Re: Planetary Invasions

>                   LARGE SCALE WARFARE IN THE IMPERIUM
>
>      From my point of view, the most interesting aspects of the Gulf War
> as  applied to Traveller were the incredible pace of operations and  the
> potential  increase in real-time tactical intelligence due to  sophisti-
> cated sensor systems.  As Traveller depicts the development of technolo-
> gy, it seems that these trends can only continue.

  Even though I know that I'm going awfully close to the edge of the TML charter
I have to comment that the Gulf war wasn't a normal war in any way. There were a
long undisturbed buildup, a long undisturbed air campaign and the climate and
geography were ideal for high-tech warfare.

>      An  attacking fleet jumps into a system as a fairly  compact  unit.

  Not nessesarily. Even during the best of circumstances, the fleet will be
spread out quite thinly in both time and space.
  1. Time: A normal jump takes 124+2D*6 h. The fleet will arrive gradually
           during several days. If the transports arrive before the escort,
	   this could spell a major fiasco.
  2. Space: No matter how smart the navigators and how skilfull the engineers,
	    one ship in thirtysix will still make a misjump that can add to
	    the error in time or add a new error in space.

  Taken as a whole, the safest way would be for the fleet to aim at some quiet
corner of the target system and spend a few days reorganizing itself before
proceeding inwards.

  (Coming to think about it, this error might be the big reason behind the
success of the carrier batrons, because they are guaranteed to arrive as a unit,
contrary to a group of battleships. Something to think about for an as anti-
carrier pro-battleship type as myself:)

> The  local  forces will learn of its existence in hours at  the  latest,

  A system has no outer limit except the limit imposed by fuel. The range of
sensors is the big unknown in this equation, because they seem to have a far
shorter range when used in combat compared to what's in the design specs.
  I suspect that if someone tried to unload a sensor with an advertised range
of Interstellar that can only discover ships at around 400000km on the IN, the
Moat would be up in arms.

> depending  on  the location of the appearance.  If they  are  scattered,
> they will attempt to withdraw, attempt to combine, or engage  piecemeal,
> depending on their commander's assessment of the relative strengths.  In
> any  case, a superior attacker can proceed to the main  world,

  Remember that the attacking force have to bring *everything* along. Every
kiloliter of payload that has to be there costs 200kCr(*) (Assuming J3 1G
unarmed 20kt transports) while the defender can have pre-positioned supplies
all over the system (As can the attacker, strictly speaking, but he might have
a hard time keeping them secret).

  (I'm well aware that the attacker probably didn't buy all the transport
capacity the day before they set out to conquer their neighbours, But the same
thing applies to the defender. I'm also aware that the attacker could bring in
supplies gradually, but a supplyline stretching possibley several jumps is
extremely vulnurable and keeping it safe would tie up large tonnages. The
attacker will *at least* have to bring enough for 3 weeks of combat, since that
is when the first transport would arrive (Sending transports to a system
without knowing if the invasion fleet had to beat feet out of there or if they
gained a foothold is not recommended. One risks giving a lot of supply ships
away to the enemy. I count with one week of fighting, one week to the the
message home and one week for the supply ships to jump back to the target
system.)

  The edge that non-jump ships have over jump capable ships is well known. I'll
just repeat that a ship with J4 will have 30% less space for useful things
than the non-jump capable ship. Besides, a jumpdrive costs a lot of money,
money that could be better used for weapons.

  The only advantage that I can see the attacker would have is that his
forces would be concentrated while the defender would have to guard the entire
system. As shown by history, this might be enough to enable the attacker to win.
'Win' in this case means that they reach the mainworld.

> engage.   In  any  case, the mainworld will be  warned.   The  planetary
> defenses  will stand ready, deep meson gun sites prepared to fire,  grav
> craft dispersed and moving or hidden in the oceans or deep bunkers as  a
> reserve.  As the fleet approaches the planet, all craft in orbit will be
> detected  and  identified.

