[FT] Orbits/Defsats, Planetary defense.

> Thanks Schoon! Here's some follow up work for you and the other space
> cowboys (come on Noam or Indy... I imagine one of you astronomical
types
> must have some thoughts...) 

As far as that goes, I'm actually more of a GROPO - I'm a geologist, not
an
astronomer. My only problem is my field areas (Eros, Mars, Venus,
Mercury,
etc.) have accessibility problems. However, I do play a vac-head in FT,
and
have an opinion or two about defsats.

If your' defsats are in Low Orbit ( a couple hundred km from an
earthsize
body), then for full, constant coverage downward (survellance, pinpoint
ortillery) you need a constellation not unlike the Irridium
communications
setup today - that's on the order of 50 plus sats in polar orbit if I
recall. 

IMO, given FT's granulariy, the best representation of an LEO
configuration
pointing "up" is :

Defsat Constellation As Ship

Buy the entire constellation as a single immobile ship or base. The
fixed
planet becomes the "body" and opponents attacking the defense net have
to
target it specifically. The entire net has aggregate screens (if bought)
and
hull (no armor, per say). Designate the 12 o clock poisiton as
"forward",
and buy wepons in arcs as appropriate. The net can be either fixed or
rotate
at a specific number of clock faces per turn (I'd stick with no more
than a
rotation of 1 or 2).

Treat the whole DCAS like a ship and threshold it as appropriate.. Don't
let
ortillery or dropships land unless the net is down to below 1/3 to 1/3
its
original strength, or has 120 degree holes in its coverage.orbital decay
would be a factor, but in the 23rd century I'd say it's negligable.
If you want to play with ballance, make the damage rows uneven lengths.
Examples say you've got a net with 16 aggreagate hull Damage rows
2/3/5/6
make it easier to threshold the first couple times, but harder to kill
the
net entirely. Or, Damage rows 6/5/3/2 make it hard to crack the net
initially, but it fails more quickluy once you so - say by killing off
command sats. Both require tweaking the DCAS cost, of course.

You could decide at the outset whether the DCAS is manned or not
(unmanned
means that "crew units" are really auto-repair systems, and you can
penalize
Damage control rolls accordingly - say require 2 units to attempt any
one
repair).

You need to be, as Schoon said, a thousand+  km above the surface to
minimize decay worries. But in the 23rd century, I'd think that that's
really a negligable worry for LEO sats.

The main drawback of DCAS in FT is that it's hard to represent with a
single
mini or set of minis.

Middle orbit requires fewer numbers for downward coverage and may be
represented by discreete units a couple inces away from the planet.

You can get global coverage from a constellation of 4 high orbit/geosych
satellites or stations. (That's for 3-D. You only need 3 for overlapping
coverage in a 2D map). These could be more souped up stations on the
order
of cruiser or cap ship in strngth depending.

I wouldn't go for ST:movie size bases that can house Battleships in
internal
bays in the FT univers, however.

On the other hand, I _would_ consider planet-based missiles (MT) and
fighter
groups as cost effective ways of defending colonies. 

Planetary Defense Missiles (PFM): =Mass 2 Cost 6, includes ground launch
system. Fixed at one point on planet surface (pick one clock face as
facing). As MT missile, but must spend first turn after lauch traversing
atmosphere. At start of second turn, Missile can make up to 1 60 degree
turn, and move 24". Missile can either have a 6-12" reaction move to
burn
it's last endurance factor (6" in any direction, 12" in forward 60
degrees),
or may move next turn at 24" and another 60 degree turn. Larger colonies
should be able to manufacture enough of these on their own that only a
major
task force would try to take one out from space. Inner colonies and core
worlds could mount a nearly impenetrable defense with < 2000 points of
PFM's.

Planet-Based Fighter Group (PBFG) - Same as regular fighter cost, but
+39
points per group for ground-based infrastructure and booster packs to
escape
planetary gravity. Fighters require 1 turn to exit planet
atmosphere/gravity, then can maneuver freely. Return to planet costs 1
Endurance, or 0 Endurance for dead-stick re-entry. If the latter,
fighters
cannot return to combat during the scenario.

Noam