Good luck. Keep us posted!

Be sure to use the "Continual expansion" to increase your shipyards as that is a lot faster. Mine took about 3-4 years to go from 10,000t cap to 30,000tons (second shipyard cost/time tech), but that was with only 1 slip. Also, I think you need to bring along a commercial "base" with you to house some human population as well as other things a population might need.

So, the closer system (Dragoon) is about 700B kilometers from the jump point, and the more distant one (Deercreek) is about 1.2T kilometers from its jump point.  I discovered both about the same time.  Both had perfectly-habitable worlds.  I know Deercreek has an NPR because they have a civilian mining colony around the "A" star, and I made contact.  As for Dragoon, I didn't know, but I have the NPR generation chance cranked up pretty high so I was hopeful.

To scout the systems, I created modified versions of my standard geo survey ship.  Typically my survey ship is a 40HS, 0.3 power civilian engine with a civilian jump engine, grav survey module, and a fuel tank strapped on.  The efficiency of the engine gets them great range already, but not quite enough for this job.  I dropped the jump engine and added fuel tanks and extra deployment time. 

The geo survey ship arrived at Dragoon-B and confirmed that there was an NPR there; the journey took about 5 years.  It has a small active scanner so I was able to determine their navy is pretty limited: three or four 8000T ships, two orbital defense bases of some kind, four FACs, and 50,000T of shipyards.  I made contact, assigned diplomats, and sent the scout ship to a remote planet.  He can fly back to the alien homeworld after relations improve, if I need a new scan. 

The survey vessel headed for Deercreek-B is still en route.  When it gets there, it will have flown about 10 years from the jump point.  I am already on friendly terms with the Deercreek aliens, but I have no idea how big their military will be.

The tug's engines are inertial fusion tech, which I just achieved.  Talbot and Saunders have been my main P+P researchers for the past four generations of engine tech breakthroughs, and both are old and sick, so I figured this engine would be their last big achievement and I named it after them.  They're 50HS and 0.3 power, very fuel efficient.  The fighters and missiles I showed earlier are magnetic fusion; new designs are on the way.

Currently my biggest military shipyards are 18000T and are in the middle of "add slipway" jobs, so I'll have to wait a couple years before I can even start expanding their tonnage.  My goal is to have 30000T war pods for those tugboats to haul into place.  Four "base stars" (carriers) and one "battlestar" (flag bridge, AMMs, and sensors) pulled by five tugs, and a bunch of long-range troopships, per invasion fleet.  I know, I'll never be able to haul away the minerals or installations I capture, but what I want most is the economic and research production.  And the glory.

Sure.  It'll probably be a few weeks, though.  It'll take 5 to 10 in-game years before I have the first fleet built.  I'll probably send it to the more distant NPR while I complete the second fleet.  Then it'll be another 5 to 10 years before they arrive!

Got my tug designed.  When I added 30,000T to the design (a large and small cargo bay) it got 5267 km/s and a range of 3192.1 billion km.  Should take 5 years to haul a 30,000T war pod to my nearer enemy, and up to 10 years for the more distant one.

Titan class Fleet Tug    84,250 tons     395 Crew     4505 BP      TCS 1685  TH 6000  EM 0
7121 km/s     Armour 1-171     Shields 0-0     Sensors 1/1/0/0     Damage Control Rating 1     PPV 0
MSP 33    Max Repair 108 MSP
Intended Deployment Time: 3 months    Spare Berths 0   
Tractor Beam     

Talbot-Saunders 480 EP Cool Fusion Lightyear Drive (25)    Power 480    Fuel Use 0.99%    Signature 240    Exp 3%
Fuel Capacity 20,000,000 Litres    Range 4315.8 billion km   (7014 days at full power)

This design is classed as a Commercial Vessel for maintenance purposes

On the note of the "building the "ship" in sections and tugging it out there. Thats actually not unheard of in the forums here. Think there there was 1 guy who was doing "modular" ship designs before.
But getting tractor systems to work can be a bit of an orginizational nightmare.
Basically though there are 2 ways to do this.