  The defending ships have nothing to do in low orbit. They are much more usable
far out in the outer system not for what they can do there but for the threat
they represent there. A threat that will tie up a portion of the attacking
fleet. Any defending ships left on the planet are better off sitting on the
ground with their powerplants and interior grav off until the attackers are in
range. The closeness to a major mass, the atmosphere, the powerplants on the
planet etc all make them much more difficult to detect that way. Add to that
that the ships can be hidden inside larger structures or below ground.

  o Passive energy scans won't see them. (It will however get a lot of clutter
from civilian sources)

  o Passive object scan won't see them. The figures for passive object scan and
pin used in space combat comes from the densitometer range/resolution tables
column 'smallest object detectable in *open space*'. Unless the target use
artificial grav which will make it stick out like a sore thumb, the only way
to detect a ship is to recognise it's shape and the materials used. And to do
that with any amount of accuracy the sensor needs to be closer than 500km
(10m resolution) or even 50km (1m resolution). [The attacking ships will on the
other hand be in open space and easy to see].

  o Active object scan probably won't see them. To see them it has to use a
frequency range where the cover the ships have (say metal and concrete) will
let the radiation through, but the ship will reflect it. And as far as I know,
anything that will penetrate metal won't be reflected by a ship. The question
is: Will superdense reflect xrays?:)

> Cheap  drones emitting the electromagnetic signature of important  craft
> may  be deployed to confuse the attacker's perception of where the  tar-
> gets  are,  but there will be no way to hide where  the  defenders  _are
> not_.

  See above.

> Drones are a two edged sword, for the attacker will use as  well
> in the next phase.  Prepared for the planetary meson guns, the attacking
> fleet does not hazard the largest ships against them. Instead they rely
> on  saturating the defenses with numerous smaller craft  and/or  drones.
> Some  will  be lost to meson gun fire, some to ground based  lasers  and
> missiles. Many will get through, and most of them will carry  substan-
> tial  sensor suites, jam-proof maser communicators, and enough  tactical
> computing  power  to pass the reconnaissance information to  the  combat
> control  center(s).

  See above. They will only be able to detect what is firing at them. It is
extremely tough to detect a defensive installation that don't want to be seen.
I think that a resolution of less than one meter is needed, because they are
as opposed to ships, not made of readily recognizable materials like super-
dense. And if the drones and small-crafts go that close, they'll begin to take
fire from the groundforces as well.

> not,  the skies above the planet will soon belong to the  attacker.   In
> either  case, this phase of operations will be comparatively  short  and
> extremely rapid.  Logistics will not be a consideration when almost  all
> craft  are  armed with energy weapons requiring no ammunition  and  have
> fuel  for days or weeks of continuous operation. The entire  atmosphere
> and  close  orbit space will be an enormous swirling dogfight  as  craft
> engage at hundred of kilometers at speeds of thousands of kilometers per
> hour.

  Since the defender have no reductions imposed by logistics (compared to the
attacker at least) they can ripple-fire arbitrarily large amounts of nukes
at the attacking small crafts, most too small to have nuke dampers, since the
larger nuke damper carrying ships are hiding out of range. The attacker can
either and use nukes too (and hope that the defender don't have a lot of
ground-based nuke dampers that work in conjunction with his crafts) which will
place even greater strain on their transport capacity. Or they can bite the
sour apple and try to fight it out anyway using only energy weaponry, in which
case they have a big force multiplier against them.

> The attackers will make a special effort  to  target  any
> immobile  communication  and sensor facilities that  are  detected...

  A Tech 15 sensor suite capable of doing a passive energy scan and pin as good
as any starship has the following data: 0.232 kl, 111kg, 430kCr. Cheaper than
a suit of battledress. It can be hooked up to the normal power net and
communicate over the civilian computer network. It is preferrably powered by
batteries or solar cells to make it harder to detect (2.6m2 solar cells) and
for 250kCr extra it can have a 500km meson link.

  Sensors such as these (or 1.5MCr more expensive if they shall be able to do
passive object scan/pin) can be hidden literally everywhere. The world might
have a law that every newbuilt house has to have one on the roof. A group of
sensors can be patched in to a computer site. That site is in communication
with a deep relay site (one of many), not directly with the meson pit to
make it impossible for attackers to find out the location of a meson pit by
conquering a sensor or a computer site.

