On Mon, Jun 22, 2015 at 12:16:22PM +1000, Greg Chalik wrote:
> A chaser commander may choose to progress through these, but an
> ambusher will simply drop the entire force in on the theatre
> objective, orbit-to-objective movement.

Yes, you can do a great deal if you have overwhelming aerospace
superiority and there are no defending weapons that can touch your
craft.  Grav technology means a huge advance in mobility, with all
sorts of follow-on effects in tactics, logistics, strategy, and even
political objectives.

If you don't have that overwhelming superiority though, it's a very
expensive form of suicide.  In an open warfare situation, even
approaching orbit is going to be difficult, since Traveller's sensors
and weapons typically have effective ranges much greater than
planetary diameters.

So it's the sort of tactic that could be employed by a powerful
interstellar force against a very lightly populated or low-tech
planet, especially if the attacking force isn't viewed as a threat,
but isn't likely to work well against any credible prepared defender.

> The tactics are simple - the entire unit drops from orbit onto the
> most obvious location of the planetary seat of Government at about
> 50km/s.

First it has to slog its way in from the 100D limit, in a good case
taking about 3 hours (though in adverse cases it could take a lot
longer).  If it can get that far, then I suppose it can be assumed
that it must have been able to destroy most of the space-based assets,
and any ground or orbital defences with significant range.

At 50 km/s, it's going to be very obvious where the ships are headed
long before they reach atmosphere.  After that it gets messy.  Whether
or not the target was the seat of planetary government, it's up to the
defenders whether the top government leaders are there by the time the
invaders arrive.  Either way, it is likely that a significant portion
of the planet's armed forces are in effective range of the landing
site.

What happens next is variable, but extremely unlikely to be "combat
takes 1 minute, surrender negotiations 59 minutes."

- Tim