ESA for starships

From: merrick@Rt66.com (Merrick Burkhardt)
Subject: ESA for starships
To: gdw-beta@quark.qrc.com (gdw)
Date: Mon, 25 Sep 1995 12:13:23 -0600 (MDT)

Howdy,

just thought I'd give a few numbers for shipboard ESAs.  I list the
armor as the Armor Value vs. KEAP.  For the value vs. HEAP, plasma, and
fusion weapons, multiply by two.  These are *on top of* the ship's own
AV.

TL15 ESAs for ships of size =<Small:
------------------------------------
Std. Turret mount, AV:1089

Barbette mount, AV:2178

50 ton Bay, AV:18,148

100 ton Bay, AV:36,296


TL15 ESAs for ships of size >Small =< Medium:
---------------------------------------------
Divide above values by 2


TL15 ESAs for ships of size >Medium =< Large:
---------------------------------------------
Divide "Small" values by 4.

Etc. for larger.



Obviously ESA isn't too practical for small ships.  A SC using it's 3
tons of cargo for ESA would defeat a 10gram particle at speed 1, or a 1
gram at speed 10, etc..  It looks like a fancy penetrator (SD, BSD etc.)
would do maybe 3 times the penetration.  

These can fire 5.78 times in a BL turn per MW of power allocated,
presumably up to a max ROF of 800 (the highest ROF used with an HPG).

On the other hand most micro meteorites are *tiny*, so this'd offer more
than enough protection from space junk at Scout/Courier velocities.

BTW, a 10g ball does 78-1/12 at speed 1---that give an idea of how nasty
KKMs are?  I assumed much smaller shot in my KKM stuff.

The only problem is that FFS never talks about what velocity ranges it
is effective within (although it does state that it is a "narrowly
defined mass and velocity parameters").  I would assume that the
particle mass, m, must be small compared to the ship mass, M---maybe
less than 1%).  Then maybe it has a lesser effect vs. particles at
higher masses and velocities---maybe halving the AV for each doubling of
velocity above some CV (what, I have no idea).

For a large number of simultaneous hits, I might allow the aggregate AV
(AV*ROF) to be divided amongst the hits equally.  This would allow the
1MW, 311MJ ESA on the SC above to have an AV of 6303 divided by all the
little hits against it... this would only be for things like my pirate
missile where a bunch of sand would hit at the same instant, not shot
from multiple KKMs.

Any ideas on the range of values for velocity and mass that must be met
for ESA to work on a spacecraft?  Would an active ESA increase the
passive signature of the ship as it moves through the interplanetary
medium?  Solar proton interactions?  Etc...

-Merrick