  The sensors are passive, and if they use batteries or solar cells they have
no neutrino signature, and they are hidden among billions of transmitters and
other electronics on the ground. All in all a tough target.

> al-
> though a deep meson gun site may have multiple sensor and  communication
> relay  stations, without the use of meson communicators the  final  link
> must  be immobile, though perhaps concealed and well  hardened.   (Meson
> communicators  will allow the deep site spotters to be mobile and  main-
> tain communications through the ground without the use of surface  level
> relay points.) (A deep meson gun site should be buried below the maximum
> resolution  level of the enemy's densitometers, which is  one  kilometer
> for  a TL15 invader.  The existence of TL16 sensor-building  planets  at
> the  Imperial Core just prior to the outbreak of the Civil War has  pre-
> sumably rendered sites buried to the 1km minimum obsolete.)

  I've always been sceptical towards the claim that the only way of discovering
the deep meson gun pits is to use densitometers. Since meson guns impacting a
meson screen gives a signature (Digest#6? It's the starship issue at least)
that should be enough to triangulate some likely positions, and the planets
transparency to mesons is a two-edged sword...
  Alternate solutions might be good oldfashioned intelligence work or good
zho-fashioned clairvoyance work:) The attacker might also try to locate the
powerplants that feeds the meson pits with neutrino sensors and blow them
away with their own meson guns. The trouble for the attackers is that they never
can be sure if they have destroyed *all* powerplants and meson pits or if there
are a few left that has been shut down to be undetectable... waiting...

> Both combat-
> ants  will attempt to attack as many of the enemy's most capable  sensor
> platforms  as  possible, but the size and power TL14+ sensors  makes  it
> easy  enough for every grav tank to be its own Gulf War  J-STARS  system
> equivalent.   If  the defender has concealed assets at the  end  of  the
> 'dogfight' phase, they may now be cut off from central command, and will
> probably  lack the opportunity for large scale surprise.

  Groundforces may also use meson communicators to communicate with deep
control sites via deep relay sites. All gravtanks may for example have the
orders that 'If out of contact with HQ, try contracting these coordinates <list
of a handful of sites> using meson link'. It would be hard for the enemy to
capture any intact enemy grav-vehicles during the early part of the battle, so
discovery of the relay sites is a minor problem.

>      After the 'dogfight' comes the 'mop-up'.  Immobile defending  posi-
> tions are assaulted as soon as overwhelming force can be brought to bear
> against  them.

  The trouble is that, to quote 'Murphys laws of combat': 'If the enemy is in
range, so are you.' If enough large ships come close enough to begin firing at
ground targets the ground targets will begin to fire back. And you can fit more
lasers on a planet than on a whole batron:)

  Small defence weapons can by the way also be deployed as the sensors above.
A small mount with self-contained powerplant and a meson link to a computer
site in the vicinity along with a number of collegues.  Almost impossible to
detect until it fires. To protect against visual and active EMS detection it
can be contructed as a pop-up facility.
  [Real-life comment:the Swedish air defence use pop-up radars that are
supposed to duck down behind heavy blastdoors and several meters of rock if any
ARMs or other missiles are heading their way. Target memory won't help a AS-12
Kedge against that.]

> Limited force, in the form of infantry with very  selec-
> tive  direct fire support, might be used against targets which  the  at-
> tacker  desired to capture intact, or where collateral damage is  to  be
> avoided,  such as cities--it has already been mentioned that an  assault
> would only be ordered with an intent to capture, so it is to be  assumed
> that  these  target would exist.

  The most effective orbit-to-ground fire support weapon is the meson gun.
With a few forward observers on the ground the attacker can surgically
annihilate defensive positions. According to Striker a meson gun used against
ground targets have a 100% kill percentage within 100 to 200 meters. The
defender may however have meson screens. As for the best way of removing a
defensive installation, I'd recommend nukes fired using direct fire from so
close that the point defence and nuke dampers never have time to react
(Either 500 meters or 50 meters according to Striker. It'll have to be small
 nukes to fire them at 50 meters:)

> With his mobile  forces  destroyed  or
> otherwise  neutralized, each of these targets/force concentrations  will
> be isolated.

