as anti-PD bombardment, or as a threat of further 
destruction.  As a threat, it's not good; If you really wanted to trash
the 
planet, that would have started immediately.  If not, and the planet
calls 
the invaders' bluff, the invader is forced to either back off some, or 
destroy that which he has come to capture - rarely acceptable, even with
a 
relatively high abundance of habitable planets.

As far as the GZG background goes, planets have a few options:
apparently 
beam weapons will fire into & out of a Terran-standard atmosphere.  I
would 
expect some degradation, but that depends on a lot of factors. 
Ortillery 
is more effective (if not, why have it?), but requires mass that is 
unusable for any other purpose.  As I use the vector system for fighters

and MT missiles (they're both FAST!), I count launching or landing as
one 
turn of endurance.  Thus, an MT missile spends it's launch turn
expending 
endurance clearing the atmosphere (no move).  The second turn, it has
the 
vector of the launching body.  It can maneuver as normal on the second 
turn.  Fighters act in a similar manner.  SML range when fired from an 
atmosphere is halved.  All of these, of course, do not apply when
dealing 
with a body that has no/negligible atmosphere - Fortress Luna, anyone?

New MT missile notes: MASS 2, Cost 6, Thrust 36, Endurance 6.  2d6
damage, 
half damage to any armor, remainder to hull.  Ignores screens.	May run 
'inert' - expends no thrust, retains previous vector, may attack if 1 
endurance remaining.  Inert missiles are automatically destroyed by 
fighters, ADS, PDS & class-1 batteries acting as PDS.  Each turn of
thrust 
expends 1 endurance.  If no endurance remains, cannot attack.  Comes in 
long-range (9 turns endurance) and fast (48 Thrust).  Various other 
warloads: EMP, KKM, EW, etc.  These are shipkillers, and are currently 
undervalued.  but not by much, they can be shot down, and for the mass
of 
2, you get 6 SM (SMR).	Harder to take down all the SMs than 2 missiles.

New Fighter/Missile movement notes: Fighters/Missiles may spin freely,
and 
expend thrust in any direction.  Essentially, they may alter their
endpoint 
by their Thrust rating.  This must be plotted as normal.  Fighters
follow 
same move rules as fighters.  This frees up missile movement (no crew to

worry about squishing), and gets fighters into the vector system.

Comment?

Noah