I suppose with DSPs coming in 2. 0 you can *mostly* do it entirely in space, but now that I think about it, could you not just find a tiny little asteroid, dump all your factories on it, and only use the ark population of your ship to achieve pretty much the same thing? It'd be pretty fun to RP a species operating entirely out of a single mothership orbiting some tiny single-comet backwater star. You could move the mothership between different systems, hoovering up minerals, then jump to the next one whenever you run out, as long as there was at least a single body to use as a base of operations. The mothership would have to be *massive* though to accommodate both a meaningful population and the cargo space for all those factories, but it could be done.
Someone correct me if this isn't how it works - I want to try this now!
Edit: FYI, the mothership would have to be a 250 *million* tonner just to accomodate 100m pop.
Tellus Mater class Mothership 350,000,000 tons 154,056 Crew 3,130,196.8 BP TCS 7,000,000 TH 3,840,000 EM 0
548 km/s Armour 60-44240 Shields 0-0 HTK 84286 Sensors 11/11/0/0 DCR 51 PPV 0
MSP 2,000,005 Max Repair 2400 MSP
Hangar Deck Capacity 100,000 tons Troop Capacity 2,500,000 tons Cargo 26,375,000 Habitation Capacity 100,000,000 Cargo Shuttle Multiplier 100 Tractor Beam
Capitán de Fragata Control Rating 3 BRG AUX PFC
Intended Deployment Time: 3 months Flight Crew Berths 2,000
Maintenance Modules: 100 module(s) capable of supporting ships of 200,000 tons
Refuelling Hub - Capable of refuelling multiple ships simultaneously
Ordnance Transfer Hub - Capable of transferring ordnance to multiple ships simultaneously
Commercial Inertial Fusion Drive EP1280.0 (3000) Power 3840000.0 Fuel Use 0.03% Signature 1280.0 Explosion 1%
Fuel Capacity 979,267,000 Litres Range 2,012.4 billion km (42502 days at full power)
Active Search Sensor AS39-R100 (1) GPS 2100 Range 39.8m km Resolution 100
Thermal Sensor TH1.0-11.0 (1) Sensitivity 11.0 Detect Sig Strength 1000: 26.2m km
EM Sensor EM1.0-11.0 (1) Sensitivity 11.0 Detect Sig Strength 1000: 26.2m km
This design is classed as a Commercial Vessel for maintenance purposes
This design is classed as a b for auto-assignment purposes
Threw this together a second ago, though it's very likely woefully insufficient. Also, it would bankrupt Earth of minerals perhaps several dozen times over. Of particular note are the 3000 engines required to move this behemoth (albeit with exceptional efficiency). It would only take 500 engines at 50% to move the same speed, though they would go through an entire billion tons of fuel in just 41 billion km. What's likely far more practical is to use a massive tug with efficiency somewhere in the middle, maybe around 20-25%.