Bug, excessive drag, or what?

[Snark]

26 minutes ago, StrandedonEarth said:

Going from, say, a 2.5m fairing down to a 1.5m tank. From what you just said, it would be better to have the adapter in there rather than a straight step...

Yes, correct, exactly.  Excellent example.

Wanna see something with freaky low drag?  Make a radial droptank that consists of two of the conical Soyuz fuel tanks from Making History, attached end-to-end (i.e. top one pointing up, bottom one pointing down).  Drag's so low it's practically zero.  As an experiment I tried making a ship that was just a 2.5m probe core with a nosecone on top, engine on bottom, and three of those pairs attached radially... darn thing was so streamlined that its terminal velocity at sea level was a full 1000 m/s!

 

[RizzoTheRat]

On 4/28/2018 at 4:38 PM, Snark said:

Be careful how you think about drag-- this isn't how it works, at all.  Positioning doesn't matter.

This seems counterintuitive, because logically (according to actual physical reality), it should.  That's how the world works.  However... KSP isn't IRL, and it uses a very simple aerodynamic model for drag.  The actual physical positioning of parts doesn't matter in the slightest.  This leads to all sorts of common player misunderstandings-- e.g. thinking "I've got part A sheltering behind part B, therefore that mitigates part A's drag."  Nope.  I've also seen people do things like trying to use clipping to "hide" parts aerodynamically (e.g. "I put some stuff inside the nosecone")... which also doesn't work.

I was expecting it to be draggy due to a couple of diameter changes, but the above is the main bit I hadn't realised,

I redesigned it for streamlining but as you say, the terriers are a massive overkill for the satellites, although I did realise I only need 3 satellites not 2 which has helped.  ,However I do need them powered as I'm working on on a kOS script where it launches the main body in to a resonant orbit, and then releases the satellites at successive Apoapsis' to circularise themselves to the calculated period.  Switching between ships in kOS is proving tricky at the moment but I'll get there in the end 

 The OKTO and batteries are the in the lower service bay, with 2 Reflectron KR-7 dishes in the upper one.  It does mean they're nearly 1.8 tonnes each but that's worth it for how much easier they launch, my standard profile works fine with an 11 degree turn at 50m/s.  A more aggressive turn would be a bit better but I've not worked drag in to my turn angle calculation so far, it just works on TWR..