  The defenders won't move their mobile forces unless the attackers forces them,
because they are much harder to detect if they sit tight (like for ships). So
what the attackers has to do is force the defenders to begin to concentrate
their forces, and the best way is to open a bridgehead at some lightly defended
part of the planet. The defenders will then have to choose between letting the
landing continue unopposed (and attackers on the ground will be as hard to
detect for the defenders as defenders on the ground are for the attackers, the
attackers may also start to deploy their own defensive networks etc) or try to
crush the beachhead with ships, grav-vehicles and ground forces.
  As those begin to move they will become visible to the attackers who will
start to attack them from orbit and air, and as the attackers units move into
range for the defensive installation the defender will start to fire back. As
'new' defensive installation and units reveal themself the attackers will have
to attack them as well, to protect their own ships and so it continues.
  If the attackers manage to supress the defensive fire they can go on with
their main mission, which is to destroy the defenders ground forces, otherwise
there will be a 'ground' (ie gravtanks, gcarriers and infantry) battle where
the defender tries to crush the bridgehead.

  It's all a question of if the attacker runs out of ships before the defender
runs out of hidden batteries, since once the attacker knows about the existance
of a battery, he can destroy it if he makes enough of a commitment.
  There is of course also the normal amount of doublecrossing etc where the
defender lets one battery among several fire and when the attacker sends some
ships after it, the others reveal themselves and destroys the ships. And
conversely: the attacker sends down some ships that are shielding what seems
to be several transports, and when the defensive batteries open up, reveal
themselves as cruisers and blows away the batteries.

  I'll suspect that when the defenders mobile forces are destroyed, the
defenders will surrender because they have lost their only way of cutting the
attackers foothold. The situation is comparable to a 20th century nation that
just have had it's army, navy and airforce destroyed, but still has some
SAMs and coastal SSMs.

>      After  the final formal surrender will be the  'occupation'  phase.
> Guerrilla  resistance  will be made difficult by the  sensor  imbalance.
> The existence of the advanced sensors postulated in the game would  seem
> to make counterinsurgency trivial for a high-tech attacker.  A guerrilla
> attack  occurs,  using  weapons hidden and not  discovered  in  searches
> during the 'mop-up' phase.  The attacker is immediately alerted,  either
> by  jam-proof communications or by the sudden appearance of  jamming  on
> the  passive sensor network.  A grav mounted rapid response  force  sur-
> round the area, sets up a sensor interdiction perimeter, and attacks any
> immediately  detectable  enemy forces.

  Densitometer scans will have to have a resolution of less than 20cm, probably
between 5 and 1cm to recognize a weapon. That means a range of less than 500
meters and a scan dimention of 5m per scan. I've forgot how long a densitometer
scan takes, but it would still be a major undertaking unless the population was
to pass through checkpoints. And scanning the entire countryside is almost out
of question. And to foul the scan's it's easy to make another law that every
house built has to have a bunch of weapons replicas walled up in the cellar:)

>    As I said at the beginning, I'm trying to extrapolate what the situa-
> tion would look like with fast, highly capable craft which can attack at
> very  long distances by current standards.  If there is any interest  in
> this, we can discuss what the 'view from the cockpit' might look like at
> different levels on each side of this sort of operation, as well as what
> it would look like to non-combatants on the ground.

  Any sensible non-combatant would hide in a shelter.

  To summarize I don't think that the balance between the defender and the
attacker will change greatly at higher TL. The attacker will have greater
capabilities than today but so will the defender. The best edge is still to
be several times more than the defenders or/and have and edge of one or more
techlevels. And the problem of logistics will still exist and it's a big problem
when the nearest source of supply is one jump away. I'm leaning towards that
it is big enough to make a planetary invasion a *major* undertaking that
requires the combined resources of a large part of the imperium for a long
time (If the target is Hi In TL14-15).

  (Ouch! 19k I think I'll end here and put the rest, a brief recouting of the
battle of Naasakiira, a planetary invasion that I've actually played, in a
separate message)

- - -bertil-
- - --
"Some people almost never think. They just reshuffle their prejudices."