Re: [Spaceships] Paying more for better system?
 

Well, just making it a Genius computer puts you at C7. You could also make it a Compact SM+5 system for C8. That's enough for a IQ 10 volitional AI (Ultra-Tech p 25) or IQ 12 mind emulation (Ultra Tech p 27). With a Talent relating to EW and Intelligence Analysis, it could be effectively IQ 16 for those skills, plus having them at IQ+4 through training.

Alternately, it could just be a plot device that doesn't obey the standard rules.

Re: [Spaceships] Paying more for better system?
 

The T-72A (HT244), at least, is buildable with Spaceships, provided you're willing to "zoom in" and get rid of some of the abstraction. The T-72A actually averages somewhere just south of dDR 20. With 12 armor modules (the least needed for the -1 SM to get the tank down to its actual SM+4 dimensions), you'd need each to give dDR 5 (keeping in mind you'd average 4 modules per section), which with the x1.8 multiplier of having 12 modules means a base dDR of 2.78, which doesn't seem inappropriate for early TL 8 metallic laminate (mature TL 8 metallic laminate is a full dDR 3). The linked post clearly lacked access to Pyramid #3/34, so let's redo the drivetrain, engine, and fuel tank - its performance is consistent with a single tracked drivetrain using 2 PP, so that'll take up 3 modules (2 ICE's, 1 drivetrain). Range is consistent with using internal fuel, so no need for a separate fuel tank module. That leaves it with 2 empty modules for wiggle room, although it may use up part of that for some Passenger Seating. The rest is probably armor, actually, as dDR2.78 may be a bit high for the T-72A's armor (13 modules would mean a base of around dDR 2.5, which I think sounds a bit more feasible).

Re: [Spaceships] Paying more for better system?
 

So I've been going through these suggestions with more care and have a couple comments.

With sensors, any bonus to Scan *IS* a bonus to range, since the primary use for high skill is to offset range penalties. There's no need to have separate bonuses here.

I'm not a rocket scientist, but it seems that a 20% and 40% boost in delta-v is unrealistically huge. I'm having a hard time finding any accurate numbers for realistic rockets over the years, but my gut just tells me that it's not right. Most rockets using the same fuel have Isp within 10% of one another, and delta-V is just Isp multiplied by the Ln of (full mass / empty mass); most increases in delta-V come from reducing empty mass of the entire rocket by tiny fractions, and those mass savings can come from anywhere from computers to better structural materials for the fuel tanks.

Re: [Spaceships] Paying more for better system?
 

Realistically, anything that boosts Delta-V at all becomes the new standard and everyone's choice. If all "normal" rocket engines in use are effectively "Very Fine" that might partially explain why they are so expensive.

Rocket engines are more likely to vary by power-to-weight ratio. For example the "Merlin" engine used in the Falcon-9 by Space-X gives out 150 lbs of thrust per lb of engine. The standard number used in Ve-2 was 100 lbs per lb. This might be where the weight savings that allow for the landding gear come from.

Re: [Spaceships] Paying more for better system?
 

It depends. Reaction engines are a category of engines where rocket engines is just one(well two if you count HEDM as separate) type.

For Rocket engines, yes there would likely not be (at least not much) d-v increase, but you may see the engine create more thrust for the same mass engine, allowing you to mount less engines and get the same acceleration.

But for things like Fission or Fusion engines you would likely be able to gain more d-v by better designed engine. In fact some of them do gain more d-v by TL as it is and as I see it the others not gaining such is likely a simplification as realistically a higher TL engine should be able to produce and transfer more energy to the reaction mass increasing it's speed and thus ISP.

Re: [Spaceships] Paying more for better system?
 

Active sensors have a maximum range (Spaceships p 45). I think there's a useful distinction between a Level 10 sensor with a range of 3 LS, a level 9 Fine (Sensitive) array with range of 2 LS that is picks up signals within its range as well as the Level 10 sensor, and a level 9 Fine (Powerful) array with a 3 LS range that can't pick up objects within its range as well as either of the other sensors.

Me neither, but I recently read Ignition! which is a history of early liquid fuel rockets. Certainly within the range of "chemical rocket fuel" there's space for trade-offs that could give ISP differences of -20% to +40%. The table of exotic rocket fuels in WW2: Motor Pool p 13 has a variation of 240 to 320 in ISP between kerosene/nitric acid and octane/oxygen, and that's not including the range of exotic rocket fuels that were developed post-WWII. Building a rocket engine to use Cl3F is not a trivial challenge, but if we could, we can get ISPs in the 350+ range.

I can believe that HEDM technology could have similar variations just between metallic hydrogen and metastable helium, and the various nuclear engines could have ISP variations based on the energy of the reaction you're eventual using. Nuclear light bulbs, for instance, seem like they would have space for a higher ISP design that heats the exhaust to even higher amounts but then require exotic materials for the nozzles and such.

On top of that, a 20% or 40% improvement is not that much compared to the TL advances, which are usually 3x or more. If a TL 10 Fusion Rocket has a delta-V of 60 mps per tank, I'm okay with the best TL 9 Fusion Rocket having a delta-V of 17 mps per tank.

Re: [Spaceships] Paying more for better system?
 

Remember that active sensors can detect objects beyond their 'maximum' range at -2 per doubling of range.

Re: [Spaceships] Paying more for better system?
 

I missed that, but it illustrates my point: the Fine (Sensitive) array is flat out better than the Fine (Powerful) within 2 LS, and usually worse at longer ranges. At 10 LS, the Sensitive array is at -5 but the Powerful array only at -4. Which option you want depends on how you expect to use the array but either option is a lot of money for a little advantage.

Re: [Spaceships] Paying more for better system?
 

Here's my attempt of recreating Yukikaze with your enhancements:

FFR-41 Mave "Yukikaze"
I didn't knew exactly how to handle Compact, do I double the CF (Compact Genius computer is worth +248 CF)?
Also, is it possible to have an engine that occupies two slots and say it's a single thing (like Spinal Battery)? It's mostly fluff so it seems probably but by the rules one of the engines could be disabled/destroyed while the other is operational, which would make it strange. Maybe it's "half-destroyed" as in badly damaged: burning, smoking but still somehow operational?

Non-Volitional AI "Yukikaze"
TL9 C7 Base Cost: $10K
Advantage: Soul of the Machine 4 [20] (Based on this advantage from Pyramid, gives bonus to Piloting, Electronic Operation, Gunner, Artillery and Navigation)
Skills: Piloting (High-Performance Airplane) DX+6 [8]; Artillery (Guided Missile) IQ+5 [4]; Artillery (Cannon) IQ+4 [2]; Gunner (Cannon) DX+4 [1]; Navigation (Air) IQ+4 [2]; Electronic Operation (EW) IQ+5 [4]; Electronic Operation (Sensors) IQ+5 [4]
Total CP: 45 (+225$)
Final Cost: $32.5K

While making up the AI I encountered two problems: Can AIs learn DX based skills like Piloting and Gunner? I think there should be one but I couldn't find an upper limit of how many points can an AI have, did I miss it or it really doesn't exist as RAW?

Re: [Spaceships] Paying more for better system?
 

Not really related to the question at hand but for the sake of it, here's also the other prominent ship from Sentou Yousei Yukikaze:

Nuclear Aeriel Aircraft Carrier "Banshee"