1. Civilian engine>Military hardware section.
In this manner you can build abnormally large Civilian engine sections that won't eat up any MSP on the long voyage or need rampant naval yard expansion. Also a bit more efficient than military engines.
Coupled with a few Engine>Fuel tank ships to act as tankers and you can get a pretty long endurance fleet. Nice thing, if 1 of the engine sections does get damaged in combat, you can switch it out with 1 off of a tanker.

2. Also possible is bringing an Engine>hanger. And store a more proper warship in the hanger section (so you don't have to worry as much about maintenance), OR bring a military engine section in the hanger, to be switched out with the civilian one when you get into combat distance of the target.

3. Drop tanks. Rather than building a civilian engine and specialized military sections. Just keep your existing warships, but build some fuel/MSP/tractor sections that can be tractored onto them for the duration of the trip. Added bonus for this method is that when getting into combat range, you just unequip the tanks, and your ships will be right at normal combat speed.
I've actually done this one before with some cruisers (cruiser to me is a ship with long endurance to hang around away from bases for long periods) to moderate degrees of sucess, helpful also that when the tanks were dropped by the ships in question, they ended up being bait for some enemy fire while my ships sped away.



Personally for your particular mission profile, 2 would be my tactic. A hanger section to house any given ship is generally 5-20% bigger as far as the hangers go. A bit of space is wasted in crew quarters, a magazine for reloads if you're using box launchers, and any other extracurriculars. But guessing that to tote around a 30kt ship, you're probably looking at a ~40kt section, which can be hauled by a 120kt engine section (~50% engine, ~50% fuel) probably wouldn't be too far off. Bonus points, when you get there, you'll have hangers for your fleet so you don't have to worry about maintenance for a while longer, because on extremely long deployments, the maint can kill you.
Also a standard hanger section can work for any kind of ship, be it a sensor scout, a battleship, or a few dozen FACs or fighters.
Anything that can be made 100% civilian though should be, because of how fast you can modify civvy shipyards.


But how you do it is up to you.
Couple things I wonder about though. Whats the orbital speed of the target planets, or the stars they are around, around the central star in the system.
You might find that it'd be a lot more efficient, to do some math, figure out how long it would take to get to the target destination. Figure out about how much farther along its orbit it will be, and head towards where the planet will be, rather than just a simple "move to" which you may find spends a lot of extra time and fuel curving along to the area.

Amimai, I noticed something; you sure do like your box launcher cheese warships. I do understand the reasoning for it, a multi-hundred alpha-strike or waves of only a few dozen, but that just means that once they fire, they are basically hunks of useless metal waiting to be blasted by the stealth ships that were lying in wait. The only ships I put them on are my smaller ships like my fighters/bombers, FACs/gunships, and on some frigates. And to the original point of this topic page; I would simply design long range warships along with a fleetcarrier/mothership/tender/invasion-ship. A thing I usually do is use slightly more efficient drives (almost to the point of them being commercial) on some of my warships. This lets me have patrol warships that can move to and from worlds without using a lot of fuel, so a modified version of this could get you there. Another thing to keep in mind is that the fuel time for your faster ships is at max power, so them slowing down to keep with the fleet makes them more efficient saving fuel for the journey (thus taking the years to expend the fuel instead of the stated time). I would also make it so those ships really wouldn't be returning (although this is conflicting with my usual nobody left behind mentality I try to keep) so that you then have (subjugation) ships adding the the PDV. A side question as well; are there any LPs in the system that you could use to get there?

Going at less than max speed doesn't make the journey use any less fuel.  It just makes the trip take more time.  So sure, you'll have burnt less fuel 1 year into the journey, but you'll also have made an equally less amount of progress.

Personally, I like the idea of making big battlewagons with commercial engines. Followed by huge tankers and magazine ships.